ORGANIC LIGHT EMITTING DISPLAY DEVICE

• US 20160189670A1
• Filed: 04/21/2015
• Published: 06/30/2016
• Est. Priority Date: 12/29/2014
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: BAEK, Jong ln, KIM, Il Nam, MOK, Rang Kyun, AHN, Yi Joon
• Granted Patent: US 9,928,804 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2310/0297 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 Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607

Abstract

An organic light emitting display device, including a display panel including red, green, first blue, and second blue sub-pixels, a data drive unit configured to receive an image signal and output data output signals, a de-multiplexer circuit configured to distribute data output signals to the data lines connected to the red, green, and the first blue sub-pixels, in response to receiving a first blue drive selection signal, or to the data lines connected to the red, green, first blue, and the second blue sub-pixels, in response to receiving a mixed drive selection signal, and a control unit configured to process a raw image data into the image signal, provide the image signal to the data drive unit, and provide the first blue drive selection signal or the mixed drive selection signal to the de-multiplexer circuit in a frame unit of the raw image data.

Claims

1. An organic light emitting display device, comprising:

a display panel comprising red sub-pixels, green sub-pixels, first blue sub-pixels, and second blue sub-pixels, each sub-pixel connected to scan lines and data lines;

a scan drive unit configured to sequentially apply scan signals to the scan lines;

a data drive unit configured to receive an image signal and output data output signals;

a de-multiplexer circuit configured to distribute data output signals to the data lines connected to the red sub-pixels, the green sub-pixels, and the first blue sub-pixels, in response to receiving a first blue drive selection signal, or distribute the data output signals to the data lines connected to the red sub-pixels, the green sub-pixels, the first blue sub-pixels, and the second blue sub-pixels, in response to receiving a mixed drive selection signal; and

a control unit configured to process a raw image data into the image signal, provide the image signal to the data drive unit, and provide the first blue drive selection signal or the mixed drive selection signal to the de-multiplexer circuit in a frame unit of the raw image data,

wherein the control unit is configured to detect an image data that corresponds to a first color gamut and a second color gamut from the raw image data, and adjust a ratio of a number of frames operating in a first blue drive mode that provides the first blue drive selection signal to the de-multiplexer circuit and a number of frames operating in a mixed drive mode that provides the mixed drive selection signal, based on the image data corresponding to the second color gamut.

2. The organic light emitting display device of claim 1, wherein the control unit comprises:

an image data processing unit configured to receive the raw image data and generate a corrected image data; and

a timing control unit configured to receive the corrected image data from the image data processing unit and process the corrected image data into the image signal.

3. The organic light emitting display device of claim 2, wherein the image data processing unit comprises:

a color gamut determination unit configured to detect the image data that corresponds to the first color gamut and the second color gamut from the raw image data, and determine a drive mode frame ratio corresponding to the ratio of the number of frames operating in the first blue drive mode and the number of frames operating in the mixed drive mode, based on the image data corresponding to the second color gamut; and

an image data correction unit configured to receive the drive mode frame ratio from the color gamut determination unit, and generate the corrected image data by correcting the image data of the frame operating in the mixed drive mode.

4. The organic light emitting display device of claim 3, wherein:

the image data correction unit is configured to transmit a mode selection signal to the timing control unit, the mode selection signal indicating whether a frame operates in the first blue drive mode or in the mixed drive mode; and

the timing control unit is configured to transmit the first blue drive selection signal or the mixed drive selection signal to the de-multiplexer circuit, depending on the received mode selection signal.

5. The organic light emitting display device of claim 4, wherein the data drive unit is configured to:

receive grayscale voltages from a grayscale voltage generation unit;

select one or more of the received grayscale voltages; and

output the selected grayscale voltages as the data output signals.

6. The organic light emitting display device of claim 5, wherein the grayscale voltage generation unit is configured to:

receive a grayscale voltage selection signal from the timing control unit; and

generate the grayscale voltages that correspond to;

a gamma curve in the first blue drive mode that drives the red sub-pixels, the green sub-pixels, and the first blue sub-pixels;

or

a gamma curve in the mixed blue drive mode that drives the red sub-pixels, the green sub-pixels, the first blue sub-pixels, and the second blue sub-pixels, depending on the received grayscale voltage selection signal.

7. The organic light emitting display device of claim 6, wherein the image data correction unit is configured to correct the raw image data by matching the grayscale value of the image data of the frame operating in the mixed drive mode in the raw image data to the gamma curve in the first blue drive mode.

8. The organic light emitting display device of claim 7, wherein the control unit further comprises a memory configured to store a reference value with respect to the gamma curve in the first blue drive mode and the gamma curve in the mixed blue drive mode.

9. The organic light emitting display device of claim 1, further comprising a grayscale voltage generation unit configured to provide grayscale voltages to the data drive unit,

wherein the data drive unit is configured to select one or more of the received grayscale voltages and provide the selected grayscale voltages to the de-multiplexer circuit as the data output signals.

10. The organic light emitting display device of claim 9, wherein the control unit comprises:

an image data processing unit configured to provide a grayscale voltage selection signal the grayscale voltage generation unit; and

a timing control unit configured to receive the raw image data and process the raw image data into the image signal.

11. The organic light emitting display device of claim 10, wherein the image data processing unit comprises:

a color gamut determination unit configured to detect an image data that corresponds to the first color gamut and the second color gamut from the raw image data, and determine a drive mode frame ratio that corresponds to a ratio of a number of frames operating in the first blue drive mode and a number of frames operating in the mixed drive mode, based on the image data corresponding to the second color gamut; and

a gamma selection signal generation unit configured to receive the drive mode frame ratio from the color gamut determination unit, provide a first gamma selection signal that corresponds to the first blue drive mode to the gamma voltage generation unit for frames operating in the first blue drive mode, and provide a second gamma selection signal that corresponds to the mixed drive mode to the gamma voltage generation unit for frames operating in the mixed drive mode.

12. The organic light emitting display device of claim 11, wherein:

the gamma voltage generation unit generates a first grayscale voltages in response to the first gamma selection signal, the first grayscale voltages corresponding to a first gamma curve that corresponds to the grayscale value when the red sub-pixels, the green sub-pixels, and the first blue sub-pixels are driven; and

the gamma voltage generation unit generates a second grayscale voltages in response to the second gamma selection signal, the second grayscale voltages corresponding to a second gamma curve that corresponds to the grayscale value when the red sub-pixels, the green sub-pixels, first blue sub-pixels, and the second blue sub-pixels are driven.

13. The organic light emitting display device of claim 11, wherein:

the image data correction unit is configured to transmit a mode selection signal to the timing control unit, the mode selection signal indicating whether the image data of the corrected image data corresponds to the first blue drive mode or the mixed drive mode; and

the timing control unit is configured to transmit the first blue drive selection signal or the mixed blue drive selection signal to the de-multiplexer circuit, depending on the received mode selection signal.

14. The organic light emitting display device of claim 1, wherein a color of light emitted from the first blue sub-pixels is lighter than a color of light emitted from the second blue sub-pixels.

15. The organic light emitting display device of claim 1, wherein the data output signal applied to the de-multiplexer circuit comprises red data signal applied to the red sub-pixels, green data signal applied to the green sub-pixels, and blue data signal applied to the first sub-pixels, the second sub-pixels, or both the first sub-pixels and the second sub-pixels arranged sequentially.

16. The organic light emitting display device of claim 1, wherein:

the first color gamut comprises a color gamut expressed by light-emission of the red sub-pixels, the green sub-pixels, and the first blue sub-pixels; and

the second color gamut comprises a color gamut expressed by light-emission of the red sub-pixels, the green sub-pixels, the first blue sub-pixels, and the second blue sub-pixels, excluding the first color gamut.

17. The organic light emitting display device of claim 1, when the raw image data comprises only the image data corresponding to the first color gamut, the organic light emitting display device is configured to operate in the first blue drive mode.

18. The organic light emitting display device of claim 1, when the raw image data comprises image data that corresponds to the first color gamut and the second color gamut, the ratio is adjusted to maximize the number of frames operating in the first blue drive to the extent that a color corresponding to the second color gamut is reproduced.

19. The organic light emitting display device of claim 1, wherein the control unit is configured to:

detect the image data corresponding to the first color gamut, the second color gamut, and a third color gamut from the image data; and

adjust the ratio of the number of frames operating in the first blue drive mode that provides the first blue drive selection signal to the de-multiplexer, the number of frames operating in the mixed drive mode that provides the mixed drive selection signal to the de-multiplexer, to a number of frames operating in a second blue drive mode that provides a second blue drive selection signal to the de-multiplexer, based on the image data belonging to the second color gamut and the third color gamut; and

the third color gamut comprises color gamut different from the first color gamut and the second color gamut.

20. The organic light emitting display device of claim 19, wherein:

the first color gamut comprises a color gamut expressed by light-emission of the red sub-pixels, the green sub-pixels, and the first blue sub-pixels;

the second color gamut comprises a color gamut expressed by light-emission of the red sub-pixels, the green sub-pixels, the first blue sub-pixels, and the second blue sub-pixels, excluding the first color gamut; and

the third color gamut comprises a color gamut expressed by light-emission of the red sub-pixels, the green sub-pixels, the first blue sub-pixels, and the second blue sub-pixels, excluding the first color gamut and the second color gamut.