Optical information reader

Abstract

Abstract PURPOSE:To obtain the incident light having the desired light quantity distribution characteristics by adding a reflection factor control means to a mirror so that the fluctuation of the illumination light, etc., can be compensated. CONSTITUTION:A mask 3a is bonded to a mirror 3 and a prescribed reflection factor distribution is secured in the width direction of the mirror 3. In other words, the light is projected on a bar code label L from a light source 2 and this reflected light is made incident on the mirror 3. In this case, the optical information B to be given to the mirror 3 contains the information produced by the unevenness of the illumination of the source 2 and the binarized information on the label L. While the information C produced by the output light of the mirror 3 contains the information B and the information obtained from the reflection factor distribution of the mirror 3 that compensates the fluctuation of illumination light of the source 2 and the characteristics of an image forming optical system 4. Then the information C is turned into the optical information D containing only the information on the label L when the information C passes through the system 4. The information D forms an image to a 1-dimensional photodetecting element 5 and is turned into electric signals. These electric signals can be processed by an arithmetic circuit part 6.

Inventors

• 👤 Seiichi Sasaki
• 👤 Takao Tawara
• 👤 Jun Aketo
• 👤 Haruhiko Machida

Bibliographic Details