Timing controller and display device including the same
Disclosed is a timing controller and a display device including the same. More specifically, the present disclosure relates to a timing controller which unequally sets a pulse width modulation (PWM) pulse width of each of one or more subframes corresponding to a gray level value of pixel data, thereby allowing the luminance of a display device to nonlinearly increase, and a display device including the same.
1 . A timing controller comprising:
a memory configured to store a plurality of subframe information obtained by time-dividing a unit frame period;
a data analysis circuit configured to receive input image data from a host and check one pixel gray value which is a gray level value of one pixel data included in the input image data; and
a pulse width setting circuit configured to set a pulse width modulation (PWM) pulse width of each of one or more subframes corresponding to the one pixel gray value unequally per each subframe,
wherein the memory is configured to further store a pulse width increase amount for preset gray level values in a lookup table, and
wherein the pulse width increase amount gradually increases as a gray level value in a low gray level section increases to a specific gray level value.
2 . The timing controller of claim 1 , wherein the preset gray level values are set for an entire gray level ranges from a first gray level which is a minimum gray level value to an N-th gray level which is a maximum gray level value, wherein N is a natural number greater than or equal to 2.
3 . The timing controller of claim 1 , wherein the pulse width setting circuit is configured to read one or more pulse width increase amounts corresponding to one or more gray level values included in a range from a minimum gray level value to one pixel gray level value, from the lookup table.
4 . The timing controller of claim 3 , wherein the pulse width setting circuit is configured to set the PWM pulse width of each of the one or more subframes using the one or more pulse width increase amounts.
5 . The timing controller of claim 2 , wherein the entire gray level range is divided into a plurality of gray level sections in the lookup table,
wherein a first gray level section among the plurality of gray level sections includes gray level values from the minimum gray level value to a first critical gray level value, and
wherein, in the first gray level section, a pulse width increase amount unequally increases whenever a gray level value increases by 1.
6 . The timing controller of claim 5 , wherein the pulse width increase amount gradually increases as the gray level value in the first gray level section approaches the first critical gray level value.
7 . The timing controller of claim 5 , wherein an emission time for each gray level in a low gray level section is non-linearly increased according to the unequal increase of the pulse width increase amount.
8 . A timing controller comprising:
a memory configured to store a plurality of subframe information obtained by time-dividing a unit frame period;
a data analysis circuit configured to receive input image data from a host and check one pixel gray value which is a gray level value of one pixel data included in the input image data; and
a pulse width setting circuit configured to set a pulse width modulation (PWM) pulse width of each of one or more subframes corresponding to the one pixel gray value unequally per each subframe,
wherein the pulse width setting circuit is configured to calculate one pixel gray level value and a pulse width increase amount for each of grays values that are lower than the one pixel gray level value using a following equation:
dPW
(
Gray
)
=
(
Gray
Gray
Max
)
Gamma
-
(
Gray
-
1
Gray
Max
)
Gamma
(
Gray_Tap
(
n
+
1
)
Gray
Max
)
Gamma
-
(
Gray_Tap
(
n
)
Gray
Max
)
Gamma
wherein, “Gray” denotes a target gray level value of which the pulse width increase amount is to be calculated,
“dPW(Gray)” denotes a pulse width increase amount of the target gray level value,
“Gray Max ” denotes the maximum gray level value,
“Gamma” denotes a gamma curve value,
“Gray−1” denotes a gray level value that is smaller than the target gray level value by one gray level,
“Gray_Tap(n+1)” denotes a critical gray level value of a gray level section including the target gray level value, and
“Gray_Tap(n)” denotes a critical gray level value of a gray level section that is lower than the gray level section including the target gray level value.
9 . The timing controller of claim 8 , wherein the pulse width setting circuit is configured to:
divide an entire gray level range from a minimum gray level value to a maximum gray level value into a plurality of gray level sections; and
set a critical gray level value for distinguishing the plurality of gray level sections for each gray level section.
10 . A display device comprising:
a gate driver configured to supply a scan signal to scan lines of a display panel in response to a gate control signal; and
a timing controller configured to time-divide a unit frame period, which is a period for displaying one image, into a plurality of subframes, unequally set a pulse width modulation (PWM) pulse width of each of one or more subframes, which corresponds to one pixel gray level value data which is a gray level value of one pixel data included in input image data received, and allow the PWM pulse width for each subframe set for each of the one or more subframes to be included in the gate control signal to supply the PWM pulse width to the gate driver,
wherein the timing controller includes:
a memory configured to store a plurality of subframe information obtained by time-dividing a unit frame period;
a data analysis circuit configured to receive input image data from a host and check one pixel gray value which is a gray level value of one pixel data included in the input image data; and
a pulse width setting circuit configured to set a pulse width modulation (PWM) pulse width of each of one or more subframes corresponding to the one pixel gray value unequally per each subframe,
wherein the memory is configured to further store a pulse width increase amount for preset gray level values in a lookup table, and
wherein the pulse width increase amount gradually increases as a gray level value in a low gray level section increases to a specific gray level value.
11 . The display device of claim 10 , wherein the preset gray level values are set for an entire gray level ranges from a first gray level which is a minimum gray level value to an N-th gray level which is a maximum gray level value, wherein N is a natural number greater than or equal to 2.
12 . The display device of claim 10 , wherein the pulse width setting circuit is configured to read one or more pulse width increase amounts corresponding to one or more gray level values included in a range from a minimum gray level value to one pixel gray level value, from the lookup table.
13 . The display device of claim 12 , wherein the pulse width setting circuit is configured to set the PWM pulse width of each of the one or more subframes using the one or more pulse width increase amounts.
14 . The display device of claim 11 , wherein the entire gray level range is divided into a plurality of gray level sections in the lookup table,
wherein a first gray level section among the plurality of gray level sections includes gray level values from the minimum gray level value to a first critical gray level value, and
wherein, in the first gray level section, a pulse width increase amount unequally increases whenever a gray level value increases by 1.
15 . The display device of claim 14 , wherein the pulse width increase amount gradually increases as the gray level value in the first gray level section approaches the first critical gray level value.
16 . The display device of claim 14 , wherein an emission time for each gray level in a low gray level section is non-linearly increased according to the unequal increase of the pulse width increase amount.
17 . The display device of claim 10 , wherein the pulse width setting circuit is configured to calculate one pixel gray level value and a pulse width increase amount for each of grays values that are lower than the one pixel gray level value using a following equation:
dPW
(
Gray
)
=
(
Gray
Gray
Max
)
Gamma
-
(
Gray
-
1
Gray
Max
)
Gamma
(
Gray_Tap
(
n
+
1
)
Gray
Max
)
Gamma
-
(
Gray_Tap
(
n
)
Gray
Max
)
Gamma
wherein, “Gray” denotes a target gray level value of which the pulse width increase amount is to be calculated,
“dPW(Gray)” denotes a pulse width increase amount of the target gray level value,
“Gray Max ” denotes the maximum gray level value,
“Gamma” denotes a gamma curve value,
“Gray−1” denotes a gray level value that is smaller than the target gray level value by one gray level,
“Gray_Tap(n+1)” denotes a critical gray level value of a gray level section including the target gray level value, and
“Gray_Tap(n)” denotes a critical gray level value of a gray level section that is lower than the gray level section including the target gray level value.