Robert C Hsieh, 74934 Calle Serra, San Dimas, CA 91773

4933777, Jun 12, 1990

Apr 26, 1989

7/343542

Robert C. Hsieh - Los Angeles CA
Eric Chen - Hsinchu, TW

Microtek Lab., Inc. - Torrance CA

H04H 140

358456

The present invention relates to a method enabling real-time conversion of the analog video signals from a charge coupled element into digital half-tone data which can be printed on a printer or displayed on a display screen and to a converting device which is developed for use with such method. The method according to the present invention serves six primary functions as follows: 1. realization of half-tone patterns and regeneration of gray scales; 2. half-tone models of high compression ratio; 3. method for controlling and adjusting the contrast and brightness; 4. half-tone rules for proportional reduction and enlargement; 5. direct current regeneration of analog video signals; and 6. compensation for uneven illumination. In addition, the present invention provides three embodiments of converter which are adequate to serve the above-mentioned functions in which: The first embodiment uses a framework comprising an analog comparator; The second embodiment uses a framework comprising a flash type analog/digital converter and a digital comparator; and The third embodiment uses a framework comprising a successive approaching register (SAR) type analog/digital converter, a normalized table look-up unit, and a digital comparator.