Display device

Patent metadata

Field	Value
Publication number	US-2017193918-A1
Application number	US-201615344196-A
Country	US
Kind code	A1
Filing date	Nov 4, 2016
Priority date	Dec 30, 2015
Publication date	Jul 6, 2017
Grant date	—

Abstract

A display device includes: a pixel unit including pixels, each including an OLED; a scan driver configured to supply scan signals to scan lines connected to the pixels; a data driver configured to supply data signals to data lines connected to the pixels; a control line driver configured to supply control signals to control lines connected to the pixels; a sensing unit configured to receive sensing voltages from the data lines during a sensing period; a switching unit configured to selectively connect the data lines to the data driver and to the sensing unit, and to perform current sensing of the OLEDs of the pixels to which the control signals are supplied from among the plurality of pixels; and a timing controller configured to control the control line driver to supply the control signals to one or more of the control lines according to externally input first data.

First claim

What is claimed is:

1 . A display device comprising:
a pixel unit comprising a plurality of pixels, each of the pixels comprising an organic light emitting diode (OLED); a scan driver configured to supply scan signals to a plurality of scan lines connected to the plurality of pixels; a data driver configured to supply data signals to a plurality of data lines connected to the plurality of pixels; a control line driver configured to supply control signals to a plurality of control lines connected to the plurality of pixels; a sensing unit configured to receive sensing voltages from the plurality of data lines during a sensing period; a switching unit configured to selectively connect the plurality of data lines to the data driver and to the sensing unit, and configured to perform current sensing of the OLEDs of the pixels to which the control signals are supplied from among the plurality of pixels; and a timing controller configured to control operations of the scan driver, the data driver, the control line driver, the sensing unit, and the switching unit, and configured to control the control line driver to supply the control signals to one or more of the control lines according to externally input first data.

2 . The display device of claim 1 , wherein the timing controller comprises:
a frame memory configured to temporarily store the first data; a register configured to store a first reference value, the first reference value configured to determine on which of the pixels the current sensing is to be performed; and a sensing line determination unit configured to calculate a representative value of data corresponding to the pixels in each row according to the first data, and configured to compare the representative value with the first reference value.

3 . The display device of claim 2 , wherein, when the representative value is greater than the first reference value, the sensing line determination unit is configured to determine to perform the current sensing of the pixels in a corresponding row.

4 . The display device of claim 3 , wherein the control line driver is configured to supply a control signal to a control line connected to the pixels in the corresponding row in response to the determination to perform the current sensing.

5 . The display device of claim 4 , wherein the switching unit is configured to connect the plurality of data lines to the sensing unit during a single horizontal period corresponding to the corresponding row.

6 . The display device of claim 2 , wherein, when the representative value is less than or equal to the first reference value, the sensing line determination unit is configured to determine to omit performing the current sensing of the pixels in a corresponding row.

7 . The display device of claim 6 , wherein, in response to a determination to omit the performing the current sensing, the control line driver is configured to omit supplying a control signal to a control line connected to the pixels in the corresponding row.

8 . The display device of claim 6 , wherein, in response to a determination to omit the performing the current sensing, the scan driver is configured to supply a scan signal to a scan line connected to the pixels in the corresponding row.

9 . The display device of claim 8 , wherein the switching unit is configured to connect the plurality of data lines to the data driver during a single horizontal period corresponding to the corresponding row.

10 . The display device of claim 9 , wherein the pixels in the corresponding row are configured to receive the data signals from the data driver through the plurality of data lines, and
wherein each of the OLEDs emits light having brightness corresponding to each of the data signals.

11 . The display device of claim 2 , wherein the representative value comprises a mean value of the data corresponding to the pixels in each row.

12 . The display device of claim 2 , wherein the representative value comprises a median value of the data corresponding to the pixels in each row.

13 . The display device of claim 2 , wherein the representative value comprises a mode value of the data corresponding to the pixels in each row.

14 . The display device of claim 1 , wherein the sensing unit is configured to generate deterioration information of the OLEDs of the pixels to which the control signals are supplied according to a result of the current sensing.

15 . The display device of claim 14 , wherein the sensing unit comprises:
a sensing circuit configured to sense voltages generated in the plurality of data lines as the result of the current sensing; and an analog-digital converter configured to convert the voltages sensed by sensing circuit into digital values of the deterioration information of the OLEDs.

16 . The display device of claim 15 , wherein the sensing circuit comprises:
a sensing current source configured to apply a sensing current to the plurality of data lines; and a voltage detector configured to detect the voltages generated in the plurality of data lines when the sensing current source applies the sensing current thereto.

17 . The display device of claim 16 , wherein the sensing current source comprises a fixed current source.

18 . The display device of claim 16 , wherein the sensing current source comprises a variable current source.

19 . The display device of claim 14 , further comprising a control block configured to store the deterioration information generated by the sensing unit.

20 . The display device of claim 19 , wherein the timing controller is configured to receive the deterioration information from the control block, and is configured to convert the first data into second data according to the deterioration information to compensate for deterioration of the OLEDs of the pixels.

21 . The display device of claim 1 , wherein the timing controller comprises:
a light emitting information storage configured to accumulate and store the input first data; a region detector configured to detect pixels in a first light emitting region from among the plurality of pixels according to the first data; and a sensing line determination unit configured to determine a sensing line on which to perform the current sensing according to the first light emitting region, and wherein the first light emitting region is a region where light is emitted at a certain brightness or greater for a certain amount of time.

22 . The display device of claim 21 , wherein the region detector comprises:
a register configured to store a second reference value and a first critical value; a pixel detector configured to detect pixels sequentially receiving grayscale data greater than the second reference value a certain number of times exceeding the first critical value; and a light emitting region determination unit configured to determine the first light emitting region according to the pixels detected by the pixel detector.

23 . The display device of claim 1 , wherein each of the pixels further comprises:
a pixel circuit connected to one of the scan lines, to one of the data lines, to one of the control lines, and to an anode electrode of the organic light emitting diode, configured to control current supplied to the organic light emitting diode, and configured to transfer a sensing current to the organic light emitting diode during a current sensing operation period.

24 . The display device of

Assignees

• Samsung Display Co Ltd

Inventors

• Bae Min Seok

Classifications

• G09G3/3283 Primary

  in which the data driver supplies a variable data current for setting the current through, or the voltage across, the light-emitting elements · CPC title

• G09G2310/027

  Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters · CPC title

• G09G2310/0297

  Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns · CPC title

• G09G3/3266

  Details of drivers for scan electrodes · CPC title

• G09G2310/08

  Details of timing specific for flat panels, other than clock recovery · CPC title