OPTICAL ROTARY ENCODER

PROBLEM TO BE SOLVED: To provide an optical rotary encoder allowing precise assembling while confirming a position of photoreception element with respect to a rotary slit plate and a fixed slit plate, and capable of reducing assembling manhours. SOLUTION: This optical rotary encoder has the rotary slit plate 5 arranged in a rotary shaft 4 supported rotatably to a spindle 1, the fixed slit plate 6 fixed to the spindle 1 opposedly to the the rotary slit plate 5, a light emitting element 7 arranged in the spindle 1 to irradiate the fixed slit plate 6 and the rotary slit plate 5, and the photoreception element 9 for receiving the light transmitted through the fixed slit plate 6 and the rotary slit plate 5. A through hole 1b penetrated through axial-directionally is formed along an arranging direction of the light emitting element 7 in the spindle 1, and the light emitting element 7 is arranged in the through hole 1b. After attaching the fixed slit plate 6 and the rotary slit plate 5, the position of the photoreception element 9 attached to a wiring board 10 is confirmed through the through hole 1b, and then the assembling is carried out under the condition where an optical axis is conformed, by inserting the light emitting element 7 into the through hole 1b to be arranged. COPYRIGHT: (C)2006,JPO&NCIPI