US Patent 7295225 Light source and light beam scanning unit

Light source and light beam scanning units with reduced deviation of beam positions over time and ambient conditions, in use for image forming apparatuses. In the light source unit for emanating light beams, including a plurality of LEDs and coupling lenses each corresponding to the LEDs, there are provided lens holders having two supporting faces aligned approximately parallel to the optical axes of the coupling lenses, elastic members for abutting the coupling lenses by pressing the side portions thereof onto the supporting faces, light source support members for holding LEDs corresponding to the coupling lenses, and bolts for fixing the light source support members. Following the proper adjustment of the position of the lens holder in the vertical direction with respect to the optical axes of the coupling lenses, the light source support members is fixed onto lens holder by bolts.