| 摘要 |
<p>Three light emitting elements (3) to (5) and one light receiving element (6) are provided on a surface (2A) of a substrate (2). The light receiving element (6) is disposed within a triangular region (TA1) connecting the three light emitting elements (3) to (5). A rectangle (RA1) circumscribed around the triangular region (TA1) is formed. In addition, a rectangle (RA0) circumscribed around a triangle (TA0) formed when intersections of a virtually set XY plane (Sxy) and optical axes (V1) to (V3) of light beams emitted from the three light emitting elements (3) to (5) are perpendicularly projected on the surface (2A) of the substrate (2), is formed. Directions of the light emitted from the three light emitting elements (3) to (5) are set such that at least either one of length and breadth dimensions (X0) and (Y0) of the rectangle (RA0) is larger than a corresponding one of length and breadth dimensions (X1) and (Y1) of the rectangle (RA1).</p> |
