| 摘要 |
<P>PROBLEM TO BE SOLVED: To satisfactorily measure patch density without complicating structure or processing with respect to a patch density measuring instrument for measuring the density of a test patch. <P>SOLUTION: While a regular reflection light reception part 81a is receiving reflection light in a non-image domain with no test patch formed therein, a contact point of a clamp switch 87 is closed. Then, a first reference voltage, which is generated by a pull-up resistor 88 and a zener diode 89, is made coincide with the potential of a terminal of an AD converter 90 at a capacitor 86. The capacitor 86 is charged by a potential difference between the reference voltage and an output voltage from the reception part 81a. Then, the contact point of the clamp switch 87 is opened. When reflection light is received from an image domain with the test patch formed thereon, the output voltage from the reception part 81a is changed, and a density difference between the image domain and the non-image domain can be converted into numerical terms by the AD converter 90. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
