| 摘要 |
PURPOSE:To reduce the cost by shifting one-end parts of the mirrors of 1st and 2nd step parts corresponding to a 1st and a 2nd positioning members respectively, and the abutting places of a hole and other-end parts then moving said places stepwise. CONSTITUTION:The hole 12 of a mirror 51 is fitted into the projection part 21 of the 1st positioning member 20 to make the front surface of the mirror 51 abut on the surface of the 1st positioning member 20 and also make the other-end front surface of the mirror 51 abut on the surface of the 2nd positioning member 30, and a pressing member 11 presses and holds the mirror 51 against the 1st positioning member 20 and 2nd positioning member 30. At this time, the height of the 1st step part 22 and 2nd step part 31 is set to the adjustment size of the optical path length. For the purpose, the abutting places of one end part of the mirror 51 and the other end part of the hole 12 are shifted and moved stepwise to adjust the optical path length between the image surface of a document 2 and an optical lens 52. Consequently, the number of components is decreased with simple constitution, the cost is reduced, and the adjusting operation is facilitated. |
