Patent US4633445A successfully refreshed from Google Patents.
US4633445A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Eraseable solid state optical memories
Assignee: Xerox Corp
•
Filing: 1984-12-14
•
Granted: 1986-12-30
•
Expires: 2004-12-14
Abstract
Abstract An eraseable solid state optical memory has an array of selectively energizeable photoemitters which are imaged by suitable imaging means onto a data mask to optically address data stored thereon. To that end, the data mask is an eraseable optical recording medium, such as a tellurium suboxide or other chalcogenide material. A data writer is provided for programming, erasing and re-programming the data mask in situ while self-aligning the imaging means with the programmed data mask. The data mask may be erased and/or re-programmed in whole or part, thereby extending the utility of these memories to the storage of data that is subject to change.
Inventors
- 👤 Robert A. Sprague
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:02
CPC Classifications
G; G11; G11C; G11C7/00; G11C7/005
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
146 words
In a solid state optical memory having a photoemitter array including a plurality of selectively and individually energizeable photoemitters, and a photodetector array including a plurality of photosensors; the improvement comprising an eraseable optical recording medium optically interposed between said photoemitter array and said photodetector array, said recording medium being optically programmable and eraseable in situ for eraseably storing optically addressable data in position to be read out selectively by said photosensors in response to the selective energization of said photoemitters, and imaging means optically aligned between said photoemitter array and said recording medium for imaging all of the photoemitters of said photoemitter array in parallel onto said recording medium at a plurality of spaced apart locations, whereby said memory is optically partitioned into a plurality of memory sectors, and each of said sectors is optically subdivided to provide a plurality of selectively illuminable memory cells.
Claim 2
Dependent Claim
146 words
In a solid state optical memory having a photoemitter array including a plurality of selectively and individually energizeable photoemitters, and a photodetector array including a plurality of photosensors; the improvement comprising an eraseable optical recording medium optically interposed between said photoemitter array and said photodetector array, said recording medium being optically programmable and eraseable in situ for eraseably storing optically addressable data in position to be read out selectively by said photosensors in response to the selective energization of said photoemitters, and imaging means optically aligned between said photoemitter array and said recording medium for imaging all of the photoemitters of said photoemitter array in parallel onto said recording medium at a plurality of spaced apart locations, whereby said memory is optically partitioned into a plurality of memory sectors, and each of said sectors is optically subdivided to provide a plurality of selectively illuminable memory cells.
Claim 3
Dependent Claim
35 words
The improvement of claim 1 wherein said memory further includes beam splitting means to define alternative optical paths for illuminating said imaging means, and said photoemitter array is located on one of said optical paths.
Claim 4
Dependent Claim
47 words
The improvement of claim 2 wherein said imaging means is a lens array having a first surface configured to define a plurality of laterally separated lenslets and a last surface bonded to said recording medium, whereby said recording medium is spatially fixed with respect to said lenslets.
Claim 5
Dependent Claim
54 words
The improvement of claim 3 wherein said recording medium is a chalcogenide material, whereby data may be optically recorded on and erased from said recording medium by exposing it to a pulsed light beam having a fall time selected to cause localized transformations in said material between an amorphous state and a crystalline state.
Claim 6
Dependent Claim
13 words
The improvement of claim 4 wherein said recording medium is a tellurium suboxide.
Claim 7
Independent Claim
142 words
A device for eraseably programming a solid state optical memory having a photoemitter array including a plurality of selectively and individually energizeable photoemitters, a photodetector array including a plurality of photosensors, and an eraseable optical recording medium located between said photoemitter array and said photodetector array: said device comprising means for scanning a light beam across said imaging means in situ in accordance with a predetermined scanning pattern, said light beam being intensity modulated during a programming mode of operation to record optically addressable data on said recording medium and being controlled during a data erasing mode of operation to optically erase data previously recorded on said recording medium, said scanning pattern being selected to permit said data to be read out selectively in response to the selective energization of said photoemitters and to allow said data to be erased when desired.
Claim 8
Independent Claim
142 words
A device for eraseably programming a solid state optical memory having a photoemitter array including a plurality of selectively and individually energizeable photoemitters, a photodetector array including a plurality of photosensors, and an eraseable optical recording medium located between said photoemitter array and said photodetector array: said device comprising means for scanning a light beam across said imaging means in situ in accordance with a predetermined scanning pattern, said light beam being intensity modulated during a programming mode of operation to record optically addressable data on said recording medium and being controlled during a data erasing mode of operation to optically erase data previously recorded on said recording medium, said scanning pattern being selected to permit said data to be read out selectively in response to the selective energization of said photoemitters and to allow said data to be erased when desired.
References Cited (Backward Citations)
US3555987A
Cited
US3593318A
Cited
US3631409A
Cited
US3676864A
Cited
US3765749A
Cited
US3899778A
Cited
US4434477A
Cited
US4551819A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-12-29 | 1990-06-30 | 1990-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-29 | 1994-06-30 | 1994-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-29 | 1998-06-30 | 1998-12-30 | $7700.00 | Window Closed / Lapsed |