| 摘要 |
PROBLEM TO BE SOLVED: To prevent charge accumulation output from being saturated due to the influence of the flickering of a light source in the case of a soft AGC drive, where charge accumulation is determined by output obtained by a previous accumulation. SOLUTION: The device has a real-time monitoring means 5 for monitoring the quantity of incidence light to a photoelectric conversion means 6 during the charge accumulation time of the charge accumulation type photoelectric conversion means 6 ' that is driven in an auto gain control system for determining soft AGC time according to output obtained by a previous charge accumulation, where an adjustment is made so that time until the output of the real-time monitoring means 5 reaches a specific threshold under the conditions of constant light becomes shorter by a specific ratio as compared with the above soft AGC time. At the same time, when a hard AGC time until the actual output of the real-time monitoring means 5 reaches the above specific threshold becomes the above specific ratio or less for the above soft AGC time, the charge accumulation of the photoelectric conversion means 6 is suspended before reching the above soft AGC time. |
