| 摘要 |
<p>PURPOSE:To effectively direct light diverged from the optical axis of a light emitting element toward a photosensor by forming an optical interface constituted of an internal or external surface resulting from a package in a curved surface. CONSTITUTION:A hollow section 6 is formed in a package 5 and a light emitting element 1, photosensor 2, the drive circuit 3 of the element 1, light emitting power control circuit 4, etc., are arranged in the section 6. On the internal surface 5i of the package 5 formed by the section 6, an optical interface is formed, because a relation n1<n2 exists between the refractive indexes n1 and n2 of the section 6 and package 5. Accordingly, the light diverged from the element 1 is reflected by the internal surface 5i and effectively directed toward the photosensor 2. Therefore, the light emitting power of the element 1 can be surely controlled to a constant level and, in the case the efficiency is the same the light receiving area of the photosensor 2 can be reduced.</p> |
