| 摘要 |
PURPOSE:To make it possible to test the characteristics of a directive light source with the use of a simple device and by a simple operation by the quantities of the lights coming from a light source and entering the two regions, which are rotationary symmetrical about a preset axis, and by obtaining their ratio. CONSTITUTION:Among the lights emanating with intrinsic directive characteristics from a light source 1, the light having an angle smaller than theta1 with respect to an axis 2 enters a first light receiving device 5, whereas the light having an angle between theta1 and theta2 with respect to the axis 2 enters a second light receiving device 6. Those lights are photoelectrically converted so that the output A from the first device 5 and the output B from the second device 6 are detected by an output processing device. It is judged that as the output ratio A/B is the smaller the center directive axis of the light source is dislocated the more from the axis 2 or the directivity is weaker than the reference. Thus, those failing to reach a preset value in the output ratio can be precluded as defectives. |
