Manual of U.S. Patent Classification
as of June 30, 2000

Class
708
ELECTRICAL COMPUTERS: ARITHMETIC PROCESSING AND CALCULATING

Class definitions may be accessed by clicking on the class title, above.
Subclass definitions may be accessed by clicking on the subclass number, below.

Patents classified in a subclass may be accessed by clicking on the " " icon following the subclass number, below.

( please note that links to definitions and classified patents may not be available for some classes and subclasses )

For search strategies, please refer to the Classification Index Explanation of Data web page.

Subclass		Title
ClassTitle		===> ELECTRICAL COMPUTERS: ARITHMETIC PROCESSING AND CALCULATING
1		ELECTRICAL HYBRID CALCULATING COMPUTER
2		. Plural complete computers
3		. Particular function performed
4		. . Evaluation of trigonometric function
5		. . Correlation, convolution, or transformation
6		. . Integration or differentiation
7		. . Multiplication or division
8		. . Function generation
9		. . . Piece-wise linear synthesis
100		ELECTRICAL DIGITAL CALCULATING COMPUTER
101		. Pulse repetition rate
102		. . Digital differential analyzer
103		. . Multiplication or division
104		. Plural complete computers
105		. Combined with diverse art device
106		. . Checkbook
107		. . Writing instrument (e.g., pen)
108		. . Tape recorder
109		. . Communication device (e.g., telephone, radio, television)
110		. . Business device (e.g., billing, memorandum)
111		. . Horological device
112		. . . Calendar
130		. Programmable calculator
131		. Having specialized input
132		. . Having supplemental environment related input
133		. . . Cooking
134		. . . Business
135		. . For security
136		. . Input verification
137		. . Fraction input
138		. . Flexible input
139		. . Including specific computing system interconnection
140		. . Modular or overlay nonkeyboard-type information entry
141		. . Including specific nonkeyboard-type information entry
142		. . Including specific keyboard-type information entry
143		. . . Nonmechanical key actuation
144		. . . User definable key
145		. . . Plural function key
146		. . . Key sequencing (i.e., sequence defines function)
160		. Having specialized output
161		. . Having supplemental environment related output
162		. . . Teaching
163		. . . Business
164		. . Output verification
165		. . Blanking
166		. . . Zero suppression
167		. . Prompting
168		. . Selective output
169		. . Sequential output
170		. . Using particular format
171		. . Symbol accompanying output
172		. . Audio
173		. . Printer
174		. . Multiple simultaneous outputs
190		. Integrated circuit
191		. Electro-optical
192		. Bubble-domain
200		. Particular function performed
201		. . Absolute value or magnitude
202		. . Median
203		. . Compression/decompression
204		. . Format conversion
205		. . . Normalization
206		. . Unit conversion
207		. . Maximum/minimum determination
208		. . Scaling
209		. . Shifting
210		. . Determining number of like-valued bits in word
211		. . Determining number of like-valued leading or trailing bits
212		. . Detecting particular sequence of bits
230		. . Multifunctional
231		. . . Microprocessor
232		. . . Array of elements (e.g., AND/OR array, etc.)
233		. . . Pipeline
234		. . . Parallel bit input of operand
235		. . . Uses look-up table
236		. . . More than two operands
250		. . Random number generation
251		. . . Oscillator controlled
252		. . . Linear feedback shift register
253		. . . Plural parallel outputs bits
254		. . . Seed value controls
255		. . . Truly random number
256		. . . Plural parallel outputs
270		. . Function generation
271		. . . Direct digital frequency synthesizer
272		. . . Memory used to store waveshape
273		. . . Counter as source (i.e., input)
274		. . . Linear
275		. . . Circular
276		. . . Trigonometric
277		. . . Logarithmic/exponential
290		. . Interpolation/extrapolation
300		. . Filtering
301		. . . Tapped delay line
303		. . . Microprocessor
304		. . . Nonlinear (e.g., median, etc.)
305		. . . Initialization
306		. . . Finite arithmetic effect
307		. . . Delta/differential coded
308		. . . Multidimensional data
309		. . . Frequency measurement
310		. . . Coherent
311		. . . Frequency detection
312		. . . . Tone detection
313		. . . Decimation/interpolation
314		. . . Matched filter type
315		. . . By convolution
316		. . . Having multiplexing
317		. . . Wave
318		. . . Lattice
319		. . . Transversal
320		. . . Recursive
321		. . . Nontime domain
322		. . . Adaptive
323		. . . . Equalizer
400		. . Transform
401		. . . Multidimensional
402		. . . Discrete Cosine Transform (i.e., DCT)
403		. . . Fourier
404		. . . . Fast Fourier Transform (i.e., FFT)
405		. . . . Discrete Fourier Transform (i.e., DFT)
406		. . . . Pipeline
407		. . . . Systolic
408		. . . . Radix greater than two
409		. . . . Butterfly circuit
410		. . . Walsh
420		. . Convolution
421		. . . Cyclic/circular
422		. . Correlation
423		. . . Single bit data
424		. . . Multidimensional data
425		. . . Using tapped delay line
426		. . . Autocorrelation
440		. . Evaluation of trigonometric function
441		. . . Vector resolver
442		. . Coordinate conversion
443		. . Differentiation
444		. . Integration
445		. . Averaging
446		. . Solving equation
490		. . Arithmetical operation
491		. . . Residue number
492		. . . Galois field
493		. . . Multi-valued
494		. . . Incremental mode
495		. . . Floating point
496		. . . . Compensation for finite word length
497		. . . . . Round off or truncation
498		. . . . . Overflow or underflow
499		. . . . . Sticky bit
500		. . . . Evaluation of root
501		. . . . Multiplication followed by addition
502		. . . . Reciprocal
503		. . . . Multiplication
504		. . . . Division
505		. . . . Addition or subtraction
506		. . . . Feedback
507		. . . . Parallel
508		. . . . Pipeline
509		. . . . Systolic
510		. . . . Microprocessor
511		. . . . Complex number format
512		. . . . Logarithmic format
513		. . . . Variable length or precision
514		. . . . Matrix array
517		. . . Logarithmic format
518		. . . Variable length
519		. . . Negative radix
520		. . . Matrix array
521		. . . Pipeline
522		. . . Systolic
523		. . . Multiplication followed by addition (i.e., x*y+z)
524		. . . Multiple parallel operations
525		. . . Status condition/flag generation or use
530		. . . Error detection or correction
531		. . . . Parity check
532		. . . . Residue code
533		. . . . Sequential repetition
534		. . . . Plural parallel devices
540		. . . Cathode-ray tube
541		. . . Contact-making device
542		. . . Radix point control
550		. . . Compensation for finite word length
551		. . . . Round off or truncation
552		. . . . Overflow or underflow
553		. . . . . Prediction
603		. . . Sum of products generation
604		. . . All four basic functions
605		. . . Evaluation of root
606		. . . Evaluation of powers
607		. . . Multiplication of matrices
620		. . . Multiplication
622		. . . . Complex number format
623		. . . . Decimal
624		. . . . Coded decimal
625		. . . . Binary
626		. . . . . Sum of cross products
627		. . . . . Repeated addition
628		. . . . . . Multiple digit
629		. . . . . . . Carry-save adders (i.e., CSAs)
630		. . . . . . . Array adders
631		. . . . . . . Pipeline
632		. . . . . . . Feedback
650		. . . Division
651		. . . . Decimal
652		. . . . Coded decimal
653		. . . . Binary
654		. . . . . Multiplication by reciprocal
655		. . . . . Repeated subtraction
656		. . . . . . Multiples of divisor
670		. . . Addition/subtraction
671		. . . . Comparison
672		. . . . Incrementation/decrementation
673		. . . . Radix correction
674		. . . . . Serial
675		. . . . Signal amplitude
676		. . . . Microwave
677		. . . . Cryogenic
678		. . . . By electronic tube
679		. . . . Magnetic
680		. . . . Decimal
681		. . . . . Serial
682		. . . . . Parallel
683		. . . . Coded decimal
684		. . . . . Serial
685		. . . . . Parallel
700		. . . . Binary
701		. . . . . Bipolar junction transistor only or combined with Field-Effect Transistor
702		. . . . . Field-Effect transistor (FET)
703		. . . . . Gate functional level
704		. . . . . For precharging (e.g., Manchester, etc.)
705		. . . . . Serial
706		. . . . . Parallel
707		. . . . . . Carry-ripple
708		. . . . . . Carry-save adders
709		. . . . . . Adding more than two numbers
710		. . . . . . Carry look-ahead
711		. . . . . . . Slice block having block ripple
712		. . . . . . . Slice block having block look-ahead
713		. . . . . . . Tree structured logic blocks
714		. . . . . . Conditional sums
800		ELECTRICAL ANALOG CALCULATING COMPUTER
801		. Particular function performed
802		. . Evaluation of equation
803		. . . Simultaneous
804		. . . Differential (e.g., differential analyzer)
805		. . Averaging
806		. . Variance or standard deviation determination
807		. . Evaluation of root (e.g., square root)
808		. . Evaluation of powers
809		. . Coordinate conversion or vector resolver
810		. . . Electromechanical
811		. . Evaluation of trigonometric function
812		. . . Single triangle
813		. . Correlation or convolution
814		. . . Of multidimensional data
815		. . . Acoustic
816		. . . Optical
817		. . . Magnetic or electromagnetic
818		. . . Having tapped delay line
819		. . Filtering
820		. . Transform
821		. . . Fourier
822		. . Differentiation
823		. . Integrator
824		. . . Plural integration
825		. . . Plural mode (e.g., plural scale)
826		. . . Reset
827		. . . Drift correction
828		. . . Having simultaneous calculation of another function
829		. . . Having a voltage to frequency converter
830		. . . Electromechanical
831		. . . Electro-optical
832		. . . Magnetic or electromagnetic
833		. . . Amplifier with additional feedback loop
834		. . . . Additional R/C feedback loop
835		. . Multiplication
836		. . . Time division
837		. . . Quarter-square
838		. . . Having charging or discharging of energy storage device
839		. . . Photomultiplier
840		. . . Electromagnetic
841		. . . . Hall effect
842		. . . Electromechanical (e.g., servo-multiplier)
843		. . . With alternative division
844		. . Division
845		. . Function generation
846		. . . Piece-wise linear synthesis
847		. . . . Interpolation/extrapolation
848		. . . . Diode breakpoint
849		. . . Cathode-ray tube
850		. . . Two or more variables
851		. . . Logarithmic/exponential
852		. . . Triangular, sawtooth, or ramp
853		. . . Hyperbolic
854		. . . Electromechanical

Information Products Division -- Contacts

Questions regarding this report should be directed to:

U.S. Patent and Trademark Office
Information Products Division
PK3- Suite 441
Washington, DC 20231

tel: (703) 306-2600
FAX: (703) 306-2737
email: oeip@uspto.gov

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Last Modified: 6 October 2000