With regard to subclass H04N (pictorial communication, e.g. television) and subclass G06T (image data processing or generation, in general), this subclass covers electronic control of display characterized by the display device itself, whereas it does not cover:

With regard to group G06F 9/00, this subclass does not cover software modules, e.g. software driver modules for the display, or their interaction, such as interaction between software modules related to the display of windows or interaction between a software driver module for the display and the operating system (covered by G06F 9/00).

Classification of invention information and additional information is obligatory.

Indexing Code symbols of the type G09G 2xx represent information orthogonal to one or to more than one ECLA group and should be used to classify information relevant for the invention, although it need not be invention information.

Illustrative examples: EP0431581 (otatable display, change of orientation of a video display; see also appropriate groups related to details specific for rotatable display arrangements, e. g. G09G 1/04 for related adaptation of deflection circuits):

US4910785 (displaying code data and image data):

US5493336 (waiting state function):

Control of the intensity of the electron beam in a CRT both directly (by control of the electron gun) and indirectly (by control of a signal having effect on the beam intensity), e. g. for brightness or contrast adjustment.

Illustrative examples: DE1212325 (brightness adjustment of characters and Lissajous curves by phase shift at a pulse):

FR2691032 (brightness and contrast adjustment):

WO9905666 (generation of a higher luminance video window):

US5504462 (control of an intensity pulse signal in relation to pixel clock in a CRT or in a laser beam printer):

EP0840272 (feedback adjustment of the electron beam current):

US5786669 (FED emitters used just to produce the electron beam in a CRT; beam intensity controlled by the number of active microtips):

Illustrative examples:

Special power supply for deflection amplifiers: US3863099.

Power control for user protection from EM radiation and excessive optical brightness: US5521652.

From X-rays: DE29900611U.

Power control for energy saving, to synchronize with computer standby / shutdown for an LCD, possibly applicabale also to a CRT: EP0863455.

In combination with a soft power switch: US6092206.

Details of power control of cathode heater: US6084355.

Use the Indexing Codes G09G 2330/021 - G09G 2330/024 for power management.

Independent management of multiple screen areas in positions that are not quickly varied by an user interface (e. g. with a fixed tiling), e. g. with use of linked row pointers for controlling the screen partition and / or scrolling, e. g. using hardware mechanisms specific for CRTs.

Illustrative examples: to change the displayed information by activating different parts of the screen: EP0680776:

Systems for plural display areas on one screen tiling in x and y directions according to a descriptor data collection, but without user interface: EP0200036.

With hardware control of the video screen in different areas: US2006044216.

Same as above: US4550386.

Hardware control of a text area and of a screen area with a character menu: EP0274439.

Systems with divided screen in two halves of the screen used by different users: EP0018759.

Display buffer/memory management; multiple monitors or variable display arrangements.

Illustrative examples: DE3607474

FR2559933

US4618858

Character generation system: EP0053661.

Details of deflection circuits specific for computer generated displays (in absence of indications of features that render a deflection circuit so specific, not to be classified in G09G).

Illustrative examples:

Deflection circuits for distortion correction: US5070281.

GB1285554

DE19529448

Deflection in specially designed CRTs in a laser CRT with reduced beam diameter: US2002057384.

Sinusoidal deflection current for bidirectional scanning: GB2157136.

Three-dimensional or perspective representation, rotation or translation of display pattern, hidden lines, shadows automatic brightness compensation half-tone display.

Illustrative examples:

Three-dimensional or perspective representation: EP0458692.

US4821210

US4841292

US3889107

Display that involves the spectator to use special glasses: DE4417664, US5162779.

GB2308284

CRTs combining a vector stroke display with a raster scan display, mostly superimposed.

Illustrative examples:

EP0158480

EP0043703

Raster displays with stroke-to-raster conversion are also placed in this class.

CRTs with vector stroke displays.

Illustrative examples:

Curve and line generators.

Curve generator: EP0288720.

Digital technique for constructing variable width lines: US4601002.

Enhancement of the resolution of end points of a line: US4939673.

Character generators specific for vector stroke displays, without reference to a specific digital or analog deflection technique.

Stroke writing character apparatus and method: EP0138339.

Video compensation apparatus.

Compensation of the delay between X and Y (deflection) channels and Z (intensity) channel in a stroke mode CRT display: US5047756.

Slew length timer for the determination of the time interval between start and end of a segment on the display: EP0108473.

For example:

Digital generation of character segments: FR2095711.

EP0130245

With introduction of a digital value to define stroke curvature: US3594756.

Line and curvature drawing.

Line generator based on Bresenham's algorithm: GB2207839.

Wide line drawing: EP0229693.

Curve stroke drawing: EP0014127.

For example:

Graphic data transcription apparatus using a writing plate: US3632874.

Use of a carrier drift arrangement to generate waveforms used for deflection in vector stroke displays: US3025342.

For example: GB2040146, FR2249597.

Illustrative example of subject matter classified in this group (DE3301103)

Illustrative examples:

Screen saver: DE4142894.

Graphics display system: WO8906415.

Raster assembly processor: US4947257.

Interfacing video information and computer-generated graphics on a visual display terminal: US4958297.

Improving apparent smootheness on gray-scale displays: US4612540.

Displaying data in a second display area (obtained by overscan): US2002149593

Radiation elimination circuit: DE29917219U, DE29917219U.

Correcting the rotation of a video display. US2003189639.

Method and apparatus for enlarging a trend graph: US5261031.

Waveform signal display controlling device and method: EP0987673.

Method to scale electrocardiograph (ECG) waveforms independent from display resolution: EP0932139.

Trace coloring system and method: US5959607.

Displaying graphic data: EP0636965.

Arrangements for data processing done in order to adapt the incoming data to the display on a CRT; details of the deflection signals or driving signals of the CRT in dependance of the data to be displayed.

The codes G09G 1/165 and below apply only if a monitor-architecture can be identified (click to see definition; the same rule applies for G09G 3/2092 and G09G 5/003). The G09G 1/165 and below is used only in exceptional cases where the processing is clearly specific to a CRT. Anything that might as well be used for other technologies is to be classified under the G09G 5/003 and its (more detailed) sub-groups.

Illustrative examples:

Monitor calibration: US2003053001.

US2002057282

Screen alignment and positioning: US2002180769.

US2003001856

US4338597

US4081797

Illustrative examples: Parallel data display of multiple executing environments:US2004226041.

Single horizontal scan range CRT monitor: WO0129811.

Improved signal restoration: US6529248.

Display monitor control and communications bus interface: US6590572.

TV-PC conversion cable. DE19630941.

Adding display data channel to existing display: GB2294135.

Separate message section on CRT display device: US5384576.

The class G09G 1/167 includes "details of the interface to a CRT display terminal". If a television set is used as a display terminal, the class G09G 5/006 should be given and not the G09G 1/167 . This is because the signals generated for a television set are standard television signals (NTSC or PAL...): the television itself might have an lcd or plasma panel. If the interface to the display terminal has some details about the signals of the interface, and if these details are clearly means for a CRT terminal (e.g. level or polarity of a h-synch or v-synch signals, black level adjustment...) then the documents are classified in the G09G 1/167 .

Illustrative example of subject matter classified in this group (US3777059):

Multiple beams and beam deflection necessary! A flat panel using deflection is considered as being a multiple beam CRT.

Illustrative examples:

Common focus: US5382883.

US4063233

Separated regions: EP1054379, DE1137143.

For intensity control: US5691608,

FR2296228.

Illustrative example of subject matter classified in this group (GB929976):

and US2925526, US2866189.

Illustrative examples of subject matter classified in this group:

US3639910

US4107741

US3902012

Specific circuits for CRT tubes (e.g. for a penetron tube).

Illustrative examples:

Color shadow mask cathode ray tube: WO8203494.

Position programmed colour CRT: NL7505346.

Colour image display system - CRT with display areas and associated circuitry: DE2329081.

Multi-color crt display system: US3280254.

Cathode ray tube with addressable nanotubes: US6515639.

Image processing system utilizing brush profile: US5412767.

Illustrative examples:

Display device with black correction unit: US2002150293.

Compensation method for improving color saturation and image quality of plasma display panel by adjusting the strength of input image signals: US2002167467.

Plasma displays

Method and apparatus for automatically calibrating a CRT: EP0539943.

Image display system that performs grayscale correction in accordance with the on-site environment: US2003147053.

Light output correction of a display monitor. EP0514025.

Multi-spectral color correction. US2002122044.

Illustrative examples of subject matter:

WO9914730 (display device with rotating display elements)

US4573048 (High speed link for rotating display)

US6877864 (projector with image modified to compensate distortions from projecting onto a screen from a side, so called "Keystone correction")

EP1528528 (projector with plurality of LCD panels).

By orienting the pixel arrays of the light modulators at different non-orthogonal angles, gaps between adjacent pixels of the panels are not aligned. As such, the "screen door" effect caused, for example, by gaps between adjacent pixels of the pixel arrays is reduced. In addition, misalignment between the pixel arrays is less noticeable.

Therefore, the driving circuit calculates modified images for at least one not aligned LCD.

EP1816638 (Coloured display which displays two different images depending onto the viewing direction)

US6175354 (Image display apparatus)

EP0546844 (Baton using light emitting cell array to form a display)

EP0887783 (Rotating drum or blade with linear array of light sources)

Display devices wherein, different from a standard panel:

Illustrative example: EP0709818

Testing or inspecting flat panel displays by electrical means, i.e. by checking electrical signals and parameters while driving the panel, possibly under special driving conditions specific for the test.

Does not apply to testing during manufacturing of non-finished flat panel displays, when the result of the testing are used to determine parameters of the subsequent manufacturing steps (such testing is regarded as a step of manufacturing).

Also, does not apply if the testing/inspecting is carried out by optical means (e.g. optical measurements), which is classified in G01R. In some "mixed" or doubtful cases classifications in both G09G 3/006 and G01R may be given.

Does not apply to mere calibration of display devices, i.e. to the setting of control parameters for properly functioning displays based on detection of operation parameters (e.g. detection of colour, luminance etc), for which Indexing Code G09G 2320/0693 applies.

Illustrative examples:

US3739370 (deflected light beam producing the displayed image on the screen)

US4097115 (Control of optical scanning device for producing a multiple line scan using a linear array of sources and a textured scanned surface)

US2006132452 (control of a display using a deflected and modulated light beam to control an array of photosensitive elements that receive it and consequently command each a pixel display element)

US5463468 (control of a display usinga deflected and modulated light beam for optically writing image data on a photosensitive surface that commands a display such as a light modulator)

Control of displays for displaying a character by selection from a plurality of complete characters.

Illustrative examples: US3218625 (control of a display wheel for converting binary code to display position)

US3200396 (control of a display using fused characters

Control of displays using controlled light sources for displaying a character composed by a fixed number of display elements as segments or dots.

In this group, documents concerning the control of character displays using controlled light sources not covered by any of the groups G09G 3/08 - G09G 3/14 are classified, e.g. the control of vacuum fluorescent character displays.

Control of displays using incandescent filaments, i.e. incandescent light bulbs, for displaying a character composed by a fixed number of display elements as segments or dots.

Control of displays using gas tubes, e.g. luminous plasma discharge cells, for displaying a character composed by a fixed number of display elements as segments or dots.

Control of displays using electroluminescent display elements for displaying a character composed by a fixed number of display elements as segments or dots.

Control of displays using electroluminescent display elements, which are semiconductor devices, e.g. diodes or transistors, for displaying a character composed by a fixed number of display elements as segments or dots.

In this group, documents concerning the control of character displays not covered by the groups G09G 3/18 or G09G 3/19 are classified, e.g. the control of electrophoretic character displays.

Control of displays using liquid crystal display elements for displaying a character composed by a fixed number of display elements as segments or dots.

Control of displays using electrochromic display elements for displaying a character composed by a fixed number of display elements as segments or dots.

For control arrangements or circuits with details concerning the control of intermediate tones of elements arranged in a matrix, a code within G09G 3/2007 is to be given, and with details concerning the colour, G09G 3/2003 is to be given. For control arrangements or circuits for elements arranged in a matrix with details of one specific display technology, a code corresponding to the specific display technology is to be given, e.g. G09G 3/38 for using electrochromic elements.

Control of a display to display a coloured image with aspects specific for flat panel displays.

Control of a display to display an image having intermediate tones with aspects specific for flat panel displays.

Does not apply to a control of the brightness of a display as a whole, for which the Indexing Code G09G 2320/0626 should be given.

Control of a display to display an image having intermediate tones by modulating the amplitude of the analog signals applied to the display elements.

This code is only given if specific details of the amplitude modulation are present or the amplitude modulation plays a significant role, but not for indicating the presence of a usual amplitude modulation in a document.

Control of a display to display an image having intermediate tones by modulating the duration of a single pulse applied to the display element or by modulating the duration of several pulses applied to the display element in the same manner.

Illustrative examples:

US2003/0117420 (modulation of the intermediate tone displayed by a pixel by varying the width applied to a data electrode during a scan period determined by the scan signal applied to the scan electrode)

For plasma display panels, this code is only to be given if specific details of the generation of intermediate tones using sub-frames are present or the generation of intermediate tones using sub-frames plays a significant role, but not for indicating the presence of a usual generation of intermediate tones using sub-frames in a document.

Control of a display to display an image having intermediate tones by using sub-frames having all the same duration, i.e. a frame rate control with the intermediate tone being generated by selectively activating a display element in a number of sub-frames.

Control of a display for displaying an image having intermediate tones by using sub-frames, wherein the durations of the sub-frames are not all binary numbers, i.e. at least for one sub-frame it does not hold that the duration of the nth shortest sub-frame is (n-1) times the duration of the shortest sub-frame.

This code is not given if for all the sub-frames the ratio of the duration of one sub-frame to the duration of another sub-frame is a binary number, but one or more of the sub-frames are split in two or more time periods, wherein the time periods are still addressed by the same binary bit.

Illustrative examples:

GB2327798 (ratio of the durations of the display period of the fourth shortest sub-frame and the shortest sub-frame is seven, not eight)

Control of a display for displaying an image having intermediate tones by using sub-frames, wherein one or more sub-frames corresponding to the most significant bits are split into two or more time periods, which are still addressed by the same bit.

This code is not given if the sub-frame corresponding to the most significant bit is not split, but only other sub-frames corresponding to lower bits are split. This code is also not given if the time periods, into which the sub-frames corresponding to the most significant bits are split, are individually addressed by separate bits, but the code G09G 3/2029 might apply.

Illustrative examples:

EP0774745 (sub-frame with the longest duration and corresponding to the most significant bit is split in two periods controlled by the same most significant bit)

Control of a display for displaying an image having intermediate tones by using sub-frames, wherein one or more sub-frames corresponding to the least significant bits are specifically controlled to increase the number of intermediate tones without applying to narrow pulses.

This code is not given if the sub-frame corresponding to the least significant bit is not specifically controlled, but only other sub-frames corresponding to higher bits.

Illustrative examples:

US5751379 (sub-frame with the shortest duration and corresponding to the least significant bit is displayed only every second frame)

Control of a display for displaying an image having intermediate tones by using sub-frames, wherein the sub-frames are organized in consecutive sub-frame groups, e.g. the groups being separated by a pause period, or the sub-frames within one group having a common addressing scheme, or a specific order with respect to the size of the corresponding bits.

Illustrative examples:

EP1710777 (sub-frames of one frame are arranged in two groups divided by an idle period and with increasing durations within each group)

Control of a display for displaying an image having intermediate tones by using dithering, i.e. by adding a noise signal to the image signal or the gradation threshold.

Control of a display for displaying an image having intermediate tones by using dithering, wherein the noise signal added to the image signal or the gradation threshold is random noise.

Control of a display for displaying an image having intermediate tones by using dithering, wherein the noise signal added to the image signal or the gradation threshold is a spatial dither pattern applied to the display element and its neighbouring display elements.

Control of a display for displaying an image having intermediate tones by using dithering, wherein the noise signal added to the image signal or the gradation threshold is a spatial dither pattern applied to the display element and its neighbouring display elements, and the spatial dither pattern is varied in time, e.g. from one frame to the next frame, and cyclically, i.e. the same pattern is reused after a certain time period.

Control of a display for displaying an image having intermediate tones by using error diffusion in space, i.e. distributing the quantization error to neighbouring display elements.

Illustrative examples:

EP1587053 (error diffusion in space; sections 0027, 0028).

Control of a display for displaying an image having intermediate tones by using error diffusion in time, i.e. distributing the quantization error to the next frame.

Illustrative examples:

EP1583063 (error diffusion in time; section 0143).

Control of a display for displaying an image having intermediate tones by using error diffusion in space and time, i.e. distributing the quantization error to the neighbouring display elements and the next frame.

Illustrative examples:

US2009/0128693 (quantization error is distributed within the same frame to neighbouring display elements and to the same display element in the next frame)

Control of a display to display an image having intermediate tones by varying the area of a display element, which is in one display state, relative to the remaining area of the display element, which is in another display state.

Control of a display to display an image having intermediate tones by display elements (pixel) having two or more physically separated or separately controllable portions (sub-pixels).

Control of a display to display an image having intermediate tones by using two or more methods of generating the intermediate tones together, e.g. by using both sub-pixels and error diffusion.

Additional codes within G09G 3/2007 should also be given, to indicate which methods of generating the intermediate tones are combined. Code G09G 3/2011 is only given if specific details of the amplitude modulation are present.

As using sub-fields for the control of a plasma display panel to display an image having intermediate tones is a standard method, this code is not given for the combination of using sub-fields with a single other method of generating the intermediate tones in a plasma display panel.

Illustrative examples:

US2009/0128473 (combination of amplitude modulation with using sub-pixels for generating intermediate tones in an LCD)

Control of a display to display an image having intermediate tones by using amplitude modulation and time modulation.

Additional codes of G09G 3/2014 or within G09G 3/2018 should also be given to indicate which time modulation method of generating the intermediate tones is used, while the code G09G 3/2011 is only given if specific details of the amplitude modulation are present.

Illustrative examples:

US2009/0051708 (combination of amplitude modulation with pulse width modulation for generating intermediate tones in an OLED display)

Details of the control of a display terminal in a monitor-architecture using a flat panel display, e.g. arrangements for processing of the image data as an adaption for display on the flat panel, or setting of parameters for a flat panel display.

Illustrative example of subject matter classified in this group:

Details of an interface to a display terminal in a monitor-architecture using a flat panel display, e.g. arrangements for processing of the image data as an adaption for display on the flat panel, or setting of parameters for a flat panel display.

Control of displays using controlled light sources as display elements arranged in a matrix.

In this group, documents concerning the control of character displays using controlled light sources not covered by any of the groups G09G 3/24 - G09G 3/30 are classified, e.g. the control of vacuum fluorescent matrix displays or of field emission matrix displays.

Control of displays using incandescent filaments, i.e. incandescent light bulbs, as display elements arranged in a matrix.

Illustrative example: US5920154 (control of an incandescent lamp matrix display)

Control of displays using incandescent filaments, i.e. incandescent light bulbs, as display elements arranged in a matrix, which are controlled to give the appearance of a moving sign.

Control of displays using luminous gas-discharge cells, e.g. luminous plasma discharge cells, as display elements arranged in a matrix.

Control of displays using luminous gas-discharge cells having intermediate tones with aspects specific for displays using luminous gas-discharge cells.

For a control of the brightness of a display as a whole, the Indexing Code G09G 2320/0626 should be given in addition.

Illustrative examples:

US5835072 (different intermediate tones are generated in a plasma display panel by varying the value of the voltage applied to the address electrodes during the addressing phase, and a subsequent sustain phase with the application of sustain pulses having different values)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix, wherein the discharge is caused by the application of signals to the gas-discharge cell having a particular high frequency, i.e. significantly higher than known from other displays using luminous gas-discharge cells as display elements arranged in a matrix.

Illustrative examples:

US2004/0056827 (application of pulses with a frequency of 1MHz to the address electrodes during the sustaining phase)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix, wherein in a discharge cell, some of the electrodes that play a role during the discharge are in contact with the ionized gas (as in DC type panels), some are not (as in AC type panels).

Illustrative examples:

US2004/0207572 (control of a plasma display panel with scan, sustain, and address electrodes not in contact with the ionized gas, and further electrodes in contact with the ionized gas)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix, wherein in a discharge cell, the electrodes that play a role during the discharge are in contact with the ionized gas.

Illustrative examples:

US5332949 (control of a plasma display panel with scan, sustain, and address electrodes in contact with the ionized gas)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in a DC panel, wherein the discharge is sequential transferred from an input position to a further display position.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel, wherein in a discharge cell the electrodes that play a role during the discharge are not in contact with the ionized gas.

Only to be given in exceptional cases, when none of the subgroups of G09G 3/288 applies.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix, wherein the discharge is sequential transferred from an input position to a further display position.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell.

This group is not used for classification. See the subgroups of G09G3/288C2, G09G3/288C4, or G09G3/288C6.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an erase discharge outside the addressing phase, a reset discharge, or a priming discharge.

This group is not used for classification; see subgroups, i.e. G09G3/288C2E, G09G3/288C2P, or G09G3/288C2R.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an erase discharge outside the addressing phase and outside the reset phase.

This code is to be given, if the erase discharge is generated at least once per frame.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating a priming discharge at the time of powering up the display or at regular intervals.

This code is to be given, if a discharge for priming, i.e. for generating charges in the discharge cell, is generated at the time of powering up the display or at regular intervals.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating a reset discharge, i.e. for initialising the gas-discharge cell as a preparation of the subsequent addressing phase.

This code is to be given, if a reset discharge, i.e. for initialising the gas-discharge cell as a preparation of the subsequent addressing phase, is generated during every sub-frame, every frame, or every multiple frames.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an address discharge, i.e. an discharge for selecting the discharge cell according to the display data so that a sustain discharge with light emission takes place in the subsequent sustain phase corresponding to the selection in the addressing phase.

Different control or pulse shapes for different sub-frames are to be indicated by the code G09G 3/2022.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an address discharge, wherein the generation of the address discharge generates sufficient wall charges in the addressed cell so that a sustain discharge with light emission takes place in the subsequent sustain phase.

Different control or pulse shapes for different sub-frames are to be indicated by the code G09G 3/2022.

Illustrative examples:

US2003/0102814 (a discharge generated selectively only in those discharge cells during an addressing phase having a pulse applied to the address electrode together with a pulse applied to the scanning electrode generates wall charges, which enable a lighting discharge in these selected cells during the subsequent sustaining phase)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an address discharge, wherein the generation of the address discharge reduces or erases the wall charges in the addressed cell so that no sustain discharge with light emission takes place in the subsequent sustain phase.

Different control or pulse shapes for different sub-frames are to be indicated by the code G09G 3/2022.

Illustrative examples:

EP0866439 (after generating wall charges in all the discharge cells during the initialisation phase, a discharge erases the wall charges selectively only in those discharge cells during an addressing phase having a pulse applied to the address electrode together with a pulse applied to the scanning electrode, which disables a lighting discharge in these selected cells during the subsequent sustaining phase)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an address discharge, wherein the generation of the address discharge takes place only in one sub-frame of a frame

Illustrative examples:

US2002/0036603 (as the resetting operation is performed only in the first sub-frame, in the following sub-frames only discharge cells not addressed by erasing in the preceding sub-frames can be selected in the addressing phase of a sub-frame by erasing to no longer emit light in the sustaining phase of the sub-frame and all the further sub-frames of the frame)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an lighting or sustain discharge, i.e. a discharge for lighting the discharge cells selected during the addressing phase, wherein after the discharge enough charges remain in the cell to generate a further discharge with the next pulse of the same shape, and wherein, if an image having intermediate tones is generated by using sub-frames, the number of lighting discharges corresponds to the grey scale bit of the sub-frame.

Different control or pulse shapes for different sub-frames are to be indicated by the code G09G 3/2022.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an lighting or sustain discharge, wherein the luminous efficiency of the panel is increased by applying special waveforms, for instance by waveforms generate two luminous discharges with a single pulse.

Different control or pulse shapes for different sub-frames are indicated by the code G09G 3/2022.

Illustrative examples:

US2002/0008680 (increase of the luminous efficiency by generating a light emitting discharge with the rising and the falling slope of each sustaining pulse)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an lighting or sustain discharge, wherein the frequency of the sustain pulses or the number of sustain pulses is varied by the same factor for each subfield of a frame.

Illustrative examples:

EP1065645 (variation of the sustain pulse number with the same factor for all the sub-frames)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an lighting or sustain discharge, wherein the frequency of the sustain pulses or the number of sustain pulses is varied for at least one subfield of a frame differently from the other subfields of the frame.

Illustrative examples:

US2005/0219158 (variation of the sustain frequency for a sub-frame according to the display load of the sub-frame, i.e. the number of cells to emit light during the sub-frame)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel with details of the control of the gas-discharge cell or the shape of the pulses applied to the electrodes of the gas-discharge cell for generating an lighting or sustain discharge, wherein the time period available for the sustaining phase is increased with respect to other time periods in the frame, e.g. pulses in the initialising phase or the addressing phase are modified in order to shorten the time periods needed for these phases and thus enable an increase in light emission by a longer time period for the sustain phase.

Illustrative examples:

EP1365382 (shorter addressing and scanning pulses for addressing the upper scanning lines saves time available for the sustain phase)

Details of a drive circuit for applying pulses to the electrodes of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel.

For displays using luminous gas-discharge cells as display elements arranged in a matrix, the Indexing Code-codes S09G213/12 and S09G213/14 are not given. Instead, details of drive circuits for applying pulses to the electrodes during a certain phase are indicated by giving an additional Indexing Code-code within S09G3/288C to indicate the phase. For instance, details of drive circuits for applying pulses to the scan electrodes or the address electrodes during the addressing phase are indicated by an additional Indexing Code-code within S09G3/288C4. But details of drive circuits for applying pulses during the sustain phase to the scan electrodes or sustain electrodes are not indicated by an additional code within S09G3/288C6, as most of the documents deal with the sustain phase, in particular in G09G3/288D2.

Details of a drive circuit for applying pulses to the electrodes of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel, which uses inductors in a circuit for recovering the energy from the electrodes of the display.

For displays using luminous gas-discharge cells as display elements arranged in a matrix, the Indexing Code-codes S09G213/12 and S09G213/14 are not given. Instead, details of drive circuits for applying pulses to the electrodes during a certain phase are indicated by giving an additional Indexing Code-code within S09G3/288C to indicate the phase. For instance, details of drive circuits for applying pulses to the scan electrodes or the address electrodes during the addressing phase are indicated by an additional Indexing Code-code within S09G3/288C4. But details of drive circuits for applying pulses during the sustain phase to the scan electrodes or sustain electrodes are not indicated by an additional code within S09G3/288C6, as most of the documents deal with the sustain phase, in particular in G09G3/288D2.

Illustrative examples:

US4866349 (sustain electrode drive circuit with energy recovery circuit using an inductor)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel, wherein in a discharge cell the electrodes that play a role during the sustain discharge are opposite to each other.

Illustrative examples:

US2007/0171174 (control of AC plasma display panel with address electrodes on a substrate as well as scan and sustain electrodes in the cell walls and opposite to each other)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel, wherein in a discharge cell the electrodes that play a role during the sustain discharge are on the same surface.

For documents published after 1997 this code is only to be given if no other class under G09G 3/288 is given for a surface discharge panel, as most of the documents after 1997 concern surface discharge panels anyway.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel, wherein in a discharge cell the electrodes that play a role during the sustain discharge are on the same surface, and the discharge cell electrodes have a non-standard arrangement.

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel, wherein in a discharge cell the electrodes that play a role during the sustain discharge are on the same surface, and with more than three electrodes involved in the operation of the discharge cell.

Also if a neighbouring electrode is involved in the operation of the discharge cell beside the three electrodes corresponding to the discharge cell, such a document is to be classified in this group.

Illustrative examples:

US2005/0116899 (operation of the discharge cell by signals applied to four electrodes, A, M, X, Y)

Control of displays using luminous gas-discharge cells as display elements arranged in a matrix in an AC panel, wherein in a discharge cell the electrodes that play a role during the sustain discharge are on the same surface, and with alternate lighting of the cells of one row and in even columns, and an adjacent other row and in odd columns.

Illustrative examples:

EP1199701 (using all the discharge gaps between the scan and sustain electrodes enables a reduction of the number of electrodes and thus a cost reduction, but requires alternate lighting of the odd and even lines)

Control of displays using electroluminescent display elements arranged in a matrix.

Control of displays using organic electroluminescent display elements, which are semiconductor devices, e.g. diodes or transistors, arranged in a matrix, wherein the semiconductive material is organic.

This code is to be given only if no details of the control of the display elements are specified, otherwise the codes of G09G 3/3216 for a passive matrix, or within G09G 3/3225 for an active matrix apply.

Control of displays using organic electroluminescent display elements arranged in a matrix, wherein each display element is located at the intersection of a scan and a data electrode, and directly controlled by the scan and data signal supplied to the scan and data electrode, respectively, i.e. without an active element such as a diode (other than the light-emitting one), or a transistor at the intersection being involved.

The figure below is an example of a passive matrix. In the figure, passive matrix is characterized as having a line driving method which lights all light-emitting devices of the line at once, and a matrix is a 2-dimensional arrangement, comprising cathode and anode strips.

The figure below is an example of selective application of a current to the anodes of OLED display elements as data signal via data electrodes Ak while a voltage is supplied to the cathodes of the display elements as scan signal via scan electrodes.

Control of displays using organic electroluminescent display elements arranged in a matrix, wherein each display element is located together with an active element such as a transistor or a diode, other than the light-emitting one, at the intersection of a scan electrode and a data electrode. The active element has to be enabled by the application of a scan signal to the scan electrode so that the display element receives the data signal.

The figure below is an example of an active-matrix. In the figure, active-matrix is an individual driving method where light-emitting devices are turned on by each film transistor (TFT), and a matrix is an arrangement of light-emitting devices or TFTs or their combinations.

Control of displays using organic electroluminescent display elements arranged in a matrix together with active elements, wherein each active element enables a driving current flowing through a display element corresponding to a data signal supplied to a data electrode. The corresponding active element must concurrently be selected by a scan signal supplied to its scan electrode.

The figure below is an example of data voltage signal supplied to the data line (14), which controls the driving current flowing through the organic electroluminescent display element.

Control of displays using organic electroluminescent display elements arranged in a matrix together with active elements, wherein each active element enables a driving current flowing through a display element corresponding to a data current supplied to a data electrode, which is supplied when the active element is activated by a scan signal supplied to a scan electrode, e.g. by a current mirror having the data current flowing through the data electrode as an input current, and the driving current flowing through the display element as an output current.

The figure below is an example of data current signal supplied to the data line DL and flowing through the input part PM2 of a current mirror circuit, which controls the driving current flowing through the output part PM1 of the current mirror circuit and the organic electroluminescent display element)

Control of displays using organic electroluminescent display elements arranged in a matrix together with active elements, wherein each active element enables a driving current flowing through a display element corresponding to a data current flowing through a data electrode and through a driving transistor, but not through the display element connected in series with the driving transistor, during a first period when the active element is activated by a scan signal supplied to a scan electrode, and with the driving current flowing through the driving transistor and the display element during a second period when the scan signal is not supplied to the scan electrode, e.g. by a first switch connecting the driving transistor to the data electrode during the first period, and a second switch connecting the driving transistor to the display element during the second period.

The figure below is an example where the data current signal Idat is applied to the data line and flows only through the driving transistor T2 during the scan period (T1 and T3 ON, T4 OFF), and through the driving transistor and the organic electroluminescent display element after the scan period (T1 and T3 OFF, T4 ON).

Control of displays using organic electroluminescent display elements arranged in a matrix together with active elements, wherein each active element enables the application of a voltage across a display element corresponding to a data signal supplied to a data electrode. The corresponding active element must concurrently be selected by a scan signal supplied to a scan electrode.

The figure below is an example where the application of a scan signal on a line, 7-j (1<=j<=m), enables the transistors of pixels belonging to that line. The light-emitting diodes of the line can then receive data by supplying a data signal on column 6-k (1<=k<=n).

Details of a drive circuit for supplying scan signals to scan electrodes of an organic electroluminescent matrix display.

Details of a drive circuit for supplying data signals to data electrodes of an organic electroluminescent matrix display.

Details of a drive circuit for supplying data signals to data electrodes of an organic electroluminescent matrix display, the data signals being in the form of a variable data current value according to the data to be displayed.

Details of a drive circuit for supplying data signals to data electrodes of an organic electroluminescent matrix display, the data signals being in the form of variable data voltage value according to the data to be displayed.

Further detail is covered by the Indexing Code symbols listed below. Classification is obligatory.

Field sequential colour displays: G09G 2310/0235

Scrolling of the light from the illumination source while scanning the screen: G09G 2310/024

Adjustment of display parameters: G09G 2320/06

The adjustment depending on the type of the information to be displayed: G09G 2320/0613

Adjustment of illumination source parameters: G09G 2320/062

For control of overall brightness: G09G 2320/0626

By amplitude modulation of the brightness of the illumination source: G09G 2320/0633

By time modulation of the brightness of the illumination source: G09G 2320/064

Modulation of brightness of the illumination source and modulation of image signal correlated to each other: G09G 2320/0646

Detecting light within display devices, e.g. using a single or a plurality of photosensors: G09G 2360/14

The light being ambient light: G09G 2360/144

The light originating from the display screen: G09G 2360/145

Calculation or use of calculated indices related to luminance levels in display data: G09G 2360/16

Illustrative examples:

EP0319293 (Standard field sequential display without specific details)

US4907862

US2001008394 (Two illumination sources without corresponding display areas)

Further detail is covered by the Indexing Code symbols listed below. Classification is obligatory.

To indicate details of the colour setup of elements in an array of light emitting elements forming the illumination source: G09G 2300/0452

Example:

US2004246275 (Filed sequential display with specific details)

US6608614 (Automatic adjustment of colour parameters)

Documents disclosing horizontal stripes or rows of pixel, each lit by a separate illumination source, each illumination source being independently controlled from the other illumination sources.

Illustrative examples:

US2002000960 (Backlight with scanning of illumination source)

WO2005093703 (Backlight without scanning of illumination source)

US6563271 (Backlight having separate light sources for different panel regions)

Documents disclosing a backlight unit usually comprising a matrix of pixel blocks or single pixels which are each lit by an separate illumination source, each illumination source being independently controlled from the other illumination sources.

Illustrative examples:

EP1380876 (Backlight unit with scanning of illumination sources)

US2001028335 (Backlight unit without scanning of illumination source, with S09206/02 Indexing Code)

EP1496497 (Display comprising stacked panels, with S09206/02 Indexing Code)

Control of display devices wherein the visual effect is obtained by controlling the displacement of microparticles in fluid or gas.

Documents in which the displacement of the microparticles is obtained with a cell electrode structure comprising more than two electrodes.

Illustrative example:

US5223115 (Item 26: cathode, item 18: anode, item 28: grid)

Control of display devices with rotating elements ("particles") that are encapsulated and suspended in a fluid and controlled by electrostatic operation.

Also control of displays wherein each pixel contains a plurality of "particles" (e.g. "Gyricon®" from Xerox).

Illustrative example of subject matter classified in this group:

US2006214880

Illustrative examples of subject matter classified in this group:

US5214419

Control of electrically switched displays composed of miniature interferometers (etalons) that are switched on and off with microelectromechanical systems. An etalon reflects light at a specific wavelength and gives pure, bright colours while consuming no power.

Illustrative examples of subject matter classified in this group:

EP1473581

US2002054424

Interferometric modulator [IMOD], Diffractive light device [DLD].

Illustrative example of subject matter classified in this group:

WO9731288

Movable elements controlled electromagnetically (also: magnetostrictive effect used in "foil" display).

Illustrative example:

DE2133121

Illustrative example of subject matter classified in this group:

EP1369844 (Piezoelectric actuator in combination with scattering of light from a waveguide. In this case the document was allocated both G09G 3/3493 and G09G 3/3473 symbols)

Control of discrete pixel electrodes on one substrate without row and column selection.

Control of a plurality of display modules combined to result in a bigger matrix.

Address matrix for selecting a row or column.

Specific circuits for crosstalk compensation (e.g. with extra electrode carrying an additional signal).

Circuit for temperature compensation in LC displays.

Control of stacked LC panels.

Control of subpixels in liquid crystal displays.

Illustrative examples: US2005174456 (Interface from external camera or host to a LCD, wherein the display data are stored in the display driver. The display controller communicates with the display unit sending RGB-data and the LCD-clock. Because no hsync / vsync are transmitted, this interface does not form a monitor_architecture)

FR2808113 (Details of wiring between drivers and rows and columns)

Control of passive matrix devices. Passive matrix means that there are no active elements (transistor, diode, MIM, ...) in the display cell at the crosspoint of a row and column.

In traditional multiplexing, the rows are addressed in sequence and only one at a time. The voltages set on the columns correspond to the pixel values in the row being addressed. This scheme leads to very low voltage selection ratios and, consequently, low contrast.

In the Active Adressing scheme, several rows are addressed simultaneously in different patterns corresponding to orthogonal functions. A set of functions is orthogonal over a certain interval if the integral of the product of any two of the functions is 0 if the functions are different, and a constant if they are the same function. From signal processing theory, we can represent a given signal as a sum of differing amounts of these orthogonal functions. If we suppose the signal we wish to represent is the sequence of pixel values in a particular column of a display, then we can create that signal by applying the correct orthogonal functions to the row lines and certain voltages on the column line that correspond to the amounts of those functions we want. If we use the same functions to represent the signals in the other columns, then we can create a whole display by applying the correct voltages to all of the column lines in parallel.

Documents classified in G09G 3/3625 shall not receive an Indexing Code for active addressing (G09G 2310/0208 ).

Illustrative example:

Order 32 Walsh functions. These kinds of functions serve as the voltage settings for the row lines in active addressing.

Control of:

Control of:

Using subpixels in memory effect LCDs for displaying gradations (common solution, together with subframe modulation, since the memory effect LCDs are normally binary devices) or for other purposes.

Documents classified in G09G 3/364 shall not receive an Indexing Code for subpixels addressing (G09G 2300/0439 and subgroups).

Video-walls, which consist out of modules, meant to be flexibly combined into a bigger size display, e.g. for installation or configuration purposes (see G06F 3/1446 and G09G 2300/026).

Matrices where the split has no impact on the driving, i.e. it is just a convenient constructional measure or it serves other purposes (heat dispersion etc.). Possible classifications for such cases are again in G06F 30/00, H01L 27/00, or in groups related to the physical structure of specific display technologies (e.g. G02F 1/13 for LCDs).

Splitting of matrices in a way that the resulting structure cannot be driven independently from each other, e.g. driving odd lines from one driver and even lines from another driver.

Control of image refresh frequency in LC displays, wherein the displays comprise a switching element (e.g. a transistor) in series with the liquid crystal cell at each matrix point.

Illustrative example of subject matter classified in this group:

EP0651368

Video-walls, which consist out of modules, meant to be flexibly combined into a bigger size display, e.g. for installation or configuration purposes (see G06F 3/1446 and G09G 2300/026).

Matrices where the split has no impact on the driving, i.e. it is just a convenient constructional measure or it serves other purposes (heat dispersion etc.). Possible classifications for such cases are again in G06F 30/00, H01L 27/00, or in groups related to the physical structure of specific display technologies (e.g. G02F 1/13 for LCDs).

Splitting of matrices in a way that the resulting structure cannot be driven independently from each other, e.g. driving odd lines from one driver and even lines from another driver.

Control of pixel circuits wherein a diode string or a variable resistor is connected in series with the LC cell.

Documents receiving this code usually do not receive G09G 2310/0275 .

However, documents should be given the following codes in addition to G09G 3/3685, if applicable when they contain the corresponding details:

Generation of driving voltages, as distinguished from power supply voltages, to be used by the drivers for the generation of waveforms applied to the electrodes.

Although some of the driving voltages may possibly be coincident with the power supply voltages (normally the extreme voltage values), driving voltages serve the purpose of composing an electrode addressing waveform, rather than supplying power to a functional unit; driving voltages may be representative of gradation levels (AM gradations) or may merely be levels required by a complex waveform (e.g. in the addressing of passive matrix LCDs, FLCDs, electrophoretic panels etc).

The lines/electrodes to which driving voltages are applied may or may not draw power from the generating circuit; driving voltages may normally be regarded as reference voltages, and normally for them only very small fluctuations are tolerated.

The generation of voltages is different than the generation of signals applied to the electrodes.

Illustrative examples:

Applicable when common to all display technology. By example when display technologies are not specific to LCD but to LCD, Plasma and OLEDS. (also CRTs but it is no more relevant in 2011).

See also image data processing or generation, in general G06T.

Resolving memory contention by CRT controller and the CPU, eventually combined with refresh of the dynamic memory

Illustrative examples:

bit-map based: US4860251

display system with video synchronization pn:US2004212734

blending graphics and video surfaces pn:US2004130558

method for bitmapping and synchronization pn:US2003043161

character based:

pn:US4581611

both bit-map and character based:

display control unit pn:US2001015727

generic:

display control unit pn:EP0155499

EP0254293

The documents in this class are subdivided in four sections:

1. bit-map only - used when the system is clearly bit mapped (newer documents); see also G09G500a bit-map (G09G)

2. character based only - used when the system is clearly character based (older documents); see also G09G500a character based (G09G)

3. both character and bit-map - used when the document discloses both a character based and a bit mapped system or when the system includes both possibilities;

4. generic / no indication - used when it is not clear if it is charachter based or bit map or if it is not relevant to know (general arbitration problems)

Refresh of the memory in combination with refreshing the screen (i.e. reading the memory)

Memory allocation: G06F 12/02 and subgroups

Details of a display terminal (*1), e.g. details of the display terminal controller, interconnection and interface between display terminal controller and display device controller, buffering of image data, calibration, on-screen display of menu data for setting of parameters, data processing independent of the type of display device.

Even though the groups G09G 1/165 and G09G 3/2092 still exist, they should be used in very special cases only in which the connection with the technology of the display unit (CRT or flat panel) determines the content of the document.

The codes G09G 5/003 and below apply only if a monitor-architecture can be identified (the same rule applies for G09G 3/2092 and G09G 1/165).

The following groups should also be searched, because they have not yet been purged of documents for G09G 5/003

G09G 3/3611: control of matrices with row and column drivers

G06F 3/147: using display panels

G06F 3/153: using cathode-ray tubes

G09G 1/285: interfacing with colour displays

The codes G09G 5/003 and below (thus including G09G 5/005) apply only if a monitor-architecture can be identified (the same rule applies for G09G 3/2092 and G09G 1/165).

Used to be a subgroup of G09G 5/006 (now G09G 5/006), this code applies independently of where the adaptiation is done, in the interface or in the controller of the terminal. Most of the documents in this group will relate to flat panels, since a CRT does not need, in general, any adaptation. It was decided, however, to have a single classification for all the documents dealing with this problem.

The output of the interface usually will be a frame or a line buffer, the latter may well be included in the data driver of the visualization unit.

The following groups should also be searched, because they have not yet been purged of documents for G09G 5/005:

G09G 3/3611: control of matrices with row and column drivers

G06F 3/147: using display panels

G06F 3/153: using cathode-ray tubes

G09G 1/285: interfacing with colour displays

Notes on new groups:

G09G 5/006 is former G09G 5/006 and G09G 5/006

G09G 5/005 is former G09G 5/005

G09G 5/008 is former G09G 5/008

Interface between a graphics controller and a display terminal

Illustrative examples:

US2003033417 - A special interface usable with everything, espacially to transmit video (and audio) data to be viualized on a display unit. It includes USB, but a lot more; it can also transmit graphic primitives. Two classes were given, G09G 5/006 and G06F 3/14.

Documents with interfaces to terminals will be classified in this group unless the structure of the interface is very much tied to the technology of the display (exceptional cases).

The codes G09G 5/003 and below (thus including G09G 5/006) apply only if a monitor-architecture can be identified (click to see definition; the same rule applies for G09G 3/2092 and G09G 1/165).

For picture scaling by changing the sampling timing of the analog signal G09G 5/005 is applied

EP0765078

EP0821340

EP1056285

For clock generation (typically by PLL) G09G 5/008 (former G09G 5/008 ) is applied

US6049318

Notes on new groups:

G09G 5/006 is former G09G 5/006 and G09G 5/006

G09G 5/005 is former G09G 5/005

G09G 5/008 is former G09G 5/008

The following groups should also be searched, because they have not yet been purged of documents for G09G 5/005:

G09G 3/3611: control of matrices with row and column drivers

G06F 3/147: using display panels

G06F 3/153: using cathode-ray tubes

G09G 1/285: interfacing with colour displays

Some digital data streams, especially high-speed serial data streams (also for analog signal with hsync and vsync synchro decoding to recreate the pixel clock) are sent without an accompanying clock signal. The receiver generates a clock from an approximate frequency reference, and then phase-aligns to the transitions in the data stream with a phase-locked loop (PLL). This process is commonly known as clock and data recovery (CDR).

In order for this scheme to work, a data stream must transition frequently enough to correct for any drift in the PLL's oscillator. The limit for how long a clock recovery unit can operate without a transition is known as its maximum consecutive identical digits (CID) specification. To ensure frequent transitions, some sort of encoding is used; 8B/10B encoding is very common, while Manchester encoding serves the same purpose.

This group used to be a subgroup of G09G 5/006 (now G09G 5/006; see notes there), this code applies if the clock recovery is performed within the display interface of a monitor-architecture. Most of the documents in this group will relate to flat panels, since a CRT does not need, in general, any adaptation. It was decided, however, to have a single classification for all the documents dealing with this problem.

Notes on new groups:

G09G 5/006 is former G09G 5/006 and G09G 5/006

G09G 5/005 is former G09G 5/005

G09G 5/008 is former G09G 5/008

The following groups should also be searched, because they have not yet been purged of documents for G09G 5/005:

G09G 3/3611: control of matrices with row and column drivers

G06F 3/147: using display panels

G06F 3/153: using cathode-ray tubes

G09G 1/285: interfacing with colour displays