| 摘要 |
PROBLEM TO BE SOLVED: To provide a light quantity controller that is reduced in offset error and has a large dynamic range. SOLUTION: The light quantity controller is provided with light emitting elements LD1 and LD2, a light receiving element 11 which receives light from the light emitting elements LD1 and LD2, and a first amplifying means 300W which amplifies an input signal from the light receiving element 11. The device is also provided with a second amplifying means 300D which has a principal section commonly constituted with the principal section of the first amplifying means 300W and amplifies non-inputted signals, an error amplifying means 600 which generates a control signal for automatically controlling a light quantity based on output signals of the first and second amplifying means 300W and 300D, and a driving means 100 which drives the light emitting elements LD1 and LD2 based on the output signal of the error amplifying means 600. COPYRIGHT: (C)2005,JPO&NCIPI
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