| 摘要 |
<p>PURPOSE:To enable the detection of various types of sheets of paper in the captioned device of a recording device by providing two types of light reflecting type sensors of high reflectance and low reflectance and judging the existence or position of a sheet of paper based on the detected output values of these. CONSTITUTION:Light reflecting type sensors 4a, 4b and reflecting plates 5a, 5b are installed in the vicinity of a platen 1. The surface of the reflecting plate 5a has a reflectance higher than the reflectance of the surface of a sheet of white paper whereas the surface of a reflecting plate 5b has a reflectance lower than the reflectance of the surface of an OHP paper. By emitting light to the reflecting plates 5a, 5b, the reflected lights are received by the sensors 4a, 4b and output voltages corresponding to the received light quantities are outputted to comparing means 21, 22. The comparing means compare same with a reference value and the results are outputted to a judging means 23 to judge the existence or position of a sheet of paper. By this structure, various types of sheets of paper can be judged.</p> |
