DISPLAY DEVICE AND DISPLAY METHOD

• US 20170269773A1
• Filed: 03/10/2017
• Published: 09/21/2017
• Est. Priority Date: 03/15/2016
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: SUZUKI, Takafumi
• Granted Patent: US 10,318,054 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• 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 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

A display device includes: a display section having a screen and a first electrode section provided at a first position in a thickness direction; a second electrode section provided at a second position in the thickness direction; a gap section which is provided between the first electrode section and the second electrode section and is deformable in the thickness direction when the screen is pressed; and a circuit section which is connected to the first electrode section and the second electrode section, displays to the screen, and detects a press onto the screen, and a capacitance value of a first capacitance between the first electrode section and the second electrode section is changeable due to deformation of the gap section. In a force period, the circuit section applies a sensor driving signal to the second electrode section, and detects a sensor detection signal based on the sensor driving signal through the first capacitance.

Claims

1. A display device comprising:

a display section including a screen and a first electrode section which is provided at a first position in a thickness direction intersecting the screen so as to face the screen;

a second electrode section which is provided at a second position farther away from the screen than the first electrode section in the thickness direction so as to face the first electrode section and face the screen through the first electrode section;

a gap section which is provided between the first electrode section and the second electrode section and is deformable in the thickness direction when the screen is pressed; and

a circuit section which is connected to the first electrode section and the second electrode section, displays to the screen, and detects a press onto the screen,

wherein a capacitance value of a first capacitance between the first electrode section and the second electrode section is changeable due to deformation of the gap section, and

the circuit section applies a sensor driving signal to the second electrode section, and detects a sensor detection signal based on the sensor driving signal through the first capacitance.

2. The display device according to claim 1,

wherein the circuit section calculates a pressing force corresponding to a state of the press onto the screen based on the change of the first capacitance and outputs a force sensing signal including the pressing force.

3. The display device according to claim 1,

wherein the circuit section applies a touch driving signal to the first electrode section, detects a change of a second capacitance between the first electrode section and an external object touching the screen, calculates presence or absence of the touch and coordinates of a touch position corresponding to a state of the touch based on the change of the second capacitance, and outputs a touch sensing signal including the presence or absence of the touch and the coordinates of the touch position.

4. The display device according to claim 1,

wherein the first electrode section has a plurality of first electrodes, and the plurality of first electrodes are arranged in a matrix on a plane at the first position.

5. The display device according to claim 4,

wherein the plurality of first electrodes are arranged side by side in a first direction parallel to the screen and a second direction intersecting the first direction, and a distance of a gap between the two adjacent first electrodes is not more than a width of each of pixels in the display section or a distance of an arrangement pitch of the pixels.

6. The display device according to claim 1,

wherein a force period in which the press is sensed is provided, and

the circuit section supplies the sensor driving signal to the second electrode section and receives the sensor detection signal from the first electrode section in the force period.

7. The display device according to claim 3,

wherein a touch period in which the touch is sensed is provided, and

the circuit section applies the touch driving signal to the first electrode section and detects the touch signal from the first electrode section in the touch period.

8. The display device according to claim 3,

wherein a time-division period includes a touch period in which the touch is sensed and a force period in which the press is sensed, and

the circuit section applies the touch driving signal to the first electrode section and detects the touch signal from the first electrode section in the touch period, and supplies the sensor driving signal to the second electrode section and receives the sensor detection signal from the first electrode section in the force period.

9. The display device according to claim 7,

wherein the circuit section applies a periodic signal as the touch driving signal to the first electrode section and applies a periodic signal having the same phase as that of the touch driving signal to the second electrode section in the touch period.

10. The display device according to claim 8,

wherein a display period in which display is performed on the screen is provided,

a sensing period in which the touch is sensed and the display period are alternately provided in the touch period, and

a sensing period in which the press is sensed and the display period are alternately provided in the force period.

11. The display device according to claim 1, further comprising:

a backlight section which supplies light to the display section,

wherein the second position is on a lower surface of the back light section located farther from the first position or on an upper surface of the backlight section located closer to the first position.

12. The display device according to claim 1, further comprising:

a housing which stores the display section and the second electrode section,

wherein the second position is on an inner surface of the housing.

13. The display device according to claim 1,

wherein the gap section is formed as a hollow layer.

14. The display device according to claim 1,

wherein the gap section has an elastic layer.

15. The display device according to claim 1,

wherein the first electrode section has a plurality of first electrodes, and includes a plurality of first electrode blocks constituted of some of the plurality of first electrodes,

the circuit section includes a plurality of detectors provided to correspond to the plurality of first electrode blocks, and

each of the plurality of detectors sequentially receives the sensor detection signals from each of some of the first electrodes in the connected first electrode block.

16. The display device according to claim 1,

wherein the first electrode section has a plurality of first electrodes, and includes a plurality of first electrode blocks constituted of some of the plurality of first electrodes,

the circuit section includes a plurality of detectors provided to correspond to the plurality of first electrode blocks, and

each of the plurality of detectors simultaneously receives the sensor detection signals from some of the first electrodes in the connected first electrode block as one signal.

17. The display device according to claim 1,

wherein the display section includes a pixel electrode provided for each of pixels in the screen, a scanning line for selecting the pixel, and a signal line for controlling a state of display of the pixel, and

the circuit section applies a scanning signal to the scanning line, applies a display signal to the signal line, and applies a common voltage signal to the first electrode section when display is performed on the screen.

18. A display method for performing force sensing and touch sensing on a screen of a display device,

wherein a time-division period includes a touch period in which the touch sensing is performed and a force period in which the force sensing is performed,

the display device includes:

a display section including a screen and a first electrode section which is provided at a first position in a thickness direction intersecting the screen so as to face the screen;

a second electrode section which is provided at a second position farther away from the screen than the first electrode section in the thickness direction so as to face the first electrode section and face the screen through the first electrode section;

a gap section which is provided between the first electrode section and the second electrode section and is deformable in the thickness direction when the screen is pressed; and

a circuit section which is connected to the first electrode section and the second electrode section, displays to the screen, and detects a press onto the screen,

a capacitance value of a first capacitance between the first electrode section and the second electrode section is changeable due to deformation of the gap section, and

steps for controlling the first electrode section and the second electrode section by the circuit section includes;

a first step in which the circuit section applies a sensor driving signal to the second electrode section, and detects a sensor detection signal based on the sensor driving signal through the first capacitance; and

a second step in which the circuit section applies a touch driving signal to the first electrode section, detects a change of a second capacitance between the first electrode section and an external object touching the screen, calculates presence or absence of the touch and coordinates of a touch position corresponding to a state of the touch based on the change of the second capacitance, and outputs a touch sensing signal including the presence or absence of the touch and the coordinates of the touch position.

19. The display method according to claim 18,

wherein the circuit section calculates a pressing force corresponding to a state of the press onto the screen based on the change of the first capacitance and outputs a force sensing signal including the pressing force in the first step.

20. The display method according to claim 18,

wherein a display period in which display is performed on the screen is provided,

a sensing period in which the touch is sensed as the second step and the display period are alternately provided in the touch period, and

a sensing period in which the press is sensed as the first step and the display period are alternately provided in the force period.