# Patent

## Title
Display apparatus and method for driving display panel thereof

## Abstract

A display apparatus and a method for driving a display panel thereof are provided. The display panel includes an inducing signal readout line and N gate lines, in which N is a natural number. The inducing signal readout line is coupled to a plurality of inducing circuits. Each inducing circuit is coupled to one of the gate lines, and the Nth gate line is coupled to one of the inducing circuits. In the method, several gate pulses are provided to drive the gate lines sequentially to turn on the corresponding inducing circuits, wherein at least a portion of the driving duration of a gate pulse provided to the Nth gate line is in a blanking time between two frames.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the priority benefit of Taiwan application serial no. 96141070, filed on Oct. 31, 2007. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a display apparatus and a method for driving a display panel thereof. More particularly, the present invention relates to a display apparatus having more uniform induction sensitivity and a method for driving a display panel thereof.
2. Description of Related Art
Among different types of input panel products, an input panel with a sensing film will have a higher cost and a lower transmittance reduced by about 20%. While in embedded input panels, inducing circuits capable of sensing touches are designed depending on characteristics of amorphous-Si, and integrated into a thin film transistor (TFT) array process of a thin film transistor-liquid crystal display (referred to as TFT-LCD). By comparison, embedded input panels have the advantages of low cost and better optical properties, so they have gradually replaced the input panels with a sensing film.
In the design of the embedded input panels, the inducing circuits are added on the original pixel layout of the display panel, so the functions of the inducing circuits must be ensured while not affecting the original optical properties. In other words, the inducing circuits must be compatible with the original panel design, thereby maintaining the display quality and realizing the input function. FIG. 1 is a schematic view of a configuration of inducing circuits of a conventional embedded input panel and gate line signals thereof. Referring to FIG. 1, a display panel is denoted by 100. Inducing circuits are denoted by 102. Gate lines are denoted by G1-GN. Inducing signal readout lines are denoted by R1-RM. A signal processing circuit is denoted by 104. Gate line signals of the gate lines G1-GN are denoted by SG1-SGN. A gate pulse is denoted by 106. A blanking time between two frames is denoted by TB, which will be described below.
Referring to FIG. 1 again, the inducing circuits 102 in FIG. 1 are disposed according to the arrangement of the original pixels (not shown), so the inducing circuits 102 are also referred to as pixel inducing circuits. In FIG. 1, each pixel works together with one inducing circuit 102, and each inducing circuit 102 is coupled to one of the gate lines and one of the inducing signal readout lines. The inducing circuits 102 output an inducing signal to the inducing signal readout lines once receiving a gate pulse, such that the signal processing circuit 104 processes the readout inducing signal.
Generally speaking, the inducing circuits 102 may be realized by two circuit structures respectively as shown in FIG. 2 and FIG. 3. FIG. 2 shows a common charge inducing circuit. Referring to FIG. 2, the charge inducing circuit is denoted by 200. The bias is denoted by VB. The inducing signal readout line is denoted by RX. The gate line is denoted by GX. The charge inducing circuit 200 consists of a TFT 202 for sensing, a TFT 204 serving as a switch, and capacitors 206-210. FIG. 3 shows a common current inducing circuit. Referring to FIG. 3, the current inducing circuit is denoted by 300. The bias is denoted by VB. The inducing signal readout line is denoted by RX. The gate line is denoted by GX. The current inducing circuit 300 consists of a TFT 302 for sensing, a TFT 304 serving as a switch, and capacitors 306-310.
Referring to FIG. 1 again, it can be known from the gate pulse timing in FIG. 1 that in each frame, gate lines in the display panel 100 are sequentially driven in the manner of gate lines G1-GN. Between two adjacent frames, in a short time period, no gate pulse drives the gate lines, which is the previously mentioned blanking time TB. In other words, the blanking time TB can be defined as the time between after the last driven gate line signal SGN closed of the first frame and before the first driven gate line signal SG1 opened of the second frame, the first frame and the second frame are adjacent frames. During the blanking time TB, as all the gate line signals SG1-SGN are in a low voltage level state, the voltage level of the inducing signal are greatly changed, and thus the induction sensitivity of the embedded input panel may be non-uniform, which will be explained with reference to FIG. 4.
FIG. 4 illustrates a relationship between the inducing signal level and the gate line signals SG1-SGN on one of the inducing signal readout lines in FIG. 1. Referring to FIG. 4, the inducing signal level on the inducing signal readout line is denoted by VROUT. The SG1-SGN and symbol TB denote the same as those in FIG. 1. As the gate pulses of the gate line signals SG1-SGN are generated at different time, the gate lines G1-GN are sequentially driven according to the generation sequence of the gate pulses. Since the time difference between driving two adjacent gate lines is extremely small, the inducing signal level VROUT on the inducing signal readout lines remains substantial constant (here, the constant inducing signal may also be referred to as a background signal). The parts denoted by 402 or 404 on the inducing signal level VROUT reflect that the inducing circuits 102 senses an input signal.
During the blanking time TB, although the gate line signals SG1-SGN are in a low level state, a current leakage of the inducing circuits 102 occurs, such that the inducing signal level VROUT is lowered. When the next frame starts, the inducing signal level VROUT is gradually raised to a normal state once again because the gate lines G1-GN is sequentially driven. However, in the course of raising the level once again, if the inputs from the user happen again, the input signals as shown by 406 or 408, as the inducing signal level VROUT has not returned to the normal state yet, the identification accuracy of the first several gate lines of the next frame when turning on will not be influenced, thus degrading the induction sensitivity of the top portion of the embedded input panel. In this manner, the overall induction sensitivity of the embedded input panel is non-uniform.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a method for driving a display panel, which can prevent the non-uniform induction sensitivity of the display panel.
The present invention is further directed to a display apparatus, which has uniform induction sensitivity.
As embodied and broadly described herein, the present invention provides a method for driving a display panel in an embodiment. The display panel includes an inducing signal readout line and N gate lines, in which N is a natural number. The inducing signal readout line is coupled to a plurality of inducing circuits. Each inducing circuit is coupled to one of the gate lines. An Nth gate line is coupled to one of the inducing circuits. In the method, several gate pulses are provided to drive the gate lines sequentially to turn on the corresponding inducing circuits, wherein at least a portion of the driving duration of a gate pulse provided to the Nth gate line is in a blanking time between two frames.
As embodied and broadly described herein, the present invention further provides a method for driving a display panel in another embodiment. The display panel includes an inducing signal readout line, N gate lines, and a dummy gate line, in which N is a natural number. The inducing signal readout line is coupled to a plurality of inducing circuits. Each inducing circuit is coupled to one of the N gate lines. The dummy gate line is coupled to one of the inducing circuits. In the method, several gate pulses are provided to drive the gate lines sequentially to turn on the corresponding inducing circuit. And an another gate pulse is provided to drive the dummy gate line, wherein at least a portion of the driving duration of the another gate pulse is in a blanking time between two frames.
As embodied and broadly described herein, the present invention further provides a display apparatus in another embodiment. The display apparatus includes a display panel and a gate driver. The display panel includes N gate lines, an inducing signal readout line, and a plurality of inducing circuits, in which N is a natural number. Each inducing circuit is coupled to the inducing signal readout line and is coupled to one of the gate lines. An Nth gate line is coupled to one of the inducing circuits. The gate driver drives the gate lines sequentially by providing several gate pulses to the gate lines, so as to turn on the corresponding inducing circuits through the gate lines. Wherein, at least a portion of the driving duration of a first gate pulse provided to the Nth gate line is in a blanking time between two frames.
As embodied and broadly described herein, the present invention provides a display apparatus in another embodiment. The display apparatus includes a display panel and a gate driver. The display panel includes N gate lines, a dummy gate line, an inducing signal readout line, and a plurality of inducing circuits, in which N is a natural number. Each inducing circuit is coupled to the inducing signal readout line and is coupled to one of the N gate lines. The dummy gate line is coupled to one of the inducing circuits. The gate driver drives the N gate lines sequentially by providing several gate pulses to the N gate lines, so as to turn on the corresponding inducing circuits through the gate lines. And the gate driver further drives the dummy gate line by providing an another gate pulse to the dummy gate line, wherein at least a portion of the driving duration of the another gate pulse is in a blanking time between two frames.
As embodied and broadly described herein, the present invention provides a method for driving a display panel in still another embodiment. The display panel includes an inducing signal readout line and N gate lines, in which N is a natural number. The inducing signal readout line is coupled to a plurality of inducing circuits. Each inducing circuit is coupled to one of the gate lines. In the method, several gate pulses are provided to driving the gate lines sequentially to turn on the corresponding inducing circuits. And an another gate pulse is provided to drive one of the gate lines again, wherein the gate line that is driven again is coupled to one of the inducing circuit and at least a portion of the driving duration of the another gate pulse is in a blanking time between two frames.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed.



BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a schematic view of a configuration of inducing circuits of a conventional embedded input panel and gate line signals thereof.
FIG. 2 is a circuit diagram of a common charge inducing circuit.
FIG. 3 is a circuit diagram of a common current inducing circuit.
FIG. 4 illustrates a relationship between the inducing signal level and the gate line signals SG1-SGN on one of the inducing signal readout lines in FIG. 1.
FIG. 5 is a schematic view of a display apparatus and a method for driving a display panel thereof according to an embodiment of the present invention.
FIG. 6 illustrates a relationship between the inducing signal level and the gate line signals SG1-SGN on one of the inducing signal readout lines in FIG. 5.
FIG. 7 is a schematic view of a display apparatus and a method for driving a display panel thereof according to another embodiment of the present invention.
FIG. 8 illustrates a relationship between the inducing signal level and the gate line signals SG1-SG(N+1) on one of the inducing signal readout lines in FIG. 7.
FIG. 9 is a schematic view of a display apparatus and a method for driving a display panel thereof according to still another embodiment of the present invention.
FIG. 10 is a schematic view of a display apparatus a method for driving a display panel thereof according to yet another embodiment of the present invention.



DESCRIPTION OF EMBODIMENTS
FIG. 5 is a schematic view of a display apparatus and a method for driving a display panel thereof according to an embodiment of the present invention. Referring to FIG. 5, the display apparatus is denoted by 500. The display apparatus 500 includes a display panel 502, a source driver 504, a signal processing circuit 506, and a gate driver 508. The display panel 502 includes inducing circuits 510, gate lines G1-GN, and inducing signal readout lines R1-RM. The gate line signals corresponding to the gate line driver 508 output by gate lines G1-GN are denoted by SG1-SGN. The gate pulse is denoted by 512. The blanking time between two frames is denoted by TB. For easier comparison with the conventional technique, in this embodiment and the following embodiments, the display panel is an embedded input panel, and the inducing circuits are realized by charge inducing circuits (in FIG. 2) or current inducing circuits (in FIG. 3).
Referring to FIG. 5 again, the inducing circuits 510 are disposed according to the arrangement of original pixels (not shown). In this embodiment, each pixel works together with one inducing circuit 510, and each inducing circuit 510 is coupled to one gate line and one inducing signal readout line. The configuration of the inducing circuits 510 may be adjusted according to different resolution requirements, and the inducing circuits 510 may not be in one-to-one correspondence to the pixel. When receiving the gate pulse, the inducing circuits 510 output an inducing signal to the inducing signal readout lines, such that the signal processing circuit 506 processes the readout inducing signal. The source driver 504 provides frame data of the pixel to which each gate line is coupled. It can be known from the gate pulse time in FIG. 5 that in each frame, the gate lines in the display panel 500 are sequentially driven in the manner of gate lines G1-GN, and the driving duration of the gate pulse of the gate line GN is extended to the blanking time TB between two frames. In detail, the gate driver 508 drives the gate lines G1-GN sequentially to turn on the corresponding inducing circuits through the gate lines, and the gate driver 508 extends the driving duration of the gate pulse of the gate line GN to the blanking time TB between two frames, so as to turn on the inducing circuits to which the gate line GN is coupled through the gate line GN during the blanking time TB. The benefits of this manner will be explained with reference to FIG. 6.
FIG. 6 illustrates a relationship between the inducing signal level and the gate line signals SG1-SGN on one of the inducing signal readout lines in FIG. 5. Referring to FIG. 6, the inducing signal level on the inducing signal readout line is denoted by VROUT. SG1-SGN and symbol TB denote the same as those in FIG. 5. As the gate pulses of the gate line signals SG1-SGN are generated at different time, the gate lines G1-GN are sequentially driven according to the generation sequence of the gate pulses. Since the time difference between driving two adjacent gate lines is extremely small, the inducing signal level VROUT on the inducing signal readout line remains substantial constant. The parts denoted by 602 or 604 on the inducing signal level VROUT reflect that the inducing circuits 502 senses the input signal.
During the blanking time TB, although the gate line signals SG1-SGN−1 are in a low level state, the gate line signal SGN is in a high level state. Thus, the inducing circuits 510 to which the gate, line GN is coupled continuously output a constant inducing signal, such that the inducing signal level VROUT on the inducing signal readout line remains at a stable level (i.e., the background signal is substantially maintained). Therefore, even if the top portion of the display panel 502 receives the input signal 606 or 608 from the user at the very beginning of the frame, the inducing signal level VROUT remains at a stable level, and thus the identification accuracy of the first several gate lines when turning on will not be influenced. In this manner, the induction sensitivity of the top portion of the display panel 502 will not be reduced, such that the overall induction sensitivity of the panel is more uniform.
Definitely, in order to ensure normal frame display, when the gate driver 508 extends the driving duration of the gate pulse of the gate line GN to the blanking time TB, the source driver 504 retains the frame data of the pixel to which the gate line GN is coupled at the blanking time TB. Further, in FIGS. 5 and 6, the driving duration of the gate pulse of the gate line GN is extended to the driving duration of the adjacent frame. However, it can be deduced from the operations of the above embodiments that, as long as the enable time of the gate pulse on the gate line signal SGN is long enough to make the inducing signal level VROUT on the inducing signal readout line remain substantial unchanged, the pulse stop time of the gate pulse on the gate line signal SGN does not need to be extended to the pulse onset time of the gate pulse on gate line signal SG1 of the next frame. That is, the enable time of the gate pulse on the SGN may be adjusted flexibly. Or, if the gate lines are sequentially driven in the manner of gate lines GN-G1, the driving duration of the gate line GN will not be extended to the blanking time TB, but the driving duration of the gate pulse on the gate line signal SG1 is extended to the preceding blanking time TB, or the pulse onset time of the gate pulse on the gate line signal SG1 is advanced to the pulse stop time of gate pulse on the gate line GN. Other operations above-mentioned can also make the overall induction sensitivity of the panel become more uniform. However, in order to ensure normal frame display, the source driver must change output manner of the frame data correspondingly.
Under the concept of the operations of the above embodiments, another solution may be deduced, as shown in FIG. 7. FIG. 7 is a schematic view of a display apparatus and a method for driving a display panel thereof according to another embodiment of the present invention. Referring to FIGS. 7 and 5 together, the difference therebetween is described as follows. The display panel 702 in FIG. 7 further includes a dummy gate line denoted by G(N+1), in addition to the gate lines G1-GN. The dummy gate line G(N+1) is coupled to a plurality of inducing circuits 710. Each inducing circuit 710 is coupled to one of the inducing signal readout lines. Further, a gate driver 708 does not extend the driving duration of the gate line GN to the blanking time TB, but outputs a gate line signal SG(N+1) corresponding to the dummy gate line G(N+1). In detail, the gate driver 708 sequentially drives the gate lines G1-GN to turn on the corresponding inducing circuits through the gate lines. The gate driver 708 drives the dummy gate line G(N+1) during the blanking time TB between two frames, so as to turn on the inducing circuit to which the dummy gate line G(N+1) is coupled through the dummy gate line G(N+1) during the blanking time TB. The benefits of this manner will be explained with reference to FIG. 8.
FIG. 8 illustrates a relationship between the inducing signal level and the gate line signals SG1-SG(N+1) on one of the inducing signal readout lines in FIG. 7. Referring to FIG. 8, the inducing signal level on the inducing signal readout line is denoted by VROUT. SG1-SG(N+1) and TB denote the same as those in FIG. 7. During the blanking time TB, although the gate line signals SG1-SGN are in a low level state, but the gate line signal SG(N+1) is in a high level state, so the inducing circuits 710 to which the gate line G(N+1) is coupled continuously output a constant inducing signal, such that the inducing signal level VROUT on the inducing signal readout line remains at a stable level. Therefore, the overall induction sensitivity of the panel is very uniform no matter the case denoted by 802 or 804 or the case denoted by 806 or 808 occurs.
Definitely, if the duration of the blanking time TB is too long, the user can also extend the pulse width of the gate pulse of the gate line signal SG(N+1) to fill the whole blanking time TB. If it is not intended to increase the pulse width of the gate pulse, a plurality of gate pulses is used to drive the gate lines G(N+1) during the blanking time TB. Or, more dummy gate lines are added in the display panel 702, and the dummy gate lines are sequentially driven during the blanking time TB with reference to the manner of the dummy gate line G(N+1). Further, the dummy gate line G(N+1) may also be driven before driving the gate line GN and does not need to be driven after the gate line GN have been driven. Furthermore, the dummy gate line G(N+1) may be placed at any position of the display panel and are not limited to be placed after the gate line GN. It should be noted that if the user adopts the manner in FIG. 7 to solve the problem of non-uniform induction sensitivity, the source driver does not need to change the output manner of the frame data since the dummy gate line G(N+1) does not need to be coupled to the pixel.
In view of the above embodiments and illustration, two solutions may be further deduced, and one of them is shown in FIG. 9. FIG. 9 is a schematic view of a display apparatus and a method for driving a display panel thereof according to still another embodiment of the present invention. Referring to FIGS. 9 and 5 together, the difference therebetween is described as follows. A gate driver 908 in FIG. 9 does not extend the driving duration of the original gate pulse of the gate line GN to the blanking time TB, but provides another gate pulse to drive the gate line GN during the blanking time TB. In detail, the gate driver 908 sequentially drives the gate lines G1-GN to turn on the corresponding inducing circuits through gate lines, and the gate driver 908 drives the gate line GN again during the blanking time TB between two frames to turn on the inducing circuits to which the gate line GN is coupled during the blanking time TB. Furthermore, in the course of driving the gate line GN shown in FIG. 9 again, a source driver 904 provides the same frame data to the pixel to which the gate line GN is coupled, so as to display a normal frame.
The other solution as shown in FIG. 10 may be deduced. FIG. 10 is a schematic view of a display apparatus and a method for driving a display panel thereof according to yet another embodiment of the present invention. Referring to FIGS. 10 and 9 together, the difference therebetween is described as follows. In the method as shown in FIG. 10, the gate line GN is not driven again during the blanking time TB, but the gate lines G2 is driven again during the blanking time TB. In detail, the gate driver 1008 sequentially drives the gate lines G1-GN to turn on the corresponding inducing circuits through the gate lines and the gate driver 1008 drives the gate lines G2 again during the blanking time TB between two frames to turn on the inducing circuits to which the gate lines G2 is coupled through the gate lines G2 during the blanking time TB. Definitely, during the blanking time TB, any one of the gate lines G1-GN, but not limited to, the gate lines G2 may be optionally driven again.
According to the teachings of the above embodiments, those skilled in the art should know that, the display panel is not limited to the embedded input panel. Further, a variety of display panels, for example, light input display panel, can also be implemented according to the above applications, so as to achieve the purpose of uniformizing the induction sensitivity. Definitely, different display panels may have different implementations of the inducing circuits, and the configuration of the inducing circuits made by different manufacturers differs. For example, some manufacturers may arrange one inducing circuit at an interval of several gate lines. However, the present invention is applicable as long as several inducing circuits share one inducing signal readout line.
In view of above, the present invention extend the driving duration of the last gate lines to the blanking time between two frames to turn on the inducing circuits to which the last gate line is coupled through the last gate line during the blanking time. Or, an additional dummy gate line is added in the display panel, and the dummy gate line is driven during the blanking time to turn on the inducing circuits to which the dummy gate line is coupled through the dummy gate line during the blanking time. Even, one of the gate lines is driven again during the blanking time, as long as the gate line to be driven again is coupled to the inducing circuit. Therefore, the inducing signal on the inducing signal readout line is always maintained at a substantially stable level, thus not affecting the identification accuracy of the first several gate lines of the next frame, and further making the induction sensitivity of the display panel more uniform.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

## Claims

1. A method for driving a display panel, wherein the display panel comprises an inducing signal readout line and N gate lines, N is a natural number, the inducing signal readout line is coupled to a plurality of inducing circuits, each inducing circuit is coupled to one of the gate lines, and the Nth gate line is coupled to one of the inducing circuits, comprising:
providing several gate pulses to drive the gate lines sequentially to turn on the corresponding inducing circuits; and
wherein at least a portion of driving duration of a gate pulse only provided to the Nth gate line is in a blanking time between two frames and fully overlaps the entire blanking time, so as to make a level of an inducing signal on the inducing signal readout line remain at a stable level during the entire blanking time,
wherein only a single pulse among all the gate lines is applied during the entire blanking time,
wherein a pulse stop time of the gate pulse only provided to the Nth gate line is an ending of the blanking time between the two frames.

2. The method for driving a display panel as claimed in claim 1, wherein the gate pulse provided to the Nth gate line is fully within the blanking time between the two frames.

3. The method for driving a display panel as claimed in claim 1, wherein each frame is driven from a 1st gate line, and the Nth gate line is a last gate line that is driven.

4. The method for driving a display panel thereof as claimed in claim 1, wherein each frame is driven from the Nth gate line, and the 1st gate line is the last gate line that is driven.

5. The method for driving a display panel as claimed in claim 1, wherein the display panel is an embedded input panel.

6. The method for driving a display panel as claimed in claim 5, wherein the inducing circuits comprise charge inducing circuits or current inducing circuits.

7. The method for driving a display panel as claimed in claim 1, further comprising making the driving duration of the gate pulse provided to the Nth gate line extend to the driving duration of an adjacent frame.

8. A display apparatus, comprising:
a display panel, comprising:
N gate lines, wherein N is a natural number;
an inducing signal readout line; and
a plurality of inducing circuits, wherein each inducing circuit is coupled to the inducing signal readout line and is coupled to one of the gate lines, and an Nth gate line is coupled to one of the inducing circuits; and
a gate driver, for providing several gate pulses to drive the gate lines sequentially to turn on the corresponding inducing circuits, and wherein at least a portion of driving duration of a first gate pulse only provided to the Nth gate line is in a blanking time between two frames and fully overlaps the entire blanking time, so as to make a level of an inducing signal on the inducing signal readout line remain at a stable level during the entire blanking time,
wherein only a single pulse among all the gate lines is applied during the entire blanking time,
wherein a pulse stop time of the gate pulse only provided to the Nth gate line is an ending of the blanking time between the two frames.

9. The display apparatus as claimed in claim 8, wherein the first gate pulse provided to the Nth gate line is fully within the blanking time between the two frames.

10. The display apparatus as claimed in claim 8, further comprising providing a second gate pulse to the Nth gate line before the first gate pulse is provided.

11. The display apparatus as claimed in claim 8, wherein each frame is driven from a 1st gate line, and the Nth gate line is a last gate line that is driven.

12. The display apparatus as claimed in claim 8, wherein each frame is driven from the Nth gate line, and the 1st gate line is the last gate line that is driven.

13. The display apparatus as claimed in claim 8, wherein the display panel is an embedded input panel.

14. The display apparatus as claimed in claim 13, wherein the inducing circuits comprise charge inducing circuits or current inducing circuits.

15. The display apparatus as claimed in claim 8, further comprising making the driving duration of the first gate pulse provided to the Nth gate line extend to the driving duration of an adjacent frame.