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:
Jan. 18, 1994
Filed:
Dec. 22, 1992
Richard C Honey, San Mateo, CA (US);
Robert A Brown, Redwood City, CA (US);
Karen M Nashold, San Francisco, CA (US);
Richard C Adamo, Palo Alto, CA (US);
Other;
Abstract
Method and apparatus for limiting optical radiation to an optical sensor are disclosed for protecting the sensor against damage from high intensity optical radiation. A fixed electric field is established between a pair of spaced electrodes by connection of the electrodes to a DC voltage source. Small solid particles oscillate back and forth in the electric field between the electrodes. Incident optical radiation is focused at a focal plane at the oscillating solid particles, and energy transmitted through the oscillating particles is focused at the optical sensor. The transmittance of the particle-containing space is substantially constant for incident optical radiation intensity up to a threshold level below which the sensor is undamaged by the radiation. Above the threshold, oscillating particles are heated to a high temperature for vaporization, ionization and thermal expansion thereof for increased scatter and absorption thereby limiting optical radiation to the sensor to an intensity below which damage to the sensor occurs.