1. A display for an electronic device comprising:
a pixel, comprising:
a first gate of a first thin-film transistor (TFT) disposed over a substrate;
a first insulator layer disposed over the first gate;
a second gate of a second TFT disposed over the first insulator layer, wherein the first insulator layer onto which the second gate is disposed is the same first insulator layer that is disposed over the first gate;
a second insulator layer disposed over the first insulator layer and the second gate, such that the first gate is interposed between the substrate and the first insulator layer and the second gate is interposed between the first insulator layer and the second insulator layer;
a TFT layer disposed directly on the second insulator layer, wherein the TFT layer comprises a source, a drain, and a channel of the first TFT or the second TFT disposed adjacent to the source and the drain;
a third insulator layer disposed over the TFT layer;
a first via coupled to the source and extending through the third insulator layer;
a second via coupled to the drain and extending through the third insulator layer;
and a pixel electrode disposed directly over the third insulator layer.
2. The display of claim 1, comprising a conductor configured to electrically couple the drain to the pixel electrode.
3. The display of claim 1, comprising an organic light emitting diode (OLED) layer disposed over the second insulator layer.
4. The display of claim 1, comprising a top electrode layer disposed over the second insulator layer.
5. An electronic display comprising:
a matrix of pixels, each comprising:
a driving thin-film transistor (TFT) comprising a first source, a first drain, a first channel, and a first gate;
a circuit TFT comprising a second source, a second drain, a second channel, and a second gate, wherein the second drain is electrically coupled to the first gate;
a first gate insulator layer disposed over the first gate of the driving TFT, and the second gate of the circuit TFT is disposed over the first gate insulator layer, wherein the first gate insulator layer onto which the second gate is disposed is the same first gate insulator layer that is disposed over the first gate of the driving TFT;
a second gate insulator layer disposed over the second gate of the circuit TFT, wherein the first source, the first drain, and the first channel of the driving TFT are disposed directly over the second gate insulator layer, and the second source, the second drain, and the second channel of the circuit TFT are disposed directly over the second gate insulator layer, such that the first gate insulator layer is positioned between the first gate of the driving TFT and the second gate of the circuit TFT and the second gate is positioned between the first insulator layer and the second insulator layer;
an interlayer dielectric (ILD) disposed over the first source, the first drain, and the first channel of the driving TFT, and the second source, the second drain, and the second channel of the circuit TFT;
a first via coupled to the first source or the second source and extending through the ILD;
a second via coupled to the first drain or the second drain and extending through the through the ILD;
and a pixel electrode disposed directly over the ILD.
6. The electronic device of claim 5, comprising an insulator layer disposed over the ILD.
7. The electronic device of claim 5, wherein the pixel electrode disposed over the ILD is electrically coupled to the first drain.
8. The electronic device of claim 5, comprising an organic light emitting diode (OLED) layer disposed over the ILD.
9. The electronic device of claim 5, comprising a top electrode layer disposed over the ILD.
10. The electronic device of claim 5, wherein the first gate of the driving TFT is electrically coupled to the second drain of the circuit TFT.
11. A display comprising:
an array of pixels, each comprising:
a first source, a first drain, and a first channel of a first thin-film transistor (TFT) disposed over a first gate of the first TFT;
a second source, a second drain, and a second channel of a second TFT disposed over a second gate of the second TFT;
a continuous gate insulator layer disposed over a substrate;
wherein the first gate of the first TFT is disposed over the substrate, and the continuous gate insulator layer is disposed over the first gate, and wherein the second gate of the second TFT is disposed over the continuous gate insulator layer such that the first gate is placed between the substrate and the continuous gate insulator layer and the second gate is disposed over the same continuous gate insulator disposed over the first gate;
a second insulator layer disposed over the continuous gate insulator layer and the second gate;
a first channel of the first TFT and a second channel of the second TFT disposed directly on the second insulator layer;
a third insulator layer disposed over the first source, the first drain, and the first channel of the first TFT, and the second source, the second drain, and the second channel of the second TFT;
a first via coupled to the first source or the second source and extending through the third insulator layer;
a second via coupled to the first drain or the second drain and extending through the third insulator layer;
and a pixel electrode disposed directly over the third insulator layer.
12. The display of claim 11, wherein the third insulator layer comprises an interlayer dielectric (ILD).
13. The display of claim 12, comprising an insulator layer disposed over the ILD.
14. The display of claim 12, wherein the pixel electrode disposed over the ILD is electrically coupled to the first drain of the first TFT.
15. The display of claim 12, comprising an organic light emitting diode (OLED) layer disposed over the ILD.
16. A method comprising:
disposing a first gate of a driving thin-film transistor (TFT) over a substrate;
disposing a first gate insulator layer over the first gate;
disposing a second gate of a circuit TFT over the first gate insulator layer,
wherein disposing the second gate comprises disposing the second gate over the identical first gate insulator layer that is disposed over the first gate;
disposing a second gate insulator layer over the second gate, such that the first gate is interposed between the substrate and the first gate insulator layer and the second gate is interposed between the first gate insulator layer and the second gate insulator layer;
disposing a first source, a first drain, and a first channel of the driving TFT directly on the second gate insulator layer, and a second source, a second drain, and a second channel of the circuit TFT directly on the second gate insulator layer;
disposing an interlayer dielectric (ILD) layer over the first source, the first drain, and the first channel of the driving TFT, and over the second source, the second drain, and the second channel of the circuit TFT;
depositing a first via, wherein the first via is coupled to the first source and extends through the ILD layer;
depositing a second via, wherein the second via is coupled to the first drain and extends through the ILD layer;
disposing a pixel electrode directly over the ILD layer;
and electrically coupling an organic light emitting diode (OLED) layer to the driving TFT.
17. The method of claim 16, wherein the pixel electrode is electrically coupled to the first drain of the driving TFT and to the OLED layer.
18. The method of claim 17, comprising disposing an insulator layer over the ILD layer and the pixel electrode.
19. The method of claim 18, comprising disposing a top electrode layer extending over the OLED layer and the insulator layer.
20. A method of manufacturing a display comprising:
providing a display panel, wherein the display panel comprises a plurality of unit pixels, each comprising:
a first gate of a first thin-film transistor (TFT) disposed over a substrate;
a first insulator layer disposed over the first gate;
a second gate of a second TFT disposed over the first insulator layer, wherein the first insulator layer onto which the second gate is disposed is the same first insulator layer that is disposed over the first gate;
a second insulator layer disposed over the first insulator layer and the second gate, such that the first gate is disposed between the substrate and the first insulator layer and the second gate is disposed between the first insulator layer and the second insulator layer;
a first TFT layer and a second TFT layer disposed directly on the second insulator layer, wherein the first TFT layer and the second TFT layer each comprises a source, a drain, and a channel disposed adjacent to the source and the drain;
a third insulator layer disposed over the first TFT layer and the second TFT layer;
a first via coupled to the first source and extending through the third insulator layer;
a second via coupled to the first drain and extending through the third insulator layer;
and a pixel electrode disposed directly over the third insulator layer;
wherein the first gate of the first TFT is electrically coupled to a second drain of the second TFT;
coupling a processing device to the display panel;
and disposing the display panel and the processing device inside a housing.
21. The method of claim 20, comprising disposing a top electrode layer over the second insulator layer.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A display device (500) comprising:
a plurality of switches (510), each of the switches comprising an operational terminal (D) and controlling a voltage on said operational terminal (D);
a plurality of pixels (555), each having a pixel state (P) that is driven by a driving voltage differential (VEP) between a pixel voltage (Vpx) applied to a pixel terminal (101) of the pixel and a common voltage (VCE) applied to a common terminal (102) of the pixel, said pixel terminal being coupled to a corresponding operational terminal (D) of the switch;
a common driver (570) for providing a variable common voltage (VCE) to the common terminals (102); and
a controller (515) controlling the switches (510) for driving the plurality of pixels (555), the controller (515) being arranged to control the common driver in a first pixel driving state (1120), wherein pixels are driven to a first colour, to provide a common voltage to the common terminals with a first polarity and to control the common driver in a second pixel driving state (1140), wherein pixels are driven to a second colour, to provide a common voltage to the common terminals with a second polarity opposite to the first polarity, wherein a swing on the common voltage is larger than a swing on the pixel voltage.
2. A display device (500) according to claim 1 wherein the plurality of switches are semiconductor switching devices (510), each comprising a first operational terminal (S), a switching control terminal (G), and a second operational terminal (D); the display device further comprising:
a column driver (530) connected to the first operational terminals (S) for providing column voltages (Vcol); and
a row driver (520) connected to the switching control terminals (G) for providing a row select voltage switching the semiconductor switching devices of a row to a conductive state and a row non-select voltage switching the semiconductor switching devices of a row to a non-conductive state; wherein
the pixel terminal of each of the pixels is coupled to the second operational terminal (D) of the corresponding semiconductor switching device and the pixel voltage (Vpx) being applied to the pixel terminal (101) by providing a column voltage to the first operational terminal (S) of a corresponding semiconductor switching device being in the conductive state;
the controller (515) is arranged for controlling the operation of the column driver (530), the row driver (520), and the common driver (570) for driving the plurality of pixels (555), such that the swing on the common voltage, is larger than a swing on the column voltage, i.e. an absolute value of the difference between a maximum column voltage and a minimum column voltage, which can be provided by the column driver.
3. A display device (500) according to claim 2, wherein a swing on the row voltage, i.e. an absolute value of the difference between the row select voltage and the row non-select voltage is larger than a swing on the column voltage, i.e. an absolute value of the difference between a maximum column voltage and a minimum column voltage, which can be provided by the column driver during the first and the second driving state, in such a way that the semiconducting switching devices (510) can be switched in their conducting state and in their non-conducting state irrespective of column and pixel voltage levels.
4. A display device (500) according to claim 2, additionally comprising a storage driver for providing a storage voltage (Vst) to a storage capacitor (Cst), connected between the storage driver and the pixel terminal (101) of the pixel, having a storage voltage swing being proportional to a common voltage swing, wherein the storage driver is controlled, by the controller (515) to change the value of the storage voltage with proportional amplitude to and at substantially the same time as the common voltage.
5. A display device (500) according to claim 4, wherein the common driver (570) and the storage driver are controlled, by the controller (515) during a start up phase (1110) for an image update before the first or second pixel driving state, in a first step (1210) to change a value of the common voltage and the storage voltage so that due to the change a value of the pixel voltage is changed to a value that keeps the semiconducting switching device (510) in its non-conducting state, wherein the column driver (520) is controlled, by the controller (515) in at least one reset step (1220) to reset the value of the pixel voltage and wherein the common driver (570) and the storage driver are controlled, by the controller (515) in a second step (1230) to change the value of the common voltage and the storage voltage to the value corresponding to the first or second driving state, which ever is applicable.
6. A display device (500) according to claim 5, wherein the common driver (570) and storage driver are controlled, by the controller (515) during the start up phase, in a third step (1710) to provide a common voltage and storage voltage enabling the provision of a zero voltage over the pixels or a common voltage with a polarity opposite to the polarity of the common voltage during the remainder of the start-up phase.
7. A display device (500) according to claim 4, wherein the common driver (570) and storage driver are controlled, by the controller (515) during a transition phase (1130,1150) from the first to the second pixel driving state or vice versa, to change the value of the common voltage and the storage voltage in a number of steps (1310) from the value corresponding to the first pixel driving state to the second pixel driving state or vice versa, each of the stepwise value changes of the common voltage and storage voltage resulting in a value change of the pixel voltage, wherein the column driver (520) is controlled, by the controller (515) in at least a reset step (1320) between the steps to change the column voltage in such a way that the value of the pixel voltage is changed in a direction opposite to the direction of the value change of the pixel voltage caused by the value change of the common voltage and the storage voltage.
8. A display device (500) according to claim 4, wherein the common driver (570) and storage driver are controlled, by the controller (515) during a shutdown phase (1160) at the end of an image update after the first or second pixel driving state to change the value of the common voltage and the storage voltage in a number of steps to their final values, each of the stepwise value changes of the common voltage and storage voltage resulting in a value change of the pixel voltage, wherein the column driver (520) is controlled, by the controller (515) in at least a reset step between the steps to change the column voltage in such a way that the value of the pixel voltage is changed in a direction opposite to the direction of the value change of the pixel voltage caused by the value change of the common voltage and the storage voltage.
9. A display device (500) according to claim 8, wherein the common driver (570) and the storage driver are controlled, by the controller (515) during the shutdown phase, in a further step (1810) to provide a common voltage and storage voltage enabling the provision of a zero voltage over the pixels or to provide a common voltage with a polarity opposite to the polarity of the common voltage during the remainder of the shutdown phase.
10. A display device (500) according to claim 2 wherein the semiconductor switching device (510) is a TFT.
11. A method for driving a display device (500) comprising:
a plurality of switches (510), each of the switches comprising an operational terminal (D) and controlling the voltage on said operational terminal (D);
a plurality of pixels (555), each having a pixel state (P) that is driven by a driving voltage differential (VEP) between a pixel voltage (Vpx) applied to a pixel terminal (101) of the pixel and a common voltage (VCE) applied to a common terminal (102) of the pixel, the pixel terminal being coupled to a corresponding operational terminal (D) of the switch;
a common driver (570) for providing a variable common voltage (VCE) to the common terminals (102);
the method comprising: controlling the switches for driving the plurality of pixels (555) and controlling the common driver (570) in a first pixel driving state (1120), wherein pixels are driven to a first colour, to provide a common voltage to the common terminals with a first polarity and in a second pixel driving state (1140), wherein pixels are driven to a second colour, to provide a common voltage to the common terminals with a second polarity opposite to the first polarity, wherein a swing on the common voltage, is larger than a swing on the pixel voltage.
12. A method according to claim 11, wherein the plurality of switches are semiconductor switching devices (510), each comprising a first operational terminal (S), a switching control terminal (G), and a second operational terminal (D); the display device further comprising:
a column driver (530) connected to the first operational terminals (S) for providing column voltages (Vcol); and
a row driver (520) connected to the switching control terminals (G) for providing a row select voltage switching the semiconductor switching devices of a row to a conductive state and a row non-select voltage switching the semiconductor switching devices of a row to a non-conductive state; wherein
the pixel terminal of each of the pixels is coupled to the second operational terminal (D) of the corresponding semiconductor switching device and the pixel voltage (Vpx) being applied to the pixel terminal (101) by providing a column voltage to the first operational terminal (S) of a corresponding semiconductor switching device being in the conductive state;
the method comprising the step of controlling the operation of the column driver (530), the row driver (520), and the common driver (570) for driving the plurality of pixels (555), such that the swing on the common voltage, is larger than a swing on the column voltage, i.e. an absolute value of the difference between a maximum column voltage and a minimum column voltage, which can be provided by the column driver.
13. A method according to claim 12, wherein a swing on the row voltage, i.e. an absolute value of the difference between the row select voltage and the row non-select voltage is larger than a swing on the column voltage, i.e. an absolute value of the difference between a maximum column voltage and a minimum column voltage, which can be provided by the column driver during the first and the second driving state, in such a way that the semiconducting switching devices (510) can be switched in their conducting state and in their non-conducting state irrespective of column and pixel voltage levels.
14. A method according to claim 12, comprising the further step of controlling a storage driver of the display device for providing a storage voltage (Vst) to a storage capacitor (Cst), connected between the storage driver and the pixel terminal (101) of the pixel and having a storage voltage swing (\u0394Vst) being proportional to a common voltage swing, to change the pixel voltage (Vpx) with proportional amplitude to and at substantially the same time as the common voltage, with proportional amplitude to and at substantially the same time as the common voltage.
15. A method according to claim 14, further comprising controlling the common driver (570) and storage driver during a start up phase (1110) for an image update before the first or second pixel driving state, in a first step (1210) to change the common voltage and the storage value to such a value that a value of the pixel voltage is changed to a value that keeps the semiconducting switching device (510) in its non-conducting state, controlling the column driver (520) in at least one reset step (1220) to reset the value of the pixel voltage and controlling the common driver (570) and storage driver in a second step (1230) to change the value of the common voltage and the storage voltage to the value corresponding to the first or second driving state, which ever is applicable.
16. A method according to claim 15, wherein the common driver and storage driver are controlled during the start up phase, in a third step (1710), which is executed before the first step, to provide a common voltage and a storage voltage, enabling the provision of a zero voltage over the pixels or to provide a common voltage with a polarity opposite to the polarity of the common voltage during the remainder of the start-up phase.
17. A method according to claim 14, further comprising controlling the common driver (570) and the storage driver during a transition phase (1130,1150) from the first to the second pixel driving state or vice versa, to change the value of the common voltage and storage voltage in a number of steps (1310) from the value corresponding to the first pixel driving state to the second pixel driving state or vice versa, each of the stepwise value changes of the common voltage and storage voltage resulting in a value change of the pixel voltage, and controlling the column driver (520) in at least a reset step (1320) between the steps to change the column voltage in such a way that the value of the pixel voltage is changed in a direction opposite to the direction of the value change of the pixel voltage caused by the value change of the common voltage and storage voltage.
18. A method according to claim 14, further comprising controlling the common driver (570) and storage driver during a shutdown phase (1160) at the end of an image update after the first or second pixel driving state to change the absolute value of the common voltage and storage voltage in a number of steps to their final values, each of the stepwise value changes of the common voltage and storage voltage resulting in a value change of the pixel voltage, and controlling the column driver (520) in at least a reset step between the steps to change the column voltage in such a way that the value of the pixel voltage is changed in a direction opposite to the direction of the value change of the pixel voltage caused by the value change of the common voltage and storage voltage.
19. A method according to claim 18, wherein the common driver (570) and storage driver are controlled, during the shutdown phase, in a further step (1810) to provide a common voltage and a storage voltage, enabling the provision of a zero voltage over the pixels or to provide a common voltage with a polarity opposite to the polarity of the common voltage during the remainder of the shutdown phase.