Patent ID: 7759634
Filing Date: 2010-07-20
Classification: G01D,G02B,H02N

Abstract:
1. A driving device comprising: a movable portion; a driving portion for driving said movable portion in a predetermined direction; a cabinet for covering said movable portion and said driving portion; and a position detecting device for detecting a position of said movable portion, wherein said position detecting device comprises an optical position detecting element and a position information portion which are disposed so as to be opposed to each other, one of said optical position detecting element and said position information portion being mounted on said movable portion, the other of said optical position detecting element and said position information portion being mounted on said cabinet, wherein said position information portion has a pattern such that a signal level produced by said optical position detecting element changes in a continuous manner when said movable portion moves in the predetermined direction, wherein the pattern of said position information portion comprises a plurality of small regions which are divided along the predetermined direction, and said signal level continuously changes in each of said small regions so as to gradually become larger or smaller, and said signal level discontinuously changes at a boundary between adjacent small regions so as to shift between a maximum level and a minimum level, wherein said position detecting device carries out position detection of said movable portion in accordance with the signal level, and wherein said position detecting device further comprises: