Bar code reader

Abstract

Abstract PURPOSE:To accurately read a bar code irrespective of the length of the bar code by providing at least two kinds of reflecting planes with different central angles so as to change the scanning angle of a laser beam at a polygonal mirror. CONSTITUTION:At least two kinds of reflecting planes with different central angles are provided at the polygonal mirror 4 of a bar code reader so as to change the scanning angle of the laser beam. In other words, the reflecting plane 4a with a narrow central angle (gamma) and the reflecting plane 4b with a wide central angle (delta) are arranged alternately. Therefore, the scan of the laser beam is performed with a large scanning angle (beta) first, and next, it is performed with a small scanning angle (alpha), and reading is performed by capturing only the bar code targeted to be read in a scanning area. In such a way, the bar code can be accurately read irrespective of the length of the bar code.

Inventors

• 👤 Shinya Takenaka
• 👤 竹中　信也

Bibliographic Details