| 摘要 |
<p>PURPOSE:To thin a hologram scanner by laminating at least two pieces of holograms, in a crossing state and forming a hologram window. CONSTITUTION:A read window is formed by a hologram window 3 provided with at least two pieces of first and second band-like holograms 31, 32 for crossing each other. Laser scanning beams 33, 34 emitted to the outside of a device pass through the hologram window 3, and also, deflected by the band- like holograms 31, 32, and become scanning beams for irradiating a medium to be read, and a signal scattered beam from the medium to be read passes through the band-like holograms 31, 32 of the hologram window 3 and detected by a photodetector of the inside of the device. Since the read window it self is synthesized in advance to a crossed scanning pattern, such a space as usual is not required, a distance extending from the read window to the window cover is shortened and a hologram scanner can be thinned.</p> |
