| 摘要 |
PROBLEM TO BE SOLVED: To assemble an optical device with high accuracy without changing a basic structure. SOLUTION: A first surface 22 and a third surface 12 formed with a receiving optics 10 are so arranged on the second surface 24 of the glass substrate of a hologram element 20 that both surfaces are approximately conjugated. The simultaneous observation of the reflected virtual image MA by the second surface of the earmark M on a hologram side and the earmark MB on the third surface side with an observation system 29 is made possible. The conduction of the assembly work, such as positioning and fixing, with the high accuracy is, therefore, made possible without changing the basic structure of an optical pickup. |
