| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain optimize an amplification ratio of a scanning signal from the point of view of second-dimensional code reading at the time of reading the second-dimensional code included in the scanning signal of a second- dimensional picture. SOLUTION: A positioning symbol being a specific frequency component ratio is detected by a frequency analyzer 18, and an area in which a second- dimensional code is present is specified from the position in one screen. Then, based on the ratio of the existing area of the second-dimensional code in a second-dimensional screen and the mean value of the signal level in the second- dimensional screen, an amplification ratio is set so that the signal level of a scanning line signal corresponding to the existing area of the second- dimensional code can be within a prescribed adjustment area. More specifically, a camera part controller 10 changes a reference voltage Vst generated by a reference voltage generating part 14 for changing and setting the amplification ratio in an AGC amplifier 12.</p> |
