| 摘要 |
PURPOSE:To improve the using factor of reading energy with high efficiency by providing the light sources which emits bright line spectra different from each other and a filter which transmits only said spectra at an illumination part which is used to a device that reads the information optically. CONSTITUTION:The character writing paper PO is illuminated by light sources L1 and L2 which emit plural bright line spectra, and the reflected light is transmitted through a filter FT and formed into an image on a sensor SS by a lens LS. The prescribed processing is applied to the output of the sensor SS through a reading part RP. Then the information on the paper PO, and an indication is given to a control mechanism C for replacement of the paper PO. A filter FT selects automatically or manually the transmitting characteristics of either one of blue, red and near infrared rays in response to the wavelength of the using bright line. For instance, the information written by a ball pen. In this case, filters that transmit red and blue when the red and blue are selected for the drop-out color, respectively. This improves both decoding factor and the energy efficiency. |
