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:
Jun. 27, 1989
Filed:
Mar. 02, 1988
Michael J Brower, Lombard, IL (US);
W. Haking Enterprises Limited, Hong Kong, HK;
Abstract
An infrared ranging system for a battery-powered camera uses a light-emitting diode and associated pulse circuitry for producing a single ranging flash concentrated by a lens into a narrow cone of light generally centrally located in the field of view. The diode is powered by a capacitor bank charged in parallel and discharged in series to provide the necessary current pulse to the diode from a 2.0 volt system. The received pulse is concentrated on a photosensing diode by means of an infrared-passing lens to produce a voltage pulse related to amplitude of the reflected light, and hence to the range to a centrally located object in the field, this pulse being processed to set the state of one or more range-indicating latch circuits. The state of the latch circuits is used to govern the final setting of a driven adjustable focus lens. The system is equally applicable to setting the camera aperture in flash mode wherein the aperture is a range-dependent function.