| 摘要 |
PROBLEM TO BE SOLVED: To reduce deformation due to a temperature rise of image-forming mirrors in an image-forming optical system comprised of the image-forming mirrors each having an off-axial reflective surface formed thereon.SOLUTION: An image reading device includes reading means for reading an image, and image-forming means for allowing the reading means to form an image. The image-forming means includes image-forming mirrors, each of which is provided with an off-axial reflective surface having a curvature, in which an incident direction and an emission direction of a reference axis ray are different from each other. The image-forming mirrors 6, 7, 8, and 9 have first metal layers 6b, 7b, 8b, and 9b on one surface of mirror bases 6a, 7a, 8a, and 9a, respectively. The off-axial reflective surfaces 6c, 7c, 8c, and 9c are formed on surfaces of these first metal layers, respectively. These image-forming mirrors have second metal layers 6d, 7d, 8d, and 9d on the rear surface of these off-axial reflective surfaces, respectively. |
