Patent US4088994A successfully refreshed from Google Patents.
US4088994A
Expired / Lapsed
US
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Paralleled output self-encoding keyboard
Assignee: Motorola Solutions Inc
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Filing: 1976-04-21
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Granted: 1978-05-09
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Expires: 1996-04-21
Abstract
Abstract A standard format keyboard provides a paralleled, binary-coded output corresponding to an alphanumeric character or a function when the appropriate key head is depressed. A signal is coupled through the key mechanism to a set of parallel conductors which are positioned to be approached by a portion of the key mechanism. The conductors have minimum or maximum areas corresponding to binary zeros and ones, whereby the level of signal coupled also corresponds to a binary code (such as ASCII) for the character or function key depressed.
Inventors
- 👤 Steven R. McNav
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:22
CPC Classifications
H; H03; H03M; H03M11/00; H03M11/22; H01; H01H; H01H13/00; H01H13/70; H01H13/702; H01H2239/00; H01H2239/006; H01H2239/026
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
202 words
A self-encoding keyboard arrangement comprising in combination: a plurality of first conductive surface portions, certain of said portions having relatively larger and smaller areas which have a predetermined relationship to a desired signal output; support means for supporting the first conductive surface portions; a plurality of key mechanisms, each comprising a key head, a second conductive surface portion, and a support member for supporting said key head and said second conductive portion, the second conductive surface portion being normally biased away from the first conductive surface portions and mounted for being movable toward a predetermined number of said first conductive surface portions when said key head is depressed; a thin flexible insulating film interposed between the first and second conductive portions; a signal source coupled to the first conductive surface portions when said key head is fully depressed; and a plurality of detectors, at least one of said detectors being coupled to each one of the first conductive surface portions for detecting a predetermined signal level on said first conductive portion in response to coupling between a relatively large area of said first conductive surface portion and the adjacent second conductive portion when the corresponding one of said key heads is depressed.
Claim 2
Dependent Claim
202 words
A self-encoding keyboard arrangement comprising in combination: a plurality of first conductive surface portions, certain of said portions having relatively larger and smaller areas which have a predetermined relationship to a desired signal output; support means for supporting the first conductive surface portions; a plurality of key mechanisms, each comprising a key head, a second conductive surface portion, and a support member for supporting said key head and said second conductive portion, the second conductive surface portion being normally biased away from the first conductive surface portions and mounted for being movable toward a predetermined number of said first conductive surface portions when said key head is depressed; a thin flexible insulating film interposed between the first and second conductive portions; a signal source coupled to the first conductive surface portions when said key head is fully depressed; and a plurality of detectors, at least one of said detectors being coupled to each one of the first conductive surface portions for detecting a predetermined signal level on said first conductive portion in response to coupling between a relatively large area of said first conductive surface portion and the adjacent second conductive portion when the corresponding one of said key heads is depressed.
Claim 3
Dependent Claim
41 words
A self-encoding keyboard arrangement according to claim 1 wherein the key mechanism further includes a resilient pressure pad affixed to the underside of the key head and wherein the second conductive portion is affixed to the underside of said pressure pad.
Claim 4
Dependent Claim
64 words
A self-encoding keyboard arrangement according to claim 1 wherein, when one of said key heads is depressed, each relatively large area of one of said first conductive portions under said one key head provides a relatively high level output signal and each relatively small area of one of said first conductive portions under said one key head provides a relatively low level output signal.
Claim 5
Dependent Claim
47 words
A self-encoding keyboard arrangement according to claim 1 and wherein the key mechanism includes a third conductive portion and the apparatus further includes conductive plate means coupled to the signal source and positioned for being contacted by the third conductive portion when the key head is depressed.
Claim 6
Dependent Claim
58 words
A self-encoding keyboard arrangement according to claim 1 wherein each key head bears one of a plurality of indicia and wherein said desired signal output has a predetermined relationship to said indicia, whereby the depression of one of said key heads provides a parallel output signal corresponding to a binary code for the indicia on said key head.
Claim 7
Dependent Claim
59 words
A self-encoding keyboard arrangement according to claim 1 and further including circuit means coupled to said signal source for inverting said signal, and capacitive means for coupling a portion of said inverted signal to at least one of said first conductive portions, said portion of said signal having a predetermined relationship to the area of said first conductive portion.
Claim 8
Dependent Claim
43 words
A self-encoding keyboard arrangement according to claim 1 and further including fourth conductive portions adjacent the first conductive portions and positioned for receiving a second predetermined level of signals from one of the second conductive portions when a corresponding key head is depressed.
Claim 9
Dependent Claim
69 words
A self-encoding keyboard arrangement according to claim 7 and wherein at least one other of the detector means is coupled to the fourth conductive portions for detecting the second predetermined level of signal, and still another detector means is coupled to the fourth conductive portions for detecting signals levels greater than the second predetermined level of signal, whereby the simultaneous depression of more than one key head is detected.
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) | 1981-05-08 | 1981-11-07 | 1982-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-08 | 1985-11-07 | 1986-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-08 | 1989-11-07 | 1990-05-09 | $7700.00 | Window Closed / Lapsed |