| 摘要 |
<p>PURPOSE:To make it possible to use remaining light emitting elements under the state they are insulated from a light emitting element, by feeding back the output of one of a plurality of light receiving elements to a driving circuit for the light emitting element, thereby stabilizing output light. CONSTITUTION:A light emitting element 2 is arranged at the central part of the surface of an insulating substrate 3. Light receiving elements 8a-8d are arranged at the peripheral part of the substrate. An output terminal 9d of the light receiving element 8d is connected to the input terminal of a driving circuit 10 for the light emitting element 2 through an output adjusting part 11, and the output of the light receiving element 8d is fed back to the driving circuit 10. Therefore, the output light from the light emitting element 2 can be made very stable with respect to external disturbance. Furthermore, the light receiving elements 8a-8c can be used under the state they are electrically insulated from the light emitting element 2.</p> |
