US4617461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescent optical switch and keyboard apparatus
Assignee: Unisys Corp
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Filing: 1984-04-25
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Granted: 1986-10-14
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Expires: 2004-04-25
Abstract
Abstract Fluorescent optical switch and keyboard apparatus wherein a plurality of fluorescent optical key switches are arranged in a matrix array of rows and columns with a key disposed at each column-row intersection and wherein each key carries a fluorescent optically reflective element thereon. A single optical photo-diode disposed at each key location is caused to operate in three discrete modes with respect to the fluorescent element. In one mode the diode emits light which is caused to be reflected upon key when the key is depressed. In another mode the reflected light striking the diode causes the diode to act as a photo-receptor effectively indicating key actuation.
Inventors
- 👤 Wunnava V. Subbarao
- 👤 Richard I. Ely
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:25
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/965; H03K17/968; H03K17/969
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
118 words
Fluorescent optical switch and keyboard apparatus comprising: photo-optical means adapted to operate in a light emitting, a light receiving and a passive mode, fluorescent means disposed adjacent to said photo-optical means and capable of movement from a light blocking to a light passing position, and circuit means interconnected to said photo-optical means for energizing said photo-optical means to a level causing said photo-optical means to emit light for impingement upon said fluorescent means when said fluorescent means is disposed in a light fluorescent position, said circuit means thereafter biasing said photo-optical means so as to cause said photo-optical means to act as a light receptor and to generate an electrical signal output indicating the actuation of the device.
Claim 2
Dependent Claim
118 words
Fluorescent optical switch and keyboard apparatus comprising: photo-optical means adapted to operate in a light emitting, a light receiving and a passive mode, fluorescent means disposed adjacent to said photo-optical means and capable of movement from a light blocking to a light passing position, and circuit means interconnected to said photo-optical means for energizing said photo-optical means to a level causing said photo-optical means to emit light for impingement upon said fluorescent means when said fluorescent means is disposed in a light fluorescent position, said circuit means thereafter biasing said photo-optical means so as to cause said photo-optical means to act as a light receptor and to generate an electrical signal output indicating the actuation of the device.
Claim 3
Dependent Claim
14 words
The combination according to claim 1 wherein said photo-optical means further comprises a photo-diode.
Claim 4
Dependent Claim
20 words
The combination according to claim 1 wherein said fluorescent means is carried by the key stem of a photo-optical keyboard.
Claim 5
Dependent Claim
18 words
The combination according to claim 1 wherein said fluorescent means comprises a fluorescent coating on a support structure.
Claim 6
Dependent Claim
121 words
Fluorescent optical switch and keyboard apparatus comprising: a matrix array of rows and columns of keys arranged to form a keyboard, a photo-diode disposed adjacent to the key stem of each key, a fluorescent material having a delay time commensurate with the response time of said photo-diode coated on one portion of said key stem, electrical circuit means for biasing said photo-diode first in a forward direction so as to cause the diode to emit light for impingement upon the fluorescent material and for then biasing said photo-diode in the reverse direction causing said diode to act as a light receptor, and microprocessor means for controlling the electrical signals input to and output from said photo-diode effective to indicate key actuation.
Claim 7
Dependent Claim
121 words
Fluorescent optical switch and keyboard apparatus comprising: a matrix array of rows and columns of keys arranged to form a keyboard, a photo-diode disposed adjacent to the key stem of each key, a fluorescent material having a delay time commensurate with the response time of said photo-diode coated on one portion of said key stem, electrical circuit means for biasing said photo-diode first in a forward direction so as to cause the diode to emit light for impingement upon the fluorescent material and for then biasing said photo-diode in the reverse direction causing said diode to act as a light receptor, and microprocessor means for controlling the electrical signals input to and output from said photo-diode effective to indicate key actuation.
Claim 8
Dependent Claim
30 words
The combination according to claim 5 further including a row driver for each row of photo-diode and being capable of responding to three discrete states of operation of said diodes.
Claim 9
Dependent Claim
20 words
The combination according to claim 5 wherein said microprocessor means further includes a separate amplifier for each column of photo-diode.
References Cited (Backward Citations)
US4379968A
Cited
US4480182A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-13 | 1990-04-14 | 1990-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-13 | 1994-04-14 | 1994-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-13 | 1998-04-14 | 1998-10-14 | $7700.00 | Window Closed / Lapsed |