Display, touch panel and electronic device

• US 8,860,687 B2
• Filed: 02/08/2010
• Issued: 10/14/2014
• Est. Priority Date: 02/27/2009
• Status: Expired due to Fees

• Current Assignee: Japan Display West Incorporated (Japan Display Incorporated)
• Original Assignee: Japan Display Incorporated
• Inventors: Mizuhashi, Hiroshi, Takahashi, Yasuo
• Primary Examiner(s): Leiby, Christopher E
• Application Number:
  US12/988,586
• Publication Number:
  US 20110043483A1
• Time in Patent Office: 1,709 Days
• Field of Search: 345173-178, 715/700, 715/863
• US Class Current: 345/174
• CPC Class Codes: G02F 1/13456 Cell terminals located on one side of the display only
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3262 Power saving in digitizer or tablet
• CPC Class Codes: G06F 2203/04101 2.5D-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 and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup
• CPC Class Codes: G06F 3/042 by opto-electronic means
• 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

A display with a touch panel allowed to achieve high response performance while reducing power consumption is obtained. The display includes a plurality of display elements performing display based on picture signals supplied to a plurality of picture signal lines, respectively, a plurality of sensor elements outputting touch signals indicating detection of an external proximity object to a plurality of sensor signal lines (SGL), respectively, a detection section (a comparator 331) detecting each of the touch signals, a transfer output section (a D-type flip-flop 332 and an output buffer circuit 36) transferring and outputting a detection result of the detection section to outside, and a control section (a transistor switch SCW, a transfer clock control circuit 37 and a timing generator 35) controlling operations of the detection section and the transfer output section, allowing the transfer output section to operate in a case where the touch signal is detected in the detection section, and suspending an operation of the transfer output section in a case where the touch signal is not detected.

Claims

1. A display comprising:

a plurality of display elements performing display based on picture signals supplied to a plurality of picture signal lines, respectively;

a plurality of sensor elements outputting touch signals indicating detection of an external proximity object to a plurality of sensor signal lines, respectively;

a plurality of detection sections, each detecting a touch signal from the corresponding sensor signal line;

a transfer output section transferring and outputting a detection result of the detection section to outside; and

a control section controlling operations of the detection section and the transfer output section, allowing the transfer output section to operate in a case where the touch signal is detected in any of the detection sections, and suspending an operation of the transfer output section in a case where the touch signal is not detected,

wherein the transfer output section includes a shift register having a plurality of flip-flops each holding and outputting an output value of the corresponding detection section, the shift register performing a parallel-serial conversion of the detection result by using the flip-flops, and

the control section includes a plurality of switches, each of which independently connects an enabling voltage to a transfer clock control circuit for allowing the shift-register to perform the parallel-serial conversion, depending upon the output value output from the corresponding flip-flop for each of the switches.

2. The display according to claim 1, wherein

the detection section divides a whole touch detection region where the plurality of sensor elements are arranged into a plurality of regions, and sequentially detects the touch signal from one of the regions to another in a time-divisional manner, and

the control section suspends the operation of the transfer output section in a period corresponding to a region, where the touch signal is not detected, in the plurality of regions.

3. The display according to claim 2, wherein

the plurality of sensor elements are arranged in a matrix form in a horizontal direction and a vertical direction in the touch detection region, and the region includes a plurality of sensor elements arranged in the horizontal direction.

4. The display according to claim 1, wherein

the control section suspends a part of a detection operation of the detection section as well when the touch signal is not detected in the detection section for a predetermined period.

5. The display according to claim 1, wherein

the detection section detects each of the touch signals through sampling with a predetermined frequency, and

the control section reduces an operation frequency in the detection section and the transfer output section when the touch signal is not detected in the detection section for a predetermined period.

6. The display according to claim 5, wherein the control section counts number of frames for the display, and reduces an operation frequency in the detection section and the transfer output section when the touch signal is not detected in the detection section for a period of one or more frames, and when the touch signal is detected after that, the control section resets a number count value in a count operation and puts the reduced operation frequency back to original operation frequency.

7. The display according to claim 6, wherein the control section shifts to a first operation mode in a case where the touch signal is not detected in the detection section in a period of one or more frames, and the control section shifts to a second operation mode in a case where the touch signal is detected thereafter, the first operation mode allowing the detection section and the transfer output section to operate at every predetermined number of frames, the second operation mode allowing the detection section and the transfer output section to operate at every frame.

8. The display according to claim 1, wherein

the sensor signal lines are used as the picture signal lines, as well,

the display includes an initialization section simultaneously applying an initialization signal to all of the plurality of sensor signal lines in an initialization period, and

the detection section detects the touch signal in a period other than a picture signal application period, where the picture signals are applied to the sensor signal lines, in a period following the initialization period.

9. The display according to claim 8, wherein

the control section includes:

a control signal generation section generating an activation signal when the touch signal is detected in the detection section and generating a stop signal when an initialization signal by the initialization section is applied, and an operation signal control section controlling the generation of a transfer clock signal to be supplied to the transfer output section and a detection activation signal to be supplied to the detection section in response to the activation signal and the stop signal, and further wherein the initialization signal that is supplied by the initialization section is applied in every initialization period with a predetermined interval.

10. The display according to claim 8, wherein

a DC signal having a constantly fixed voltage level is used as the initialization signal.

11. The display according to claim 8, wherein

the display element is a liquid crystal display element including:

a pixel electrode to which the picture signal is supplied,

a drive electrode to which a common signal is supplied, the common signal being commonly supplied to the plurality of display elements, and

a liquid crystal layer driven in response to a potential difference between a voltage of the pixel electrode and a voltage of the drive electrode,

the sensor element is a contact type sensor element configured of the pixel electrode and the drive electrode, and

the detection section detects a voltage change as the touch signal in the sensor signal line occurring when the pixel electrode and the drive electrode comes close to or in contact with each other by being pressed by an external proximity object.

12. The display according to claim 11, wherein

the liquid crystal display element is driven in a manner of a polarity inversion drive where the polarity of the potential difference is inverted at every predetermined period,

a signal based on the common signal having potential which changing at every predetermined period above-mentioned is used as the initialization signal, and

a logic gate circuit is inserted between the detection section and the control signal generation section, the logic gate circuit generating an effective logic of a detection result of the detection section based on the initialization signal and outputting the effective logic to the control signal generation section.

13. The display according to claim 1, wherein

the sensor element is a capacitive type sensor element including an electrode which forms a capacitance and outputting a signal to the sensor signal line based on the capacitance which changes depending on an external proximity object.

14. The display according to claim 1, wherein

the sensor element is an optical type sensor element including a photosensitive element which detects light and outputs a signal according to an amount of the light, and outputting a signal to the sensor signal line based on an output signal from the photosensitive element, the output signal changing depending on an external proximity object.

15. The display according to claim 1, wherein

the display element is an EL display element.

16. A touch panel comprising:

a plurality of sensor elements outputting touch signals indicating detection of an external proximity object to a plurality of sensor signal lines, respectively;

a plurality of detection sections each detecting a touch signal from the corresponding sensor line;

a transfer output section transferring and outputting a detection result of the detection section to outside; and

a control section controlling operations of the detection section and the transfer output section, allowing the transfer output section to operate in a case where the touch signal is detected in any of the detection sections, and suspending an operation of the transfer output section in a case where the touch signal is not detected,

wherein the transfer output section includes a shift register having a plurality of flip-flops each holding and outputting an output value of the corresponding detection section, the shift register performing a parallel-serial conversion of the detection result by using the flip-flops, and

the control section includes a plurality of switches, each of which independently connects an enabling voltage to a transfer clock control circuit for allowing the shift-register to perform the parallel-serial conversion, depending upon the output value output from the corresponding flip-flop for each of the switches.

17. The display according to claim 16, wherein

the transfer output section converts the detection result of the detection section from parallel data to serial data, and transfers and outputs the detection result.

18. An electronic device comprising:

a display having a touch sensor function of detecting an external proximity object; and

a processing section performing a predetermined process based on information inputted by the touch sensor function,

wherein the display includes;

a plurality of display elements performing display based on picture signals supplied to a plurality of picture signal lines, respectively,

a plurality of sensor elements outputting touch signals indicating detection of an external proximity object to a plurality of sensor signal lines, respectively,

a plurality of detection sections each detecting a touch signal from the corresponding sensor signal line,

a transfer output section transferring and outputting a detection result of the detection section to outside, and

a control section controlling operations of the detection section and the transfer output section, allowing the transfer output section to operate in a case where the touch signal is detected in any of the detection sections, and suspending an operation of the transfer output section in a case where the touch signal is not detected,

wherein the transfer output section includes a shift register having a plurality of flip-flops each holding and outputting an output value of the corresponding detection section, the shift register performing a parallel-serial conversion of the detection result by using the flip-flops, and

the control section includes a plurality of switches, each of which independently connects an enabling voltage to a transfer clock control circuit for allowing the shift-register to perform the parallel-serial conversion, depending upon the output value output from the corresponding flip-flop for each of the switches.

19. An electronic device comprising;

a touch panel detecting an external proximity object; and

a processing section performing a predetermined process based on information inputted by the touch panel,

wherein the touch panel includes;

a plurality of sensor elements outputting touch signals indicating detection of an external proximity object to a plurality of sensor signal lines, respectively,

a plurality of detection sections each detecting a touch signal from the corresponding sensor signal line,

a transfer output section transferring and outputting a detection result of the detection section to outside, and

a control section controlling operations of the detection section and the transfer output section, allowing the transfer output section to operate in a case where the touch signal is detected in any of the detection sections, and suspending an operation of the transfer output section in a case where the touch signal is not detected,

wherein the transfer output section includes a shift register having a plurality of flip-flops each holding and outputting an output value of the corresponding detection section, the shift register performing a parallel-serial conversion of the detection result by using the flip-flops, and

the control section includes a plurality of switches, each of which independently connects an enabling voltage to a transfer clock control circuit for allowing the shift-register to perform the parallel-serial conversion, depending upon the output value output from the corresponding flip-flop for each of the switches.