TW201317973A - Display device, method for driving same, and display system including the display device - Google Patents

Abstract

The purpose of the present invention is to provide a display device for improving touch panel detection accuracy and reducing power consumption. The display device drives at least part of a display element through interlaced scanning by alternatingly repeating a scanning period and a horizontal blanking period at least as long as the minimum period necessary for detection operation of an external detection device, outputs a detection instruction signal for instructing detection to the detection device during the horizontal blanking period, and does not output a detection instruction signal during the scanning period.

Description

Display device and driving method thereof, and display system having the same

The present invention relates to a display device, a method of driving the same, and a display system including the display device.

In recent years, a display device that is thin, lightweight, and low in power consumption, which is represented by a liquid crystal display device, is widely used. Such a display device is more prominently mounted on, for example, a mobile phone, a smart phone, or a laptop computer (personal computer). In addition, it is expected that the development and popularization of thinner display devices, that is, electronic paper, will also develop rapidly. Under such circumstances, reducing the power consumption of various display devices has become a common issue.

Patent Document 1 discloses a driving method of a display device that realizes low power consumption by providing a rest period, which is a scanning period in which all scanning signal lines are in a non-scanning state and are scanned one time. Long non-scanning period.

Further, a touch panel provided on a display screen of a display device is also popular (for example, Patent Document 2). The touch panel is a position input device that detects a position on the indicated display screen by a user's finger or a pen, and outputs the detected position information. Compared with an input device such as a keyboard or a mouse, the touch panel can be operated intuitively, and thus, for example, it can be mounted on a mobile phone, a smart phone, or a laptop PC.

As one method for improving the detection accuracy of the touch panel, there is a method in which the detection operation of the touch panel is performed during the vertical blanking period without being affected by noise from the display device. For example, a patent application In 2011-86813, there is disclosed a method of increasing the detection accuracy by increasing the number of detections of the touch panel by setting the number of vertical blanking periods twice during the frame period. According to the above method, the detection operation of the touch panel can be performed at a frequency higher than the refresh rate of the display device, thereby improving the detection accuracy.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2001-312253 (published on November 9, 2001)

[Patent Document 2] Japanese Laid-Open Patent Publication No. 2001-060079 (published on March 6, 2001)

However, in the method of performing the touch panel detection operation during the vertical blanking period, it is necessary to ensure the vertical blanking period for a long period of time, so that the cost due to the mounting of the frame memory is increased, or the frequency of the logic circuit is increased. Problems caused by the increase in power consumption. Such a problem is more pronounced in display devices with higher resolution.

Accordingly, the present invention has been made in view of the above problems, and an object thereof is to provide a display device and a driving method thereof that can improve the detection accuracy of a touch panel, and can reduce power consumption, and a display system including the display device.

In order to solve the above problems, a display device according to an aspect of the present invention includes: a display element that displays an image on a screen; and a driving mechanism Driving the display element in such a manner that the scanning period during which scanning is performed and the horizontal masking period in which the scanning is stopped are alternately repeated, and at least a portion of the display element is driven by interlaced scanning, the horizontal blanking period having at least external detection The length of the shortest period of time required for the detection operation of the device; and the output unit outputs a detection instruction signal indicating the detection to the external detection device during the horizontal blanking period, and the detection instruction signal is not output during the scanning period.

Further, in order to solve the above problems, a driving method of a display device according to an aspect of the present invention is a method of driving a display device having a display element for displaying an image on a screen, comprising: a driving step of causing scanning Driving the display element in a manner of alternately repeating during the scanning period and stopping the horizontal blanking period of the scanning, and driving the display element by interlaced scanning, wherein the horizontal blanking period has at least the minimum required for the detecting operation of the external detecting device The length of the period; the output step of outputting the detection instruction signal indicating the detection to the external detecting device during the horizontal blanking period, and not outputting the detection instruction signal during the scanning period.

According to the above configuration and method, the detection instruction signal is output to the detection device during each horizontal blanking period, and when the detection instruction signal is output, the detection device performs the detection operation. The horizontal blanking period is set between the scanning period and the scanning period, so the detecting device can perform the detecting operation at a frequency far higher than the refresh rate. As a result, the detection accuracy of the detecting device can be greatly improved.

In particular, in one aspect of the present invention, by performing interlaced scanning to extend the horizontal blanking period, the detection accuracy of the detecting device can be improved, so It is necessary to mount a novel member such as a frame memory to suppress power consumption.

Further, in the display system including the display device having the above configuration and the detecting device that detects based on the detection instruction signal from the display device, the same effects as those described above can be exhibited.

Other objects, features, and advantages of the present invention will be made apparent by the appended claims. Further, the advantages of the present invention can be understood by referring to the following description made with the accompanying drawings.

As described above, the display device according to an aspect of the present invention can realize the interlaced scanning with a long horizontal blanking period, so that the detection indicating signal is output to the external detecting device during the horizontal blanking period, so that the detection can be increased. The number of times the device detects the action and improves the accuracy of the test result.

The embodiments of the present invention will be described in detail based on the drawings. In the following description, members that exhibit the same functions and functions are denoted by the same reference numerals, and description thereof will be omitted.

[First Embodiment] (Configuration of display system 1)

The configuration of the display system 1 of the present embodiment will be described with reference to Fig. 2 . Fig. 2 is a block diagram showing the details of the configuration of the display system 1 of the present embodiment. As shown in FIG. 2, the display system 1 has a display device 2, a touch panel 3, and a control unit 10. The control unit 10 in the display system 1 of the present embodiment displays and outputs an image via the display device 2, acquires an instruction from the user via the touch panel 3, and performs various processes based on the acquired instruction. In addition, except In addition to the video, arbitrary information such as a still image or a symbol can be displayed and output via the display device 2.

The display device 2 includes a display panel 2a (display element), a scanning line drive circuit 4 (drive mechanism), a signal line drive circuit 5 (drive mechanism), a common electrode drive circuit 6, and a timing control unit 7 (output unit). Further, the touch panel 3 includes a detecting unit 8 and a detecting unit control unit 9.

The display panel 2a is provided with a screen including a plurality of pixels arranged in a matrix. Further, the display panel 2a is provided with N (N-series arbitrary integer) scanning signal lines G for selecting and scanning the screens in line order. Further, the display panel 2a includes M (M-number arbitrary integer) data signal lines S (source lines), and the data signal lines S supply data signals to the selected lines including one of the columns of pixels. The scanning signal line G and the data signal line S cross each other.

G(n) shown in FIG. 2 indicates the nth (n is an integer of 1 or more and N) scanning signal lines. For example, G(1), G(2), and G(3) indicate the scanning signals G of the first, second, and third roots, respectively. On the other hand, S(i) indicates the i-th (i is an integer of 1 or more and M) data signal line S. For example, S(1), S(2), and S(3) indicate the first, second, and third data signal lines S, respectively.

The scanning line driving circuit 4 sequentially scans each scanning signal line G from the top to the bottom of the screen, for example. At this time, a rectangular wave for turning on the switching element (TFT) connected to the pixel electrode included in the pixel is output to each scanning signal line G. Thereby, one column of pixels in the screen is set to the selected state.

However, the scanning of the scanning line driving circuit 4 is not limited to the above-described sequential scanning. Description. For example, after scanning the scanning signal line G of the odd-numbered numbers such as the first root, the third root, the fifth root, etc., the second root, the fourth root, the sixth root, etc. may be even-numbered. A skip scan (interlaced scan) in which the scanning signal line G is scanned.

The signal line drive circuit 5 receives the video signal (arrow C) input from the control unit 10 to the timing control unit 7 from the timing control unit 7 (arrow E). The signal line drive circuit 5 calculates a voltage value to be output to each of the selected one column based on the video signal input from the timing control unit 7, and outputs a voltage corresponding to the value to each data signal line S. As a result, image data is supplied to each pixel located on the selected scanning signal line G.

The display device 2 includes a common electrode (not shown) provided for each pixel in the screen. The common electrode drive circuit 6 outputs a specific common voltage for driving the common electrode to the common electrode (arrow B) based on the signal (arrow A) input from the timing control unit 7.

The sequence control unit 7 outputs a standard signal for causing each circuit to operate in synchronization with each circuit based on the clock signal, the horizontal synchronization signal, and the vertical synchronization signal (arrow C) input from the control unit 10. Specifically, in the scan line driving circuit 4, the gate start pulse signal GSP, the gate clock signal GCK, and the gate output enable signal GOE (arrow) are output based on the clock signal, the horizontal synchronization signal, and the vertical synchronization signal. D). The signal line drive circuit 5 outputs a source start pulse SSP, a source latch strobe signal SLS, and a source clock signal SCK (arrow E) based on a clock signal, a horizontal synchronizing signal, and a vertical synchronizing signal.

The scanning line driving circuit 4 starts scanning of the display panel 2a with the gate start pulse signal GSP received from the timing control unit 7, and performs scanning by conversion The signal of the selected state of the signal line G, that is, the gate clock signal GCK, sequentially applies a selection voltage to each of the scanning signal lines G. The signal line drive circuit 5 is based on the source start pulse signal SSP received from the timing control unit 7, and stores the image data of each input pixel in the register in accordance with the source clock signal SCK. Further, after the signal line drive circuit 5 stores the image data, the image data is written into each of the data signal lines S of the display panel 2a based on the next source latch strobe signal SLS. When writing image data, for example, an analog amplifier included in the signal line drive circuit 5 is used.

In the touch panel 3, the detecting unit 8 is provided close to the screen of the display panel 2a of the display device 2, and detects the position on the screen instructed by the user's finger or the like. The detecting unit control unit 9 controls the detecting unit 8. Specifically, the detection unit control unit 9 drives the detection unit 8 via the drive line Tx, that is, inputs a rectangular wave. The detecting unit 8 transmits a detection signal to the detecting unit control unit 9 via the sensing line Rx based on the input rectangular wave. Here, in the case where an indication of the position is generated on the touch panel by the user's finger or the like, the signal formed by the rectangular wave and the signal formed by the user's finger or the like are in the sensing line Rx in the vicinity thereof. The superimposed form is sent to the detection unit control unit 9. The detection unit control unit 9 creates detection data indicating the detected position by the superimposed signals, and transmits the detection data to the control unit 10 (arrow G).

The control unit 10 recognizes the user's operation based on the detection data from the touch panel 3, and performs various processes such as transmitting the video signal and the video synchronization signal to the display device 2 in order to control the display of the display device 2.

Further, the voltage required for the operation of each circuit in the display system 1 is supplied, for example, from a power generation circuit (not shown), but the power generation circuit may be included in In the control unit 10. In this case, each voltage is supplied from the control unit 10 to the display device 2, and each voltage is supplied from the control unit 10 to the touch panel 3. As an example of the voltage required for the operation of each circuit in the display system 1, the signal line drive circuit 5 is supplied with the power supply voltage Vdd.

In the present specification, a period in which the scanning line driving circuit 4 scans one scanning signal line G, that is, a period in which image data is supplied to each pixel existing on the selected scanning signal line G is referred to as a one-scan period. A horizontal blanking period is set between two consecutive scanning periods. The horizontal blanking period is a period until one scanning signal line is scanned until the scanning of the next scanning signal line G is started. The scanning by the scanning line driving circuit 4 is stopped during the horizontal blanking period. In addition, the 1 horizontal period is a period in which one scanning period and one horizontal blanking period are combined.

The timing control unit 7 outputs a detection instruction signal (arrow F) indicating a detection operation of the touch panel 3 to the detection unit control unit 9 of the touch panel 3 during the horizontal blanking period. In the touch panel 3, when the detection unit control unit 9 receives the detection instruction signal from the timing control unit 7 of the display device 2, the detection unit 8 performs a detection operation, and the detection unit control unit 9 outputs the detection data indicating the detection result. To the control unit 10.

(Change of display system 1)

Fig. 3 is a block diagram showing the details of the configuration of the display system 1' of the embodiment. The difference between the display system 1 and the display system 1' is the path of the detection indication signal. As described above, in the display system 1 of FIG. 2, the detection instruction signal is directly output from the timing control unit 7 of the display device 2 to the detection unit control unit 9 of the touch panel 3.

On the other hand, in the display system 1' of FIG. 3, the detection instruction signal is output from the timing control unit 7 of the display device 2 to the detection unit control unit 9 of the touch panel 3 via the control unit 10. Specifically, the sequence control unit 7 of the display device 2 outputs the first detection instruction signal (arrow F1) to the control unit 10. Then, the control unit 10 that has received the first detection instruction signal outputs a second detection instruction signal (arrow F2) whose timing is substantially equal to the first detection instruction signal to the detection unit control unit 9 of the touch panel 3.

As described above, the control of the detection operation of the touch panel 3 can also be performed via the control unit 10. In other words, it suffices that the detection operation of the touch panel 3 can be performed during the horizontal blanking period of the display panel 2a. That is, the effect of the present invention can be exerted regardless of any of the application display system 1 and the display system 1'.

(composition of pixels)

Here, the configuration of the pixels included in the display panel 2a is shown in FIG. 4 is a diagram showing the configuration of two pixels (pixels (i, n) and pixels (i+1, n)) among a plurality of pixels included in the panel 2a. The pixel (i, n) represents a pixel connected to the data signal line S(i) and the scanning signal line G(n). The pixel (i+1, n) represents a pixel connected to the data signal line S(i+1) and the scanning signal line G(n). The other pixels included in the display panel 2a are the same as those of the pixels.

As shown in FIG. 4, a TFT 200 as a switching element is provided in a pixel. The gate electrode of the TFT 200 is connected to the corresponding scanning signal line G. In addition, the source electrode of the TFT 200 is connected to the corresponding data signal line S. Moreover, the drain electrode of the TFT 200 is connected to the liquid crystal capacitor C1c and the holding capacitor Ccs. When the pixel data is written to the pixel, first, the on-voltage is supplied from the scanning signal line G to the gate electrode of the TFT 200. Thereby, the TFT 200 is switched to the on state. When the TFT 200 is in the on state, when the data signal is supplied from the corresponding data signal line S, the data signal is supplied from the drain of the TFT 200 to the pixel electrode of the liquid crystal capacitor C1c and the holding capacitor Ccs.

In this way, the data signal is supplied to the pixel electrode of the liquid crystal capacitor C1c, whereby the alignment direction of the liquid crystal to which the electric field is applied between the pixel electrode of the liquid crystal capacitor C1c and the common electrode is based on the supplied data signal. The difference between the voltage level and the voltage level supplied to the common electrode changes, and an image corresponding to the difference is displayed.

Further, by supplying the data signal to the holding capacitor Ccs, the electric charge of the voltage corresponding to the data signal is accumulated in the holding capacitor Ccs. Moreover, by accumulating the charge of the holding capacitor Ccs, the pixel can maintain the state of displaying the image for a certain period of time.

As shown in FIG. 4, a parasitic capacitance Cgs and a parasitic capacitance Cgd are generated in each pixel. The parasitic capacitance Cgs is a parasitic capacitance generated at the intersection of the metal layer, that is, the data signal line S and the scanning signal line G. The parasitic capacitance Cgd is a parasitic capacitance generated between the scanning signal line G and the drain electrode.

Further, in each pixel, a parasitic capacitance Csd1 and a parasitic capacitance Csd2 are generated. The parasitic capacitance Csd1 is a parasitic capacitance generated between the scanning signal line G and the drain electrode. The parasitic capacitance Csd2 is a parasitic capacitance generated between the adjacent scanning signal line G and the drain electrode.

(Composition of the touch panel 3)

In this embodiment, a touch panel using a projection type electrostatic capacitance method is used. 3. In the case of the projection type capacitive touch panel 3, the detecting portion 8 is formed on a transparent substrate such as glass or plastic by a transparent electrode pattern formed of ITO (Indium Tin Oxide) or the like. .

Fig. 5 is a view showing details of the configuration of the touch panel 3 of the embodiment. As shown in FIG. 5, the touch panel 3 has drive lines Y(1) to Y(27) and sensing lines X(1) to X(42), and the detection unit control unit 9 via the drive lines Y(1) to Y. (27) The detection unit 8 is driven. Here, since the metal intersects near the intersection of the respective drive lines Y(1) to Y(27) and the sensing lines X(1) to X(42), the parasitic capacitance C is generated. Further, in order to simplify the drawing, the number of driving lines Y is set to 27, and the number of sensing lines X is set to 42, but the invention is not limited thereto.

When the user's finger or the like comes into contact with or approaches the detecting portion 8, the electrostatic capacitance of the plurality of transparent electrode patterns in the vicinity thereof changes. Therefore, the detecting unit control unit 9 scans the drive lines Y(1) to Y(27) one by one from the top to the bottom of the screen, and inputs a pulse waveform. When the pulse waveform is input to each of the driving lines Y, the current or voltage on the sensing line X changes via the parasitic capacitance C of the intersection. This change is caused when the user's finger or the like exists in the vicinity of the sensing line X and the case where it does not exist. The detection unit control unit 9 calculates based on the degree of this change. The detection data as the position information is created and sent to the control unit 10. In this manner, the position on the instructed screen can be detected by the user's finger or the like in the touch panel 3. In addition, although the method of sequentially scanning the drive line Y for the drive line Y is employed in FIG. 5, it is not limited thereto. Further, the detecting unit control unit 9 may be configured to transmit digitally digitized data of the analog data from the sensing line to the control unit 10, and the control unit 10 calculates the data. Create location information.

In addition, the touch panel 3 also detects that the user's finger or the like is in contact with or close to an arbitrary position on the screen. In this case, it is possible to detect the contact or proximity of the user's finger or the like, and it is not necessary to detect the position. In the present embodiment, the touch panel 3 of the projection type electrostatic capacitance type is used. However, the touch panel 3 of any detection method such as a surface type capacitance method or a resistive film method may be used. Further, in the case of the display system 1 of the touch panel 3 having a mode that is susceptible to the driving of the display panel 2a as in the projection type electrostatic capacitance method, the display device 2 of the present embodiment can be expected to be used. The effect of the invention.

(Scanning method of display device 2)

In the present embodiment, in order to improve the detection accuracy of the touch panel 3 and to reduce the power consumption of the display system 1, the display device 2 performs skip scanning (interlaced scanning). The details of this will be described with reference to Fig. 1 . Fig. 1 is a timing chart showing the driving timing of each scanning signal line G when the interleaved scanning of the present embodiment is performed.

As shown in FIG. 1, in the interlaced scanning, a frame for scanning data in the odd-numbered lines of the scanning signal G (nth frame) and a frame for scanning in even lines (n+1 frame) ) Repeatedly. In this interlaced scanning, the number of lines scanned in one frame is half of that of a normal sequential scan, so there is an advantage that the frequency of the horizontal synchronizing signal can be suppressed low.

At this time, in the present embodiment, the horizontal blanking period has at least the length of the shortest period required for the detection operation of the touch panel 3. For example, after a certain period of time has elapsed since the start of the scanning period of the scanning signal line G(1), horizontal shading is performed with at least the length of the shortest period required for the detecting operation of the touch panel 3. In the absence of a period, the scanning period of the scanning signal line G(3) is started. The shortest period of time required for the detection operation of the touch panel 3 is the period during which the rectangular wave is outputted to one drive line Y. Therefore, the horizontal blanking period may have a length of a period in which the rectangular wave is outputted to at least one driving line Y.

Here, FIG. 6 is a timing chart showing the driving timing of each scanning signal line G when a normal sequential scanning is performed. In addition, FIG. 7 is a timing chart showing the driving timing of each scanning signal line G in the case of performing normal interleave scanning. As shown in FIG. 6, in the case of a normal sequential scan, the horizontal blanking period between the scanning period and the scanning period is short. Similarly, in the case of a normal interlaced scan, the horizontal blanking period between the scanning period and the scanning period is also short.

On the other hand, in the present embodiment, the horizontal blanking period as described above has at least the length of the shortest period required for the detecting operation of the touch panel 3. Therefore, the horizontal blanking period in the scanning method of the present embodiment is longer than in the previous sequential scanning and interlaced scanning. Therefore, the touch panel 3 can perform a detection operation during the horizontal blanking period.

The timing control unit 7 outputs a detection instruction signal to the detection unit control unit 9 for each horizontal blanking period, and when the detection instruction signal is output, the detection unit control unit 9 controls the detection unit 8 and performs a detection operation. The horizontal blanking period is set between the scanning period and the scanning period, so that the touch panel 3 can perform the detecting operation at a frequency far higher than the refresh rate. As a result, the detection accuracy of the touch panel 3 can be greatly improved.

In particular, in the present embodiment, since the interlaced scanning is performed, the scanning period can be sufficiently ensured. Therefore, it is not necessary to carry novels such as frame memory. Components, thereby suppressing power consumption.

(Driving method of display device 2)

Fig. 8 is a timing chart showing the control signals of the scanning line driving circuit 4 and the output signals from the scanning line driving circuit 4. In FIG. 8, the time change of the gate clock signal GCK, the gate output enable signal GOE, and the scan signals G1 to G7 is sequentially shown from the top. The scanning signals G1 to G7 are rectangular waves that are output from the scanning line driving circuit 4 to the scanning signal lines G(1) to (7) in order to turn on the respective TFTs. Here, in order to simplify the drawing, only the G1 to G7 are displayed on the scan signal, but the present invention is not limited thereto.

The gate output enable signal GOE rises during a certain period of time from the start of the falling of the gate clock signal GCK (before the gate clock signal GCK rises), and is in a specific period during which the gate clock signal GCK rises. After falling. When the gate output enable signal GOE rises, the scan signal G which is currently at the H level falls, and the next scan signal G rises when it falls. For example, the gate output enable signal GOE falls, whereby the scan signal G1 rises and the scan signal G becomes a selected state. Further, the gate output enable signal GOE rises, whereby the scan signal G1 falls, and the scan signal G(1) becomes a non-selected state. Thereafter, the gate output enable signal GOE is lowered, whereby the scan signal G3 rises and the scanning signal line G(3) becomes a selected state. Thus, after the scanning signal G1 is output to the scanning signal line G(1), the scanning signal G3 is output to the scanning signal line G(3), thereby achieving interlaced scanning.

At this time, the gate timing signal GCK is repeated such that the first period in which the first time is the H level and the second time in which the second time is shorter than the first time is the second period of the H level. Control unit 7. Further, the timing control unit 7 Control is performed as follows: the gate output enable signal GOE rises before the gate clock signal GCK of the second period rises, and then continues until the gate period signal GCK of the next first period rises after a certain period of time rises, and is maintained. H level. In other words, the timing control unit 7 controls the gate output enable signal GOE to maintain the H level only during the one horizontal scanning period after maintaining the L level for only one scanning period.

As described above, the timing control unit 7 controls the gate clock signal GCK and the gate output enable signal GOE, whereby interleaved scanning with a long horizontal blanking period can be realized. In addition, during the period in which the gate output enable signal GOE is at the H level, all the scanning signals G are at the L level, and the driving of all the scanning signal lines G is stopped. That is, it is a horizontal obscuration period.

Therefore, when the horizontal blanking period is reached, the timing control unit 7 outputs a detection instruction signal to the detection unit control unit 9 for each horizontal blanking period. The touch panel 3 performs a detection operation while the detection instruction signal is at the H level. Therefore, the operation of detecting the touch panel 3 can be performed at any timing as long as it is longer than the shortest period required for the operation and the detection instruction signal is in the H level. That is, the detection period of the touch panel 3 can be variously changed.

Alternatively, the gate output enable signal GOE itself may be output as a detection instruction signal to the touch panel 3.

(TFT characteristics)

In order to further improve the detection accuracy of the touch panel 3, in the display device 2 of the present embodiment, it is preferable to use a TFT as the TFT 200, and a so-called oxide semiconductor is used for the semiconductor layer in the TFT. Oxide semiconductor Among them, for example, IGZO (InGaZnOx) is contained. The reason for this will be described with reference to Fig. 9 . Fig. 9 is a view showing characteristics of various TFTs. In FIG. 9, various characteristics of a TFT using an oxide semiconductor, a TFT using a-Si (amorphous silicon), and a TFT using LTPS (Low Temperature Poly Silicon) are shown. In the figure, the horizontal axis (Vgh) indicates the voltage value of the ON voltage supplied to the gate of each TFT, and the vertical axis (Id) indicates the amount of current between the source and the drain of each TFT. In particular, the period shown as "TFT-on" in the figure indicates a period in which the voltage is turned on in accordance with the voltage value of the on-voltage, and the period shown as "TFT-off" in the figure indicates the voltage value corresponding to the on-voltage. The period of being closed.

As shown in FIG. 9, the amount of current (i.e., electron mobility) in the on state of the TFT using the oxide semiconductor is higher than that of the TFT using a-Si. Although not shown in the drawings, specifically, in the TFT using a-Si, the Id current at the time of TFT-on is 1 uA, whereas in the TFT using an oxide semiconductor, the Id current at the time of TFT-on is 20~50uA. Therefore, compared with the TFT using a-Si, the electron mobility of the TFT using the oxide semiconductor is as high as 20 to 50 times in the on state, and the on-characteristics are excellent.

According to the above, in the display device 2 of the present embodiment, the TFT using the oxide semiconductor is used in each pixel, so that the on-characteristics of the TFTs of the respective pixels are excellent. Therefore, the electron mobility at the time of writing the pixel data for each pixel is increased, and the time taken for the writing can be further shortened. In other words, in the display device 2 of the present embodiment, the period in which the touch panel 3 performs the detecting operation, that is, the horizontal blanking period can be made longer, and the period during which the touch panel performs the detecting operation can be sufficiently ensured. Therefore, The detection accuracy of the touch panel 3 is further improved.

[Second Embodiment] (Scanning method of display device 2)

Hereinafter, another scanning method for improving the detection accuracy of the touch panel 3 and reducing the power consumption of the display system 1 will be described. The details of this will be described with reference to Fig. 10 . Fig. 10 is a timing chart showing the driving timing of each scanning signal line G when the interleaved scanning of the present embodiment is performed.

As shown in Fig. 10, in this embodiment, interlaced scanning is also performed. Specifically, the frame (nth frame) in which the data is scanned in the odd-numbered lines of the scanning signal line G and the frame (the n+1th frame) in which the data is scanned in the even-numbered lines are alternately repeated.

At this time, in the present embodiment, the one scanning period is substantially equal to the one horizontal blanking period. In addition, the scanning period and the horizontal blanking period are switched at a timing corresponding to the gate clock signal GCK. For example, after the start of the scanning period of the scanning signal line G(1), after a predetermined period of time has elapsed based on the gate clock signal GCK, after moving to the horizontal blanking period, the specific state is passed based on the gate clock signal GCK. After the period, the scanning period of the scanning signal line G(3) is started.

Here, as shown in FIGS. 6 and 7, when the normal sequential scanning and the interlaced scanning are performed, the horizontal blanking period is short. However, in the present embodiment, the one scanning period and the one horizontal blanking period are set to be substantially equal. Therefore, the horizontal blanking period of the scanning method of the present embodiment is longer than that of the previous sequential scanning and interlaced scanning. Therefore, the touch panel 3 can perform a detection operation during the horizontal blanking period.

From the timing control unit 7, the indication signal is detected during each horizontal blanking period. It is output to the detection unit control unit 9. When the detection instruction signal is output, the detection unit control unit 9 controls the detection unit 8 and performs a detection operation. The horizontal blanking period is set between the scanning period and the scanning period, so that the touch panel 3 can perform the detecting operation at a frequency far higher than the refresh rate. As a result, the detection accuracy of the touch panel 3 can be greatly improved.

In particular, in the present embodiment, since the interlaced scanning is performed, the scanning period can be sufficiently ensured. Therefore, it is not necessary to mount a novel member such as a frame memory, and power consumption can be suppressed.

(Driving method of display device 2)

Fig. 11 is a timing chart showing the control signals of the scanning line driving circuit 4 and the output signals from the scanning line signal circuit 4. In Fig. 11, the time change of the gate clock signal GCK, the gate output enable signal GOE, and the scan signals G1 to G7 is sequentially indicated by the above. The scanning signals G1 to G7 are rectangular waves that are output from the scanning line driving circuit 4 to the scanning signal lines G(1) to (7) in order to turn on the respective TFTs. Here, in order to simplify the drawing, only G1 to G7 are displayed on the scanning signal, but the present invention is not limited thereto.

The method of interlaced scanning is the same as that of the first embodiment described above, but the gate clock signal GCK is output as usual. Specifically, the output repeats the gate clock signal GCK of the third period in which only the third time is the H level. At this time, the timing control unit 7 controls the gate output signal GOE to rise before the gate clock signal GCK in the third period rises until the gate clock signal of the next third period is controlled as follows. The G level is maintained until the specific period of GCK rises and then falls. And, the control is performed in such a manner that it rises before the gate clock signal GCK of the next third period rises. Thereafter, the H level of the gate output enable signal GOE is maintained until the specific period of the rise of the gate clock signal GCK in the next third period falls. In other words, the timing control unit 7 controls the gate output enable signal GOE to maintain the H level during only one horizontal blanking period after maintaining the L level during only one scanning period.

As described above, the timing control section 7 controls the gate output enable signal GOE, whereby interleaved scanning with a long horizontal blanking period can be realized. In addition, during the period in which the gate output enable signal GOE is at the H level, all the scanning signals G are at the L level, and the driving of all the scanning signal lines G is stopped. That is, it is a horizontal obscuration period. Here, when the horizontal blanking period is reached, the touch panel 3 performs the detecting operation in the same manner as in the first embodiment.

Further, in the present embodiment, only the gate output enable signal GOE is controlled, and an interleaved scan having a long horizontal blanking period can be realized. Therefore, the circuit of the display device 2 can be made comparatively compared with the first embodiment. It's easier.

[variation]

The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the claims. Therefore, as a variation of the above embodiment, the following modifications are shown.

(Variation 1)

Fig. 12 is a schematic view showing a display system 11 of another embodiment. As shown in FIG. 12, a plurality of scanning line driving circuits 4a and 4b (two in FIG. 12) may be provided, and the scanning signal lines G are driven by a plurality of scanning line driving circuits 4a and 4b. For example, it can be set such that the scanning line driving circuit 4a (first scanning line driving circuit) controls the odd-numbered lines of the scanning signal line G, and the scanning line driving circuit 4b (second scanning line driving circuit) controls the even number of the scanning signal lines G. line. Accordingly, the scanning line driving circuit 4a in the nth frame operates, and the scanning line driving circuit 4b in the n+1th frame is driven. Thus, interleaved scanning can be realized by separately using the scanning line driving circuits (4a, 4b) used for the odd-numbered lines and the even-numbered lines of the scanning signal line G. In other words, for one scanning line driving circuit 4, it is not necessary to control the odd-numbered lines of the scanning signal line G for the nth frame, and to drive the scanning signal lines G for the n+1th frame. The circuit for controlling the even line is used, so that the circuit of the display device 2 can be made simpler.

Similarly to the data signal line S, a plurality of (three in FIG. 12) signal line drive circuits 5a to 5c may be provided, and the plurality of signal line drive circuits 5a to 5c may drive the data signal line S.

(Variation 2)

Fig. 13 is a schematic view showing a display system 11' of another embodiment. The interlaced scanning shown in the first and second embodiments may not be scanned on the entire screen of the display panel 2a. Specifically, a partial area of the display panel 2a can also be driven by interlaced scanning, and the remaining areas can be driven by sequential scanning. For example, in the upper half of the screen shown in FIG. 13, the display of the touch panel 3 is not required for video display or text display, and in the lower half of the screen, the touch panel 3 is required for keyboard display and the like. The display. In this case, it is only necessary to perform interlaced scanning in an area where display of the touch panel 3 is required, and to perform normal sequential scanning in other areas.

The driving method in the case of this will be described with reference to Fig. 14 . Figure 14 is a diagram showing the control signal of the scanning line driving circuit 4 and the driving power from the scanning line Timing diagram of the output signal of way 4. In Fig. 14, the time change of the gate clock signal GCK, the gate output enable signal GOE, and the scan signals G1 to GN is sequentially shown from the top. The scanning signals G1 to GN are rectangular waves that are output from the scanning line driving circuit 4 to the scanning signal lines G(1) to G(N) in order to turn on the TFT.

As shown in FIG. 14, the scanning signal lines G(1) to G(m+3) included in the normal scanning area where the display of the touch panel 3 is not required are driven by normal sequential scanning. On the other hand, the scanning signal lines G(m+4) to G(N) included in the interleaved scanning area requiring display of the touch panel 3 are interleaved by the first or second embodiment. Scan and drive.

The control for sequentially scanning or interlacing scanning on which scanning signal line G is performed by the control unit 10. The control unit 10 outputs, to the timing control unit, which region on the screen of the display panel 2a is to be displayed without requiring the touch panel 3 to be displayed, and in which region the display region information requiring the display of the touch panel 3 is required. 7. The timing control unit 7 performs normal driving on the scanning signal line G corresponding to the display region (normal scanning region) where the touch panel 3 is not required, based on the display region information. On the other hand, for the scanning signal line G corresponding to the display area (interlaced scanning area) of the touch panel 3, the gate clock signal GCK and the gate output enable signal GOE corresponding to the interleaved scanning are output to The scanning line drive circuit 4. Thereby, interlaced scanning can be performed only in the interlaced scanning area. As described above, the interlaced scanning can be partially performed as long as the scanning signal line G for interlaced scanning is appropriately selected in accordance with the display area in which the touch panel 3 is required.

The present invention is not limited to the above embodiments and modifications, and may be requested as Various changes are made within the scope of the item. In other words, the embodiments obtained by the technical means disclosed in the respective embodiments or variations which are appropriately combined are also included in the technical scope of the present invention.

For example, the display panel 2a described above may be a liquid crystal panel including a liquid crystal layer. In this case, the display device 2 is a liquid crystal display device. Further, the pixel of the display panel 2a may have an element that emits light at a luminance corresponding to the current flowing, that is, an organic electroluminescence (EL) diode. In this case, the display device 2 is an organic EL display (organic electroluminescence display device). The organic EL display consumes a large amount of current in the scanning mode, and the influence of the driving signal of the organic EL display on the detecting device is increased. In this regard, it is more effective to apply the display device 2 to the organic EL display.

Further, the display device 2 described above can be suitably applied to a display device of a full HD (FHD) image having a resolution higher than 1920×1080. In the case of a high-resolution display device, the load capacitance is large, so it is difficult to ensure the charging time of the pixel electrode in one scanning period. However, since the interleaved scanning is performed in the display device 2, it is easy to ensure the charging time of the pixel electrode. Thereby, the display device 2 having a higher display quality can be realized. In the above aspect, in other words, the display device 2 is applicable to a high-definition display device of 200 ppi or more.

[Generalization of the embodiment]

As described above, in order to solve the above problems, a display device according to an aspect of the present invention includes: a display element that displays an image on a screen; and a drive mechanism that performs scanning during scanning and stops Driving the display element in a manner that alternately repeats during the horizontal line of the scan And driving at least a portion of the display element by interlaced scanning, wherein the horizontal blanking line has at least a length of a shortest period required for an detecting operation of an external detecting device; and an output portion is attached to the horizontal covering In the absence period, the detection instruction signal indicating the detection is output to the external detecting device, and the detection instruction signal is not output during the scanning period.

Further, in order to solve the above-described problems, a driving method of a display device according to an aspect of the present invention is characterized in that it is provided with a method of driving a display device for displaying an image and a display element on a screen, and has a driving step And driving the display element in such a manner that the scanning period during scanning and the horizontal blanking period of stopping the scanning are alternately repeated, and the display element is driven by interlaced scanning, and the horizontal blanking period has at least external detection a length of a shortest period of time required for the detecting operation of the device; and an outputting step of outputting a detection indicating signal indicating the detection to the external detecting device during the horizontal blanking period, and not outputting the detection indicating signal during the scanning period .

According to the above configuration and method, the detection instruction signal is output to the detection device during each horizontal blanking period, and when the detection instruction signal is output, the detection device performs the detection operation. The horizontal blanking period is set between the scanning period and the scanner, so the detecting device can perform the detecting operation at a frequency far higher than the refresh rate. As a result, the detection accuracy of the detecting device can be greatly improved.

In particular, in one aspect of the present invention, the horizontal blanking period can be extended by performing the interlaced scanning, and the detection accuracy of the detecting device can be improved. Therefore, it is not necessary to mount a novel member such as a frame memory, and power consumption can be suppressed.

Further, in the display device according to one aspect of the present invention, the scanning period and the above The length of the horizontal occlusion period is approximately the same.

According to the above configuration, the scanning period and the horizontal blanking period can be switched in accordance with the timing of the gate clock signal GCK, so that the circuit of the driving mechanism can be made simpler.

Further, in the display device according to the aspect of the invention, the display device includes a matrix display element in which a plurality of pixel electrodes are arranged in a matrix, and further includes a plurality of data signal lines for driving the pixel electrodes and a plurality of scans. And a signal line, wherein the driving mechanism includes a plurality of scanning line driving circuits that respectively drive one of the plurality of scanning signal lines different from each other.

Further, in the display device according to the aspect of the invention, the drive mechanism includes: a first scanning line driving circuit that drives the plurality of pixel electrodes arranged in an odd-numbered line; and a second scanning line driving circuit; The plurality of pixel electrodes arranged in the even number are driven.

According to the above configuration, interlaced scanning can be realized by using a plurality of scanning line driving circuits, respectively. In other words, for one scanning line driving circuit, it is not necessary to control which one of the scanning signal lines G of the nth frame is driven, and to drive the scanning signal line G of the (n+1)th frame. Which one of the circuits is controlled, so that the circuit of the display device can be simplified.

Further, in the display device according to the aspect of the invention, the drive mechanism drives a partial region of the display element by the interlaced scanning, and drives the remaining regions by sequential scanning.

According to the above configuration, the interlaced scanning can also be performed locally, that is, The normal scanning is performed in an area where the detection device does not need to be displayed, and interlaced scanning or the like is performed in an area where display of the detection device is required.

Further, in the display device according to the aspect of the invention, the resolution of the display element is higher than the resolution of 1920 × 1080.

Further, in the display device according to the aspect of the invention, the display element has a fineness of 200 ppi or more.

In the case of a high-resolution display device, since the charge capacitance is large, it is difficult to ensure the charging time of the pixel electrode in one scanning period. However, according to the above configuration, since the interlaced scanning is performed, it is easy to ensure the charging time of the pixel electrode. Therefore, a display device with higher display quality can be realized.

Further, in the display device according to the aspect of the invention, the external detecting device includes a plurality of sensing lines and a plurality of driving lines crossing the plurality of sensing lines, and each of the driving lines is selected for scanning, for each of The selected drive line outputs a rectangular wave that drives each of the drive lines, and the shortest period required for the detection operation of the external detection device is a period in which the rectangular wave is outputted to one of the drive lines.

According to the above configuration, at least one drive line outputs a rectangular wave in one horizontal blanking period. Thereby, the detection device can obtain a higher detection accuracy.

Further, in the display device according to an aspect of the present invention, an oxide semiconductor is used in a semiconductor layer of each TFT constituting a plurality of pixels of the display element.

Further, in the display device according to the aspect of the invention, the oxide semiconductor is preferably IGZO.

According to the configuration described above, a TFT using an oxide semiconductor having a high electron mobility (for example, IGZO) is used as the TFT of the plurality of pixels, whereby the amount of electron mobility is increased when pixel data is written for each pixel. The time taken for this write can be shortened. Thereby, the horizontal blanking period, which is a period during which the detecting device performs the detecting operation, can be sufficiently provided. Therefore, the detection accuracy of the detecting device can be improved.

Further, examples of the display device according to one aspect of the present invention include a liquid crystal display device, an organic electroluminescence (EL) display device, and the like. In the organic EL display device, the current consumption in the scanning mode is large, and the influence of the driving signal of the display device on the detecting device is increased. Therefore, it is more effective to use a display device according to one aspect of the present invention for an organic EL display device.

Further, the display system having the display device having the above configuration and the detecting device for detecting based on the detection instruction signal from the display device can have the same effects as those described above.

Further, examples of the detecting device include a touch panel or the like provided on the screen of the display device.

The touch panel is disposed close to the display device or disposed inside the display device, so the driving signal of the display device has a great influence on the touch panel. Therefore, it is more effective to use a touch panel as a detecting device.

DETAILED DESCRIPTION OF THE INVENTION The specific embodiments and examples of the invention are intended to be illustrative only and not to be construed as limited to It is implemented by making various changes within the scope of the request.

[Industrial availability]

As described above, the display device of the present invention can realize the interlaced scanning with a long horizontal blanking period, so that the detection indicating signal is output to the external detecting device during the horizontal blanking period, and therefore, the detecting action of the detecting device can be increased. The number of times and the accuracy of the detection result can be improved, so that it can be applied to any display device that performs scanning.

1‧‧‧Display system

1'‧‧‧Display System

2‧‧‧Display device

2a‧‧‧ display panel

3‧‧‧Touch panel

4‧‧‧Scan line driver circuit

4a‧‧‧Scan line driver circuit

4b‧‧‧Scan line driver circuit

5‧‧‧Signal line driver circuit

5a‧‧‧Signal line driver circuit

5b‧‧‧Signal line driver circuit

5c‧‧‧Signal line driver circuit

6‧‧‧Common electrode drive circuit

7‧‧‧Sequence Control Department

8‧‧‧Detection Department

9‧‧‧Detection Department Control Department

10‧‧‧Control Department

11‧‧‧Display system

11'‧‧‧Display System

200‧‧‧TFT

A‧‧‧ arrow

B‧‧‧ arrow

C‧‧‧ arrow

CCK‧‧‧AC low voltage distribution cabinet

Ccs‧‧‧Support Capacitor

Cgd‧‧‧ parasitic capacitance

Cgs‧‧‧ parasitic capacitance

COE‧‧‧High-level orthogonal system

Csd1‧‧‧ parasitic capacitance

Csd2‧‧‧ parasitic capacitance

D‧‧‧ arrow

E‧‧‧ arrow

F‧‧‧ arrow

F1‧‧‧ arrow

F2‧‧‧ arrow

G‧‧‧ scan signal line

G1‧‧‧ scan signal

G2‧‧‧ scan signal

G3‧‧‧ scan signal

G4‧‧‧ scan signal

G5‧‧‧ scan signal

G6‧‧‧ scan signal

G7‧‧‧ scan signal

G8‧‧‧ scan signal

Rx‧‧‧ readout line

S‧‧‧ data signal line

Tx‧‧‧ drive line

Vdd‧‧‧Power supply voltage

Fig. 1 is a timing chart showing driving timings of scanning signal lines G in the case of performing interleave scanning according to an embodiment of the present invention.

Fig. 2 is a block diagram showing the details of the configuration of a display system according to an embodiment of the present invention.

Fig. 3 is a block diagram showing the details of the configuration of a display system according to an embodiment of the present invention.

Fig. 4 is a view showing the configuration of a pixel included in a display panel according to an embodiment of the present invention.

Fig. 5 is a view showing the details of the configuration of a touch panel according to an embodiment of the present invention.

Fig. 6 is a timing chart showing the driving timing of each scanning signal line G when a normal sequential scanning is performed.

Fig. 7 is a timing chart showing the driving timing of each scanning signal line G when a normal interleaved scanning is performed.

Fig. 8 is a timing chart showing control signals of a scanning line driving circuit and output signals from a scanning line driving circuit according to an embodiment of the present invention.

Fig. 9 is a view showing characteristics of various TFTs.

Figure 10 is a diagram showing the interlaced scanning of an embodiment of the present invention. A timing chart of the driving timing of each scanning signal line G at the time of the shape.

Fig. 11 is a timing chart showing control signals of a scanning line driving circuit and output signals from a scanning line driving circuit according to an embodiment of the present invention.

Fig. 12 is a schematic view showing a display system according to another embodiment of the present invention.

Fig. 13 is a schematic view showing a display system according to another embodiment of the present invention.

Fig. 14 is a timing chart showing control signals of a scanning line driving circuit and output signals from a scanning line driving circuit according to another embodiment of the present invention.

G1‧‧‧ scan signal

G2‧‧‧ scan signal

G3‧‧‧ scan signal

G4‧‧‧ scan signal

G5‧‧‧ scan signal

G6‧‧‧ scan signal

G7‧‧‧ scan signal

G8‧‧‧ scan signal

Claims (15)

A display device, comprising: a display element for displaying an image on a screen; and a driving mechanism for driving the display element in such a manner that a scanning period during scanning and a horizontal blanking period in which the scanning is stopped are alternately repeated And driving at least a portion of the display element by interlaced scanning, the horizontal blanking period having at least the length of the shortest period required for the detecting operation of the external detecting device; and the output portion being tied to the horizontal blanking period The detection instruction signal indicating the detection is output to the external detecting device, and the detection instruction signal is not output during the scanning period. The display device of claim 1, wherein the lengths of the scanning period and the horizontal blanking period are substantially the same. The display device according to claim 1 or 2, wherein the display element is a matrix type display element including a plurality of pixel electrodes arranged in a matrix, and further comprising a plurality of data signal lines for driving the pixel electrodes and a plurality of The scanning signal line; the driving mechanism includes a plurality of scanning line driving circuits respectively driving one of the plurality of scanning signal lines. The display device of claim 3, wherein the drive mechanism includes a first scan line drive circuit that drives the plurality of pixel electrodes arranged in the odd-numbered row; and a second scan line drive circuit that is driven in the even-numbered The above plurality of pixel electrodes of the line of the number. The display device according to any one of claims 1 to 4, wherein the driving mechanism drives a partial region of the display element by the interlaced scanning, and drives the remaining regions by sequential scanning. The display device according to any one of claims 1 to 5, wherein the resolution of the display element is higher than the resolution of 1920×1080. The display device according to any one of claims 1 to 6, wherein the display element has a fineness of 200 ppi or more. The display device according to any one of claims 1 to 7, wherein the external detecting device comprises a plurality of sensing lines and a plurality of driving lines crossing the plurality of sensing lines, and each of the driving lines is selected for scanning, Each of the selected drive lines outputs a rectangular wave that drives each of the drive lines; and the shortest period required for the detection operation of the external detection device is a period during which the rectangular wave is output to one of the drive lines. The display device according to any one of claims 1 to 8, wherein the semiconductor layer of the TFT constituting each of the plurality of pixels of the display element uses an oxide semiconductor. The display device of claim 9, wherein the oxide semiconductor system is IGZO. The display device according to any one of claims 1 to 10, wherein the display device is a liquid crystal display device. The display device according to any one of claims 1 to 11, wherein the display device is an organic electroluminescence display device. A display system comprising: the display device according to any one of claims 1 to 12; The detecting device detects based on a detection instruction signal from the display device. The display system of claim 13, wherein the detecting device is a touch panel disposed on a screen of the display device. A driving method, characterized in that it is a method of driving a display device having a display element for displaying an image on a screen, comprising: a driving step of masking a scanning period during which scanning is performed and stopping the scanning Driving the display element in an alternately repeated manner, and driving the display element by interlaced scanning, the horizontal blanking period being longer than a shortest period required for an external detecting device detecting operation; and an outputting step of the above During the horizontal blanking period, the detection instruction signal indicating the detection is output to the external detecting device, and the detection instruction signal is not output during the scanning period.