| 摘要 |
PURPOSE:To make it easy and accurate to position a photodetector by forming on a light-transmissive film a taper pattern for focus adjustment and parallel patterns for rotation-angle adjustment. CONSTITUTION:Reference flank 6 of positioning film sheet 11 is positioned in contact with the reference flank of the unit and the photodetector is placed on orthgonal line 12 tapered. Then, focusing is carried out by edges of the black line and white line of this pattern. Next, cross pattern 13 is used to adjust the position of a read character. Next, the angle of rotation is adjusted by adjusting the angle of the photodetector so that the photodetector will agree with parallel lines 14 of different widths arrayed in parallel to reference flank 6. Next, the magnification of image formation is adjusted by magnification reference pattern 15. Consequently, it can be made easy and accurate to position the photodetector. |
