TOUCH SCREEN LIQUID CRYSTAL DISPLAY

• US 20120268423A1
• Filed: 06/29/2012
• Published: 10/25/2012
• Est. Priority Date: 06/09/2006
• Status: Active Grant

• Current Assignee: Andrew Bert Hodge, Brian Richards Land, Christoph Horst Krah, John Greer Elias, John Z. Zhong, Steve Porter Hotelling, Wei Chen, Wei Hsin Yao, Willem Den Boer
• Original Assignee: Andrew Bert Hodge, Brian Richards Land, Christoph Horst Krah, John Greer Elias, John Z. Zhong, Steve Porter Hotelling, Wei Chen, Wei Hsin Yao, Willem Den Boer
• Inventors: HOTELLING, Steve Porter, Chen, Wei, Krah, Christoph Horst, Elias, John Greer, Yao, Wei Hsin, Zhong, John Z., Hodge, Andrew Bert, Land, Brian Richards, Boer, Willem Den
• Granted Patent: US 8,432,371 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0444 using a single conductive element covering the whole sensing surface, e.g. by sensing the electrical current flowing at the corners
• 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: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0439 Pixel structures
• CPC Class Codes: G09G 2300/0478 related to liquid crystal pixels
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Disclosed herein are liquid-crystal display (LCD) touch screens that integrate the touch sensing elements with the display circuitry. The integration may take a variety of forms. Touch sensing elements can be completely implemented within the LCD stackup but outside the not between the color filter plate and the array plate. Alternatively, some touch sensing elements can be between the color filter and array plates with other touch sensing elements not between the plates. In another alternative, all touch sensing elements can be between the color filter and array plates. The latter alternative can include both conventional and in-plane-switching (IPS) LCDs. In some forms, one or more display structures can also have a touch sensing function. Techniques for manufacturing and operating such displays, as well as various devices embodying such displays are also disclosed.

Claims

1. An integrated device including a liquid crystal display and a touch screen, comprising:

a first polarizer;

a second polarizer;

a first substrate having display control circuitry formed thereon, the first substrate being disposed between the first polarizer and the second polarizer;

a second substrate disposed between the first polarizer and the second polarizer;

a liquid crystal layer disposed between the first and second substrates;

a plurality of touch drive electrodes and a plurality of touch sense electrodes disposed between the first and second substrates an operative as a touch sensor during a touch mode of operation;

a counter electrode segmented to form the plurality of touch sense electrodes, the counter electrode operating as a Vcom electrode during a display mode of operations and operating as the plurality of touch sense electrodes during the touch mode of operation; and

display select lines configured to act as the plurality of touch drive electrodes, the display select lines forming part of the display control circuitry formed on the first substrate.

2. The device of claim 1, wherein the counter electrode is disposed between the liquid crystal layer and the second substrate.

3. The device of claim 1, wherein a color filter is disposed between the second substrate and the liquid crystal layer.

4. The device of claim 1, wherein a color filter is disposed between the second substrate and the liquid crystal layer, and the counter electrode is disposed between the color filter and the liquid crystal layer.

5. The device of claim 4, further comprising at least one capacitance sensing circuit operatively coupled to the plurality of touch sense electrodes during the touch mode of operation.

6. The device of claim 1, further comprising at least one capacitance sensing circuit operatively coupled to the plurality of touch sense electrodes during the touch mode of operation.

7. The device of claim 1, wherein the display select lines comprises gate lines.

8. The device of claim 7, wherein the gate lines provide gate signals to TFT controlling the liquid crystal display.

9. The device of claim 1, wherein each of the plurality of touch sense electrodes covers a plurality of display pixels.

10. The device of claim 1, wherein the capacitance sensing circuit comprises a virtual charge amplifier.

11. The device of claim 1, wherein each of the plurality of touch sense electrodes has a window disposed above a display select lines.

12. The device of claim 1, wherein the device is incorporated into an electronic device comprising at least one of a handheld computer, a personal digital assistant, a media player, a mobile telephone, a desktop computer, a tablet computer and a notebook computer.