| 摘要 |
PURPOSE:To compensate any non-linear distortion of LED driving signals by a method wherein after rectifying the positive and negative side half-waves of LED driving signals and mixing both rectifying outputs with each other, compensating signals with signal wave form almost reverse to that of LED driving signals are transmitted as negative feedback to LED driving system. CONSTITUTION:Any positive side halfwaves of LED 18 driving signals are rectified by the first rectifying circuit 20 comprising diodes D1, D2 and any negative side half-waves are simultaneously rectified by the second rectifying circuit 21 comprising diodes D3, D4 while both rectifying outputs are mixed with each other by a variable mixed circuit 22 comprising a variable resistor etc. to form compensating signals with signal wave form almost reverse to that of LED 18 driving signals by means of adjusting the mixing ratio. Finally after reversing the phase of said compensating signals by a phase reversing circuit 23, a reversing input terminal 16b of a signal amplifier 16 may be inputted to constitute a negative feedback loop. |
