US3778818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Keyboard with roll-over feature
Assignee: US Philips Corp
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Filing: 1972-11-07
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Granted: 1973-12-11
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Expires: 1992-11-07
Abstract
Abstract A keyboard has a roll-over feature in that a bistable element (flipflop) is associated with each key. The keys are successively interrogated. When a depressed key is interrogated, the code data thereof is passed on, and the flipflop is set. If the key is interrogated again, the flipflop blocks the passage of the code data. When the key is released, the flipflop is reset.
Inventors
- 👤 J Scholten
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:03
CPC Classifications
H; H04; H04L; H04L13/00; H04L13/16; H03; H03M; H03M11/00; H03M11/003
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
129 words
A keyboard with a roll-over function comprising: a plurality of keys; an interrogation unit connected to said keys for generating interrogation signals for interrogating said keys, said interrogation signals enabling code data of respectively depressed keys to appear upon outputs connected to each of said keys; and a blocking unit connected to and associated with each key for allowing requestable code data to pass under control of a first interrogation signal when a key is kept depressed, but which blocks said code data under the influence of further interrogation signals, each blocking unit having a bistable element which is set by said first interrogation signal, and a blocking element which is activated thereby and which is resettable after a depressed key is released, so that it can be de-activated.
Claim 2
Dependent Claim
129 words
A keyboard with a roll-over function comprising: a plurality of keys; an interrogation unit connected to said keys for generating interrogation signals for interrogating said keys, said interrogation signals enabling code data of respectively depressed keys to appear upon outputs connected to each of said keys; and a blocking unit connected to and associated with each key for allowing requestable code data to pass under control of a first interrogation signal when a key is kept depressed, but which blocks said code data under the influence of further interrogation signals, each blocking unit having a bistable element which is set by said first interrogation signal, and a blocking element which is activated thereby and which is resettable after a depressed key is released, so that it can be de-activated.
Claim 3
Dependent Claim
69 words
A keyboard as claim 1, wherein the keys are arranged in rows and columns in the form of a matrix and are connected by row conductors and column conductors said keys being capable of columnwise interrogation by successive driving of the column conductors by the interrogation unit, said interrogation unit being constructed as an integrated circuit together with the blocking units which are row-wise connected to the row conductors.
References Cited (Backward Citations)
US3683370A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |