Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G1/00—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data
  • G09G1/28—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data using colour tubes
  • G09G1/285—Interfacing with colour displays, e.g. TV receiver

Definitions

• Coupler Decoding Device The present invention relates to a decoding device which, on the basis of a video signal coming from a computer and. designed to produce certain images in the NTSC color television system in use in the United States of America, allows similar images to be recreated on R.V.B signals. (red, green and blue) which can be used directly (for example on a "PERlTEL" socket in France) or indirectly recoded into SECAM or PAL.
• This video signal makes it possible in NTSC to produce three different types of visualization: a text screen of 24 lines of 40 characters (7x8 dots matrix), a high resolution color screen of 280x192 dots (6 colors possible), a low resolution color screen of 40x48 stitches (16 colors possible).
• Existing devices are content with sampling the video information at constant frequency and position independently of the viewing modes that this signal can represent.
• the sampling frequency is then a compromise between these different viewing modes and the result is then very approximate.
• the invention is characterized by a differentiated decoding of the viewing modes and the simple sampling at constant frequency and position is replaced by an advanced logical analysis of the information conveyed by the video signal.
• This invention makes it possible to find the three visualizations on R.V.B signals. and add the following extensions: in text mode, you can choose the color of the text page from 1.6 colors per program from the computer; in low resolution mode, the few imperfections visible in NTSC (burrs, uneven dot sizes) have been removed; in high resolution mode, you can choose by program to keep the visualization produced in NTSC or to access some extensions: nine different colors on the same image, choice of each of these colors among 16, possibility of keeping the accuracy of black images and white.
• the elementary information composing the video signal is spread using a shift register transmitting 8 bits in parallel at the frequency H1, bits named B1 to B8 in the following, the first shifted bit appearing at B8, then in B7, etc. This information is then used in three different ways corresponding to each of the three viewing modes.
• the invention uses a flip-flop system with write authorization, the common clock being H2, the authorization depending on the configuration of bits B1, B2, B4, B6 and B8 (fig. 2).
• This system makes it possible to obtain 4 signals which are distributed over the address and reading input inputs of two 4x4 registers, making it possible to obtain 8 color information of 4 bits previously loaded in these registers therefore programmable from the computer.
• a parallel system makes it possible to replace these registers with predefined color information when the computer is turned on (fig. 4).
• FIG. 1 represents an exemplary embodiment of a circuit of filtering and synchronization of signals, decoding in low resolution mode and multiplexing of the 4 bits of low and high resolution output.
• Figure 2 gives an example of an analysis of the video signal in high resolution mode.
• Figure 3 provides an example circuit for storing high resolution color information.
• FIG. 4 gives an example of a circuit decoding the text mode and determining the predefined high resolution color information.
• FIG. 5 provides an exemplary embodiment of an output circuit on a "PERITEL" socket.

Landscapes

• Engineering & Computer Science (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Physics & Mathematics (AREA)
• Computer Hardware Design (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Color Television Systems (AREA)
• Processing Of Color Television Signals (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9260457

Family Applications (1)

Country Status (3)

Citations (1)

• 1981
  • 1981-07-10 FR FR8113684A patent/FR2509560A1/fr active Granted
• 1982
  • 1982-06-14 WO PCT/FR1982/000098 patent/WO1983000250A1/fr not_active Ceased
  • 1982-06-14 EP EP19820901844 patent/EP0084029A1/fr not_active Withdrawn

Patent Citations (1)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events