Display device, controller driver and driving method for display panel
View Patent ↗A display device includes a display panel, an environmental sensor, a correction circuit and a driving circuit. The correction circuit is configured to generate a corrected gray-scale data on the basis of input gray-scale data. The driving circuit is configured to drive the display panel in response to the corrected gray-scale data. The correction circuit generates the corrected gray-scale data by executing a correction using a polynomial in which the input gray-scale data are used as variables. Coefficients of the polynomial are changed in response to an output signal of the environmental sensor.
1. A controller driver, comprising:
an area specifying correction point data setting register configured to store a plurality of correction data, each of which is set correspondingly to one of a plurality of display areas of a display panel;
a correction circuit configured to generate a corrected gray-scale data on a basis of input gray-scale data; and
a driving circuit configured to drive respective ones of said plurality of display areas of said display panel in response to said corrected gray-scale data,
wherein said correction circuit generates said corrected gray-scale data by executing a correction using a polynomial in which said input gray-scale data are used as variables, and
wherein coefficients of said polynomial are changed in response to an output signal supplied from outside of said correction circuit,
wherein said area specifying correction point data setting register selects a corresponding one of said plurality of correction data on a basis of said respective display area including a display position of said input gray-scale data supplied to said correction circuit,
wherein said polynomial is a quadratic polynomial with respect to said input gray-scale data, which is set such that a gamma correction, which corresponds to a gamma curve with respect to a second gamma value of γ logic , is approximately executed,
wherein an entire gamma value of γ display is defined by a following formula:
γ display =γ drive ×γ logic ,
said γ drive is set not to exceed said γ display .
2. The controller driver according to claim 1 ,
wherein said output signal is supplied from said area specifying correction point data setting register and includes said corresponding one of said plurality of correction data, and
wherein coefficients of said polynomial are set by using said corresponding one of said plurality of correction data.
3. The controller driver according to claim 1 ,
wherein said corrected gray-scale data is calculated by using a following formula:
D
γ
=
D
γ
MIN
(
D
IN
3
-
D
IN
)
2
+
2
CP
1
(
D
IN
3
-
D
IN
)
(
D
IN
-
D
IN
MIN
)
(
D
IN
3
)
2
+
CP
3
(
D
IN
-
D
IN
MIN
)
2
,
wherein, when said input gray-scale data is in said first range,
said corrected gray-scale data is calculated by using a following formula:
D
γ
=
CP
2
(
D
IN
MAX
-
D
IN
)
2
+
2
CP
4
(
D
IN
MAX
-
D
IN
)
(
D
IN
-
D
IN
2
)
(
D
IN
MAX
-
D
IN
2
)
2
+
D
γ
MAX
(
D
IN
-
D
IN
2
)
2
,
when said input gray-scale data is in said second range,
wherein said Dγ is said corrected gray-scale data, said D IN is said input gray-scale data, said CP 1 to CP 4 are said first to fourth correction data, said Dγ MIN , said Dγ MAX , said D IN2 and said D IN3 are predetermined parameters.
4. The controller driver according to claim 3 , wherein said D IN3 is a number expressed by using an exponential of two.
5. The controller driver according to claim 4 , wherein said D IN2 is defined as a number, of which (D IN MAX −D IN2 ) is a number expressed by using an exponential of two.
6. The controller driver according to claim 4 , wherein said D IN2 and said D IN3 are set to satisfy a following formula:
D IN MIN <D IN2 <D IN Center <D IN3 <D IN MAX ,
wherein Gamma[x] is defined by a following formula:
Gamma[ x]=Dγ MAX ·( x/D IN MAX ) γ logic ,
said CP 1 to CP 4 are represented by following formulas, respectively,
CP
1
=
4
Gamma
[
(
D
IN
3
-
D
IN
MIN
)
/
2
]
-
Gamma
[
D
IN
MIN
]
-
Gamma
[
D
IN
3
]
2
,
CP
2
=
Gamma
[
D
IN
2
]
,
CP
3
=
Gamma
[
D
IN
3
]
,
CP
4
=
Gamma
[
(
D
IN
MAX
-
D
IN
2
)
/
2
]
-
Gamma
[
D
IN
2
]
-
Gamma
[
D
IN
MAX
]
2
.
7. A controller driver, comprising:
an area specifying correction point data setting register configured to store a plurality of correction data, each of which is set correspondingly to one of a plurality of display panels;
a correction circuit configured to generate a corrected gray-scale data on a basis of input gray-scale data; and
a driving circuit configured to drive a display panel in response to said corrected gray-scale data, the driving circuit being commonly used by said plurality of said display panels,
wherein said correction circuit generates said corrected gray-scale data by executing a correction using a polynomial in which said input gray-scale data are used as variables,
wherein coefficients of said polynomial are changed in response to an output signal supplied from outside of said correction circuit,
wherein said area specifying correction point data setting register stores a plurality of correction data for said plurality of the display panels, and selects a corresponding one of said plurality of correction data based on to which of said plurality of the display panels said input gray-scale data supplied to said correction circuit are displayed,
wherein said driving circuit selects a selection gray-scale voltage from said plurality of gray-scale voltage, and drives a signal line of said display panel into said selection gray-scale voltage,
wherein said polynomial is a quadratic polynomial with respect to said input gray-scale data, which is set such that a gamma correction, which corresponds to a gamma curve with respect to a second gamma value of γ logic , is approximately executed, and
wherein an entire gamma value of γ display is defined by a following formula:
γ display =γ drive ×γ logic ,
said γ drive is set not to exceed said γ display .
8. The controller driver according to claim 7 , wherein said output signal is supplied from said area specifying correction point data setting register and includes said corresponding one of said plurality of correction data, and
wherein coefficients of said polynomial are set by using said corresponding one of said plurality of correction data.
9. The controller driver according to claim 7 , wherein coefficients of said polynomial are set by using said corresponding one of said plurality of correction data.
10. The controller driver according to claim 7 , wherein said corrected gray-scale data is calculated by using a following formula:
D
γ
=
D
γ
MIN
(
D
IN
3
-
D
IN
)
2
+
2
CP
1
(
D
IN
3
-
D
IN
)
(
D
IN
-
D
IN
MIN
)
(
D
IN
3
)
2
+
CP
3
(
D
IN
-
D
IN
MIN
)
2
,
when said input gray-scale data is in said first range, and
said corrected gray-scale data is calculated by using a following formula:
D
γ
=
CP
2
(
D
IN
MAX
-
D
IN
)
2
+
2
CP
4
(
D
IN
MAX
-
D
IN
)
(
D
IN
-
D
IN
2
)
(
D
IN
MAX
-
D
IN
2
)
2
+
D
γ
MAX
(
D
IN
-
D
IN
2
)
2
,
when said input gray-scale data is in said second range,
wherein said Dγ is said corrected gray-scale data, said D IN is said input gray-scale data, said CP 1 to CP 4 are said first to fourth correction data, said Dγ MIN , said Dγ MAX , said D IN2 and said D IN3 are predetermined parameters.
11. The controller driver according to claim 10 , wherein said D IN3 is a number expressed by using an exponential of two.
12. The controller driver according to claim 11 , wherein said D IN2 is defined as a number, of which (D IN MAX −D IN2 ) is a number expressed by using an exponential of two.
13. The controller driver according to claim 11 , wherein said D IN2 and said D IN3 are set to satisfy a following formula:
D IN MIN <D IN2 <D IN Center <D IN3 <D IN MAX ,
wherein Gamma[x] is defined by a following formula:
Gamma[ x]=Dγ MAX ·( x/D IN MAX ) γ logic ,
said CP 1 to CP 4 are represented by following formulas, respectively,
CP
1
=
4
Gamma
[
(
D
IN
3
-
D
IN
MIN
)
/
2
]
-
Gamma
[
D
IN
MIN
]
-
Gamma
[
D
IN
3
]
2
,
CP
2
=
Gamma
[
D
IN
2
]
,
CP
3
=
Gamma
[
D
IN
3
]
,
CP
4
=
Gamma
[
(
D
IN
MAX
-
D
IN
2
)
/
2
]
-
Gamma
[
D
IN
2
]
-
Gamma
[
D
IN
MAX
]
2
.