Shadow mask color system with calligraphic displays

• US 4,499,457 A
• Filed: 05/14/1982
• Issued: 02/12/1985
• Est. Priority Date: 10/05/1978
• Status: Expired due to Term

• Current Assignee: Evans & Sutherland Computer Corp. (Elevate Entertainment, Inc.)
• Original Assignee: Evans & Sutherland Computer Corp. (Elevate Entertainment, Inc.)
• Inventors: Hintze, Richard A.
• Primary Examiner(s): Trafton, David L.
• Application Number:
  US06/378,149
• Time in Patent Office: 1,005 Days
• Field of Search: 358/22, 358/81, 358/103, 358/183, 358/222, 358/242, 358/903, 340/27 NA, 340/703, 340/720, 340/729, 340/751, 340/701, 340/739, 315/371, 315/387, 315/389, 315/397, 315/408, 315/31 TV, 343/108 SM, 364/515, 364/522, 35/10.2
• US Class Current: 345/22
• CPC Class Codes: G09G 1/07 with combined raster scan and calligraphic display
• CPC Class Codes: G09G 1/285 Interfacing with colour displays, e.g. TV receiver
• CPC Class Codes: H04N 9/28 Arrangements for convergence or focusing

Abstract

A display system is disclosed utilizing a cathode ray display device utilizing three electron beams which are directed through a shadow mask to excite three-color phosphor dots, and which is incorporated in a system to alternately provide raster scan display signals and calligraphic display signals to obtain the benefits of both raster scan and calligraphic displays (dot or line drawings). A deflection unit is disclosed with the X and Y deflection coils each driven by two pairs of transistor circuits. The transistor circuits are controlled so that alternatively one transistor in each set passes current to provide bi-directional currents at desired levels to obtain specific beam displacement. A resistive element between individual deflection coils provides an indication of deflection current, which indication is processed by a differential amplifier to indicate displacement. In accordance with the instant position of the beam, a convergence unit is controlled to reflect spherical considerations. Specifically, the convergence of each color beam is varied in accordance with first and higher orders of X and Y displacement. Focus is controlled to avoid certain effects and obtain others.

Claims

1. A color display system for providing a dynamic color presentation, comprising:

a cathode ray display device incorporating deflection means and a shadow mask in combination with a color screen;

means for providing raster scan color display signals for modulating said display device to produce a display;

means for providing calligraphic display signals for modulating said display device to produce a display;

driver means for said deflection means to provide beam deflection in said cathode ray display device to accommodate both said raster scan display signals and said calligraphic display signals;

sequencing means to sequence both the operation of said driver means and the alternative application of said raster scan signals and said calligraphic display signals to control said cathode ray display device for producing a dynamic color presentation manifesting both said raster scan color display signals and said calligraphic display signals; and

focus control means to vary the focus of said cathode ray display device with the sequencing of a raster scan signal and a calligraphic display signal.

2. A color display system for providing a dynamic color presentation, comprising:

a cathode ray display device incorporating deflection means and a shadow mask in combination with a color screen;

means for providing raster scan color display signals for modulating said display device to produce a display;

means for providing calligraphic display signals for modulating said display device to produce a display;

driver means for said deflection means to provide beam deflection in said cathode ray display device to accommodate both said raster scan display signals and said calligraphic display signals;

sequencing means to sequence both the operation of said driver means and the alternative application of said raster scan signals and said calligraphic display signals to control said cathode ray display device for producing a dynamic color presentation manifesting both said raster scan color display signals and said calligraphic display signals; and

focus control means to vary the focus of said cathode ray display device with variations of display intensity and relative viewpoint.

3. A color display system for providing a dyanamic color presentation, comprising:

a cathode ray display device incorporating deflection means and a shadow mask in combination with a color screen;

means for providing raster scan color display signals for modulating said display device to produce a display;

means for providing calligraphic display signals for modulating said display device to produce a display;

driver means for said deflection means to provide beam deflection in said cathode ray display device to accommodate both said raster scan display signals and said calligraphic display signals;

sequencing means to sequence both the operation of said driver means and the alternative application of said raster scan signals and said calligraphic display signals to control said cathode ray display device for producing a dynamic color presentation manifesting both said raster scan color display signals and said calligraphic display signals; and

focus control means to vary the focus of said cathode ray display device with variations of angular roll of said raster scan signal.

4. A color display system according to claim 3 wherein said focus control means operates to overfocus said cathode ray display device during periods of sequencing said calligraphic display signals and to underfocus said cathode ray display device during periods of sequencing said raster scan display signals.

5. A color display system for providing a dynamic color presentation, comprising:

a cathode ray display device incorporating deflection means and a shadow mask in combination with a color screen;

means for providing calligraphic display signals for modulating said display device to produce a display;

driver means for said deflection means to provide beam deflection in said cathode ray display device to accommodate said calligraphic display signals;

means to actuate said driver means by said calligraphic display signals to control said cathode ray display device for producing a dynamic color presentation manifesting said calligraphic display signals; and

focus control means to vary the focus of said cathode ray display device with variations of display intensity and relative viewpoint.