US4926388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic device for independently erasing secret and non-secret data from memory
Assignee: Sharp Corp
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Filing: 1988-05-25
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Granted: 1990-05-15
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Expires: 2008-05-25
Abstract
Abstract In an electronic appliance capable of storing secret data to be kept secret and data other than the secret data in distinction from each other, only the secret data can be erased upon a first reset operation and the data other than the secret data can be erased upon a second reset operation.
Inventors
- 👤 Hisao Kunita
- 👤 Akitaka Morita
- 👤 Eichika Matsuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:12
CPC Classifications
G; G06; G06F; G06F21/00; G06F21/70; G06F21/78; G06F15/00; G06F15/02; G06F15/025; G06F15/0283; G06F2221/00; G06F2221/21; G06F2221/2105
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
156 words
An electronic memory device comprising: means for inputting alphanumeric and code data; memory means for storing said input data; means for storing said input data in said memory means as secret data, non-secret data, and secret code data; means for recalling only said secret data from said memory means; means for recalling only said non-secret data from said memory means; means, responsive to said means for recalling, for displaying said secret and non-secret data; means for resetting said device to clear only said secret data and said secret code data from said memory means; and means for resetting said device to clear all remaining data in said memory means subsequent to clearing only said secret data and said secret code data, wherein said secret data and said secret code data is selectively input, stored, recalled and cleared by an operator, thereby controlling access to said secret data by an unauthorized operator of said electronic memory device.
Claim 2
Dependent Claim
156 words
An electronic memory device comprising: means for inputting alphanumeric and code data; memory means for storing said input data; means for storing said input data in said memory means as secret data, non-secret data, and secret code data; means for recalling only said secret data from said memory means; means for recalling only said non-secret data from said memory means; means, responsive to said means for recalling, for displaying said secret and non-secret data; means for resetting said device to clear only said secret data and said secret code data from said memory means; and means for resetting said device to clear all remaining data in said memory means subsequent to clearing only said secret data and said secret code data, wherein said secret data and said secret code data is selectively input, stored, recalled and cleared by an operator, thereby controlling access to said secret data by an unauthorized operator of said electronic memory device.
Claim 3
Dependent Claim
45 words
The electronic memory device according to claim 1, wherein said means for inputting alphanumeric data is a keyboard including numerical and lettered keys and said means for inputting code data include a plurality of predefined function keys on a keyboard of said electronic memory device.
Claim 4
Dependent Claim
37 words
The electronic memory device according to claim 1, wherein said memory means includes a first memory area for storing said secret data and said secret code data and a second memory area for storing said non-secret data.
Claim 5
Dependent Claim
42 words
The electronic memory device according to claim 1, wherein said means for storing said input data as either secret or non-secret data includes actuation of a predetermined sequence of alphanumeric and function keys for specifying storage in secret and non-secret memory areas.
Claim 6
Dependent Claim
36 words
The electronic memory device according to claim 1, wherein said means for recalling only said secret data from said memory means includes input of said secret code data followed by bi-directional searching of the memory contents.
Claim 7
Dependent Claim
28 words
The electronic memory device according to claim 1, wherein said means for recalling only said non-secret data from said memory means includes bi-directional searching of the memory contents.
Claim 8
Dependent Claim
20 words
The electronic memory device according to claim 1, wherein said means for displaying is a two-stage liquid crystal display unit.
Claim 9
Dependent Claim
34 words
The electronic memory device according to claim 1, wherein said means for resetting said device to clear only said secret data and said secret code data includes a single actuation of a reset switch.
Claim 10
Dependent Claim
28 words
The electronic memory device according to claim 1, wherein said means for resetting said device to clear all remaining data includes a dual actuation of a reset switch.
References Cited (Backward Citations)
US4819204A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-14 | 1993-11-13 | 1994-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-14 | 1997-11-13 | 1998-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-14 | 2001-11-13 | 2002-05-15 | $7700.00 | Window Closed / Lapsed |