| 摘要 |
PURPOSE:To enable stable discrimination of color components of a color film, by providing a color film sensor for detecting a film color of a color film, an external light sensor for detecting external light in the vicinity of the color film sensor, and a subtracting circuit for subtracting an output of the external light sensor from an output of the color film sensor. CONSTITUTION:The signal of each of three colors of a color film detected by a color film sensor 1 is detected in such a state that a voltage eA corresponding to the component of external light in the vicinity of the sensor 1 is superimposed thereon. External light is detected as a voltage eB by an external light sensor 2. The voltages from the sensors 1, 2 are inputted to a subtracting circuit 3 to take out only a color signal component indicating the color of the color film. The subtraction is performed after correcting the voltages eA, eB to approximately equal values. The color signal amplifying circuit 4 to such a level that the three colors of the color film can be sufficiently discriminated from each other. Accordingly, the external light component is eliminated, and stable discrimination of the tree colors of the color film can be achieved. |
