# US 11,910,671 B2 · Display device and method for driving same

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- Number: US 11,910,671 B2
- Document ID: US11910671B2
- Status: Granted
- Kind: B2
- Application number: 17/436,537
- Filed: 2019-03-28
- Published: 2022-06-02
- Granted: 2024-02-20
- Earliest claimed: 2019-03-28
- Assignees: Sharp Kabushiki Kaisha
- Applicants: Sharp Kabushiki Kaisha
- Inventors: Keiichi Yamamoto; Kohhei Tanaka; Takayuki Nishiyama
- Web page: https://patentgrep.com/patent/US11910671B2

## CPC

- H10K 59/131: Interconnections, e.g. wiring lines or terminals
- G09G 3/3266: Details of drivers for scan electrodes
- G09G 3/3275: Details of drivers for data electrodes
- H10K 59/1213: {the pixel elements being TFTs}
- H10K 59/1216: {the pixel elements being capacitors}
- G09G 2300/0814: used for selection purposes, e.g. logical AND for partial update
- G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing
- G09G 2300/0842: forming a memory circuit, e.g. a dynamic memory with one capacitor
- G09G 2310/0262: The addressing of the pixel, in a display other than an active matrix LCD, involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependent on signals of two data electrodes
- G09G 2310/0278: Details of driving circuits arranged to drive both scan and data electrodes
- G09G 2310/08: Details of timing specific for flat panels, other than clock recovery
- G09G 2320/0233: Improving the luminance or brightness uniformity across the screen
- G09G 2320/029: by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
- G09G 2320/043: Preventing or counteracting the effects of ageing
- G09G 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)

## Abstract

With respect to a display device having an external compensation function, a monitor time can be shortened without increasing the number of wiring lines. A pixel circuit in an i-th row and a j-th column includes an organic EL element (display element), a writing control transistor, a drive transistor, a monitor control transistor, and a holding capacitor. A control terminal of the drive transistor is connected to a data signal line S(j) in the j-th column via the write control transistor. The monitor control transistor includes a first conduction terminal connected to a second conduction terminal of the drive transistor, and a second conduction terminal connected to a data signal line S(j+1) in a (j+1)-th column.

## Claims

### Claim 1

A display device comprising:
a plurality of data signal lines;
a plurality of scanning signal lines;
a plurality of monitor control lines corresponding to the plurality of scanning signal lines on a one-to-one basis; and
pixel circuits of m rows×n columns (where m and n are integers of 2 or more) provided corresponding to intersections of the plurality of data signal lines and the plurality of scanning signal lines and including a display element, luminance of the display element being controlled by a current, and a drive transistor configured to control a current to be supplied to the display element, the display device having a function of detecting a characteristic of the drive transistor,
wherein the display device includes a data signal line drive circuit configured to apply a data signal to the plurality of data signal lines, a scanning signal line drive circuit configured to apply a scanning signal to the plurality of scanning signal lines, and a monitor control line drive circuit configured to apply a monitor control signal to the plurality of monitor control lines,
the data signal line drive circuit has a function of measuring a current flowing through each of the plurality of data signal lines, and
a pixel circuit in an i-th row and a j-th column (where i is an integer of 1 or more and m or less, and j is an integer of 1 or more and n or less) includes
the display element provided between a first power supply voltage line supplied with a first supply voltage and a second power supply voltage line supplied with a second supply voltage and including a first terminal and a second terminal connected to the second power supply voltage line,
the drive transistor including a control terminal, a first conduction terminal connected to the first power supply voltage line, and a second conduction terminal,
a writing control transistor including a control terminal connected to a scanning signal line in the i-th row, a first conduction terminal connected to a data signal line in the j-th column, and a second conduction terminal connected to the control terminal of the drive transistor, and
a monitor control transistor including a control terminal connected to a monitor control line in the i-th row, a first conduction terminal connected to the second conduction terminal of the drive transistor and a second conduction terminal connected to a data signal line in a (j+1)-th column.

### Claim 2 (depends on 1)

The display device according to claim 1,
wherein when the characteristic of the drive transistor included in the pixel circuit in the i-th row and the j-th column is detected, the data signal line drive circuit is configured to start application of a characteristic detection potential as a data signal configured to detect the characteristic of the drive transistor to the data signal line in the j-th column and application of a current measurement potential as a data signal configured to measure a current representative of the characteristic of the drive transistor to the data signal line in the (j+1)-th column at a same timing.

### Claim 3 (depends on 1, 2)

The display device according to claim 1 or 2,
wherein the data signal line drive circuit includes a current measuring unit corresponding to each of the plurality of data signal lines and configured to measure a current flowing through each of the plurality of data signal lines,
when the characteristic of the drive transistor included in the pixel circuit in the i-th row and the j-th column is detected, by the monitor control line drive circuit turning the monitor control transistor to an on state, the second conduction terminal of the drive transistor is connected to a current measuring unit corresponding to the data signal line in the (j+1)-th column.

### Claim 4 (depends on 1)

The display device according to claim 1,
wherein (n+1) data signal lines are provided as the plurality of data signal lines.

### Claim 5 (depends on 1)

The display device according to claim 1,
wherein with respect to a processing of detecting the characteristic of the drive transistor included in the pixel circuit in the i-th row and the j-th column, during a select period for the i-th row, being a period from when the scanning signal line in the (i−1)-th row changes from an on state to an off state to when the scanning signal line in the (i+1)-th row changes from the off state to the on state, the data signal line drive circuit sequentially applies a plurality of characteristic detection potentials different from each other as data signals configured to detect the characteristic of the drive transistor to the data signal line in the j-th column.

### Claim 6 (depends on 1)

The display device according to claim 1,
wherein the display device further has a function of detecting a characteristic of the display element, and
the first conduction terminal of the monitor control transistor is connected to the first terminal of the display element in addition to the second conduction terminal of the drive transistor.

### Claim 7 (depends on 6)

The display device according to claim 6,
wherein when the characteristic of the display element included in the pixel circuit in the i-th row and the j-th column is detected, the data signal line drive circuit is configured to start application of a characteristic detection potential as a data signal configured to detect the characteristic of the display element to the data signal line in the j-th column and application of a current measurement potential as a data signal configured to measure a current representative of the characteristic of the display element to the data signal line in the (j+1)-th column at a same timing.

### Claim 8 (depends on 6)

The display device according to claim 6,
wherein the data signal line drive circuit includes a current measuring unit corresponding to each of the plurality of data signal lines and configured to measure a current flowing through each of the plurality of data signal lines,
when the characteristic of the display element included in the pixel circuit in the i-th row and the j-th column is detected, by the monitor control line drive circuit turning the monitor control transistor to an on state, the first terminal of the display element is connected to a current measuring unit corresponding to the data signal line in the (j+1)-th column.

### Claim 9 (depends on 8)

The display device according to claim 8,
wherein with respect to a processing of detecting the characteristic of the display element included in the pixel circuit in the i-th row and the j-th column, during a select period for the i-th row, being a period from when the scanning signal line in the (i−1)-th row changes from an on state to an off state to when the scanning signal line in the (i+1)-th row changes from the off state to the on state, the data signal line drive circuit sequentially applies a plurality of characteristic detection potentials different from each other as data signals configured to measure a current representative of the characteristic of the display element to the data signal line in the (j+1)-th column.

### Claim 10 (depends on 8)

The display device according to claim 8,
wherein the data signal line drive circuit includes a current measuring unit corresponding to each of the plurality of data signal lines and configured to measure a current flowing through each of the plurality of data signal lines,
when the characteristic of display element included in the i-th row is detected, by the monitor control line drive circuit turning the monitor control transistor included in the i-th row to the an state, a first terminal of a display element included in a pixel circuit in the i-th row and a z-th column (where z is an integer of 1 or more and n—1 or less) is connected to a current measuring unit corresponding to a data signal line in a (z+1) column, and a first terminal of the display element included in the pixel circuit in the i-th row and the (z+1) column is connected to a current measuring unit corresponding to a data signal line in a (z+2) column, and
the data signal line drive circuit applies a current measurement potential as a data signal configured to measure a current representative of the characteristic of the display element to both of the data signal line in the (z+1) column and the data signal line in the (z+2) column.

### Claim 11 (depends on 1)

The display device according to claim 1,
wherein each pixel circuit further includes a holding capacitor including a first electrode connected to the control terminal of the drive transistor and a second electrode connected to the first conduction terminal or the second conduction terminal of the drive transistor or the second terminal of the display element.

### Claim 12

A driving method of a display device including a plurality of data signal lines, a plurality of scanning signal lines, and pixel circuits of m rows×n columns (m and n are integers of 2 or more) provided corresponding to intersections of the plurality of data signal lines and the plurality of scanning signal lines, the display device having a function of detecting a characteristic of a circuit element included in each pixel circuit, the driving method comprising steps of:
applying an initialization potential configured to initialize a state of the pixel circuit to each of the plurality of data signal lines
applying a characteristic detection potential as a data signal configured to detect the characteristic of the circuit element to each of the plurality of data signal lines,
applying a current measurement potential as a data signal configured to measure a current representative of a characteristic of the circuit element to each of the plurality of data signal lines,
performing current measurement charging based on a current flowing through each of the plurality of data signal lines, and
performing A/D conversion based on a charging voltage obtained in the performing current measurement charging,
wherein at least two of the applying an initialization potential, the applying a characteristic detection potential, the applying a current measurement potential, the performing current measurement charging, and the performing A/D conversion are started at a same timing.

### Claim 13 (depends on 12)

The driving method according to claim 12,
wherein each pixel circuit includes, as the circuit element, a display element, luminance of the display element being controlled by a current, and a drive transistor configured to control a current to be supplied to the display element, and
a characteristic of the drive transistor is detected by a series of steps of the applying an initialization potential, the applying a characteristic detection potential, the applying a current measurement potential, the performing current measurement charging, and the performing A/D conversion.

### Claim 14 (depends on 13)

The driving method according to claim 13,
wherein the applying a characteristic detection potential and the applying a current measurement potential are started at a same timing.

### Claim 15 (depends on 13)

The driving method according to claim 13,
wherein when the characteristic detection potential is applied to the data signal line in the j-th column (where j is an integer of 1 or more and n or less) in the applying a characteristic detection potential, the current measurement potential is applied to the data signal line in the (j+1)-th column in the applying a current measurement potential.

### Claim 16 (depends on 15)

The driving method according to claim 15,
wherein with respect to a processing of detecting the characteristic of the drive transistor included in the pixel circuit in the i-th row and the j-th column (where i is an integer of 1 or more and m or less, and j is an integer of 1 or more and n or less), during a select period for the i-th row, being a period from when the scanning signal line in the (i−1)-th row changes from the on state to the off state to when the scanning signal line in the (i+1)-th row changes from the off state to the on state, the series of steps is repeated a plurality of times.

### Claim 17 (depends on 12)

The driving method according to claim 12,
wherein each pixel circuit includes, as the circuit element, a display element, luminance of the display element being controlled by a current, and a drive transistor configured to control a current to be supplied to the display element, and
a characteristic of the display element is detected by a series of steps of the applying an initialization potential, the applying a characteristic detection potential, the applying a current measurement potential, the performing current measurement charging, and the performing A/D conversion.

### Claim 18 (depends on 17)

The driving method according to claim 17,
wherein the applying a characteristic detection potential and the applying a current measurement potential are started at a same timing.

### Claim 19 (depends on 17)

The driving method according to claim 17,
wherein with respect to a processing of detecting the characteristic of the display element included in the pixel circuit in the i-th row, during the (K+1)-th processing, the characteristic detection potential is applied to the data signal lines in the odd-numbered column in the applying a characteristic detection potential, and the current measurement potential is applied to the data signal lines in the even-numbered column in the applying a current measurement potential, and
during the (K+1)-th processing, the characteristic detection potential is applied to the data signal lines in the even-numbered column in the applying a characteristic detection potential, and the current measurement potential is applied to the data signal lines in the odd-numbered column in the applying a current measurement potential.

### Claim 20 (depends on 19)

The driving method according to claim 19,
wherein in the applying a characteristic detection potential, the characteristic detection potential as the data signal configured to detect the characteristic of the display element is applied to both of the data signal lines in the odd-numbered column and the data signal lines in the even-numbered column, and
in the applying a current measurement potential, the current measurement potential as the data signal configured to measure a current representative of the characteristic of the display element is applied to both of the data signal lines in the odd-numbered column and the data signal lines in the even-numbered column.