| 摘要 |
PROBLEM TO BE SOLVED: To provide a light quantity detecting circuit and an electro-optical device which can raise light detection accuracy by correcting sensitivity deterioration without changing manufacturing conditions. SOLUTION: The light quantity detecting circuit is provided with a pair of light detecting sections LS1, LS2. The one light detecting section LS1 outputs an output signal Ia responsive to the quantity of external light, while the other light detecting section LS2 outputs an output signal Ib responsive to the quantity of the external light with its light quantity reduced to 1/n by a light reducing means. The detecting circuit is provided with a multiplying section 11 for multiplying the output signal Ib of the light detecting section LS2 by n<SP>2</SP>, a subtracting section 12 for subtracting the output signal Ia of the light detecting section LS1 from the output value of the multiplying section 11, a multiplying section 13 for multiplying (n-1) by an initial sensitivity K, and a dividing section 14 for dividing the output value of the subtracting section 12 by the output value of the multiplying section 13. The output value of the dividing section 14 is determined to be the light quantity (luminous intensity L) of the external light. COPYRIGHT: (C)2009,JPO&INPIT
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