US3984973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital watch with liquid crystal and light emitting diode displays
Assignee: Raytheon Co
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Filing: 1975-03-13
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Granted: 1976-10-12
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Expires: 1995-03-13
Abstract
Abstract A digital watch system with a dual display demultiplexer, a liquid crystal display for use in daylight or bright light and a light emitting diode display for use in dim light. The digital watch system includes a crystal oscillator with frequency division which controls a set of counters, each counter carrying coded horological data. Selected counter data is multiplexed into a seven segment decoder which is then demultiplexed into memories, one for each of the segments in each of the liquid crystal display digits. These memories then control segment drivers for the liquid crystal digital displays. In parallel with the liquid crystal demultipliexer, the seven segment decoder outputs operate segment and digit drivers which drive light emitting diodes as a second display for the digital watch.
Inventors
- 👤 Ernest C. Ho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:05
CPC Classifications
G; G04; G04G; G04G9/00; G04G9/08; G04G9/082; G04C; G04C9/00; G04G9/087
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
142 words
A digital watch for displaying selectable horological information comprising: first and second optical displays; an electronic circuit for providing information to be selectively displayed on said displays, said electronic circuit comprising an oscillator, a frequency divider coupled to the output of said oscillator for producing a timing signal, and counters for receiving said timing signal and maintaining a plurality of sets of horological information; a first and second control connected between said counters and said displays; means for causing said first display to continuously display a first set of horological information when said first and second controls are unactivated and to display a second set of horological information on said first display when said first control is activated, also said means causes said second display to display said first set of horological information when said first and second controls are simultaneously activated.
Claim 2
Dependent Claim
142 words
A digital watch for displaying selectable horological information comprising: first and second optical displays; an electronic circuit for providing information to be selectively displayed on said displays, said electronic circuit comprising an oscillator, a frequency divider coupled to the output of said oscillator for producing a timing signal, and counters for receiving said timing signal and maintaining a plurality of sets of horological information; a first and second control connected between said counters and said displays; means for causing said first display to continuously display a first set of horological information when said first and second controls are unactivated and to display a second set of horological information on said first display when said first control is activated, also said means causes said second display to display said first set of horological information when said first and second controls are simultaneously activated.
Claim 3
Dependent Claim
19 words
A digital watch as recited in claim 1, wherein said first display comprises a plurality of liquid crystals devices.
Claim 4
Dependent Claim
19 words
A digital watch as recited in claim 1 wherein said second display comprises a plurality of light emitting diodes.
Claim 5
Dependent Claim
14 words
A digital watch as recited in claim 1, wherein said controls are manually operable.
Claim 6
Dependent Claim
88 words
A digital watch as recited in claim 1, wherein said means for causing said first and second displays to display comprises switching means for connecting counters containing the first set of horological information to said first display when said first and second controls are unactivated and for connecting counters containing said second set of horological information to said first display when said first control is activated and for connecting said counters containing said first set of horological information to said second display when said second control is activated.
Claim 7
Dependent Claim
44 words
A digital watch as recited in claim 5, wherein said first display comprises seven-segment liquid crystal display devices and a seven-segment decoder is connected to said counters and first display in parallel with said means for causing said first and second displays to display.
Claim 8
Dependent Claim
110 words
A digital watch as recited in claim 6, wherein said switching means comprises multiplexing means for multiplexing the counters containing the first set of horological information into said decoder when said first and second control means are unactivated, and for multiplexing the counters containing the second set of horological information into said decoder when said first control means is activated, and for multiplexing the counters containing the first set of horological information into said decoder when said second control means is activated; said switching means selects which liquid crystal will receive the horological information from said decoder and which light emitting diode will receive the horological information from said decoder.
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) | 1979-10-12 | 1980-04-12 | 1980-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-12 | 1984-04-12 | 1984-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-12 | 1988-04-12 | 1988-10-12 | $7700.00 | Window Closed / Lapsed |