Integrated touch screens

• US 8,804,056 B2
• Filed: 12/22/2010
• Issued: 08/12/2014
• Est. Priority Date: 12/22/2010
• Status: Expired due to Fees

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chang, Shih Chang, Zhong, John Z.
• Primary Examiner(s): Vu, Phu
• Application Number:
  US12/976,997
• Publication Number:
  US 20120162584A1
• Time in Patent Office: 1,329 Days
• Field of Search: 349/12, 345/147
• US Class Current: 349/12
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G06F 1/16 Constructional details or arrangements
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04108 Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• 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

Abstract

Integrated touch screens are provided including drive lines formed of grouped-together circuit elements of a thin film transistor layer and sense lines formed between a color filter layer and a material layer that modifies or generates light. The common electrodes (Vcom) in the TFT layer can be grouped together during a touch sensing operation to form drive lines. Sense lines can be formed on an underside of a color filter glass, and a liquid crystal region can be disposed between the color filter glass and the TFT layer. Placing the sense lines on the underside of the color filter glass, i.e., within the display pixel cell, can provide a benefit of allowing the color filter glass to be thinned after the pixel cells have been assembled, for example.

Claims

1. A method of operating an touch screen including a plurality of circuit elements, dedicated sense lines disposed between a pixel material and a color filter layer, and drive lines disposed on a TFT substrate, the method comprising:

operating a first portion of a group of the circuit elements as display circuitry by applying preset voltages to common electrodes of the first portion of the group of circuit elements disposed on the TFT substrate in a first display operation that displays an image on the touch screen during a first time period; and

operating a second portion of the group of the circuit elements distinct from and non-overlapping with the first portion of the group of circuit elements, as touch sensing circuitry in a first touch sensing operation by

applying stimulation signals along the drive lines to common electrodes of the second portion of the group of circuit elements disposed on the TFT substrate during the first time period; and

transmitting sense signals along the dedicated sense lines disposed between the pixel material and the color filter layer to sense channels of the touch sensing circuitry during the first time period;

wherein operating the first group in the first display operation occurs concurrently with operating the second group in the first touch sensing operation.

2. The method of claim 1, further comprising:

operating the first portion of the group as touch sensing circuitry in a second touch sensing operation during a second time period different from the first time period.

3. The method of claim 2, further comprising:

operating a third portion of the group of circuit elements as display circuitry in a second display operation, wherein operating the third portion of the group in the second display operation occurs concurrently with operating the first group in the second touch sensing operation.

4. The method of claim 2, wherein the second touch sensing operation includes operating one or more additional portions of the groups of circuit elements as touch sensing circuitry concurrently with operating the first group.

5. The method of claim 1, wherein operating the second portion of the group of circuit elements as touch sensing circuitry in the first touch sensing operation includes providing at least one buffer region between the drive lines, the buffer region having common electrodes unconnected from the drive lines.

6. The method of claim 5, wherein the drive lines are disposed in sets of rows and the buffer region is disposed between a first and second set of the rows of drive lines.

7. The method of claim 1, wherein the first portion of the group of circuit elements includes a first row of the common electrodes, and operating the first portion of the group of circuit elements in the first display operation includes applying a first preset voltage to the first row of the common electrodes.

8. The method of claim 7, further comprising:

applying a second preset voltage to a second row of the common electrodes, the second preset voltage being an opposite polarity of the first preset voltage.

9. The method of claim 1, wherein the second portion of the group of circuit elements includes a plurality of rows of common electrodes.

10. The method of claim 9, wherein the plurality of rows of common electrodes are electrically connected through fixed conductive connections.