| abstract |
An n-channel thin film transistor (TFT) (L) 26 connected to a transparent pixel electrode 24 is connected to a source line 22 and a gate line 23, and a p-channel TFT(D) 27 connected to a cathode of a photo diode 25 is also connected to the same source line 22 and gate line 23. The TFTs are constituted so that they can be independently controlled to the ON state by applying positive voltage VL or negative voltage VD to the gate line 23. Backlight 18 placed at the back of active matrix panel 13 has single color light sources 18a, 18b, and 18c which emit a single color of red, green, and blue respectively, and the panel 13 displays the image of each color in time division. When the device of the present invention is used to read images, the elements of red, green, and blue colors are read in each single pixel by using each single color light source 18a, 18b, or 18c one after another. Pixels P1 are arranged alternately in both vertical and horizontal directions. In a liquid crystal layer 14, only the portions to which the pixels P1 correspond are set in a transmissible state as well as a certain amount of electric charge is accumulated in photodiodes 25 in the pixels P1 and thus the photodiodes 25 exposed, and the images in the pixels P1 are thereby read. The same workings are repeated in the pixels adjacent to the pixels P1, and the original images corresponding to all the pixels are thereby read. |