| 摘要 |
PURPOSE:To obtain an image superior in the gradation reprodubility by casting the laser of a wavelength having a different spectral reflecting characteristic to toners of a plurality of colors, and obtaining both the data related to the adhering amount and the data related to the reflecting amount of light. CONSTITUTION:The laser beam from a laser beam generating device 101 to a toner image 106 on a photosensitive body 105 is focused by a movable objective lens 104 through a beam splitter 103. The laser beam cast to the image 106 becomes the reflecting light, and passes again through the beam splitter 103 and is focused on photosensors 107, 108. The data of the focusing position is fed back to the lens 104 by a feedback circuit 109. The lens 104 is moved based on the positional data to focus the laser beam. The moving amount of the lens 104 at this time corresponds to the amount of the displacement of the image 106 in the direction of the optical axis of the laser beam. Therefore, the value is detected as the data of the toner layer in the thicknesswise direction. At the same time, the amount of the reflecting light input to the photosensors 107, 108 is measured thereby to obtain the data of the amount of the reflecting light. Thus, the material and the color difference of the toner can be obtained. |
