초록 ▼

A gate-on voltage generator that can enhance display quality at low temperatures, a driving device, and a display apparatus having the same, in which the gate-on voltage generator includes a temperature sensor having an operational amplifier configured to receive a driving voltage and produce a temp

A gate-on voltage generator that can enhance display quality at low temperatures, a driving device, and a display apparatus having the same, in which the gate-on voltage generator includes a temperature sensor having an operational amplifier configured to receive a driving voltage and produce a temperature-dependent variable voltage, the level of which varies according to the ambient temperature, and a charge pumping unit shifting the temperature-dependent variable voltage by the voltage level of a pulse signal and generating a gate-on voltage.

대표청구항 ▼

1. A driving device comprising: a boost converter which receives and boosts a first input voltage and outputs a driving voltage and a pulse signal, the driving voltage and an amplitude of the pulse signal being irrelevant to an ambient temperature;a gate-on voltage generator comprising: a temperatur

1. A driving device comprising: a boost converter which receives and boosts a first input voltage and outputs a driving voltage and a pulse signal, the driving voltage and an amplitude of the pulse signal being irrelevant to an ambient temperature;a gate-on voltage generator comprising: a temperature sensor provided with an operational amplifier configured to receive a driving voltage and produce a temperature-dependent variable voltage, the level of which varies according to the ambient temperature, anda charge pumping unit configured to shift the temperature-dependent variable voltage by the amplitude of the pulse signal and to generate a gate-on voltage;a gate-off voltage generator configured to shift the voltage level of a second input voltage by the amplitude of the pulse signal and to generate a gate-off voltage; anda switching unit generating a clock signal having a swing of a voltage difference between the gate-on voltage and the gate-off voltage. 2. The driving device of claim 1, wherein the voltage level of the temperature-dependent variable voltage increases when the ambient temperature falls, and the voltage level of the temperature-dependent variable voltage decreases when the ambient temperature rises. 3. The driving device of claim 2, wherein the operational amplifier increases a change of the temperature-dependent variable voltage according to the change of the ambient temperature. 4. The driving device of claim 2, wherein the temperature sensor comprises: a comparison voltage generator including one or more diodes each having a variable threshold voltage according to a change of the ambient temperature and generating a comparison voltage having a variable voltage level according to the ambient temperature; andan amplifier including the operational amplifier and amplifying a difference between the comparison voltage and the reference voltage. 5. The driving device of claim 4, wherein the comparison voltage generator further includes a fixed resistor connected between a first node and a second node and the diodes that are connected in series between the second node and a third node, wherein a positive voltage is applied to the first node, the comparison voltage is output via the second node, and a ground voltage is applied to the third node. 6. The driving device of claim 4, wherein the comparison voltage generator includes a fixed resistor connected between a first node and a second node and the diodes that are connected in series between the second node and a third node, wherein a positive voltage is applied to the first node, the comparison voltage is output via the second node, and a negative voltage is applied to the third node. 7. The driving device of claim 6, wherein the temperature sensor further comprises a voltage divider that divides the gate-off voltage and provides the negative voltage to the third node. 8. The driving device of claim 4, wherein the temperature sensor further comprises a buffer that provides the amplifier with the comparison voltage without alteration. 9. A driving device, comprising: a boost converter receiving and boosting a first input voltage and outputting a driving voltage and a pulse signal, the driving voltage and an amplitude of the pulse signal not being influenced by an ambient temperature;a gate-on voltage generator comprising: a first temperature sensor configured to output a first temperature-dependent variable voltage; anda first charge-pumping unit configured to shift the first temperature-dependent variable voltage by the amplitude of the pulse signal and to output a gate-on voltage, the first temperature-dependent variable voltage varying in inverse proportion to the ambient temperature;a gate-off voltage generator comprising: a second temperature sensor configured to output a second temperature-dependent variable voltage; anda second charge-pumping unit configured to shift the second temperature-dependent variable voltage by the amplitude of the pulse signal and to output a gate-off voltage, the second temperature-dependent variable voltage varying in proportion to the ambient temperature; anda switching unit which outputting a clock signal that swings between the gate-on voltage and the gate-off voltage. 10. The driving device of claim 9, wherein the first temperature sensor comprises: a comparison voltage generator including one or more diodes having a variable threshold voltage that varies in inverse proportion to the ambient temperature, and providing a comparison voltage that varies according to the ambient temperature; anda non-inverting amplifier receiving the comparison voltage and increasing a range of variation of the first temperature-dependent variable voltage according to the ambient temperature. 11. The driving device of claim 10, wherein the comparison voltage generator further includes a fixed resistor connected between a first node and a second node and the diodes that are connected in series between the third node and a third node, wherein the driving voltage is applied to the first node, the comparison voltage is output via the second node, and a negative voltage is applied to the third node. 12. The driving device of claim 10, wherein the comparison voltage generator further includes a fixed resistor connected between a first node and a second node and the diodes that are connected in series between the third node and a third node, wherein the driving voltage is applied to the first node, the comparison voltage is output via the second node, and a ground voltage is applied to the third node. 13. The driving device of claim 9, wherein the second temperature sensor comprises: a comparison voltage generator including one or more diodes having a variable threshold voltage that varies in inverse proportion to the ambient temperature, and providing a comparison voltage that varies according to the ambient temperature; anda inverting amplifier receiving the comparison voltage and increasing a range of variation of the second temperature-dependent variable voltage according to the ambient temperature. 14. A display apparatus comprising: a driving device comprising: a boost converter configured to receive and boost a first input voltage and to output a driving voltage and a pulse signal, the driving voltage and an amplitude of the pulse signal not being influenced by an ambient temperature;a gate-on voltage generator comprising: a temperature sensor configured to receive a driving voltage and to produce a temperature-dependent variable voltage, the level of which varies according to an ambient temperature; anda charge pumping unit configured to shift the temperature-dependent variable voltage by an amplitude of the pulse signal and to generate a gate-on voltage;a gate-off voltage generator configured to shift a voltage level of a second input voltage by the amplitude of the pulse signal and to generate a gate-off voltage; anda switching unit configured to generate a clock signal having a swing of a voltage difference between the gate-on voltage and the gate-off voltage;a gate driver configured to receive the clock signal and to output gate-on voltages having an amplitude that increases when the ambient temperature falls and that decreases when the ambient temperature rises consecutively;a data driver configured to provide gray voltages corresponding to image data; anda display panel configured to display images corresponding to the gray voltages responsive to the gate-on voltages. 15. The display apparatus of claim 14, wherein the voltage level of the temperature-dependent variable voltage increases when the ambient temperature falls, and the voltage level of the temperature-dependent variable voltage decreases when the ambient temperature rises. 16. The display apparatus of claim 14, wherein the gate driver comprises one or more stages that receive the clock signal and output the gate-on voltages, each of the stages including an a-Si thin film transistor that receives the clock signal. 17. The display apparatus of claim 14, wherein the temperature sensor comprises: a comparison voltage generator provided with one or more diodes each having a variable threshold voltage according to a change of the ambient temperature and generating a comparison voltage having a variable voltage level according to the ambient temperature; andan amplifier including an operational amplifier for amplifying a difference between the comparison voltage and the reference voltage. 18. The display apparatus of claim 17, wherein the temperature sensor further comprises a fixed resistor connected between a first node and a second node and one or more diodes that are connected in series between the second node and a third node, wherein the driving voltage is applied to the first node, the comparison voltage is output via the second node, and a ground voltage is applied to the third node. 19. The display apparatus of claim 17, wherein the temperature sensor further comprises a fixed resistor connected between a first node and a second node and one or more diodes that are connected in series between the second node and a third node, wherein the driving voltage is applied to the first node, the comparison voltage is output via the second node, and a negative voltage is applied to the third node. 20. The display apparatus of claim 19, wherein the temperature sensor further comprises a voltage divider that divides the gate-off voltage and provides the negative voltage to the third node. 21. The display apparatus of claim 17, wherein the temperature sensor further comprises a buffer that provides the amplifier with the comparison voltage without alteration.