초록 ▼

A TFT(L) 26 with n-channel, which is connected to a transparent pixel electrode 24, and a TFT(D) 27 with p-annel, which is connected to a cathode side of a photodiode 25, are connected to a common source line 22 and a common gate line 23 and are composed so that each of them can be controlled in an

A TFT(L) 26 with n-channel, which is connected to a transparent pixel electrode 24, and a TFT(D) 27 with p-annel, which is connected to a cathode side of a photodiode 25, are connected to a common source line 22 and a common gate line 23 and are composed so that each of them can be controlled in an ON state independently by impressing a positive voltage VL or a negative voltage VD on the gate line 23. A backlight 18 which is provided on a backside of an active matrix panel 13 comprises monochromatic light sources 18a-18c for emitting each monochromatic light of red, blue or green, and a picture of each color is displayed in a time division. While reading a picture, the picture of the components of red, blue and green are read at each simplex pixel by using each of the monochromatic light sources 18a-18c sequentially. A picture at a pixel P1 are read by storing a predetermined electric charge only at the photodiode 25 of the pixel P1 and exposing the photodiode 25 as well as making a liquid crystal layer 14 corresponding to every two pixels P1vertically and horizontally a transmission state, and an original picture is read at all pixels by repeating similar operation at each of pixels which are adjacent to the pixel P1.

대표청구항 ▼

[ What is claimed is:] [1.]1. A liquid crystal display device with a function of reading a picture comprising:a plurality of source lines for transferring a picture signal;a plurality of gate lines for transferring a scanning signal which are provided in a crossing direction with said source lines;a

[ What is claimed is:] [1.]1. A liquid crystal display device with a function of reading a picture comprising:a plurality of source lines for transferring a picture signal;a plurality of gate lines for transferring a scanning signal which are provided in a crossing direction with said source lines;a pixel electrode which is provided corresponding to each crossing section of the source lines and the gate lines;a first transistor which is connected to the source lines and the gate lines as well as each of the pixel electrodes;an opposite electrode which is provided opposite to the pixel electrode;a liquid crystal which is provided between the pixel electrode and the opposite electrode; anda photo detector for detecting a quantity of a reflected light from an original which is provided corresponding to each of the pixel electrodes; er comprising:a second transistor which is connected to said source lines and said gate lines as well as one end of the photo detector; andthe other end line which is connected to the other end of the photo detector;said liquid crystal display device with a function of reading a picture wherein:a threshold value of a gate voltage in said first transistor and a threshold value of a gate voltage in said second transistor are determined so that at least only the second transistor can be made an ON state.