Patent ID: 7614801

Claim:
An optical axis adjusting method for adjusting a tilt angle of an optical axis in two regions that are optically coupled through a lens optical system held by a holding member having an assembly formed by welding multiple members, comprising the steps of: irradiating a first region of the two regions held by the holding member with a laser beam, the first region and a reference point being located on the same side of the lens optical system; and irradiating a second region on the holding member with a laser beam, the second region being located on the opposite side of the lens optical system from the reference point, the first region and the second region being defined as regions other than welded portions in which said welded portions are formed between the multiple members when said multiple members are configured to be welded to form the assembly for the holding member, one of the first region and the second region being a region in which the tilt angle of the optical axis is roughly adjusted, and the other one of the first region and the second region being a region in which the tilt angle of the optical axis is finely adjusted.