Touch sensitive LCD panel

• US 8,547,345 B2
• Filed: 05/04/2009
• Issued: 10/01/2013
• Est. Priority Date: 05/04/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Whitted, J. Turner
• Primary Examiner(s): Nguyen, Kevin M
• Assistant Examiner(s): Lee, Jr., Kenneth B
• Application Number:
  US12/434,689
• Publication Number:
  US 20100277423A1
• Time in Patent Office: 1,611 Days
• Field of Search: 345156-182
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• 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 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/047 using sets of wires, e.g. crossed wires

Abstract

Described herein is a liquid crystal display apparatus that includes a liquid crystal display panel. The liquid crystal display panel includes a receiver component that receives a sensed parameter of a column line in the liquid crystal display apparatus, wherein electrical voltage is transmitted along the column line and directed at a particular sub-pixel. An output component outputs an indication that a member is in physical contact with the display panel based at least in part upon the received sensed parameter of the column line.

Claims

1. A liquid crystal display apparatus that includes a liquid crystal display panel, comprising:

a column driver that transmits electrical voltage along a column line in the liquid crystal display apparatus directed at a particular sub-pixel, wherein the column driver is configured to output at least two successive voltage spikes of opposing polarities and a charging pulse on the column line directed to the particular sub-pixel;

a sensor that is positioned electrically in parallel with the column line or in series with the column line that is configured to sense a sensed parameter when the column driver outputs the at least two successive voltage spikes on the column line;

a receiver component that receives the sensed parameter of the column line; and

an output component that outputs an indication that a member is in physical contact with the display panel based at least in part upon the received sensed parameter of the column line, wherein the sensed parameter of the column line corresponds to capacitance between conducting layers of the display panel at the particular sub-pixel, wherein a liquid crystal element is between the conducting layers of the display panel at the particular sub-pixel, and wherein the member being in physical contact with the display panel at a location corresponding to the particular sub-pixel alters the capacitance between the conducting layers of the display panel at the particular sub-pixel.

2. The liquid crystal display apparatus of claim 1, wherein the sensed parameter is current on the column line when the particular sub-pixel is addressed.

3. The liquid crystal display apparatus of claim 1, wherein the sensed parameter is impedance of the column line when the particular sub-pixel is addressed.

4. The liquid crystal display apparatus of claim 1, wherein the sensed parameter is reflected voltage on the column line when the particular sub-pixel is addressed.

5. The liquid crystal display apparatus of claim 1 being a television.

6. The liquid crystal display apparatus of claim 1 being a computer.

7. The liquid crystal display apparatus of claim 1, further comprising a calibration component that is configured to generate a table of observed parameters on the column line for different voltages applied to various sub-pixels, wherein the output component outputs the indication that the member is in physical contact with the display panel based at least in part upon an analysis of the table of observed parameters with respect to the received sensed parameter of the column line.

8. The liquid crystal display apparatus of claim 1, wherein the receiver component receives sensed parameters with respect to multiple column lines, and wherein the output component outputs an indication that multiple members are simultaneously in contact with the display panel at different locations on the display panel.

9. The liquid crystal display apparatus of claim 1, wherein each column line in the display panel has a sensor corresponding thereto that is configured to sense a parameter corresponding to the column lines during operation of the liquid crystal display apparatus.

10. The liquid crystal display apparatus of claim 1, further comprising:

a labeler component that labels certain sub-pixels as being contacted by a member and creates a matrix that is indicative of which sub-pixels are contacted by the member; and

a centroid determiner component that determines a centroid in the matrix of sub-pixels that are found to be contacted by the member.

11. The liquid crystal display apparatus of claim 10, further comprising an interface component that causes an interaction to occur on the liquid crystal display panel based at least in part upon a location of the centroid in the matrix.

18. The liquid crystal display apparatus of claim 1, wherein the at least two electrical voltage spikes of opposing polarities precede the charging pulse in a given frame.

19. The liquid crystal display apparatus of claim 1, wherein an emitted color at the sub-pixel is based on voltage of the charging pulse.

20. The liquid crystal display apparatus of claim 1, wherein the at least two successive voltage spikes of opposing polarities have fixed voltages.

12. A method comprising the following computer-executable acts:

configuring a column driver in a liquid crystal display panel to output at least two electrical voltage spikes of opposing polarity and a charging pulse on a column line for each frame, wherein the column line provides current to a sub-pixel in the liquid crystal display panel, wherein the at least two electrical voltage spikes of opposing polarities precede the charging pulse in each frame, and wherein an emitted color at the sub-pixel is based on voltage of the charging pulse;

configuring a sensor in a liquid crystal display panel to output a parameter with respect to the column line, wherein the sensor is configured to output the parameter with respect to the at least two electrical voltage spikes of opposing polarities; and

configuring a processor that corresponds to the liquid crystal display panel to determine that a member is in physical contact with the liquid crystal display panel at a particular position on the liquid crystal display panel corresponding to the sub-pixel based at least in part upon the parameter output by the sensor, wherein the parameter output by the sensor corresponds to capacitance between conducting layers of the liquid crystal display panel at the sub-pixel corresponding to the particular position, wherein a liquid crystal element is between the conducting layers of the liquid crystal display panel at the sub-pixel, and wherein the member being in physical contact with the liquid crystal display panel at the particular position alters the capacitance between the conducting layers of the liquid crystal display panel at the sub-pixel.

13. The method of claim 12, wherein the parameter is current on the column line.

14. The method of claim 12, wherein the parameter is impedance of the column line.

15. The method of claim 12, further comprising configuring the processor to detect that multiple members are in simultaneous contact with the liquid crystal display panel at different locations thereon.

16. The method of claim 12, further comprising:

configuring the processor to analyze the parameter output by the sensor with an expected value; and

determining that the member is in physical contact with the liquid crystal display based at least in part upon the analysis.

17. A liquid crystal display panel, comprising:

a plurality of liquid crystal elements between conducting layers;

a plurality of column lines that are configured to provide electrical charge to the plurality of liquid crystal elements;

a column driver that is configured to selectively control an amount of electrical charge to be provided to each of the plurality of liquid crystal elements by way of the corresponding plurality of column lines, wherein the column driver is additionally configured to control timing with respect to providing electrical charges to each of the plurality of liquid crystal elements by way of the column line, and wherein the column driver is configured to cause successive voltage spikes of opposing polarities and a charging pulse to be transmitted on each of the plurality of column lines during a frame; and

a plurality of sensors that are positioned electrically in parallel with the plurality of column lines, such that each of the plurality of column lines has a sensor in parallel thereto, wherein each of the plurality of sensors is configured to detect voltage on the column line and output a value indicative of capacitance between the conducting layers.