| 摘要 |
<p>PURPOSE:To read easily various print optical information with high accuracy, by providing plural light emitting means emitting a high luminance light of each emitting wavelength of plural different wavelength regions to a light source so as to eliminate the need for an infrared ray cut-off filter. CONSTITUTION:High luminance red LEDs 1, 1 are emitted with the operation of a changeover switch 12 by arranging a reader to a bar code label 4 printed with a heat-sensing printer. The red light emitted in this way is illuminated on the label 4 through an illuminating lens 3. The image of bar code in the orthogonal direction of each bar is formed on a reading line arranged with photo elements of an image sensor 9 through an optical system comprising a lens 7 and a diaphragm member 8 having different reflection factor according to the white and black bars on the label 4 through the irradiation of light and corresponding distribution of intensity of light to the bar code 5. On the other hand, in reading the bar code printing black bars in black ink on the label 4 colored on blue background, the infrared LEDs 2, 2 are emitted with the switching of the switch 12 and the image of bar code is image-formed similarly on the sensor 9.</p> |
