| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an integral photometric circuit in which deterioration of photometric characteristics can be avoided by decreasing integral errors by a switching element when a photo current decreases due to reduction of a photodiode receiving surface area. <P>SOLUTION: The photometric circuit comprises a photodiode 1, a bias setting unit 4 which sets a bias of the photodiode 1 as approximately 0 or a reverse bias, a current amplifying part 3 which amplifies a current output from the photodiode 1 which bias is set as approximately 0 or a reverse bias, and an integration output part 2 which integrates the amplified output current by the current amplifying part 3, and outputs a signal corresponding to the amount of receiving light by the photodiode. <P>COPYRIGHT: (C)2004,JPO |
