US3881807A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal display for small-sized electronic calculator
Assignee: Suwa Seikosha KK
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Filing: 1973-12-03
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Granted: 1975-05-06
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Expires: 1993-12-03
Abstract
Abstract A cover for at least a portion of the top surface of a smallsized electronic calculator is provided, a portion of said cover being adapted to transmit light onto the display surface, the cover also being dimensioned to be large relative to the display surface of the liquid crystal display of said calculator so as to insure proper contrast for said display surface.
Inventors
- 👤 Minoru Hosokawa
- 👤 Kouji Kakizawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:31
CPC Classifications
H; H01; H01H; H01H36/00; H01H36/0006; H01H36/0066; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/133308; G02F1/1335; G04; G04C; G04C3/00; G04C3/001; G04C3/004; G06; G06C; G06C11/00; G06C11/02; G06C7/00; G06C7/02; G06F; G06F3/00; G06F3/01; G06F3/02; G06F3/0202; G09; G09G; G09G3/00; G09G3/04; G09G3/16; G09G3/18
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
107 words
In a small-sized electronic calculator, the improvement which comprises liquid crystal display means having a display surface disposed on said calculator; and cover means pivotally mounted on said calculator for displacement between a first position in which said cover overlays said liquid crystal display surface, the second position in which said cover is positioned to intercept light reflected from said liquid crystal display surface relative to the eye of the observer, said cover further including a transparent plate proximate the viewing surface of the calculator to provide light from behind the cover to thereby enhance the contrast of said display device to the eye of the observer.
Claim 2
Dependent Claim
107 words
In a small-sized electronic calculator, the improvement which comprises liquid crystal display means having a display surface disposed on said calculator; and cover means pivotally mounted on said calculator for displacement between a first position in which said cover overlays said liquid crystal display surface, the second position in which said cover is positioned to intercept light reflected from said liquid crystal display surface relative to the eye of the observer, said cover further including a transparent plate proximate the viewing surface of the calculator to provide light from behind the cover to thereby enhance the contrast of said display device to the eye of the observer.
Claim 3
Dependent Claim
53 words
In a small-sized electronic calculator as claimed in claim 1 wherein said cover includes a black surface and a light source and a switch coupled thereto, said light source being disposed on the black surface of said cover proximate to the digital display to enhance viewing of the digital display under darkened conditions.
Claim 4
Dependent Claim
189 words
In a small-sized electronic calculator, the improvement which comprises liquid crystal display means having a display surface positioned on said calculator; and cover means pivotally mounted on said calculator for displacement between a first position in which said cover overlays said liquid crystal display surface, and a second position in which said cover is positioned to intercept light reflected from said liquid crystal display surface relative to the eye of the observer, said cover including a transparent plate disposed in proximity to the crystal display surface for providing incident light from behind the cover onto the display surface, said calculator being formed with an operative surface including said display surface, said cover means being pivotally displaceable along the line on one side of display surface, and being dimensioned to extend along said operative surface at a substantial distance beyond the other side of display surface so as to cover all of said operative surface when said cover means is in said first position, the inner surface of said cover means except in the region of said transparent plate being formed of substantially non-reflective black material having a rough surface.
Claim 5
Dependent Claim
189 words
In a small-sized electronic calculator, the improvement which comprises liquid crystal display means having a display surface positioned on said calculator; and cover means pivotally mounted on said calculator for displacement between a first position in which said cover overlays said liquid crystal display surface, and a second position in which said cover is positioned to intercept light reflected from said liquid crystal display surface relative to the eye of the observer, said cover including a transparent plate disposed in proximity to the crystal display surface for providing incident light from behind the cover onto the display surface, said calculator being formed with an operative surface including said display surface, said cover means being pivotally displaceable along the line on one side of display surface, and being dimensioned to extend along said operative surface at a substantial distance beyond the other side of display surface so as to cover all of said operative surface when said cover means is in said first position, the inner surface of said cover means except in the region of said transparent plate being formed of substantially non-reflective black material having a rough surface.
References Cited (Backward Citations)
US3499112A
Cited
US3592527A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |