| 摘要 |
PURPOSE:To give an accurate white reference to a read unit by providing a white face to be installed slightly apart from a transparent board so as to avoid the gray coloring of the white face or production of interference fringes due to the close contact between the white face and the transparent board. CONSTITUTION:A shallow recessed part 20 is formed at the side of home position of the read unit 10 on the rear face of a retaining plate 3. The recessed part 20 is formed rectangle longer in the main scanning direction of an image sensor and the length is equal to the width of an original placing region 5. A bottom face 21 of the recessed part 20 is formed flat and a white sheet is adhered to the bottom face to form a white reference. Moreover, a comparatively short projection stripe 22 is formed to the recessed part 20 in the main scanning direction of the image sensor and the apex face is colored in black. The read unit is moved to read the bottom face 21 of the recessed part 20 at first and the result is set as the white reference level in reading an original, then the projected stripe mark is read and it is used as an original mark to read the original.
|
