The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 10, 1979
Filed:
Nov. 25, 1977
William J Coates, Jr, San Diego, CA (US);
Science Applications, Inc., La Jolla, CA (US);
Abstract
A method and apparatus for modulating the perceptible intensity of the presentation of a light emitting display which light emitting display emits light by gas discharge and recombination of ions and free electrons of a display medium; includes a system clock, the interruption of which causes the interruption of the presentation of the light emitting display; and is capable of retaining display information upon the interruption of a light sustaining signal or the electrical power as a result of an accumulation and retention of electrical charge across the display medium. The apparatus comprising a repetition means for generating a repetition pulse train signal having a controllable frequency and duty cycle; an indication means for generating a retention signal that identifies when the light emitting display is capable of retaining display information; a synchronization means coupled to said repetition means and to said indication means for generating a gating signal which is synchronized with the retention signal and the repetition pulse train signal; and stopping means coupled to said synchronization means for interrupting the system clock in synchronization with the gating signal. Variations of this invention include circuitry which generates a control system clock signal by clock pulse train generator and modified stopping means. Other variations enable the light emitting display to be turned off over extended periods of time.