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:
Nov. 03, 1998
Filed:
Feb. 26, 1997
Tsutomu Banno, Ohtsu, JP;
NEC Corporation, Tokyo, JP;
Abstract
A device for measuring a distance between a panel and a shadow mask included in a color CRT (Cathode Ray Tube) of the present invention includes a range finder having an emitter for emitting an ultrasonic pulse, and a receiver for receiving it. The emitter emits the ultrasonic pulse toward the inner surface of the panel on which the shadow mask is mounted. The distance or so-called Q value is measured on the basis of a lag between the time when a first reflection from the shadow mask reaches the receiver and the time when a second reflection from the inner surface of the panel reaches the receiver. The device is capable of measuring the Q value without resorting to the removal of the shadow mask, and measuring Q values even smaller than 5 mm without contacting the shadow mask. In addition, the device is easy to handle and small size.