US3747322A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light control for timing displays
Assignee: HMW Industries Inc
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Filing: 1971-05-20
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Granted: 1973-07-24
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Expires: 1991-05-20
Abstract
Abstract Disclosed is an electronic wristwatch having no moving parts and incorporating a light responsive solid state control circuit for the time display. An electro-optic digital display, either of active or passive elements, is switched off when the ambient light falls below a predetermined level. The active display is also turned off when the light is too bright and both the active and passive displays are provided with a manual override switch for actuating the display under dark conditions at the option of the wearer.
Inventors
- 👤 J Eckenrode
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:24
CPC Classifications
G; G04; G04G; G04G9/00; G04G9/0017; G04G9/0023; G04G9/0029; G04G9/0047; G04G9/0052
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
63 words
In a timepiece having an electro-optical time display, a photosensor, switch means coupling said photosensor to said display whereby said display is switched off when the light incident on said photosensor falls below a predetermined level, and a second photosensor, said switch means including means for switching off said display when the light incident of said second photosensor rises above a predetermined level.
Claim 2
Dependent Claim
63 words
In a timepiece having an electro-optical time display, a photosensor, switch means coupling said photosensor to said display whereby said display is switched off when the light incident on said photosensor falls below a predetermined level, and a second photosensor, said switch means including means for switching off said display when the light incident of said second photosensor rises above a predetermined level.
Claim 3
Dependent Claim
111 words
A timepiece of sufficiently small size and power consumption for use as a wristwatch comprising a source of constant frequency electrical signals, a frequency divider coupled to the output of said source for producing a low frequency timing signal, an electro-optical time display, a display actuator coupling said frequency divider to said time display, said display actuator comprising a sWitch for switching off said display, and light responsive means coupled to said switch for actuating said switch when the light incident on said display falls below a predetermined level, said actuator comprising a display logic circuit, said switch comprising a plurality of logic gates coupling said logic circuit to said display.
Claim 4
Dependent Claim
111 words
A timepiece of sufficiently small size and power consumption for use as a wristwatch comprising a source of constant frequency electrical signals, a frequency divider coupled to the output of said source for producing a low frequency timing signal, an electro-optical time display, a display actuator coupling said frequency divider to said time display, said display actuator comprising a sWitch for switching off said display, and light responsive means coupled to said switch for actuating said switch when the light incident on said display falls below a predetermined level, said actuator comprising a display logic circuit, said switch comprising a plurality of logic gates coupling said logic circuit to said display.
Claim 5
Dependent Claim
13 words
Apparatus according to claim 2 wherein said display is of the passive type.
Claim 6
Dependent Claim
14 words
Apparatus according to claim 3 wherein said display comprises a plurality of liquid crystals.
Claim 7
Dependent Claim
27 words
Apparatus according to claim 2 wherein said display actuator includes a manual override switch for turning on said display when said light is below said predetermined level.
Claim 8
Dependent Claim
13 words
A timepiece according to claim 2 wherein said logic gates are NOR gates.
Claim 9
Dependent Claim
32 words
A timepiece according to claim 6 wherein said light responsive means comprises a resistance divider including a photosensor, and means coupling an intermediate point on said resistance divider to said NOR gates.
Claim 10
Dependent Claim
28 words
A timepiece according to claim 7 including a manual override switch coupled to said resistance divider for momentarily shorting out at least a portion of said resistance divider.
Claim 11
Dependent Claim
54 words
A timepiece according to claim 7 wherein said display comprises a plurality of passive elements, an auxiliary light source adjacent said display for directing light on said display, and a manual override switch for energizing said auxiliary light source when said light is below said predetermined level at the option of the timepiece wearer.
Claim 12
Dependent Claim
15 words
A timepiece according to claim 9 wherein said auxiliary light source comprises a beta light.
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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |