Liquid crystal display device performing both image display mode and fingerprint recognition mode

1. A liquid crystal display panel having an image display region on which images are displayed and having a fingerprint recognition region within said image display region, said fingerprint recognition region being capable of both actively displaying images and generating signals that represent fingerprints on finger tips that are placed on said fingerprint recognition region, said liquid crystal display panel having a plurality of thin film transistors (TFTs) in the image display region that drive display pixels arranged in rows and further having a plurality of TFTs in the fingerprint recognition region said plurality of TFTs in the fingerprint recognition region being a subset of the plurality of TFTs in the image display region, and, which drive display pixels arranged in rows and which detect light reflected from finger tips wherein the liquid crystal display panel comprises:

a scan drive unit which selectively outputs turn-on signals to sensor TFTs of a specific row and turn-off signals to sensor TFTs of other rows in an image display mode and which outputs turn-off signals to sensor TFTs in the fingerprint recognition region in a fingerprint recognition mode;

a data drive unit which outputs one or more data signals in the image display mode;

a switch control unit which outputs turn-off signals to switch TFTs in the image display mode and which selectively outputs turn-on signals to switch TFTS in of a specific row and turn-off signals to switch TFTs of other rows in the fingerprint recognition region in the fingerprint recognition mode;

a reading unit which outputs fingerprint image information read in the fingerprint recognition mode;

a plurality of sensor thin film transistors (TFTs) in the fingerprint recognition region which drive liquid crystal in the image display mode, sensor thin film transistors having a channel with a first end and a second end, a drain and a source and, in which the first end of the channel is connected to an output terminal of the data drive unit, a photosensitive layer is formed between the drain and the source of the sensor thin film transistor, and the drain and the source become electrically conductive when light exceeding a predetermined amount of light is incident into the photosensitive layer; and

a plurality of switch thin film transistors (TFTs) in the fingerprint recognition region, switch film transistors having a channel with a first end and a second end, a drain and a source, in which the first end of the channel of the switch thin film transistor is connected to the second end of the channel of the sensor thin film transistor, and the second end of the channel of the switch thin film transistor is connected to an input terminal of the reading unit;

wherein the image display region and said fingerprint recognition region are substantially co-planar.

2. The liquid crystal display panel according to claim 1 , wherein switch thin film transistors are switched on for each frame in order to scan a fingerprint image.

3. The liquid crystal display panel according to claim 1 , wherein the second end of the channel of a sensor thin film transistor and the first end of the channel of a switch thin film transistor are connected to a transparent electrode.

4. The liquid crystal display panel according to claim 1 , wherein a sensor thin film transistor and a switch thin film transistor are formed on a transparent substrate, and the liquid crystal display panel further comprises a light-emitting unit under the transparent substrate.

5. The liquid crystal display panel according to claim 1 , wherein the liquid crystal display panel further comprises an electricity charging unit, one end of the charging unit being connected to the second end of the channel of a sensor thin film transistor and to the first end of the channel of a switch thin film transistor the other end of the charging unit being connected to the scan drive unit, and wherein electric charges generated from the sensor thin film transistors are accumulated in the electricity charging unit.

6. The liquid crystal display panel according to claim 1 , further comprising a light shut-off layer formed on the top of the switch thin film transistor.