Optical compensation device, display device, and optical compensation method of display device
An optical compensation device includes a luminance measurer that measures display luminance of a display device including a plurality of areas. A gamma corrector corrects a gamma voltage so that a first area of the plurality of areas has a gamma characteristic corresponding to a target gamma value based on the display luminance, and calculates a gamma value for each of the plurality of areas based on the display luminance. An optical compensator calculates a compensation parameter for each grayscale based on the display luminance and the gamma value. A luminance deviation for each of plurality of areas of the display device is compensated based on the compensation parameter.
1. An optical compensation device for a display device including a plurality of areas, the optical compensation device comprising:
a luminance measurer which measures a display luminance of the display device;
a gamma corrector which corrects a gamma voltage so that a first area of the plurality of areas has a gamma characteristic corresponding to a target gamma value based on the display luminance, and calculates a gamma value for each of the plurality of areas based on the display luminance; and
an optical compensator which calculates a compensation parameter for each of grayscales based on the display luminance and the gamma value,
wherein a luminance deviation for each of the plurality of areas of the display device is compensated based on the compensation parameter, and
wherein after the gamma voltage is corrected by the gamma corrector, in a process of generating the compensation parameter, the luminance measurer measures the display luminance for only one reference grayscale.
2. The optical compensation device of claim 1 , wherein the gamma corrector calculates the gamma value based on display luminances measured corresponding to a plurality of reference grayscales in a process of correcting the gamma voltage.
3. The optical compensation device of claim 2 , wherein at least two areas of the plurality of areas have different gamma values from each other.
4. The optical compensation device of claim 2 , wherein the display device further includes a pixel, and
wherein a first compensation parameter for a first grayscale of the grayscales is defined as a ratio of a first target luminance to a first display luminance of the pixel corresponding to the first grayscale.
5. The optical compensation device of claim 4 , wherein the optical compensator calculates a second target luminance of the pixel for a second grayscale of the grayscales based on the first target luminance and the target gamma value, predicts a second display luminance of the pixel corresponding to the second grayscale based on the first display luminance and the gamma value, and calculates a second compensation parameter for the second grayscale based on the second target luminance and the second display luminance.
6. The optical compensation device of claim 5 , wherein the optical compensator calculates the compensation parameter based on an equation below,
C
i
=
L
Ti
L
Pi
=
L
T
1
·
(
Gi
/
G
1
)
Υ
T
L
P
1
·
(
Gi
/
G
1
)
Υ
P
[
Equation
]
wherein Ci denotes a compensation parameter for an i-th grayscale of the grayscales where i is a positive integer, L Ti denotes a target luminance for an i-th reference grayscale of the plurality of reference grayscales, L T1 denotes a target luminance for a first reference grayscale of the plurality of reference grayscales, Gi denotes a value of the i-th reference grayscale, G1 denotes a value of the first reference grayscale, γ T denotes a target gamma value, L Pi denotes a predicted luminance of a corresponding pixel for the i-th reference grayscale, L P1 denotes a measured luminance of the corresponding pixel for the first reference grayscale, and γ P denotes a gamma value of an area of the plurality of areas including the corresponding pixel.
7. The optical compensation device of claim 5 , wherein the optical compensator generates first compensation data including the first compensation parameter and second compensation data including the second compensation parameter, respectively.
8. The optical compensation device of claim 5 , wherein the optical compensator calculates a compensation value for the first grayscale based on the first display luminance and the first compensation parameter, and
wherein the compensation value corresponds to a grayscale of the grayscales which causes the pixel to emit light with the first target luminance.
9. A display device comprising:
a display panel including pixels;
a storage which stores compensation data including a compensation parameter set for at least a pixel of the pixels;
a data compensator which generates compensated data by compensating image data based on the compensation data; and
a data driver which generates data voltages based on the compensated data and provides the data voltages to the pixels,
wherein the data compensator calculates a display luminance for each of grayscales of the pixels based on the compensation parameter, calculates a compensation value based on a difference between the display luminance and a target luminance for each of the grayscales, and compensates a data value included in the image data based on the compensation value, and
wherein the compensation parameter for a first grayscale of the grayscales is defined as a ratio of the target luminance to the display luminance of the pixels corresponding to the first grayscale.
10. The display device of claim 9 , wherein the compensation data further includes a gamma value for the at least the pixel of the pixels.
11. An optical compensation method for a display device including a plurality of areas, the method comprising:
while measuring display luminance of the display device, correcting a gamma voltage based on the display luminance so that a first area of the plurality of areas has a gamma characteristic corresponding to a target gamma value;
calculating a gamma value for each of the plurality of areas based on the display luminance; and
calculating a compensation parameter for each of grayscales based on the display luminance and the gamma value,
wherein the calculating the compensation parameter includes measuring only the first display luminance of the display device for the first grayscale once.
12. The optical compensation method of claim 11 , wherein a luminance deviation for each of the plurality of areas of the display device is compensated based on the compensation parameter.
13. The optical compensation method of claim 11 , wherein the correcting the gamma voltage includes:
providing a first data voltage corresponding to a first reference grayscale to the display device, and measuring the first display luminance of the display device displaying an image corresponding to the first data voltage;
determining whether a difference between a first target luminance for the first reference grayscale and the first display luminance is within a reference range; and
determining the first data voltage as an updated gamma voltage when the difference between the first target luminance and the first display luminance is within a reference range.
14. The optical compensation method of claim 11 , wherein the calculating the compensation parameter includes:
measuring the first display luminance of the display device for the first grayscale of the grayscales;
calculating a first compensation parameter for the first grayscale based on the first display luminance; and
calculating a second compensation parameter for a second grayscale of the grayscales different from the first grayscale based on the first display luminance and the gamma value.
15. The optical compensation method of claim 14 , wherein the first compensation parameter is defined as a ratio of a first target luminance for the first grayscale to the first display luminance.
16. The optical compensation method of claim 15 , wherein the calculating the second compensation parameter includes:
calculating a second target luminance of a pixel for the second grayscale based on the first target luminance and the target gamma value;
predicting a second display luminance of the pixel corresponding to the second grayscale based on the first display luminance and the gamma value; and
calculating the second compensation parameter based on the second target luminance and the second display luminance.
17. The optical compensation method of claim 16 , wherein in the calculating the second compensation parameter, the compensation parameter is calculated based on a following equation,
C
i
=
L
Ti
L
Pi
=
L
T
1
·
(
Gi
/
G
1
)
Υ
T
L
P
1
·
(
Gi
/
G
1
)
Υ
P
[
Equation
]
wherein Ci denotes a compensation parameter for an i-th grayscale of the grayscales where i is a positive integer, L Ti denotes a target luminance for an i-th reference grayscale, L T1 denotes a target luminance for a first reference grayscale, Gi denotes a value of the i-th reference grayscale, G1 denotes a value of the first reference grayscale, γT denotes a target gamma value, L Pi denotes a predicted luminance of a corresponding pixel for the i-th reference grayscale, L P1 denotes a measured luminance of the corresponding pixel for the first reference grayscale, and γP denotes a gamma value of an area of the plurality of areas including a corresponding pixel.
18. The optical compensation method of claim 16 , wherein the calculating the first compensation parameter includes calculating a compensation value for the first grayscale based on the first display luminance and the first compensation parameter, and
wherein the compensation value corresponds to a grayscale of the grayscales which causes the pixel to emit light with the first target luminance.