| 摘要 |
PURPOSE:To miniaturize the structure of a cassette and to enable the detection of a paper size out of a definite form, by providing a light emitting part and a light receiving part in opposed relation to each other in an up-and-down direction so as to hold the paper in the cassette therebetween and detecting the size of the paper on the basis of the photoelectric conversion output of the light receiving part. CONSTITUTION:Light from a light emitting part 27 is always passed through slits 25 and irradiated downwardly. When no cassette 1 is mounted, an entire light emitting amount is passed through slits 24 and allowed to irradiate a light receiving part 26 but, if the cassette 1 is mounted, the light receiving part 26 is not irradiated with light at parts blocked from light by paper P and limit plates 8, 8. This signal is small if the paper P is large but becomes large if the paper P is small. Therefore, the size of the paper P can be detected by the signal from the light receiving part 26. By this mechanism, the structure of the cassette becomes simple and is miniaturized while the detection of the paper size out of a definite form can be also enabled. |
