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

• US 7,418,117 B2
• Filed: 12/30/2002
• Issued: 08/26/2008
• Est. Priority Date: 03/12/2002
• Status: Active Grant

• Current Assignee: BOE HYDIS Technology Company Limited (SK Hynix Inc.)
• Original Assignee: BOE HYDIS Technology Company Limited (SK Hynix Inc.)
• Inventors: Park, Kyu Chang, Kim, Choong Hoo, Shim, Min Soo
• Primary Examiner(s): Werner; Brian P.
• Assistant Examiner(s): DULANEY, KATHLEEN YUAN
• Application Number:
  US10/331,530
• Publication Number:
  US 20030174870A1
• Time in Patent Office: 2,066 Days
• Field of Search: 382/124, 382/115
• US Class Current: 382/124
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 1/1601 Constructional details related to the housing of computer displays, e.g. of CRT monitors, of flat displays constructional details related to flat displays integrated in a portable computer, e.g. laptop, handheld computer G06F1/1637; constructional details related to television receivers H04N5/64
• CPC Class Codes: G06F 2203/0339 Touch strips, e.g. orthogonal touch strips to control cursor movement or scrolling; single touch strip to adjust parameter or to implement a row of soft keys
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/042 by opto-electronic means
• CPC Class Codes: G06V 40/1318 using electro-optical elements or layers, e.g. electroluminescent sensing
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

Disclosed is a liquid crystal display device of novel construction, in which a fingerprint recognition device is integrally formed with the liquid crystal display device, thereby minimizing the increase in the price and size of a final product. The liquid crystal display device comprises an image display panel and a fingerprint recognition panel which are integrally formed, wherein the image display panel comprises a scan drive unit which sequentially turns on rows formed in the image display panel for each frame in order to display images, and a data drive unit which outputs data signals to a turned-on row provided in the image display panel, and wherein the fingerprint recognition panel comprises a switch control unit which sequentially turns on rows formed in the fingerprint recognition panel for each frame in order to perform fingerprint recognition, and a reading unit, to which fingerprint information recognized from a turned-on row is outputted.

Claims

1. A liquid crystal display (LCD) panel comprised of:

a single panel lying in a single plane, having a first plurality of thin film transistors (TFTs) arranged in rows, said rows of TFTs in the panel being capable of displaying images throughout said single panel in a display mode; and

a second plurality of TFTs in a fingerprint detection area of the single panel, which is within a first area of the single panel, said second plurality of TFTs being a subset of said first plurality of TFTs said TFTs in the fingerprint detection area being capable of both actively displaying images in said display mode and generating signals that represent a fingerprint touching the single panel in the fingerprint detection area in a fingerprint recognition mode;

wherein the single panel further comprises a scan drive unit which sequentially turns on rows of the first plurality of TFTs and the second plurality of TFTs to display images in the display mode, and a data drive unit which outputs data signals to a turned-on row provided in the image display panel, and

wherein the fingerprint detection area comprises a switch control unit which sequentially turns on rows of TFTs in the fingerprint detection area in order to perform fingerprint recognition in the fingerprint detection area of the single panel, and a reading unit, to which fingerprint information recognized from a turned-on row is outputted.

2. The liquid crystal display device according to claim 1, wherein the fingerprint detection area is formed from an array of fingerprint recognition components, each of the fingerprint recognition components comprising:

a sensor thin film transistor, in which a photosensitive layer is formed between a first end and a second end of the sensor thin film transistor, and when light exceeding a predetermined amount of light is incident into the photosensitive transistor, the first end and the second end become electrically conductive; and

a switch thin film transistor, in which a gate of the switch thin film transistor is connected to an output terminal of the switch control unit, a first end of a channel of the switch thin film transistor is connected to a second end of a channel of the sensor thin film transistor and a second end of the channel of the switch thin film transistor is connected to an input terminal of the reading unit.

3. The liquid crystal display device according to claim 2, wherein the second end of the channel of the sensor thin film transistor and the first end of the channel of the switch thin film transistor are connected to a transparent electrode.

4. The liquid crystal display device according to claim 2, wherein the sensor thin film transistor and the switch thin film transistor are formed on a transparent substrate, and the liquid crystal display device further comprises a light-emitting unit under the transparent substrate.

5. The liquid crystal display device according to claim 2, further comprising an electricity charging unit, wherein one end of the charging unit is connected to the second end of the channel of the sensor thin film transistor and to the first end of the channel of the switch thin film transistor, and electric charges generated from the sensor thin film transistor are accumulated in the electricity charging unit.

6. The liquid crystal display device according to claim 2 further comprising a light shut-off layer formed on the top of the switch thin film transistor.