| 摘要 |
PURPOSE: To detect a stuck material without having effect on printing. CONSTITUTION: The lights of two wavelengths λ1 and λ2 having the different absorbance are emitted from a light emitting source 10 on a printed material 5, respectively, for a piece of tape 6. The lights transmitted through the printed material 5 are divided for the respective wavelengths λ1 and λ2 by a dichroic mirror 12. The amounts of the respective split transmitted lights of the respective wavelengths λ1 and λ2 are detected by respective optical sensors 15 and 16. Based on the detected amounts of the respective transmitted lights, the presence or absence of the tape is judged by a signal processing circuit 17. |
