| 摘要 |
PURPOSE:To obtain a device having an interchangeability with a conventional-type device and the advantages of possessing a reflection-type sensor and an image sensor in combination, by using two detecting means the presence of characters and marks is detected by a reflected light which is irradiated on a medium. CONSTITUTION:A character and mark detecting device which detects the presence of characters and marks by a reflected light which is irradiated on a medium is equipped with a first detecting means 1 detecting an output change of a sensor with a self-scanning function in a self-scanning direction thereof and a second detecting device 2 detecting a mark density higher than a fixed level and a mark size larger than a fixed size. By using this device, the first detecting means 1 can recognize the ink bleeding of characters printed on the back-face page, the irregularities of a paper surface, and a printing with a low surface density, and the second detecting means 2 can detect a mark with a small height, such as a hyphen mark. If either of these means detects the presence of characters and marks, the presence of characters and marks is judged. Therefore, by setting a printing position on a line next to the like which is judged to have characters and marks, an overlapped printing can be printed, and a processing can be carried out in safety. |
