IN-CELL MULTI-TOUCH DISPLAY PANEL SYSTEM

• US 20130285952A1
• Filed: 04/12/2013
• Published: 10/31/2013
• Est. Priority Date: 04/27/2012
• Status: Active Grant

• Current Assignee: FocalTech Systems Co.,Ltd
• Original Assignee: Orise Technology Co., Ltd (FocalTech Systems Co.,Ltd)
• Inventors: HUANG, Yen-Lin, HUANG, Chien-Ying
• Granted Patent: US 9,601,067 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• 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 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 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

An in-cell multi-touch display panel system includes a touch LCD panel and a touch display control subsystem. The touch LCD panel has a TFT layer, a conductive electrode layer, and a common-voltage and touch-driving layer. The TFT layer has K gate driving lines and L source driving lines for a display operation. The conductive electrode layer has M first conduct lines for a touch detection operation by sampling a touch detection result from the M first conduct lines. The common-voltage and touch-driving layer has N second conduct lines for receiving a common voltage signal in display and receiving a touch-driving signal in touch detection. The K gate driving lines are divided into N groups respectively corresponding to the N second conduct line. When one group of gate driving lines has the display driving signal, the corresponding second conduct line is connected to the common voltage signal.

Claims

1. An in-cell multi-touch display panel system, comprising:

a touch liquid crystal display (LCD) panel, including;

a thin film transistor (TFT) layer, having K gate driving lines in a second direction and L source driving lines in a first direction, for driving corresponding transistors and capacitors based on a display pixel signal and a display driving signal in display, where K and L are each a positive integer;

a conductive electrode layer, having M first conduct lines in the first direction for detecting an external object based on a touch driving signal, where M is a positive integer; and

a common-voltage and touch-driving layer, having N second conduct lines in the second direction, for receiving a common voltage signal in display and receiving a touch-driving signal in touch detection, where N is the positive integer and K>

N; and

a touch display control subsystem, connected to the TFT layer, the conductive electrode layer, and the common-voltage and touch-driving layer, to provide the display driving signal sequentially to the K gate driving lines and turn on the corresponding transistors for providing the display pixel signal to the L source driving lines in display, and provide the touch driving signal to the N second conduct lines and sample touch voltages from the M first conduct lines for detecting if there is the external object or not;

wherein the K gate driving lines are divided into N groups each corresponding to one of the N second conduct lines, such that the second conduct line corresponding to one group of gate driving lines is connected to the common voltage signal when the group of gate driving lines has the display driving signal, and the touch display control subsystem determines whether the display driving signal is provided to an i-th second conduct line at the same time when the touch display control subsystem provides the touch driving signal to the i-th second conduct line, and provides the touch driving signal to the i-th second conduct line when the display driving signal is not provided to the i-th second conduct line at the same time, where i is an index.

2. The in-cell multi-touch display panel system as claimed in claim 1, wherein the touch display control subsystem provides the touch driving signal to an (i−

1)-th second conduct line when the display driving signal is provided to an i-th group of gate driving lines.

3. The in-cell multi-touch display panel system as claimed in claim 2, wherein when the display driving signal is provided to the first group of gate driving lines, the touch display control subsystem provides the common voltage signal to the N second conduct lines for connecting the N second conduct lines to the common voltage signal.

4. The in-cell multi-touch display panel system as claimed in claim 3, wherein the touch display control subsystem provides the touch driving signal to the N-th second conduct lines after the display driving signal is provided to the N-th group of gate driving lines.

5. The in-cell multi-touch display panel system as claimed in claim 1, wherein the touch display control subsystem is based on a predetermined time to provide the display driving signal to the N groups of gate driving lines and provide the touch driving signal to the N second conduct lines simultaneously.

6. The in-cell multi-touch display panel system as claimed in claim 5, wherein the touch display control subsystem provides the display driving signal sequentially to the first to N-th groups of gate driving lines in the predetermined time.

7. The in-cell multi-touch display panel system as claimed in claim 6, wherein the touch display control subsystem provides the touch driving signal sequentially to the 2-th to N-th second conduct lines and the first second conduct line in the predetermined time.

8. The in-cell multi-touch display panel system as claimed in claim 5, wherein the touch display control subsystem non-sequentially provides the touch driving signal to an i-th second conduct line.

9. The in-cell multi-touch display panel system as claimed in claim 1, wherein the first direction and the second direction are vertical each other.

10. The in-cell multi-touch display panel system as claimed in claim 5, wherein the touch display control subsystem comprises:

a source driver, connected to the touch LCD panel, for driving the touch LCD panel based on the display pixel signal;

a gate driver, connected to the touch LCD panel, for generating the display driving signal to drive the touch LCD panel;

a sensor, connected to the touch LCD panel, for detecting a signal of the touch LCD panel;

a touch driving signal generator, for generating the touch driving signal;

a common-voltage generator, for generating the common voltage signal;

a switch connected to the touch LCD panel, the touch driving signal generator, and the common voltage generator; and

a control device, connected to the source driver, the gate driver, the common voltage generator, the sensor, the touch driving signal generator, and the switch, for configuring the switch to provide the touch driving signal or the common voltage signal to the N second conduct lines, configuring the gate driver to sequentially output the display driving signal to the K gate driving lines, and configuring the source driver to output the display pixel signal to the L source driving lines.

11. The in-cell multi-touch display panel system as claimed in claim 10, wherein the control device comprises:

a display clock controller, connected to the source driver, the gate driver, and the common voltage generator, for providing a timing of the display pixel signal outputted by the source driver, a timing of the display driving signal outputted by the gate driver, and a timing of the common voltage signal generated by the common voltage generator; and

a touch clock controller, connected to the display clock controller, the sensor, the touch driving signal generator, and the switch, for configuring the switch to provide the touch driving signal and the common voltage signal to the N second conduct lines.

12. The in-cell multi-touch display panel system as claimed in claim 11, wherein the M first conduct lines and the N second conduct lines respectively have parasitic and stray capacitance, and there is a mutual capacitance formed respectively in overlaps between the M first conduct lines and the N second conduct lines.

13. The in-cell multi-touch display panel system as claimed in claim 12, wherein the sensor comprises M sensing circuits for detecting the mutual capacitance and further generating corresponding M detection signals.

14. The in-cell multi-touch display panel system as claimed in claim 13, wherein the touch display control subsystem further comprises:

a programmable gain amplifier, connected to the sensor, for amplifying the M detection signals to generate M amplified detection signals;

an analog-to-digital converter (ADC), connected to the programmable gain amplifier, for converting the M amplified detection signals into M digital detection signals; and

a coordinate decision device, connected to the ADC, for determining a coordinate of the approached external object based on the M digital detection signals.

15. The in-cell multi-touch display panel system as claimed in claim 13, wherein each of the M sensing circuits consists of an operational amplifier (OA) and a feedback capacitor, the feedback capacitor has one end connected to an inverting input terminal of the OA and the other end connected to an output terminal of the OA, the inverting input terminal of the OA is connected to one of the M first conduct lines, and the non-inverting input terminal of the OA is connected to the common voltage signal.