| 摘要 |
PROBLEM TO BE SOLVED: To provide a monitoring camera device constituted so that the residual quantity of a silver salt film can be easily and surely confirmed. SOLUTION: The perforation of the silver salt film of a film cartridge loaded in a camera main body is detected and a detection signal is outputted by a photointerrupter 406. Then, a motor control part 402 is controlled by a control part 412 so that the angular velocity of the winding-up shaft or the take-up shaft of the film cartridge becomes constant. Besides, the time when a light state is maintained by the detection signal inputted from the photointerrupter 406, that is, the passing time (t) of the perforation is measured and the traveling speed of the silver salt film is calculated based on the time (t). Based on the traveling speed, the residual quantity of the silver salt film is obtained.
|
