| 摘要 |
PURPOSE:To improve accuracy in terms of reading a scan pattern by changing the intensity of light projected on a scan pattern surface or a signal processing level in a light receiving device in accordance with the projection angle of light from an optical scanner. CONSTITUTION:A light source controller 8 controls a light source 1 so that the intensity of the light of the light source 1 can increase as the absolute value theta of a deflections angle detected by a deflection angle detector 7 becomes greater. When the optical scanner 2 changes the projection angle of the projected light, that is, the deflection angle theta, the controller 8 strengthens the output of the light source 1 as the angle theta becomes larger. Although the incident ratio of light to a light receiving element 5 drops as the angle theta become greater, the intensity of the light incident on the element 5 can be at the same level regardless of the angle theta as the light from the light source 1 is projected at a reference angle. Thus the change in the incident ratio due to the change in the angle theta is offset, and a read signal outputted from a light receiving device 4 can be matched precisely to the darkness of the scan pattern surface 3, thereby improving accuracy in terms of reading the scan pattern.
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