| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a document size detector capable of preventing erroneous detection of a document size, and to provide a document reader and an image forming apparatus. <P>SOLUTION: The image forming apparatus 10 has a document size detecting section 14 that detects a document size. The document size detecting section 14 includes reflection type photo-sensors 14a to 14d. Each of the reflection type photo-sensors 14a to 14d has: a light source 31 that emits light for illuminating the detection area 1 of a document table 11; an emission light hole 33 through which emission light 32 from a light source 31 is passed; a light quantity limiting part 34 that limits an amount of emission light 32; a reflected light hole 35 through which light reflected by a document 5 in the detection area 1 is passed; and a light receiving element 37 that receives passage light 36 passed through the reflected light hole 35. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
