| 摘要 |
PURPOSE:To reproduce faithfully the color of an original picture regardless of the ground color of the printer paper by providing a means which detects the color of the printer paper and correcting the color signals to be printed by the output of said color detecting means. CONSTITUTION:A printer paper 1 is fed through paper feed rolls 6 and 7 and detected by a paper position detecting sensor 5. Then a paper position detecting sensor circuit 34 works, and a light emitting part 8 of a light emitting circuit 30 for paper color detecting sensor. Thus the paper 1 is irradiated. The reflected light of the paper 1 is received by photodetecting parts 9-11 of the paper color sensor. The output signals R', G' and B' are processed by a YMC conversion circuit 21 and a gamma correction circuit 22 and stored to a latch circuit 29 (in the form of Y', M' and C' signals). Changeover switches 26 and 27 supply the input signals R, G and B to the circuit 21 and connects the circuit 22 to a subtractor circuit 28 after a delay time produced by a delay circuit 32. While the circuits 30 and 28 are turned off respectively and on after a delay time of a delay circuit 33 to produce the difference signals between signals R, G and B and signal Y', M' and C' obtained by giving the YMC conversion to signals Y, M and C respectively. |
