Bar code scanner

Abstract

Abstract PURPOSE:To obtain the output of a large high/low difference and a large S/N by installing a photodetecting element in a manner that the element is made inclined against a plane perpendicular to the optical axis of a lens by turning the element around the line perpendicular to the bar of a bar code. CONSTITUTION:In a bar code scanner main body 6, the lens 1 and the photodetecting element 3 such as CCD inclined against the optical axis 2 of the lens 1, are provided. In the vicinity of an opening 7 in the front side of the main body 6, an lighting lamp 5 is disposed. The bar code is held in such posture as its bar runs up-and-down direction on the paper surface. The bar code passes the front of the said opening 7, and is made by the lens 1 to form an image on the element 3. When the bar code 4 is positioned in a prescribed distance, the image is formed sharply in the middle part of the element 3 but obscurely in upper and lower end parts. In case the bar code 4 is farther or closer than the prescribed distance from the lens 1, a sharp portion is included, and the waveform of output signal sufficient to discriminate patterns can be obtained.

Inventors

• 👤 Junichi Yazawa
• 👤 純一 矢澤

Bibliographic Details