| 摘要 |
PURPOSE:To automatically detect an erroneous record by applying a wavelength band and a light quantity to recorded dot picture and detecting the intensity of illumination of reflective light, etc. CONSTITUTION:A recorded dot picture detection part 25 mechanically directs a light from an irradiated light source 41 to a dot picture recording part in a free form, adjusted to the structure of a recording head 22, so that an intensity of illumination required for detection is obtained. A recording signal delay circuit 23 shifts a recording signal by means of an output from the recording head 22 and delays by a required cycle. After this process, the said delay circuit outputs to an erroneous record decision circuit 24, synchronized to an output from the recording head 22. The erroneous record decision circuit 24 compares an output from the recording signal delay circuit 23 with an output from a recorded dot picture detection part 25, deciding the existence of a dot picture recorded on a recording paper 26. In case there is no dot picture or there are a prearranged number of continuous dot pictures, an output signal is output to a drive part 21 stopping a drive. It is possible to optionally change the mentioned prearranged number. |
