Patent ID: 7173381
Filing Date: 2007-02-06
Classification: G02F,G09G,H05B,Y10S

Abstract:
1. An apparatus for checking a status of a light emitting device, the apparatus comprising: a light emitting device; a voltage supply coupled to the light emitting device for making a current flow through the light emitting device; an electrically conductive device spaced apart from the light emitting device for generating a voltage in response to the current flowing through the light emitting device; a status determining device for determining the status of the light emitting device based on the voltage from the electrically conductive device; and a rectifier circuit having a first node and a second node, wherein the first node is connected to the electrically conductive device and the second node is connected to a signal detector, wherein the voltage supply is an AC voltage supply, further comprising an RC filter circuit for converting an output from the rectifier circuit into a DC signal, wherein the RC filter circuit is connected to the rectifier circuit and the signal detector.