| 摘要 |
PURPOSE:To detect abnormal nonillumination without interrupting the video display of a video display device constituted by being regularly arrayed corresponding to DC discharging lamp pixels for display. CONSTITUTION:A DC discharging lamps 1 for display is made to discharge a constant current through a transistor(TR) 4 for lamp current control and the base potential is set with the voltage division ratio of a resistance 7 for a base bias and a base potential controller 6. A lamp illumination state detection comparator 8 compares the base voltage with the voltage of a reference voltage source 14 to know abnormal nonillumination and outputs a '1' level to an AND gate 9, and a lamp illumination control signal of '1' level is inputted to the AND gate 9. which then outputs a lamp nonillumination signal 16. |
