REFLECTION TYPE PHOTOSENSOR AND IMAGE FORMING APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a reflection type photosensor capable of reducing the fluctuation of output voltage caused by a change in the angle with a reflecting surface, and to provide an image forming apparatus having the photosensor at a low cost.

SOLUTION: An LED 71 and a phototransistor 72 are housed in the respective housing holes 75 and 76 provided in the case 74 of the reflection type photosensor 70. The phototransistor 72 receives the reflected light R obtained when the irradiation light L of the LED 71 is regularly reflected from a surface 29a. A reflected light regulating opening 761a is provided in the opening 76a positioned on the side of the surface 29a of the housing hole 76 and a concave lens 96 is provided in the reflected light regulating opening 761a. The concave lens 96 is constituted of a lens which has a shape diffusing the reflected light R passed through the reflected light regulating opening 761a so that the diameter W of the light path of the reflected light R arriving at the phototransistor 72 becomes the same or almost the same as the outer diameter D of a head 84 as a light receiving unit.

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