Display device and driving method thereof
View Patent ↗The present invention relates to a display device capable of reducing power consumption and preventing flicker, as well as a driving method thereof. An exemplary display device includes: a display panel configured for display of a still image and a motion picture; a signal controller programmed to transmit control signals for driving the display panel; and a graphic processing unit transmitting input image data to the signal controller. The signal controller includes a frame memory storing the input image data, and the display panel is driven at a first frequency when the motion picture is displayed and alternatingly driven at the first frequency and a second frequency when the still image is displayed, the second frequency being lower than the first frequency.
1. A display device, comprising:
a display panel configured for display of a still image and a motion picture;
a signal controller programmed to transmit control signals for driving the display panel; and
a graphic processing unit transmitting input image data to the signal controller,
wherein the signal controller includes a frame memory storing the input image data, and
wherein the display panel is driven at a first frequency when the motion picture is displayed, and alternatingly driven at the first frequency and a second frequency when the still image is displayed, the second frequency being lower than the first frequency, a length of a second vertical blank period when the display panel is driven at the second frequency is larger than a length of a first vertical blank period when the display panel is driven at the first frequency, the signal controller providing a dummy data enable signal during the second vertical blank period, wherein one of the dummy data enable signals is provided during each frame period of the second vertical blank period.
2. The display device of claim 1 , wherein:
the graphic processing unit is programmed to transmit a still image start signal and a still image end signal to the signal controller.
3. The display device of claim 2 , wherein:
the signal controller is configured to store the input image data in the frame memory and to interrupt transmission of the input image data to the display panel when the still image start signal is received, and is configured to resume transmission of the input image data when the still image end signal is received.
4. The display device of claim 3 , wherein:
the signal controller is configured to output image data stored in the frame memory to the display panel at the first frequency and the second frequency in alternating manner when the still image start signal is received, and to output the input image data to the display panel at the first frequency when the still image end signal is received.
5. The display device of claim 4 , wherein the signal controller further includes:
a signal receiving unit for receiving the input image data from the graphic processing unit; and
a driving frequency selecting unit configured to alternately select the first frequency and the second frequency when the still image is displayed, and to select the first frequency when the motion picture is displayed.
6. The display device of claim 1 , wherein:
the signal controller is configured to transmit first and second clock signals so as to control a timing of display of images on the display panel, and
when the display panel is driven at the second frequency, the second clock signal has a clock speed lower than that of the first clock signal when the display panel is driven at the first frequency.
7. A display device, comprising:
a display panel configured for display of a still image and a motion picture;
a signal controller programmed to transmit control signals for driving the display panel; and
a graphic processing unit transmitting input image data to the signal controller,
wherein the signal controller includes a frame memory storing the input image data, and
wherein the display panel is driven at a first frequency when the motion picture is displayed, and alternatingly driven at the first frequency and a second frequency when the still image is displayed, the second frequency being lower than the first frequency,
a length of a second vertical blank period when the display panel is driven at the second frequency is larger than a length of a first vertical blank period when the display panel is driven at the first frequency, the signal controller providing a dummy data enable signal during the second vertical blank period, wherein:
the dummy data enable signals are not provided during at least one frame period of the second vertical blank period.
8. A driving method of a display device, comprising:
(a) transmitting input image data to a signal controller from a graphic processing unit;
(b) applying a still image start signal;
(c) driving a display panel at a first frequency and a second frequency in alternating manner;
(d) applying a still image end signal; and
(e) driving the display panel at the first frequency,
wherein the second frequency is lower than the first frequency, wherein:
in (c), a length of a second vertical blank period when the display panel is driven at the second frequency is larger than a length of a first vertical blank period when the display panel is driven at the first frequency and a dummy data enable signal is applied during the second vertical blank period, wherein:
one of the dummy data enable signals is provided during each frame period of the second vertical blank period.
9. The driving method of a display device of claim 8 , wherein:
after (a), the input image data is stored in the frame memory and the transmitting is suspended when the still image start signal is applied and,
the transmitting is resumed when the still image end signal is applied.
10. The driving method of a display device of claim 9 , wherein:
in (c), the image data stored in the frame memory is output to the display panel at the first frequency and the second frequency in alternating manner once the still image start signal is applied, and
in (e), the input image data is output to the display panel at the first frequency once the still image end signal is applied.
11. The driving method of a display device of claim 10 , wherein:
the display panel is configured to display a still image and a motion picture, and
the display panel is driven at the first frequency and the second frequency in alternating manner when the still image is displayed, and is driven at the first frequency when the motion picture is displayed.
12. The driving method of a display device of claim 8 , wherein:
in (c), the signal controller is configured to transmit first and second clock signals so as to control a timing of display of images on the display panel, and when the display panel is driven at the second frequency, the second clock siunal has a clock speed lower than that of the first clock signal when the display panel is driven at the first frequency.
13. A driving method of a display device, comprising:
(a) transmitting input image data to a signal controller from a graphic processing unit;
(b) applying a still image start signal;
(c) driving a display panel at a first frequency and a second frequency in alternating manner;
(d) applying a still image end signal; and
(e) driving the display panel at the first frequency, wherein the second frequency is lower than the first frequency, wherein in (c), a length of a second vertical blank period when the display panel is driven at the second frequency is larger than a length of a first vertical blank period when the display panel is driven at the first frequency and a dummy data enable signal is applied during the second vertical blank period, wherein:
the dummy data enable signals are not provided during at least one frame period of the second vertical blank period.