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:
Feb. 16, 1982
Filed:
Mar. 27, 1979
John H Jacobs, Altadena, CA (US);
Bell & Howell Corporation, Chicago, IL (US);
Abstract
Methods and apparatus for recording varying electric signals with a plurality of electrically actuable light gates illuminate the light gates with light of a first intensity above zero light intensity and provide a light-sensitive recording medium sensitive to illumination levels at light intensities including the mentioned first light intensity and starting at a second light intensity below such first intensity and above zero light intensity. These methods and apparatus precondition the light gates to subsequent opening in response to varying electric signals by electrically biasing the light gates to an initially open condition wherein the gates pass light from the mentioned illumination at an intensity below the second light intensity. The recording medium is thus exposed to light passed by the preconditioned gates at below the second intensity. Thereafter, the preconditioned light gates are selectively energized and further opened in response to varying electric signals to pass light at at least the second light intensity for a recording of such electric signals on the recording medium. The same principle may be employed for reading information with the aid of electrically controlled light gates.