TOUCH-SENSOR-EMBEDDED DISPLAY PANEL, DISPLAY DEVICE PROVIDED THEREWITH, AND METHOD FOR DRIVING TOUCH-SENSOR-EMBEDDED DISPLAY PANEL

• US 20140327654A1
• Filed: 12/14/2012
• Published: 11/06/2014
• Est. Priority Date: 12/19/2011
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Sugita, Yasuhiro, Kida, Kazutoshi, Tanaka, Kohhei
• Granted Patent: US 9,513,753 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 3/042 by opto-electronic means
• 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: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

There is provided a touch-sensor-embedded display panel with reduced decrease in aperture ratio and reduced increase in frame area, with lowered power consumption and improved operation performance.

A driving pixel (21) is constituted by: a thin film transistor (T1); a pixel electrode (Epix1); a driving common electrode (COM1); and a liquid crystal capacitance (Clc1) which is formed between the pixel electrode (Epix1) and the driving common electrode (COM1). A sensing pixel (22) is constituted by a thin film transistor (T2), a pixel electrode (Epix2), a sensing common electrode (COM2), and a liquid crystal capacitance (Clc2) which is formed between the pixel electrode (Epix2) and the sensing common electrode (COM2). Neither the driving pixel (21) nor the sensing pixel (22) include an auxiliary capacitance. The thin film transistors (T1, T2) have their channel layers formed of IGZO.

Claims

1. A touch-sensor-embedded display panel comprising a plurality of pixel formation portions disposed correspondingly to a plurality of image signal lines and to a plurality of scanning signal lines formed on a first substrate, wherein

each pixel formation portion comprises:

a pixel switching element disposed on the first substrate and having a control terminal connected to a corresponding one of the scanning signal lines;

a pixel electrode disposed on the first substrate and connected to a corresponding one of the image signal lines via the pixel switching element;

common electrodes belonging to a first group or a second group and disposed on a second substrate opposed to the first substrate; and

a pixel capacitance formed between the pixel electrode and the common electrode as an only capacitance for holding a voltage which corresponds to a signal applied to the image signal lines;

wherein

the common electrodes belonging to the first group provide a plurality of driving lines which are driven by driving signals during a touch detection operation whereas

the common electrodes belonging to the second group provide a plurality of sensing lines crossing the driving lines, for receiving a signal responsive to the driving signal during the touch detection operation.

2. The touch-sensor-embedded display panel according to claim 1, wherein the pixel switching element is provided by a thin film transistor which has a channel layer formed of an oxide semiconductor.

3. The touch-sensor-embedded display panel according to claim 2, wherein the oxide semiconductor contains indium, gallium, zinc and oxygen as primary ingredients.

4. The touch-sensor-embedded display panel according to claim 1, wherein the liquid crystal display panel is of a non-IPS type.

5. The touch-sensor-embedded display panel according to claim 4, wherein the liquid crystal display panel is of a VA type.

6. The touch-sensor-embedded display panel according to claim 1, wherein each driving line is formed by an array of generally rectangular driving segments provided by part of the common electrodes belonging to the first group, arranged in a first direction and electrically connected to each other, whereas

each sensing line is formed by an array of generally rectangular sensing segments provided by part of the common electrodes belonging to the second group, arranged in a second direction and electrically connected to each other.

7. The touch-sensor-embedded display panel according to claim 6, wherein the driving segments which provide each driving line or the sensing segments which provide each sensing line are electrically connected to each other via a wiring provided near an edge of the second substrate.

8. The touch-sensor-embedded display panel according to claim 1, wherein each driving line is formed by an array of substantially diamond-shaped driving segments provided by part of the common electrodes belonging to the first group, arranged in a first direction and electrically connected to each other, whereas

each sensing line is formed by an array of substantially diamond-shaped sensing segments provided by part of the common electrodes belonging to the second group, arranged in a second direction and electrically connected to each other.

9. The touch-sensor-embedded display panel according to claim 8, wherein mutually adjacent ones of the driving segments which provide each driving line, or mutually adjacent ones of the sensing segments which provide each sensing line are electrically connected to each other via a wiring which is provided in a layer different from the layer provided with the driving segment and the sensing segment.

10. The touch-sensor-embedded display panel according to claim 1, wherein

each pixel formation portion includes:

a first sub-pixel formation portion which includes the pixel switching element, the pixel electrode, the common electrode and the pixel capacitance; and

a second sub-pixel formation portion which includes the pixel switching element, the pixel electrode, the common electrode, the pixel capacitance, a variation switching element having a control terminal connected to a scanning signal line which immediately follows the scanning signal line that corresponds to the pixel; and

a variation capacitance;

the variation switching element being between the pixel electrode and one end of the variation capacitance,

the variation capacitance having the other end being connected to an electrode which is provided with a predetermined fixed electric potential at least during the display operation.

11. The touch-sensor-embedded display panel according to claim 10, wherein the variation switching element is provided by a thin film transistor which has a channel layer formed of an oxide semiconductor.

12. The touch-sensor-embedded display panel according to claim 11, wherein the oxide semiconductor contains indium, gallium, zinc and oxygen as primary ingredients.

13. A touch-sensor-embedded display panel according to claim 1, wherein

a display control unit for controlling the pixel formation portions during a display operation;

and

a touch detection control unit for controlling the pixel formation portions during a touch detection operation.

14. The display device according to claim 13, wherein the touch detection control unit drives a predetermined number not smaller than two of the driving lines simultaneously.

15. A method for driving a touch-sensor-embedded display panel which includes a plurality of pixel formation portions disposed correspondingly to a plurality of image signal lines and a plurality of scanning signal lines formed on a first substrate, the method comprising the steps of:

driving a plurality of driving lines which are provided by common electrodes belonging to a first group and formed on a second substrate which is opposed to the first substrate, by means of driving signal during a touch detection operation; and

receiving a signal responsive to the driving signal from a plurality of sensing lines which cross the driving lines and are provided by common electrodes belonging to a second group and formed on the second substrate, during the touch detection operation;

wherein

each pixel formation portion includes;

a pixel switching element disposed on the first substrate and having a control terminal connected to a corresponding one of the scanning signal lines;

a pixel electrode disposed on the first substrate and connected to a corresponding one of the image signal lines via the pixel switching element;

the common electrodes; and

a pixel capacitance formed between the pixel electrode and the common electrode as an only capacitance for holding a voltage which corresponds to a signal applied to the image signal lines.

16. The driving method according to claim 15, wherein a predetermined number not smaller than two of the driving lines are simultaneously driven in the step of driving the driving lines.