Liquid crystal display device including sensing element

• US 8,395,575 B2
• Filed: 05/10/2010
• Issued: 03/12/2013
• Est. Priority Date: 07/26/2004
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Joo-Hyung, Uh, Kee-Han, Park, Jong-Woung, Park, Sang-Jin
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Lee, Gene W
• Application Number:
  US12/776,566
• Publication Number:
  US 20100214203A1
• Time in Patent Office: 1,037 Days
• Field of Search: 345 11-111, 345173-178, 345205-215, 345690-699, 349 1-202
• US Class Current: 345/92
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• 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: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: G09G 2360/148 the light being detected by light detection means within each pixel
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

A liquid crystal display includes a first panel, a second panel facing the first panel and spaced apart from the first panel, a liquid crystal layer disposed between the first panel and the second panel, a variable capacitor having a capacitance that varies by a touch and generating a control voltage that has a magnitude depending on the capacitance, and a sensing element disposed on the second panel and generating a sensing signal based on the control voltage.

Claims

1. A liquid crystal display device comprising:

a first substrate;

a common electrode formed on the first substrate;

a second substrate facing the first substrate and spaced apart from the first substrate;

an image scanning line disposed on the second substrate;

an image data line disposed on the second substrate and intersecting the image scanning line;

a first thin film transistor connected to the image scanning line and the image data line;

a pixel electrode connected to the first thin film transistor and facing the common electrode;

a sensing electrode disposed on the second substrate and facing the common electrode;

a second thin film transistor comprising;

an input electrode;

a control electrode connected to the sensing electrode; and

an output electrode; and

a liquid crystal layer disposed between the first substrate and the second substrate,

wherein the sensing electrode, and the control electrode of the second thin film transistor, are floating.

2. The liquid crystal display device of claim 1, further comprising a rising disposed between the first substrate and the common electrode and facing the sensing electrode.

3. The liquid crystal display device of claim 2, wherein the liquid crystal layer on the rising has a thickness from about 0.01 microns to about 2.0 microns.

4. The liquid crystal display device of claim 2, further comprising an insulating layer disposed between the second thin film transistor and the sensing electrode, and a contact hole connecting the sensing electrode and the control electrode of the second thin film transistor.

5. The liquid crystal display device of claim 4, wherein

the sensing electrode and the pixel electrode are in a same layer, and

a distance between the sensing electrode and the pixel electrode is larger than about 3 microns.

6. The liquid crystal display device of claim 2, further comprising a third thin film transistor comprising an input electrode connected to the output electrode of the second thin film transistor.

7. The liquid crystal display device of claim 2, further comprising a spacer propping the first substrate and the second substrate.

8. The liquid crystal display device of claim 2, wherein the pixel electrode comprises a transparent electrode and a reflective electrode having an opening exposing the second thin film transistor.