US3887791A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prismatic display window for a calculator
Assignee: Texas Instruments Inc
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Filing: 1973-11-08
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Granted: 1975-06-03
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Expires: 1993-11-08
Abstract
Abstract Disclosed is a calculator casing having a prism display window for shifting the angle of light transmission therethrough to provide a more desirable viewing angle. A low profile calculator having a liquid crystal, light emitting diode, or gas discharge tube display has interposed between the viewer and the display elements a prism window for shifting the viewing angle and filtering undesirable ambient light.
Inventors
- 👤 Lee Glen Kitchens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 01:55
CPC Classifications
G; G06; G06C; G06C11/00; G06C11/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
68 words
In a calculator system having a keyboard and having a visible output display contained in a casing for displaying visual data representations, the improvement comprising: a. a display source, disposed substantially in the same plane as the keyboard; and b. a prism attached to the casing for altering the angle of transmission of the visual data representations the transmission angle being acute with respect to the vertical plane.
Claim 2
Dependent Claim
68 words
In a calculator system having a keyboard and having a visible output display contained in a casing for displaying visual data representations, the improvement comprising: a. a display source, disposed substantially in the same plane as the keyboard; and b. a prism attached to the casing for altering the angle of transmission of the visual data representations the transmission angle being acute with respect to the vertical plane.
Claim 3
Dependent Claim
68 words
In a calculator system having a keyboard and having a visible output display contained in a casing for displaying visual data representations, the improvement comprising: a. a display source, disposed substantially in the same plane as the keyboard; and b. a prism attached to the casing for altering the angle of transmission of the visual data representations the transmission angle being acute with respect to the vertical plane.
Claim 4
Dependent Claim
68 words
In a calculator system having a keyboard and having a visible output display contained in a casing for displaying visual data representations, the improvement comprising: a. a display source, disposed substantially in the same plane as the keyboard; and b. a prism attached to the casing for altering the angle of transmission of the visual data representations the transmission angle being acute with respect to the vertical plane.
Claim 5
Dependent Claim
15 words
The calculator system according to claim 1 wherein said prism is shaped as a trapezoid.
Claim 6
Dependent Claim
16 words
The calculator system according to claim 2 further comprising a magnifying lens overlying the display source.
Claim 7
Dependent Claim
21 words
The calculator system according to claim 3 wherein the transmission angle with respect to the vertical plane is less than 20*.
Claim 8
Dependent Claim
14 words
The calculator system according to claim 4 wherein said prism is comprised of plastic.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |