| 摘要 |
PURPOSE:To enable the formation of images having high image quality on a photosensitive body and the generation of the exact electric signal corresponding to external image information by making the coeffts. of thermal expansion of the frame-shaped casing and housing of a long-sized lens array substantially the same. CONSTITUTION:The housing 4 consists of acrylonitrile butadiene styrene(ABS) resin, etc., and its coefft. of thermal expansion is substantially the same as the coefft. of thermal expansion of the frame-shaped casing of the lens array 3 fixed to the housing 4. Then, even if heat is impressed to the housing 4 and the lens array 3 from the outside after fixing of the lens array 3, the large thermal stress occurring in the difference in the coefft. of thermal expansion does not arise between both. Consequently, the generation of curving by the thermal stress of the lens array 3 does not arise and the lens array 3 fixed to the housing 4 is positioned on the optical axes of respective self-focusing lenses 8 and the respective light emitting diodes 2a of a light emitting diode array 2 at all times. |
