Liquid crystal display device having a digitizer

• US 20040080678A1
• Filed: 10/14/2003
• Published: 04/29/2004
• Est. Priority Date: 06/21/1999
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: Young-Jin Oh, Young-Soo Ahn, Yun-Cheol Jeong
• Inventors: Ahn, Young-Soo, Jeong, Yun-Cheol, Oh, Young-Jin
• Granted Patent: US 7,009,593 B2
• Time in Patent Office: Days
• US Class Current: 349/12
• CPC Class Codes: G02F 1/133334 Electromagnetic shields
• 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/147 using display panels

Abstract

The present invention discloses a first frame, a liquid crystal panel supported by the first frame, the liquid crystal panel having a display region and a side wall portion, a digitizer located on the liquid crystal panel, the digitizer having a peripheral portion, and a second frame having a front surface with an opening region and a side wall portion, the front surface pressurizing the peripheral portion of the digitizer, the opening region formed at a location corresponding to the display region of the liquid crystal panel.

Claims

1. A liquid crystal display device having a digitizer, comprising:

a first frame;

a liquid crystal panel supported by the first frame, the liquid crystal panel having a display region and a side wall portion;

a digitizer located on the liquid crystal panel, the digitizer having a peripheral portion; and

a second frame having a front surface with an opening region and a side wall portion, the front surface pressurizing the peripheral portion of the digitizer, the opening region formed at a location corresponding to the display region of the liquid crystal panel.

2. The liquid crystal display device of claim 1, further comprising,

a printed circuit board having a drive circuit, the drive circuit driving the digitizer;

and

a first connection electrically connecting the printed circuit board with the digitizer, the first connection passing between the side wall portion of the liquid crystal panel and the side wall portion of the second frame.

3. The liquid crystal display device of claim 1, further comprising, a printed circuit board located on a back surface of the first frame, the printed circuit board having a controlling circuit for controlling both the liquid crystal panel and the digitizer. The liquid crystal display device of claim 1, the digitizer including a plurality of digitizer electrodes, the digitizer electrodes being covered by the front surface.

4. A liquid crystal display device used by a main system, comprising:

a digitizer for producing signals indicative of a location by an external input and driven according to a first clock generated by a first clock generator;

a liquid crystal display device for displaying a predetermined information according to the signal from the digitizer, the liquid crystal display device having first and second substrates with a liquid crystal layer interposed therebetween, and data and gate lines; and

a printed circuit board having a controlling circuit for controlling the digitizer and the liquid crystal display.

5. The liquid crystal display device of claim 4, wherein the drive circuit including:

a power supply for supplying a voltage to the LCD panel and the digitizer;

a clock generator for producing clock signals to drive the LCD device and the digitizer;

an analog to digital (A/D) converter for converting analog signals to digital signals;

a gamma circuit for correcting gamma characteristics of the LCD device;

a first input/output (I/O) unit for conveying analog signals from the digitizer to the A/D converter and conveying signals from the controller to the digitizer;

a second input/output (I/O) unit for transferring digital signals in the form of x-y coordinate values from the A/D converter to the main system;

data and gate drivers driven by the clock generator; and

a controller for controlling all components of the drive circuit.

6. The liquid crystal display device of claim 5, wherein the first I/O unit is one of a serial port, a parallel port, a universal serial bus (USB), and IEEE 1394 bus.

7. The liquid crystal display device of claim 4, wherein the digitizer includes:

a) a first digitizer substrate having a rectangular shape over the upper substrate of the liquid crystal display device;

b) a second digitizer substrate having a rectangular shape over the first digitizer substrate;

c) a protective layer on the second digitizer substrate,

d) first two digitizer electrodes disposed parallel to each other and along opposite edges of the first digitizer substrate;

d) second two digitizer electrodes disposed parallel to each other and along opposite edges of the second digitizer substrate, the second two digitizer electrodes perpendicular to the first two digitizer electrodes,

e) first and second drive circuit boards for driving the first and second digitizer electrodes, each boards disposed along neighbering edges of the first and second transparent conductive layers, and

f) electric connections for connecting the first and second drive circuit boards to the corresponding digitizer electrodes, the electric connections having the same length.