公开(公告)号：US3600077A

公开(公告)日：1971-08-17

申请号：US3600077D

申请日：1968-08-09

Applicant: WESTON INSTRUMENTS INC

Inventor： PAIVA ANTONIO S ,  PAULAUSKAS JUSTIN V

IPC: A47K10/06 ,  D06F57/12 ,  F28F9/00 ,  G01D7/06 ,  G03B21/10

CPC classification number: G01D7/06 ,  A47K10/06 ,  D06F57/12 ,  F28F9/00 ,  G03B21/10

Abstract: An indicating instrument is described which displays the value of some driving or control signal on a viewing screen as a sharp, bright image which is devoid of noticeable light-dispersion effects, such as image shadowing or rainbowing. This result is accomplished by focusing a concentrated light beam onto the path of movement of the image-forming element which takes the more specific form of a movable transparent vane. The diverging vane image is focused onto the viewing screen by means of a concave mirror having its concave reflecting surface spaced from, and facing, the back surface of the viewing screen. The vane is caused to move in the prescribed path in response to the signal applied to the instrument. The concave mirror is preferably of spherical or aspheric shape and serves as an efficient collector and reflector of incident light rays. Also disclosed is a panelmountable indicating instrument of overall rectangular shape and a flat and relatively thin edgewise appearance made possible by an optical system which provides vane images having the abovedescribed characteristics.