US3781848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Display system
Assignee: Xerox Corp
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Filing: 1971-12-28
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Granted: 1973-12-25
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Expires: 1991-12-28
Abstract
Abstract Apparatus for generating characters or symbols by deflecting the electron beam of a cathode ray tube with signals derived from a read only character memory. The character memory provides an output under the influence of memory control. This output is loaded into registers and then fed as a bit stream to a decoder. The decoder interprets the bit stream and sends X and Y increments and control signals to digital to analog converters which generate strokes to form the desired characters on the screen of the cathode ray tube.
Inventors
- 👤 J Rosenthal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:29
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/06; G09G1/08; G09G1/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
239 words
Character generating apparatus for controlling the horizontal and vertical deflection circuits of a cathode ray tube to move an electron beam across the screen of the cathode ray tube to display a character thereon, said apparatus comprising memory means including addressable storage locations for storing indicia representing characters, said indicia including horizontal and vertical deflection increment information, means for receiving a character code defining a character to be displayed and translating said received code into a memory means address corresponding to the character defined by the received character code, means responsive to said memory means address for retrieving from said memory means the indicia representing said defined character, horizontal and vertical deflection increment shift register means, means for loading the horizontal and vertical deflection increment information of said retrieved indicia in parallel fashion into the respective shift register means, means for serially shifting said horizontal and vertical deflection increment information of said retrieved indicia out of the respective shift register means as respective bit streams for the horizontal and vertical deflection circuits of said cathode ray tube, a single horizontal converter and a single vertical converter for converting the respective bit streams into stroke signals for application to the respective deflection circuits, and logic means responsive to said bit streams for controlling the deflection circuits of said cathode ray tube in accordance with the stroke signals to display said defined character on the screen of said cathode ray tube.
Claim 2
Dependent Claim
239 words
Character generating apparatus for controlling the horizontal and vertical deflection circuits of a cathode ray tube to move an electron beam across the screen of the cathode ray tube to display a character thereon, said apparatus comprising memory means including addressable storage locations for storing indicia representing characters, said indicia including horizontal and vertical deflection increment information, means for receiving a character code defining a character to be displayed and translating said received code into a memory means address corresponding to the character defined by the received character code, means responsive to said memory means address for retrieving from said memory means the indicia representing said defined character, horizontal and vertical deflection increment shift register means, means for loading the horizontal and vertical deflection increment information of said retrieved indicia in parallel fashion into the respective shift register means, means for serially shifting said horizontal and vertical deflection increment information of said retrieved indicia out of the respective shift register means as respective bit streams for the horizontal and vertical deflection circuits of said cathode ray tube, a single horizontal converter and a single vertical converter for converting the respective bit streams into stroke signals for application to the respective deflection circuits, and logic means responsive to said bit streams for controlling the deflection circuits of said cathode ray tube in accordance with the stroke signals to display said defined character on the screen of said cathode ray tube.
Claim 3
Dependent Claim
50 words
The apparatus of claim 1 wherein said logic means includes means for recognizing control signals in said bit streams indicating direction of travel for said electron beam and blanking of said electron beam, and responsive to said control signals for controlling said deflection circuits in accordance with said control signals.
Claim 4
Dependent Claim
42 words
The apparatus of claim 2 wherein said logic means further comprises means for recognizing an end of character control signal in said bit streams for resetting said deflection circuits so as to position said electron beam for the display of another character.
Claim 5
Dependent Claim
192 words
Character generating apparatus comprising a cathode ray tube having X and Y axis deflection control circuits for controlling the movement of the electron beam of the cathode ray tube across the screen of said cathode ray tube, address selector means for receiving a character code from a data source and transforming said character code into an address code, character memory means responsive to said address code for each character in memory for furnishing two words which contain control bits and respective X and Y incremental pulse train bits, shift register means for receiving said two words and for converting each of said words into a bit stream, decoder and steering logic means for interpreting said control bits in said bit streams, a single X digital to analog converter and a single Y digital to analog converter responsive to said decoder and steering logic means for converting the respective X and Y incremental pulse train bits in said bit streams into character stroke signals, and X and Y deflection amplifiers responsive to said character stroke signals for deflecting the electron beam on the screen of said cathode ray tube to form characters thereon.
Claim 6
Dependent Claim
192 words
Character generating apparatus comprising a cathode ray tube having X and Y axis deflection control circuits for controlling the movement of the electron beam of the cathode ray tube across the screen of said cathode ray tube, address selector means for receiving a character code from a data source and transforming said character code into an address code, character memory means responsive to said address code for each character in memory for furnishing two words which contain control bits and respective X and Y incremental pulse train bits, shift register means for receiving said two words and for converting each of said words into a bit stream, decoder and steering logic means for interpreting said control bits in said bit streams, a single X digital to analog converter and a single Y digital to analog converter responsive to said decoder and steering logic means for converting the respective X and Y incremental pulse train bits in said bit streams into character stroke signals, and X and Y deflection amplifiers responsive to said character stroke signals for deflecting the electron beam on the screen of said cathode ray tube to form characters thereon.
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |