| 摘要 |
PURPOSE:To stably discriminate whether the recording paper sheet of a printer is ordinary paper or OHP paper, and improve image quality in using the OHP paper. CONSTITUTION:An OHP sensor 56 serves as a reflection-type photosensor is disposed near the front of the third paper feed roller 53. The OHP sensor 56 discriminates recording paper based on the level of reflected light quantity from the recording paper. An interval between carrier guide plates 54, 55 is set so that the recording paper can exist within an distance area where detection accuracy by the OHP sensor 56 can be ensured even if the recording paper waves. A through hole through which the light transmitted through the recording paper passes is formed at the carrier guide plate 55 to prevent the light transmitted through OHP paper from reflecting at the carrier guide plate 55. With the above constitution, transfer current is increased, linear velocity of fixing is decreased, and paper discharge is made smooth when the paper is discriminated to be the OHP paper. |
