| 摘要 |
PROBLEM TO BE SOLVED: To provide a photosensor which prevents deterioration of detection accuracy, and an HUD device.SOLUTION: A photosensor includes a detection element 52 for detecting light intensity and a cylindrical tube section 54 having openings 57a, 57b on each end and an inner bore 58 whose diameter DI becomes gradually smaller toward the detection element 52. The tube section 54 splits incident light entering from a side opposite to the detection element 52 into reflection light, which is collected toward the detection element 52 by reflection, and transmission light which is discharged to outside by being transmitted through the tube section 54. |
