Gate line signal drive circuit with improved suppression of the theshold voltage shift or switching elements applied with high voltage
View Patent ↗A gate signal line drive circuit and a display device which realize the suppression of a threshold voltage of an element which is used for a long time are provided. With respect to elements to which a HIGH voltage is applied for a long time, a plurality of elements are connected parallel to each other and are controlled such that at least any one of the plurality of elements is driven by a switching element, and a period during which the element is not driven is set longer than a frame display period.
1. A display device comprising:
a gate signal line drive circuit which is configured to apply a HIGH voltage to a gate signal line during a signal HIGH period which is repeated periodically and to apply a LOW voltage to the gate signal line during a signal LOW period which is a period other than the signal HIGH period,
wherein the gate signal line drive circuit comprises:
a HIGH voltage applying switching element which includes an input electrode, an output electrode, and a gate electrode, and which is brought into an ON state in response to the signal HIGH period and applies a HIGH voltage to the gate signal line from the output electrode, and is brought into an OFF state in response to the signal LOW period;
at least first and second LOW voltage applying switching elements which are connected to the gate signal line parallel to each other, and each of which includes an input electrode, an output electrode, and gate electrode, and which are configured to apply a LOW voltage to the gate signal line from the output electrode in an ON state;
a first AC voltage supplying line being electrically connected with the input electrode of the first LOW voltage applying switching element; and
a second AC voltage supplying line being electrically connected with the input electrode of the second LOW voltage applying switching element,
wherein, in a first period, which includes a predetermined number being two or more of the signal HIGH periods sequentially arriving and which starts during the signal LOW period, the first LOW voltage applying switching element is brought into an OFF state, while the second LOW voltage applying switching element is brought into an ON state in response to the signal LOW period and is brought into an OFF state in response to the signal HIGH period, and
wherein, in a second period, which includes the predetermined number of the signal HIGH periods sequentially arriving, which starts during the signal LOW period, and which follows the first period, the second LOW voltage applying switching element is brought into an OFF state, while the first LOW voltage applying switching element is brought into an ON state in response to the signal LOW period and is brought into an OFF state in response to the signal HIGH period.
2. The display device according to claim 1 , wherein a HIGH voltage is applied to the input electrode of the second LOW voltage applying switching element in response to starting of the second period with a delay from a time at which the second LOW voltage applying switching element is turned off.
3. The display device according to claim 1 , wherein the first LOW voltage applying switching element is turned on in response to starting of the second period with a delay from a time at which a LOW voltage is applied to the input electrode of the first LOW voltage applying switching element.
4. The display device according to claim 1 , wherein the second LOW voltage applying switching element is turned off in response to starting of the second period with a delay from a time at which the first LOW voltage applying switching element is turned on.
5. The display device according to claim 1 ,
wherein the gate signal line drive circuit further comprises at least first and second switching signal supply switching elements which are connected to the gate electrode of the HIGH voltage applying switching element parallel to each other, and each of which includes an input electrode, an output electrode, and a gate electrode, and which apply a LOW voltage to the gate electrode of the HIGH voltage applying switching element from the output electrode in an ON state,
wherein, in the first period, the first switching signal supply switching element is brought into an OFF state, while the second switching signal supply switching element is brought into an ON state in response to the signal LOW period and is brought into an OFF state in response to the signal HIGH period, and
wherein, in the second period, the second switching signal supply switching element is brought into an OFF state, while the first switching signal supply switching element is brought into an ON state in response to the signal LOW period and is brought into an OFF state in response to the signal HIGH period.
6. The display device according to claim 5 , wherein a HIGH voltage is applied to the input electrode of the second switching signal supply switching element in response to starting of the second period with a delay from a time at which the second switching signal supply switching element is turned off.
7. The display device according to claim 5 , wherein the first switching signal supply switching element is turned on in response to starting of the second period with a delay from a time at which a LOW voltage is applied to the input electrode of the first switching signal supply switching element.
8. The display device according to claim 5 , wherein the second switching signal supply switching element is turned off in response to starting of the second period with a delay from a time at which the first switching signal supply switching element is turned on.
9. The display device according to claim 5 ,
wherein the first AC voltage supplying line is further electrically connected with the input electrode of the first switching signal supply switching element, and the second AC voltage supplying line is further electrically connected with the input electrode of the second switching signal supply switching element.
10. A display device comprising:
a display panel; and
a gate signal line drive circuit which is configured to supply a gate signal to the display panel via a gate signal line which extends on the display panel, the gate signal line drive circuit being configured to apply a HIGH voltage to the gate signal line during a signal HIGH period and a LOW voltage to the gate signal line during a signal LOW period which is a period other than the signal HIGH period repeatedly for every frame period which is a period where 1 frame of the display panel is displayed,
wherein the gate signal line drive circuit comprises:
a HIGH voltage applying switching element which includes an input electrode, an output electrode, and a gate electrode, and which is brought into an ON state in response to the signal HIGH period and applies a HIGH voltage to the gate signal line from the output electrode, and is brought into an OFF state in response to the signal LOW period;
at least first and second LOW voltage applying switching elements which are connected to the gate signal line parallel to each other, and each of which includes an input electrode, an output electrode, and a gate electrode, and which are configured to apply a LOW voltage to the gate signal line from the output electrode in an ON state;
a first AC voltage supplying line being electrically connected with the input electrode of the first LOW voltage applying switching element; and
a second AC voltage supplying line being electrically connected with the input electrode of the second LOW voltage applying switching element,
wherein, in a first period, which is a predetermined integer being 2 or more times as long as the frame period, the first LOW voltage applying switching element is brought into an OFF state, while the second LOW voltage applying switching element is brought into an ON state in response to the signal LOW period and is brought into an OFF state in response to the signal HIGH period, and
wherein, in a second period, which is the predetermined integer times as long as the frame period and follows the first period, the second LOW voltage applying switching element is brought into an OFF state, while the first LOW voltage applying switching element is brought into an ON state in response to the signal LOW period and is brought into an OFF state in response to the signal HIGH period.
11. The display device according to claim 10 , wherein a HIGH voltage is applied to the input electrode of the second LOW voltage applying switching element in response to starting of the second period with a delay from a time at which the second LOW voltage applying switching element is turned off.
12. The display device according to claim 10 , wherein the first LOW voltage applying switching element is turned on in response to starting of the second period with a delay from a time at which a LOW voltage is applied to the input electrode of the first LOW voltage applying switching element.
13. The display device according to claim 10 , wherein the second LOW voltage applying switching element is turned off in response to starting of the second period with a delay from a time at which the first LOW voltage applying switching element is turned on.
14. The display device according to claim 10 ,
wherein the gate signal line drive circuit further comprises: at least first and second switching signal supply switching elements which are connected to the gate electrode of the HIGH voltage applying switching element parallel to each other, and each of which includes an input electrode, an output electrode, and a gate electrode, and which apply a LOW voltage to the gate electrode of the HIGH voltage applying switching element from the output electrode in an ON state,
wherein, in the first period, the first switching signal supply switching element is brought into an OFF state, and the second switching signal supply switching element is brought into an ON state in response to the signal LOW period and is brought into an OFF state in response to the signal HIGH period, and
wherein, in the second period, the second switching signal supply switching element is brought into an OFF state, while the first switching signal supply switching element is brought into an ON state in response to the signal LOW period and is brought into an OFF state in response to the signal HIGH period.
15. The display device according to claim 14 , wherein a HIGH voltage is applied to of the second switching signal supply switching element in response to starting of the second period with a delay from a time at which the second switching signal supply switching element is turned off.
16. The display device according to claim 14 , wherein the first switching signal supply switching element is turned on in response to starting of the second period with a delay from a time at which a LOW voltage is applied to the input electrode of the first switching signal supply switching element.
17. The display device according to claim 14 , wherein the second switching signal supply switching element is turned off in response to starting of the second period with a delay from a time at which the first switching signal supply switching element is turned on.
18. The display device according to claim 14 ,
wherein the first AC voltage supplying line is further electrically connected with the input electrode of the first switching signal supply switching element, and the second AC voltage supplying line is further electrically connected with the input electrode of the second switching signal supply switching element.