DISPLAY APPARATUS AND DRIVING METHOD THEREOF

• US 20170199616A1
• Filed: 08/15/2016
• Published: 07/13/2017
• Est. Priority Date: 01/08/2016
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Group)
• Original Assignee: Samsung Display Company Limited (Samsung Group)
• Inventors: KIM, BEOMSHIK, RYU, DOHYUNG, LEE, JONGSEO
• Granted Patent: US 10,001,873 B2
• Time in Patent Office: Days
• 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 3/04146 using pressure sensitive conductive elements delivering a boolean signal and located between crossing sensing lines, e.g. located between X and Y sensing line layers
• 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: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0852 being a dynamic memory with more than one capacitor
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2310/0218 with collection of electrodes in groups for n-dimensional addressing
• CPC Class Codes: G09G 2310/0245 Clearing or presetting the whole screen independently of waveforms, e.g. on power-on G09G2310/063 takes precedence
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes

Abstract

A display apparatus and driving method are provided. The display apparatus, which operates in a display mode or a sensing mode, includes: a first signal line configured to apply a first driving signal to a pixel circuit during the display mode and to apply a sensing input signal to the pixel circuit during the sensing mode; a second signal line configured to apply a second driving signal to the pixel circuit during the display mode and to transfer a sensing output signal from the pixel circuit during the sensing mode; and a pixel including the pixel circuit, wherein a first current path for image display is formed in the pixel circuit during the display mode, and a second current path, configured to measure a resistance of a pressure resistance layer between the first signal line and the second signal line, is formed in the pixel circuit during the sensing mode.

Claims

1. A display apparatus operating in a display mode or a sensing mode, the apparatus comprising:

a first signal line configured to apply a first driving signal to a pixel circuit during the display mode and to apply a sensing input signal to the pixel circuit during the sensing mode;

a second signal line configured to apply a second driving signal to the pixel circuit during the display mode and to transmit a sensing output signal generated from the pixel circuit during the sensing mode; and

a pixel comprising the pixel circuit, wherein a first current path for image display is formed in the pixel circuit during the display mode, and a second current path, configured to measure a resistance of a pressure resistance layer between the first signal line and the second signal line, is formed in the pixel circuit during the sensing mode.

2. The apparatus of claim 1, wherein the pressure resistance layer comprises polysilicon.

3. The apparatus of claim 1, wherein the first signal line comprises one of an initialization line, configured to apply a signal initializing a gate electrode of a transistor of the pixel circuit, and a data line, configured to apply a data signal to the pixel circuit during the display mode, and the second signal line comprises the other of the initialization line and the data line.

4. The apparatus of claim 1, wherein the pixel circuit comprises:

a first transistor connected to the first signal line and a first scan line; and

a second transistor connected to the second signal line and a second scan line,

wherein the first transistor and the second transistor are turned on by a scan signal applied to both the first scan line and the second scan line, such that the second current path is formed between the first signal line and the second signal line during the sensing mode.

5. The apparatus of claim 4, wherein

the first transistor comprises:

a first gate electrode connected to the first scan line, a first electrode connected to the first signal line, a second electrode connected to a first node, and a first pressure resistance layer connected to the first electrode and the second electrode; and

the second transistor comprises;

a second gate electrode connected to the second scan line, a third electrode connected to the second signal line, a fourth electrode connected to the first node, and a second pressure resistance layer connected to the third electrode and the fourth electrode.

6. The apparatus of claim 4, wherein the pixel circuit further comprises:

a third transistor connected between one node of the second current path and a capacitor storing a voltage corresponding to a data signal,

wherein the third transistor is turned on during the display mode and turned off during the sensing mode.

7. The apparatus of claim 4, wherein the pixel circuit further comprises:

at least one transistor connected to the first scan line or the second scan line and connected between the first transistor and the second transistor, and

the at least one transistor is turned on with the first transistor and the second transistor by the scan signal applied to the first scan line and the second scan line, such that the second current path is formed between the first signal line and the second signal line during the sensing mode.

8. The apparatus of claim 7, wherein

the first transistor comprises:

a first gate electrode connected to the first scan line, a first electrode connected to the first signal line, a second electrode connected to a first node, and a first pressure resistance layer connected to the first electrode and the second electrode,

the second transistor comprises;

a second gate electrode connected to the second scan line, a third electrode connected to the second signal line, a fourth electrode connected to a second node, and a second pressure resistance layer connected to the third electrode and the fourth electrode, and

the at least one transistor connected between the first transistor and the second transistor comprises;

a third transistor comprising a third gate electrode connected to the first node, a fifth electrode connected to the second node, a sixth electrode, and a third pressure resistance layer connected to the fifth electrode and the sixth electrode; and

a fourth transistor comprising a fourth gate electrode connected to the first scan line, a seventh electrode connected to the third gate electrode of the third transistor, an eighth electrode connected to the sixth electrode of the third transistor, and a fourth pressure resistance layer connected to the seventh electrode and the eighth electrode.

9. The apparatus of claim 1, wherein the sensing mode is performed during a blank section of one frame.

10. The apparatus of claim 1, wherein each of the display mode and the sensing mode is performed in one of an even-numbered frame and an odd-numbered frame, and the display mode and the sensing mode alternate.

11. The apparatus of claim 1, further comprising:

a scan driver configured to apply a scan signal to a scan line connected to the pixel circuit during the display mode and the sensing mode;

a panel driving and output unit configured to apply the first driving signal to the first signal line during the display mode and to apply the sensing input signal to the first signal line during the sensing mode; and

a panel driving and sensing unit configured to apply the second driving signal to the second signal line during the display mode, to read out the sensing output signal from the second signal line during the sensing mode, and to measure a resistance change of the pressure resistance layer during the sensing mode.

12. The apparatus of claim 11, wherein the scan driver comprises:

a first scan driver configured to apply the scan signal to the scan line during the display mode; and

a second scan driver configured to apply the scan signal to the scan line during the sensing mode.

13. The apparatus of claim 11, wherein the first signal line comprises an initialization line applying an initialization signal, and the second signal line comprises a data line applying a data signal,

the panel driving and output unit comprises a first switching unit configured to connect the initialization line to a first input line supplying the initialization signal during the display mode, and to connect the initialization line to a second input line supplying the sensing input signal during the sensing mode, and

the panel driving and sensing unit comprises:

a data driver supplying the data signal to the data line during the display mode;

a sensing unit reading out the sensing output signal via the data line during the sensing mode; and

a second switching unit selectively connecting the data line to the data driver and the sensing unit, depending on a driving mode.

14. The apparatus of claim 11, wherein the first signal line comprises a data line applying a data signal, and the second signal line comprises an initialization line applying an initialization signal,

the panel driving and output unit comprises:

a data driver configured to supply the data signal to the data line during the display mode; and

a first switching unit configured to connect the data line to the data driver during the display mode and to connect the data line to a first input line supplying the sensing input signal during the sensing mode; and

the panel driving and sensing unit comprises;

a sensing unit reading out the sensing output signal via the initialization line during the sensing mode; and

a second switching unit configured to connect the initialization line to a second input line supplying the initialization signal during the display mode, and to connect the initialization line to the sensing unit during the sensing mode.

15. The apparatus of claim 11, wherein the scan driver simultaneously applies scan signals every N scan lines, N being greater than or equal to two.

16. A method of driving a display apparatus comprising a plurality of pixels, each of the pixels having a pixel circuit and a pressure resistance layer, the method comprising:

receiving a scan signal;

receiving a data signal during a display mode;

emitting light by using a driving current during the display mode;

receiving a sensing input signal during a sensing mode; and

generating a sensing output signal during the sensing mode,

wherein the driving current corresponds to the data signal and flows along a first current path formed in the pixel circuit during the display mode, and

wherein the sensing output signal corresponds to a resistance of the pressure resistance layer and flows along a second current path formed between a pair of signal lines connected to the pixel circuit during the sensing mode.

17. The method of claim 16, further comprising:

receiving the sensing output signal at a sensing unit; and

measuring a resistance change of the pressure resistance layer from the sensing output signal.

18. The method of claim 16, wherein scan signals are simultaneously applied to pixels arranged in a plurality of rows during the sensing mode, each row of pixels having a common scan line.

19. The method of claim 16, wherein the sensing mode is performed during a blank section of one frame.

20. The method of claim 16, wherein each of the display mode and the sensing mode is performed in one of an even-numbered frame and an odd-numbered frame, and the display mode and the sensing mode alternate.