OPTICAL SENSOR ELEMENT, MANUFACTURING METHOD THEREOF, AND ILLUMINANCE DETECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide an optical sensor element in which measurement errors due to variation of a driving voltage can be reduced.SOLUTION: A bridge circuit is constituted of first to fourth light detection parts 3 to 6 with first to fourth terminals 21 to 24 therebetween, and each of the first to fourth light detection parts 3 to 6 comprises a photosensitive film 8 formed on a substrate 2 and having photoconductivity and at least a pair of electrodes out of electrodes 9 to 16 being in contact with the photosensitive film 8. A potential difference (output voltage) between the first terminal 21 and the third terminal 23 is measured while a driving voltage is applied between the second terminal 22 and the fourth terminal 24, whereby illuminance of light irradiating an optical sensor element 1 is obtained. The optical sensor element is so designed that a change rate of an output current to the illuminance of irradiating light is different between the first light detection part 3 and the second light detection part 4 and between the third light detection part 5 and the fourth light detection part 6 and an output voltage at illuminance of light for higher detection accuracy is 0 V.