| US 7,338,162 B2 | ||
| Workplace screen lens | ||
| Helmut Altheimer, Baisweil-Lauchdorf (Germany); Gregor Esser, Munich (Germany); Walter Haimerl, Munich (Germany); Edda Wehner, Emmering (Germany); and Andrea Welk, Munich (Germany) | ||
| Assigned to Rodenstock GmbH, Munich (Germany) | ||
| Appl. No. 10/576,929 PCT Filed Oct. 25, 2004, PCT No. PCT/EP2004/012032 § 371(c)(1), (2), (4) Date Mar. 02, 2007, PCT Pub. No. WO2005/040894, PCT Pub. Date May 06, 2005. |
||
| Claims priority of application No. 103 49 726 (DE), filed on Oct. 23, 2003. | ||
| Prior Publication US 2007/0252949 A1, Nov. 01, 2007 | ||
| Int. Cl. G02C 7/06 (2006.01) | ||
| U.S. Cl. 351—169 [351/177] | 20 Claims |
| 1. Workplace screen lens, having
an area designed for seeing at room distance, hereinafter referred to as the far part,
an area designed for seeing at short distances, in particular for reading a keyboard and documents, hereinafter referred to
as the near part and
a progressive zone situated between the near part and the far part, which is designed specifically for seeing on the screen
and in which the effect of the lens increases continuously along a curve toward the nose, hereinafter referred to as the main
line, which is not an umbilical curve, increasing from the value at the far reference point situated in the far part to the
value at the near reference point situated in the near part, whereby
the workplace screen lens is optimized at the middle of the lens for the middle viewing distances of approximately 60 centimeters
to approximately 90 centimeters,
the progressive channel at the middle of the lens is at least 4 millimeters wide,
the effect increases from the middle of the lens toward the bottom with the vertical coordinate y equal to approximately 0,
reaching a near vision zone with an essentially constant effect at y equal to approximately −12 millimeters,
the progressive channel has a width of least 15 millimeters in the near vision zone, preferably at the near-reference point,
the effect decreases from the middle of the lens up to y equal to approximately +10 millimeters to approximately +12 millimeters
above the middle of the lens,
the progressive length amounts to approximately 20 millimeters to approximately 25 millimeters,
the main progressive length is between approximately 7 millimeters and approximately 12 millimeters and
the minimum width of the progressive channel amounts to at least 4 millimeters.
|