| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical unit for an optical symbol reader having an optical scanning mechanism which has a relatively simple and small-sized structure and makes two-dimensional scanning possible. <P>SOLUTION: The optical symbol reader is provided with a light source 11 for emitting a laser beam, the optical scanning mechanism for angularly oscillating a reflective surface 18a for reflecting the laser beam by electromagnetic force, and a photodetector 15 for receiving the reflected light from the optical symbol and converting the same to an electric signal. The optical scanning mechanism is provided with a loose bearing structure for freely angularly oscillatably supporting a rotor 12 having the reflective surface 18a to a base 10. The bearing spacing between the external diameter of a shaft 19 configurating the loose bearing structure and the inner diameter of a bearing hole 26 is set at about 50% of the external diameter of the shaft 19. A coil spring 29 elastically energizes the rotor 12 in a specified direction so as to allow a portion of the outer peripheral surface of the shaft 19 to touch the inner peripheral surface of the bearing hole 26. The angle of the reflective surface 18a is set at about 45° with the direction of the elastic energization. <P>COPYRIGHT: (C)2004,JPO |
