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:
Oct. 19, 1999
Filed:
Jul. 31, 1998
Shigeki Nishina, Tokyo, JP;
Advantest Corporation, Tokyo, JP;
Abstract
A light-measuring device is disclosed for continuously and accurately measuring the intensity of light beams of from low intensity to high intensity. The intensity of a light beam to be measured is measured by a photodiode. A bias voltage is applied to the photodiode by a bias power source to improve the saturation characteristic. When the measured light beam is of high intensity, an analog switch and a photo MOS relay are switched on. When measuring a light beam with medium intensity, only the analog switch is turned off and a bias voltage is not applied to the photodiode. When measuring a light beam with low intensity, the bias voltage is not applied to the photodiode by switching off the photo MOS relay.