Display device, and methods for manufacturing and controlling the display device

• US 8,059,070 B2
• Filed: 06/15/2010
• Issued: 11/15/2011
• Est. Priority Date: 05/28/2008
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Odawara, Rie, Kato, Toshiyuki
• Primary Examiner(s): OSORIO, RICARDO
• Application Number:
  US12/815,887
• Publication Number:
  US 20100253715A1
• Time in Patent Office: 518 Days
• Field of Search: 345/76, 345/77, 345/82, 345/83, 315/169.3
• US Class Current: 345/77
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/029 by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element

Abstract

A display device corrects uneven luminance due to uneven element characteristics by simple measurement and correction with a low cost. The display device includes pixels that each include a light emitter and a driver. Data lines supply a voltage signal to the driver of each pixel. A data line driver supplies the voltage signal to each data line. A first memory stores, for each pixel, a luminance gain for adjusting a luminance corresponding to a video signal to a standard luminance. A second memory stores conversion curve information representing a representative conversion curve common to the pixels. A corrector converts, for each pixel, the luminance into a corresponding standard luminance value based on a corresponding luminance gain stored in the first memory, while a converter converts, for each pixel, the corresponding standard luminance into a corresponding voltage signal based on the conversion information stored in the second memory.

Claims

1. A display device, comprising:

a plurality of pixels, each of the plurality of pixels including a light emitter and a driver, the driver supplying current to the light emitter;

a plurality of data lines, each of the plurality of data lines supplying a voltage signal to one of the plurality of pixels, the voltage signal corresponding to a voltage to be supplied to a gate of the driver included in the corresponding one of the plurality of pixels;

a data line driver that supplies the voltage signal to each of the plurality of data lines;

a first memory configured to store, for each of the plurality of pixels, a luminance gain, the luminance gain being used for adjusting a luminance corresponding to a video signal for each of the plurality of pixels to a standard luminance value;

a second memory configured to store conversion information representing a representative conversion curve, the representative conversion curve representing a relationship between a common voltage and a common luminance, the relationship being common to the plurality of pixels;

a corrector configured to convert, for each of the plurality of pixels, the luminance corresponding to the video signal into a corresponding standard luminance value, based on a corresponding luminance gain stored in the first memory; and

a converter configured to convert, for each of the plurality of pixels, the corresponding standard luminance value into a corresponding voltage signal, based on the conversion information stored in the second memory.

2. The display device according to claim 1,

wherein the second memory is configured to store the conversion information representing the representative conversion curve for common use to each of the plurality of pixels.

3. The display device according to claim 1,

wherein the standard luminance value is one of an arbitrary luminance of an arbitrary pixel among the plurality of pixels and an average luminance obtained by averaging luminance values of at least two pixels among the plurality of pixels, and

the luminance gain is a value corresponding to a ratio between (i) the standard luminance value and (ii) one of the luminance of each pixel among the plurality of pixels and the average luminance obtained by averaging the luminance values the at least two pixels among the plurality of pixels.

4. The display device according to claim 1,

wherein the corrector is configured to read the corresponding luminance gain corresponding to the luminance of each pixel from the first memory, and

correct the luminance to the corresponding standard luminance value by one of multiplying and dividing the luminance by the corresponding luminance gain.

5. The display device according to claim 1,

wherein the luminance gain stored for each of the plurality of pixels is obtained based on a measured luminance of each of the plurality of pixels driven under a same driving condition used to obtain the standard luminance value.

6. The display device according to claim 5,

wherein the same driving condition is to supply a same voltage signal to the one of the plurality of data lines connected to each of the plurality of pixels.

7. The display device according to claim 5,

wherein the same driving condition is to measure a luminance of each of the plurality of pixels while driving each of the plurality of pixels at a same temperature as a temperature at a time when the standard luminance value is obtained.

8. The display device according to claim 1,

wherein the representative conversion curve represents relational characteristics between voltages and luminance values of an arbitrary pixel among the plurality of pixels.

9. The display device according to claim 1,

wherein the representative conversion curve represents characteristics obtained by averaging values indicating relational characteristics between voltages and luminance values of at least two pixels among the plurality of pixels.

10. The display device according to claim 1,

wherein the conversion information representing the representative conversion curve is an association table of voltages and luminance values, and

the converter is configured to convert the corresponding standard luminance value of each of the plurality of pixels into the corresponding voltage signal with reference to the association table stored in the second memory.

11. The display device according to claim 1,

wherein the conversion information representing the representative conversion curve is a relational expression representing voltages and luminance values, and

the converter is configured to convert the corresponding standard luminance value of each of the plurality of pixels into the corresponding voltage signal using the relational expression stored in the second memory.

12. The display device according to claim 1,

wherein the driver is a thin film transistor.

13. The display device according to claim 1,

wherein the light emitter is an organic electroluminescence element.

14. A method for manufacturing a display device which includes:

a plurality of pixels, each of the plurality of pixels including a light emitter and a driver, the driver supplying current to the light emitter;

a plurality of data lines, each of the plurality of data lines supplying a voltage signal to one of the plurality of pixels, the voltage signal corresponding to a voltage to be supplied to a gate of the driver included in the corresponding one of the plurality of pixels;

a data line driver that supplies the voltage signal to each of the plurality of data lines; and

the method comprising;

obtaining conversion information representing a representative conversion curve, the representative conversion curve representing a relationship between a common voltage and a common luminance, the relationship being common to the plurality of pixels;

storing the conversion information representing a representative conversion curve in a memory of the display device;

obtaining, for each of the plurality of pixels, a luminance gain, the luminance gain being used for adjusting a luminance corresponding to a video signal for each of the plurality of pixels to a standard luminance value; and

storing, for each of the plurality of pixels, the luminance gain obtained in the obtaining into the memory of the display device.

15. A method for controlling a display device which includes:

a plurality of pixels, each of the plurality of pixels including a light emitter and a driver, the driver supplying current to the light emitter;

a plurality of data lines, each of the plurality of data lines supplying a voltage signal to one of the plurality of pixels, the voltage signal corresponding to a voltage to be supplied to a gate of the driver included in the corresponding one of the plurality of pixels;

a data line driver that supplies the voltage signal to each of the plurality of data lines;

a first memory configured to store, for each of the plurality of pixels, a luminance gain, the luminance gain being used for adjusting a luminance corresponding to a video signal inputted from outside for each of the plurality of pixels to a standard luminance value;

a second memory configured to store conversion information representing a representative conversion curve, the representative conversion curve representing a relationship between a common voltage and a common luminance, the relationship being common to the plurality of pixels; and

the method comprising;

correcting, for each of the plurality of pixels, the luminance corresponding to the video signal into a corresponding standard luminance value, based on a corresponding luminance gain stored in the first memory;

converting, for each of the plurality of pixels, the corresponding standard luminance value into a corresponding voltage signal, based on the conversion information stored in the second memory; and

outputting, for each of the plurality of pixels, the corresponding voltage signal to the data line driver.

16. The method for controlling the display device according to claim 15, the method further comprising:

detecting position information of each of the plurality of pixels regarding the video signal inputted from outside;

reading, for each of the plurality of pixels, the corresponding luminance gain based on the detected position information from the first memory;

converting, for each of the plurality of pixels, the video signal inputted from outside into the luminance; and

calculating, for each of the plurality of pixels, the corresponding standard luminance value based on the corresponding luminance gain corresponding to the luminance and read from the first memory.