Optical reader

Abstract

Abstract PURPOSE:To drastically reduce the number of mirrors and to enhance the thinning and to contrive the cost down of a reader by reflecting a light beam every deflection angle, projection it from a reading window and drawing a desirable scanning pattern in mirror group. CONSTITUTION:The laser light 7 from a light source 1 passes through the hole 81 of a lens 8 and is reflected on one surface of plural reflecting surfaces 31 of a polygonal mirror 30, whose tilt angle are different. And it passes through the mirror group 31 and is projected from a reading window 21, then the barcode of a commodity 24 which moves on the window 21 is read. A part of the signal light 25 passes through the window 21 and returns to the polygonal mirror 30 on an opposite path, then it is detected by a detecting unit 28. The mirror group 32 is constituted of the mirrors 32a-32c which makes horizontal, vertical and oblique scanning lines drawn and the diffraction angle of the light beam by the polygon mirror 30 can be optionally set in a horizontal or a nearly horizontal direction, and the light beam can be directly projected from a reading window 21 in a desirable scanning pattern only with the reflection of one mirror. The number of mirrors is drastically reduced and they are arranged in long sideways, so that the thinning and the cost down of the reader can be attained.

Inventors

• 👤 Hiroshi Watanuki

Bibliographic Details