| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an illumination function reduction detection device capable of certainly detecting reduction of illumination function of an illumination unit even under a phenomenon in which a slight amount of current variation only occurs and responding to detection of function reduction of LED or the like of D.C. power source specification. <P>SOLUTION: A light receiving element 20 for converting a light-emission amount of a light-emitting body 10 to an electric signal is installed near the light-emitting body 10 of the illumination unit S installed on an automobile while directed to the light-emitting body 10. Disconnection, failure and reduction of intensity of illumination of the illumination unit S are detected based on a variation amount of the electric signal converted by the light receiving element 20. A signal comparison means 30 for mutually comparing the electric signal obtained from the light-emitting body 10 of the same kind of the illumination unit S is provided. The electric signal of the light receiving element 20 is compared by the signal comparison means to detect disconnection, failure and reduction of intensity of illumination of the illumination unit S. In the signal comparison means, even if the respective light-emitting bodies emit the light with time difference, a circuit for memorizing a signal level of the light receiving element is provided and the value is compared to detect disconnection, failure and reduction of intensity of illumination of the illumination unit. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
