Shadow mask color system with calligraphic displays

• US 4,982,178 A
• Filed: 09/19/1986
• Issued: 01/01/1991
• Est. Priority Date: 10/05/1978
• Status: Expired due to Fees

• 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
• Application Number:
  US06/909,522
• Time in Patent Office: 1,565 Days
• Field of Search: 340/703, 340/732, 340/739, 315/368, 315/397
• 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 displacment. Focus is controlled to avoid certain effects and obtain others.

Claims

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

a display device incorporating a three color screen, multiple beam excitation means for providing three color beams for the excitation of said screen, and coordinate deflection means for said excitation beams in combination with a color screen;

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

driver means for said deflection means to deflect said beams relative to said screen whereby to accommodate said calligraphic display signals;

a plurality of independent color-convergence tuning control means for each of said beams;

means for selectively providing correction signals to each of said plurality of control means including at least four coordinate quadrant correction signals, one for each coordinate quadrant of said screen, said quadrant correction signals each having value only when said beams are deflected to the quadrant; and

means for summing the outputs of said control means for each of said beams to provide convergence signal for each of said beams.

2. A color display system according to claim 1 wherein said correction signals are representative of orders of coordinate deflection of said beams as provided by said driver means.

3. A color display system according to claim 2 wherein said correction signals include signals representative of at least two orders of coordinate deflection values.

4. A color display system according to claim 1 further including a second plurality of independent color-convergence tuning control means for one of said three color beams.

5. A color display system according to claim 1 wherein said means for selectively providing correction signals further includes means for providing at least two hemisphere correction signals, one for each coordinate half of said screen, said hemisphere correction signals having value only when said beams are deflected to the hemisphere.

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

a display device incorporating a three color screen, multiple beam excitation means for providing three color beams for the excitation of said screen, and coordinate deflection means for said excitation beams in combination with a color screen;

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

driver means for said deflection means to deflect said beams relative to said screen whereby to accommodate said calligraphic display signals;

a plurality of independent color-convergence tuning control means for each of said beams;

means for selectively providing correction signals to each of said plurality of control means, including at least two coordinate hemisphere correction signals, one for each hemisphere of said screen, said hemisphere correction signals each having value only when said beams are deflected to the hemisphere; and

means for summing the outputs of said control means for each of said beams to provide convergence signals for each of said beams.