Display device with color and luminance characterization and compensation methods
Improved display devices, information handling systems and related methods are provided for color and luminance characterization and compensation. According to one embodiment, a characterization method is provided for correlating the color/luminance measured from light emitted by a light source disposed within the display device to the color/luminance measured from light output from the display device at the time of manufacture. After the display device is characterized and a set of characterization values are stored, a compensation method is used during operation of the display device to perform color/luminance compensation for the light output from the display device by measuring the color/luminance of the light source illumination, and adjusting color gain values to maintain the color/luminance of the output light at a reference set point.
1. A method for characterizing a display device, the method comprising:
driving a light source of the display device to emit light at a reference set point;
obtaining a first set of color values corresponding to the light emitted by the light source, wherein the first set of color values are obtained from a light sensor disposed within the display device for receiving the emitted light;
obtaining a second set of color values corresponding to light output from the display device, wherein the second set of color values are obtained from a light analyzer disposed outside of the display device for receiving the output light;
generating a set of display device characterization values, which correlate the first set of color values to the second set of color values obtained at the reference set point; and
storing the set of display device characterization values within a storage medium of the display device.
2. The method as recited in claim 1 , wherein the steps of driving a light source, obtaining a first set of color values, obtaining a second set of color values, generating a set of display device characterization values and storing the set of display device characterization values are performed during manufacturing of the display device.
3. The method as recited in claim 1 , wherein the first set of color values comprises XYZ tristimulus values, and wherein the second set of color values comprise XYZ tristimulus values.
4. The method as recited in claim 1 , wherein the first set of color values comprises RGB color values, and wherein the second set of color values comprises RGB color values.
5. The method as recited in claim 1 , wherein the step of generating a set of display device characterization values comprises dividing the second set of color values by the first set of color values.
6. The method as recited in claim 1 , wherein the reference set point comprises a white balance set point, a red set point, a green set point or a blue set point.
7. The method as recited in claim 1 , further comprising repeating the steps of driving a light source, obtaining a first set of color values, obtaining a second set of color values, generating a set of display device characterization values and storing the set of display device characterization values for a plurality of different reference set points.
8. A method for maintaining a color and a luminance of light output from a display device over time, the method comprising:
driving a light source of the display device to emit light at a reference set point;
obtaining a first set of color values corresponding to the light emitted by the light source, wherein the first set of color values are obtained from a light sensor disposed within the display device for receiving the emitted light;
calculating a second set of color values corresponding to the light output from the display device by combining the first set of color values with a stored set of display device characterization values;
deriving a set of gain values from the second set of color values and a third set of color values, which corresponds to the reference set point; and
using the set of gain values to maintain the color and the luminance of the light output from the display device at the reference set point.
9. The method as recited in claim 8 , wherein the steps of driving, obtaining, calculating, deriving and using are performed repeatedly over time during operation of the display device to maintain the color and the luminance of the light output from the display device at the reference set point.
10. The method as recited in claim 8 , wherein the reference set point comprises a white balance set point, a red set point, a green set point or a blue set point.
11. The method as recited in claim 8 , further comprising changing the reference set point to a new reference set point, and repeating the steps of driving, obtaining, calculating, deriving and using to change the color and the luminance of the light output from the display device to the new reference set point.
12. The method as recited in claim 8 , wherein the first set of color values comprises XYZ tristimulus values, and wherein the second set of color values comprise XYZ tristimulus values.
13. The method as recited in claim 8 , wherein the first set of color values comprises RGB color values, and wherein the second set of color values comprises RGB color values.
14. The method as recited in claim 8 , wherein the stored set of display device characterization values comprises values, which were previously determined during manufacturing of the display device and stored within a storage medium of the display device.
15. The method as recited in claim 14 , wherein the stored set of display device characterization values were previously determined by dividing a fifth set of color values by a fourth set of color values, wherein the fourth set of color values were previously obtained from the light sensor disposed within the display device upon receiving light emitted from the light source at the reference set point, and wherein the fifth set of color values were previously obtained from a light analyzer disposed outside of the display device for receiving light output from the display device.
16. A system, comprising:
a light source configured to emit light at a reference set point;
a light sensor coupled to receive the emitted light and configured to generate a first set of color values corresponding to the emitted light;
a processing device coupled to receive the first set of color values from the light sensor, and configured to:
calculate a second set of color values corresponding to light output from the system by combining the first set of color values with a stored set of characterization values; and
derive a set of gain values from the second set of color values and a third set of color values, which corresponds to the reference set point; and
driver circuitry coupled to the light source and to the processing device, wherein the driver circuitry is configured to use the set of gain values to alter a drive signal supplied to the light source, so as to maintain a color and a luminance of the light output from the system at the reference set point.
17. The system as recited in claim 16 , wherein the system comprises a display device, which includes a display panel arranged above the light source for receiving the emitted light and for generating images for display on a display screen of the display device.
18. The system as recited in claim 17 , wherein the light sensor is arranged behind the light source near a center point of the display panel.
19. The system as recited in claim 17 , further comprising a plurality of light sensors, each arranged behind the light source and centered behind a different section of the display panel.
20. The system as recited in claim 16 , further comprising a storage medium containing the stored set of characterization values, which were previously determined during manufacturing of the system.