| 摘要 |
PURPOSE:To enlarge a photodetecting quantity of a cut-off state and an open state by providing a light shielding plate for cutting off an optical path from a light emitting element, which takes a roundabout route in a light-transmissive resin and reaches a receiving element, on a lead frame, and also, forming a lens consisting of the light- transmissive resin, in front of the light emitting and the light receiving elements. CONSTITUTION:A lead frame 8 loaded with a semiconductor light emitting element 1, and a lead frame 9 loaded with a semiconductor light receiving element 2 are sealed with a light-transmissive resin 10, and covered with a case 15 of a non-light- transmissive resin having an opening part 15a. Also, light shielding plates 6, 7 for cutting off an optical path 4 which takes a roundabout route in the light-transmissive resin 10 and formed between the light emitting element 1 and the light receiving element 2 are provided, and semi-columnar lenses 11, 12 consisting of the light- transmissive resin are formed in front of the light emitting and the light receiving elements 1, 2. In this way, a photodetecting current in a cut-off state of a photointerrupter, and a photodetecting current in an open state can be set to about 1/5 of a conventional one, and about two times of a conventional one, respectively, and the sensitivity can be improved.
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