Optical unit for use in an image forming apparatus

摘要

In an optical unit of the present invention, a laser element and a glass lens are contained in a lens barrel. The ray axis of the laser beam is aligned with the optical axis of the glass lens without accidental displacement. By surely fixing the lens barrel, shift of the lens along the optical axis or variation in distance between the lens and laser element can be prevented. In contrast, a manufacturing precision of a lens barrel holding member may be lowered and low-in-cost. In order to ensure exact fixing of the lens barrel, a leaf-spring and a bonding agent are used. In this case, it is desirable that the force per unit contact length exerted by the leaf-spring onto the lens barrel be in the range of 100<F<400 [gf/mm]. The amount of the bonding agent is determined so as to be sufficient for fixing the lens barrel and to prevent flowing-out of the bonding agent and an increase in time for drying.