US3864905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Horological instrument incorporating means for illuminating a liquid crystal display
Assignee: F Hoffmann La Roche AG
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Filing: 1973-11-14
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Granted: 1975-02-11
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Expires: 1993-11-14
Abstract
Abstract A liquid crystal horological instrument employing a display comprising a layer of liquid crystal material sandwiched between transparent parallel plates and incorporating a reflective surface on the side of the display opposite that side which is viewed by an observer. Electrical lamp means are incorporated into the horological instrument for evenly illuminating the display in the absence of ambient light. The lamp means is powered by the same battery as that used to power the display and the driving circuitry therefor.
Inventors
- 👤 Kenneth J Richardson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:50
CPC Classifications
G; G04; G04G; G04G9/00; G04G9/08; G04G9/12; G04G17/00; G04G17/02; G04G17/04; G04G17/045; G04G9/0023; G04G9/0029; G04G9/0035; G04G9/0041
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
154 words
A liquid crystal horological instrument including a display comprising a layer of liquid crystal material sandwiched between transparent parallel plates, transparent conductive patches on the plates adapted to form numerals when a source of potential is applied across selected ones of the patches, light reflective means on the side of the display opposite that which is viewed by an observer of the horological instrument, means for illuminating said display in the absence of ambient light, said lattermentioned neans comprising a single electric lamp extending along an edge of the display, the lamp being shorter than the edge of the display and being positioned substantially midway between the edges of the display such that the lamp, without any dispersing means, will illuminate only the central portion of the display, a source of power for the lamp, and means for dispersing light produced by said lamp throughout substantially the entire area of said light reflective means.
Claim 2
Dependent Claim
154 words
A liquid crystal horological instrument including a display comprising a layer of liquid crystal material sandwiched between transparent parallel plates, transparent conductive patches on the plates adapted to form numerals when a source of potential is applied across selected ones of the patches, light reflective means on the side of the display opposite that which is viewed by an observer of the horological instrument, means for illuminating said display in the absence of ambient light, said lattermentioned neans comprising a single electric lamp extending along an edge of the display, the lamp being shorter than the edge of the display and being positioned substantially midway between the edges of the display such that the lamp, without any dispersing means, will illuminate only the central portion of the display, a source of power for the lamp, and means for dispersing light produced by said lamp throughout substantially the entire area of said light reflective means.
Claim 3
Dependent Claim
19 words
The horological instrument of claim 1 wherein said light reflective means will scatter polarized light without depolarizing the same.
Claim 4
Dependent Claim
24 words
The horological instrument of claim 1 wherein said for dispersing light produced by said lamp means comprises a notch formed in a transparent plate.
Claim 5
Dependent Claim
30 words
The horological instrument of claim 3 wherein said notch is in the form of W providing reflecting surfaces for reflecting light from said lamp to either side of the lamp.
Claim 6
Dependent Claim
13 words
The horological instrument of claim 3 wherein said notch is parabolic in configuration.
Claim 7
Dependent Claim
34 words
The horological instrument of claim 1 including a transparent plate between the light reflective means and one of said first-mentioned transparent parallel plates, said means for dispersing light being incorporated into said latter-mentioned plate.
Claim 8
Dependent Claim
20 words
The horological instrument of claim 6 wherein said means for dispersing light comprises light pipes formed in said latter-mentioned plate.
Claim 9
Dependent Claim
189 words
A liquid crystal horological instrument including a display comprising a layer of liquid crystal material sandwiched between transparent parallel plates, transparent conductive patches on the plates adapted to form numerals when a source of potential is applied across selected ones of the patches, reflective means on the side of the display opposite that which is viewed by an observer of the horological instrument, means for illuminating said display in the absence of ambient light, said latter-mentioned means comprising an electric lamp positioned adjacent an edge of the display, a source of power for the lamp, switch means incorporated into said horological instrument for selectively connecting the lamp to the source of power, means including a crystal oscillator, a counter and driving circuitry for said display, means for permanently connecting said oscillator, said counter and said driving circuitry to said source of power whereby the source comprises a single source of power for both the lamp as well as the electrical circuitry for driving said display, the display being energized continually, and means for dispersing light produced by said lamp throughout substantially the entire area of said light reflective means.
Claim 10
Dependent Claim
189 words
A liquid crystal horological instrument including a display comprising a layer of liquid crystal material sandwiched between transparent parallel plates, transparent conductive patches on the plates adapted to form numerals when a source of potential is applied across selected ones of the patches, reflective means on the side of the display opposite that which is viewed by an observer of the horological instrument, means for illuminating said display in the absence of ambient light, said latter-mentioned means comprising an electric lamp positioned adjacent an edge of the display, a source of power for the lamp, switch means incorporated into said horological instrument for selectively connecting the lamp to the source of power, means including a crystal oscillator, a counter and driving circuitry for said display, means for permanently connecting said oscillator, said counter and said driving circuitry to said source of power whereby the source comprises a single source of power for both the lamp as well as the electrical circuitry for driving said display, the display being energized continually, and means for dispersing light produced by said lamp throughout substantially the entire area of said light reflective means.
Claim 11
Dependent Claim
20 words
The horological instrument of claim 1 wherein said lamp is rated at about 1 1/2 volts and about 16 milliamperes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |