US4414545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Memory circuit for generating liquid crystal display characters
Assignee: Hitachi Ltd
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Filing: 1981-12-09
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Granted: 1983-11-08
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Expires: 2001-12-09
Abstract
Abstract A liquid crystal display character generator circuit comprises a first RAM for temporarily storing information to be displayed on a liquid crystal display unit, a ROM for storing standard character patterns corresponding to the information to be displayed, a second RAM operable to store special character patterns corresponding to the information to be displayed, and a data selector for enabling the designation of an address in one of the ROM and the second RAM in accordance with the information stored in the first RAM.
Inventors
- 👤 Hiroshi Sakurada
- 👤 Naofumi Aoyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:09
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/04; G09G3/16; G09G3/18; G09G3/20; G09G3/34; G09G3/36; G09G3/3611; G09G5/00; G09G5/22; G09G5/222
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
182 words
A liquid crystal display character generator circuit comprising: a first RAM for temporarily storing information to be displayed on a liquid crystal display unit; a ROM for storing in its respective addresses standard character patterns corresponding to information to be displayed and producing, when one of the addresses is designated, a signal representative of a character pattern stored in the designated address; a second RAM capable of being dedicated for storing in at least one of its addresses at least one special character pattern corresponding to information to be displayed and operable to produce, when the address is designated, a signal representative of the character pattern stored in the designated address; and a data selector for selecting one of the ROM and the second RAM in accordance with contents of the information stored in the first RAM and enabling the designation of the address in the selected one of the ROM and the second RAM in accordance with the information stored in the first RAM, said first RAM, ROM, second RAM and data selector being integrated in a one chip integrated circuit.
Claim 2
Dependent Claim
182 words
A liquid crystal display character generator circuit comprising: a first RAM for temporarily storing information to be displayed on a liquid crystal display unit; a ROM for storing in its respective addresses standard character patterns corresponding to information to be displayed and producing, when one of the addresses is designated, a signal representative of a character pattern stored in the designated address; a second RAM capable of being dedicated for storing in at least one of its addresses at least one special character pattern corresponding to information to be displayed and operable to produce, when the address is designated, a signal representative of the character pattern stored in the designated address; and a data selector for selecting one of the ROM and the second RAM in accordance with contents of the information stored in the first RAM and enabling the designation of the address in the selected one of the ROM and the second RAM in accordance with the information stored in the first RAM, said first RAM, ROM, second RAM and data selector being integrated in a one chip integrated circuit.
Claim 3
Dependent Claim
20 words
A character generator circuit according to claim 1 which further comprises a battery power source always connected with the circuit.
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) | 1986-11-07 | 1987-05-09 | 1987-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-07 | 1991-05-09 | 1991-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-07 | 1995-05-09 | 1995-11-08 | $7700.00 | Window Closed / Lapsed |