TW201308158A - Display device and method for controlling same - Google Patents

Abstract

A control unit (110) of the present device controls a display control circuit (200) to perform an intermittent sleep operation (S20) after initial setting (S10). Thereafter, when contact with a touch panel is detected (S30), the control unit (110) controls the display control circuit (200) to perform a continuous normal operation (S40). After that, when contact with touch panel is no longer being detected (S50), the sleep operation is executed (S20). As such, when an input to the touch panel is detected during the sleep operation, the operation is switched to a normal operation, and when the input is discontinued, the operation is switched to the sleep operation, whereby the reaction of a screen display in response to an input operation is improved while minimizing the power consumption of the device.

Description

Display device and control method thereof

The present invention relates to a display device and a control method thereof, and more particularly to an active matrix type display device including a touch sensor and a control method thereof.

In general, in a liquid crystal display device, AC driving is performed in order to suppress deterioration of liquid crystal and maintain display quality. Further, in recent years, for portable information devices such as mobile phones, high-quality display capabilities are required due to improvement in processing performance and utilization. Therefore, as the alternating current driving method of the liquid crystal module used in the portable information device, the positive and negative polarities of the applied voltage are reversed for each horizontal scanning line, and the positive and negative polarities are reversed for each frame. The driving method (referred to as "1 scan line inversion driving method"). In addition, a driving method in which the positive and negative polarities of the applied voltage are reversed for each pixel adjacent in the vertical or horizontal direction, and the positive and negative polarities are reversed for each frame (referred to as "1 point" Reverse drive mode").

However, when the above-described one scanning line inversion driving method is employed, the frequency of the polarity of the image signal applied to the liquid crystal panel is reversed (the inversion frequency becomes high), and the driving IC (Integrated Circuit) The required withstand voltage is lowered, so that the switching frequency of the potential of the common electrode also becomes high. As a result, power consumption increases. Further, when the one-dot inversion driving method is employed, the common electrode cannot be reversely driven, and therefore the withstand voltage required for the driving IC is increased. As a result, the manufacturing cost of the device is increased, and the power consumption is also increased. Big.

Therefore, in recent years, there has been a case where a low-frequency driving method is adopted which reduces the inversion frequency as a whole by providing a scanning stop period for forming a state in which only the applied voltage does not change for a specific period (for example) Reference is made to Japanese Patent Laid-Open Publication No. 2001-312253. By inserting such a scanning stop period (suspend period), it is possible to satisfy the demand for low power consumption of a mobile phone or the like.

However, the longer the scanning stop period is set, the more power consumption can be reduced, and conversely, the capacitive element provided in the pixel forming portion of the liquid crystal panel for holding the applied voltage generates a current during the scanning stop period. Leakage, and the voltage that should be maintained is lowered. As a result, the luminance change of the pixel (which should be the same one) displayed after the end of the scanning stop period becomes significant corresponding to the supplied applied voltage. As a result, there is a case where the change in luminance is regarded as flicker.

Moreover, in a display device including a touch sensor that detects (presses, contacts, or approaches), when there is an input to the touch sensor, the display screen is usually based on the input result. When the input to the touch sensor is performed by the driving state (continued) in which the above-described scanning stop period is inserted, the problem that the response (reaction speed) of the device becomes slow is generated.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-312253

However, in a display device including the touch sensor, when there is an input to the touch sensor when driving in a driving state in which the scanning stop period is inserted, it is difficult to use the original The pattern continues to drive while eliminating the above problems.

Accordingly, it is an object of the present invention to provide a display device that includes a display device of a touch sensor and that is present when driving in a driving mode during insertion of a scanning stop (during a pause period) When the sensor is input, it is driven in such a manner that the response of the device is not slowed down.

A first aspect of the present invention is a display device including a sensor circuit that accepts an operation input using a finger or an object to approach or contact or press; and includes: a display panel including two a plurality of pixel circuits arranged in a dimension; a driving circuit that continuously or intermittently performs an operation of writing a signal corresponding to display material for displaying an image into the plurality of pixel circuits; and a control unit The sensor circuit receives information indicating the operation input, and when determining that the operation input exists according to the information, causes the drive circuit to continuously perform the above operation, and when determining that the operation input is not present, The drive circuit intermittently performs the above operation.

According to a second aspect of the present invention, in the first aspect of the present invention, the control unit determines whether the display material is a moving image data, and determines the above When the display data is a moving image data, the above-described drive circuit is continuously operated.

According to a second aspect of the present invention, in the second aspect of the present invention, the control unit is configured to determine a time point at which the operation input is not present after determining that the operation input is present based on the information or from the time point At a specific time point, it is determined whether the above display data is dynamic image data.

According to a fourth aspect of the present invention, in the aspect of the present invention, the control unit is configured to determine a time from when a operation input is determined based on the information to determine that the operation input is not present, and a time elapsed During the period until the point, the above-described driving circuit is continuously operated.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the sensor circuit detects proximity of the finger or the object within a predetermined first distance; and the control unit is configured by the sensing The driver circuit detects the approach period described above, and causes the drive circuit to continuously perform the above operation.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the sensor circuit is configured to be close to or in contact with the finger or the object within a second distance shorter than the first distance. The above operation input.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the plurality of pixel circuits respectively correspond to intersections of a plurality of image signal lines and a plurality of scanning signal lines crossing the plurality of image signal lines. And the plurality of image signal lines are used to transmit a plurality of image signal lines representing the image to be displayed on the display panel to the plurality of pixel forming portions, and the plurality of pixel circuits respectively include: a switching element that is turned on or off according to a signal applied to the connected scanning signal line; a pixel electrode connected to the connected video signal line via the switching element; and a common electrode sharing The pixel capacitor is formed by the pixel electrode and the common electrode, and the liquid crystal element displays a gray scale display pixel corresponding to a voltage held by the pixel capacitor.

An eighth aspect of the invention is the seventh aspect of the invention, wherein the switching element comprises a thin film transistor comprising a semiconductor layer of an oxide semiconductor.

A ninth aspect of the present invention is a control method, characterized in that it is a method of controlling a display device, the display device including a sensor circuit for accepting an operation input using a finger or an object approaching or contacting or pressing, and including a display panel of a plurality of pixel circuits arranged in two dimensions; and the control method includes: a driving step of continuously or intermittently writing a signal corresponding to the display material for displaying the image into the plurality of pixel circuits And a driving control step of receiving, from the sensor circuit, information indicating the operation input, and determining that the operation input exists according to the information, performing the operation continuously in the driving step, and determining In the case where the above operation input is not present, the above-described operation is intermittently performed in the above-described driving step.

According to the first aspect of the present invention, when it is determined that there is an operation input based on information from the sensor circuit, the drive circuit is continuously driven, and when it is determined that there is no operation input, the drive is driven. The circuit performs the driving operation intermittently, whereby the power consumption of the device can be suppressed, and the screen display is made to respond well to the input operation.

According to the second aspect of the present invention, when it is determined that the display material is the moving image data, the driving circuit is continuously driven, so that the intermittent driving can be performed in the case of displaying the moving image. Perform a smooth dynamic image display.

According to the third aspect of the present invention, after determining that there is an operation input, it is determined that there is no operation input time point (or a time point when a specific time has elapsed from the time point), and it is determined whether the display material is moving image data, The above determination is not made as long as the operation input is not detected. Therefore, the determination can be repeated in vain, thereby further reducing power consumption.

According to the fourth aspect of the present invention, the drive circuit is continuously driven in a period from the time point when it is determined that there is no operation input after the operation input is determined to the time point when the operation input has elapsed, and therefore the operation input ends. When the screen display is switched immediately afterwards, for example, when the time from the input operation to the display takes time or when the display itself takes time (for example, when an animation is displayed), the display can be performed immediately in response.

According to the fifth aspect of the present invention described above, the proximity of the finger or the object within the first distance (proximity detection distance) is detected by the sensor circuit, and the proximity is detected. In the meantime, since the drive circuit is continuously driven, the display can be performed immediately in response to the reaction.

According to the sixth aspect of the present invention, the sensor input receives the operation input by the proximity or contact of the finger or the object within the second distance shorter than the first distance, so that the continuous drive is earlier than the operation input. On the other hand, the intermittent driving is performed later than the end of the operation input, whereby the display can be performed immediately in response to the reaction.

According to the seventh aspect of the invention described above, the configuration of the active matrix type liquid crystal display device can be manufactured at low cost.

According to the eighth aspect of the present invention, since the semiconductor layer of the thin film transistor uses an oxide semiconductor, current leakage can be made very small, so that power consumption can be sufficiently reduced.

According to the ninth aspect of the invention described above, the same effects as those of the first aspect of the invention described above can be exhibited in the display method.

Hereinafter, each embodiment of the present invention will be described with reference to the accompanying drawings.

<1. First embodiment> <1.1 Overall composition and operation of carrying information terminal>

Fig. 1 is a perspective view showing the appearance of a portable information terminal device according to a first embodiment of the present invention. The portable information terminal 100 includes a display unit 500 including a liquid crystal panel. Further, a transparent touch panel is disposed on the upper surface (surface) of the display portion 500, and is detected by pressing (contacting) the screen with a finger or a pen (typically, the user's dominant hand). The pressed position on the screen. on The configuration of the display unit and the touch panel will be described below.

Fig. 2 is a block diagram showing the main components of a display unit and an input unit of the portable information terminal of the embodiment. The portable information terminal 100 includes a control unit 110 that performs various controls including the following pause control (intermittent drive) and normal drive (continuous drive) switching control; a display unit 500; and a source driver 300. And a gate driver 400, which drives the display unit 500, a display control circuit 200, a matrix type resistive film touch panel 150, which is disposed on the display portion 500, and an X coordinate sensor 130 and The Y coordinate sensor 140 is configured to detect that the user's finger or pen is equal to the position on the touch panel 150; and the coordinate processing circuit 120.

Here, the touch panel 150 is not a conventional resistive film type touch panel in which the contact points of the two resistive films are analogously detected, but includes a plurality of transparent electrodes arranged in parallel in the column direction, and A plurality of transparent electrodes arranged in parallel in the row direction opposite to each other in a manner corresponding to a predetermined short distance from the vertical direction. The X coordinate sensor 130 is connected to the respective electrodes along the row direction, and the Y coordinate sensor 140 is connected to the respective electrodes along the column direction. Therefore, if the electrodes in the intersecting direction and the row direction are in contact with the finger pressed by the user's finger or the pen, the X coordinate sensor 130 and the Y coordinate sensor 140 can be detected. Therefore, the plurality of coordinates on the touch panel 150 can be individually identified by the resolution corresponding to the arrangement pitch of the electrodes.

Further, as long as the touch panel can individually recognize a plurality of coordinates, a touch panel of various types such as a matrix type electrostatic capacitance method, a photo sensor method, or a mechanical sensor method can be employed. Further, it can also be used in combination A plurality of touch panels that can recognize only one coordinate. In addition, in general, the electrostatic capacitance method or the photo sensor method does not need to press a finger to the touch panel as in the resistive film method, but only slightly touches or approaches, so that it is more suitable in the present embodiment. More. Further, the configuration of the fact that the detection is close to a specific distance is described in detail in the third embodiment. In this way, the proximity detection method does not need to detect the contact, but in the case of adopting this method, it is also referred to herein as a touch panel.

The display unit 500 includes an active matrix liquid crystal panel, and the source driver 300 and the gate driver 400 perform selection and data assignment of pixels in the liquid crystal panel to form a display image. Hereinafter, a detailed configuration of a liquid crystal display device including constituent elements for such display will be described with reference to FIGS. 3 and 4.

Fig. 3 is a block diagram showing the overall configuration of an active matrix liquid crystal display device of the embodiment. The liquid crystal display device includes a drive control unit, a display unit 500, and a common electrode drive circuit 600. The drive control unit includes a display control circuit 200, a source driver (video signal line drive circuit) 300, and a gate driver (scanning signal line). Drive circuit) 400. The display unit 500 includes a plurality of (M) image signal lines SL(1) to SL(M), a plurality of (N) scanning signal lines GL(1) to GL(N), and a plurality of image signals along the plurality of image signals A plurality of (M × N) pixel forming portions provided by the lines SL(1) to SL(M) and the plurality of scanning signal lines GL(1) to GL(N).

As the driving method of the display unit 500, the column inversion method is employed, but the voltage of the image signal to be applied to the liquid crystal portion of the pixel forming portion may be reversely driven by inversion of polarity for each image signal line. square formula. Further, the display unit 500 is configured to be normally white in a TN (Twisted Nematic) alignment method, for example.

Hereinafter, the reference symbol "P(n, m)" is associated with the intersection of the scanning signal line GL(n) and the video signal line SL(m), and is disposed near the intersection (the intersection is shown in the figure) A pixel forming portion near the lower right side). Fig. 3 shows an equivalent circuit of the pixel formation portion P(n, m) of the display unit 500 of the present embodiment.

Moreover, FIG. 4 shows a detailed configuration of a part of the display unit 500 for explaining the above-described connection relationship. Further, in the liquid crystal television in which the values of N and M are usually 40 inches or more, for example, N = 1920 × 3 (RGB (Red Green Blue) color), and M = 1080.

As shown in FIG. 3 and FIG. 4, each of the pixel formation portions P(n, m) includes a TFT (Thin Film Transistor) 10 as a switching element, which is tied to the scanning signal line GL(n) or The adjacent scanning signal line GL(n+1) is connected to the gate terminal, and the active terminal is connected to the image signal line SL(m) passing through the intersection; the pixel electrode Epix is connected to the TFT 10 a drain terminal; a common electrode Ecom which is commonly provided in the plurality of pixel forming portions P(i, j) (i=1 to N, j=1 to M); and a liquid crystal layer as a photovoltaic element It is sandwiched between the pixel electrode Epix and the common electrode Ecom which are provided in common to the plurality of pixel formation portions P(i, j) (i=1 to N, j=1 to M).

In the case where the high-speed response or the small current leakage is not required as such, the TFT 10 described above can be used as an amorphous silicon which can be easily and inexpensively manufactured as a semiconductor layer, but is suspended as described below. Driven by the situation, so the current leakage is very small (specifically, It is an In-Ga-Zn-O (IGZO (Indium Gallium Zinc Oxide)) oxide semiconductor which is smaller than a single digit or more. Of course, although there is a problem of current leakage, other well-known semiconductors such as the above-mentioned amorphous germanium or CG (continuous crystal) may be used.

Further, each of the pixel formation portions P(n, m) displays any one of red (R), green (G), and blue (B), and displays pixel formation portions P(n, m) of the same color. It is arranged along the image signal lines SL(1) to SL(M), and is arranged repeatedly in the order of RGB along the scanning signal lines GL(1) to GL(N).

In each of the pixel formation portions P(n, m), a liquid crystal capacitor (also referred to as "pixel capacitance") Clc is formed by the pixel electrode Epix and a counter electrode shared with the liquid crystal layer. Two video signal lines SL(m) and SL(m+1) are disposed in the vicinity of the pixel electrode Epix, and the video signal line SL(m) is connected to the pixel electrode Epix via the TFT 10. Further, as shown in FIG. 4, a storage capacitor line CsL is formed in parallel with each scanning signal line GL(n), and between each pixel forming portion P(n, m), between the pixel electrode Epix and the auxiliary capacitance line CsL A storage capacitor Ccs is formed. Further, the total capacitance (that is, the total capacitance associated with the pixel electrode Epix) formed between the pixel electrode Epix and the other electrode in one pixel formation portion P(n, m) is also referred to as a pixel capacitance.

The display control circuit 200 receives the display data signal DAT and the timing control signal TS transmitted from the outside, and outputs a digital image signal DV for controlling the source start pulse signal SSP of the timing of displaying the image on the display unit 500, The source clock signal SCK, the latch strobe signal LS, the gate start pulse signal GSP, and the gate clock signal GCK, and the polarity for controlling the potential of the common electrode Ecom Reverse signal .

The gate driver 400 sequentially applies an effective scan signal G to each of the scanning signal lines GL(1) to GL(N) according to the gate start pulse signal GSP and the gate clock signal GCK output from the display control circuit 200. 1)~G(N).

Further, the gate driver 400 applies a specific potential to each of the scanning signal lines GL(1) to GL(N) simultaneously in the pause period (scanning stop period) described below. As long as the potential is not the effective scanning signals G(1) to G(N), that is, as long as the scanning signal line can be set to the non-selected state, the scanning signals of the non-selected state during the scanning period can be used. The scan signal potentials which are ineffective for the supply of the lines GL(1) to GL(N) are the same, and may be predetermined well-known fixed potentials such as the common electrode potential. Further, similarly, in the source driver 300, a specific potential (which is different from or equal to the above potential) is simultaneously applied to each of the video signal lines SL(1) to SL(M) in the pause period described below. The actions in these pause periods are described below.

The source driver 300 receives the digital image signal DV, the source start pulse signal SSP, the source clock signal SCK, and the latch strobe signal LS output from the display control circuit 200 for forming pixels for each of the display portions 500. The pixel capacitance (liquid crystal capacitor Clc and auxiliary capacitor Ccs) of the portion P(n, m) is charged, and the driving image signals S(1) to S(M) are applied to the respective image signal lines SL(1) to SL(M). . At this time, in the source driver 300, the digital image signal DV indicating the voltage to be applied to each of the video signal lines SL(1) to SL(M) is sequentially held at the timing of the pulse generating the source clock signal SCK. Then to produce The timing of the pulse of the latch strobe signal LS is latched, and the digital image signal DV held as described above is converted into an analog voltage. Such D/A (Digital to Analog) conversion is performed by a gray scale voltage generating circuit. The gray scale voltage generating circuit generates an analog voltage corresponding to each display gray scale by, for example, dividing a reference voltage for generating a gray scale voltage supplied from the outside of the source driver 300. The analog voltage generated by the gray scale voltage generating circuit is simultaneously applied to all of the video signal lines SL(1) to SL(M) as a driving video signal. That is, in the present embodiment, the driving method of the video signal lines SL(1) to SL(M) is a line sequential driving method.

Here, the polarities of the driving video signals S(1) to S(M) applied to the respective video signal lines SL(1) to SL(M) are inverted in units of columns as described above. For example, the driving image signals S(1) to S(M) when the effective scanning signal G(1) is applied to the scanning signal line GL(1) and the effective scanning signal G(2) are applied to the scanning signal. The driving image signals S(1) to S(M) at the time of the line GL(2) have opposite polarities. Further, in order to reduce power consumption, the common electrode potential Vcom of the common electrode Ecom is supplied from the specific two potentials by the common electrode drive circuit 600 so that the polarity inversion is reversed. Furthermore, the polarity inversion signal indicating the timing of the polarity inversion It is generated by the display control circuit 200 and supplied to the common electrode driving circuit 600 and the source driver 300. With this configuration, column inversion driving is realized.

In this manner, a driving video signal is applied to each of the video signal lines SL(1) to SL(M), and a scanning signal is applied to each of the scanning signal lines GL(1) to GL(N) to be displayed on the display unit. The image is displayed in 500. Furthermore, the auxiliary capacitance line CsL is held by a power supply circuit (not shown) that receives a supply of a specific voltage. It is the same potential, but it can also be driven in the same manner by the same circuit as the common electrode driving circuit. Next, the control operation of the display control circuit 200 by the control unit 110 will be described with reference to FIG. 5.

<1.2 Control action by the control unit>

Fig. 5 is a flow chart showing the flow of processing for switching the control unit of the normal drive and the pause drive. In step S10 shown in FIG. 5, the control unit 110 performs initial setting processing for performing the control operation on the display control circuit 200 and receiving the coordinates from the coordinate processing circuit 120. Then, in step S20, the control unit 110 controls the display control circuit 200 to perform the pause driving as shown in FIG. 6.

Fig. 6 is a view showing the timing of the scanning signal and the driving image signal when the driving is suspended. As shown in FIG. 6, the gate driver 400 in the pause driving does not sequentially output the valid scan signals G(1) to G(N) during the entire frame period, but from the time in the frame period. In the scanning period Ts from t11 to time t12, the (effective) scanning signals G(1) to G(N) are sequentially output. Further, in the scanning period Ts, the source driver 300 (in the line sequential driving method) outputs the driving image signals S(1) to S(M) in which the polarity is reversed in units of columns is as described above. . The change in the pixel potential held by the pixel electrode Epix of the pixel formation portion P (1, 1) is exemplified in the drawing. Further, the length of the active period of each of the scanning signals G(1) to G(N) is approximately Ts/N, but is shown in different lengths for convenience of observation in the drawing.

When the scanning period Ts is completed, the scanning signals G(1) to G(N) and the driving image signal S(1) are not output in the scanning stop period Th from the time t12 to the time t13. S(M), so that each scan signal The lines GL(1) to GL(N) and the respective image signal lines SL(1) to SL(M) are held (fixed) to a specific potential. Therefore, the pixel potential of the pixel formation portion P (1, 1) does not change. Further, in actuality, the above-described pixel electric power is gradually reduced in a small amount during the pause period due to the current leakage of the TFT 10, but this is ignored because the current leakage is extremely small. As described above, when the operation in the one frame period is completed, the same operation is performed in the next frame period from the subsequent time t13 to the time t15, and the operation is repeatedly performed thereafter. As described above, in the pause driving, the drive system realized by the source driver 300 and the gate driver 400 is intermittently performed.

Further, the scanning period Ts is, for example, 1/60 [sec], and the pause period Th is, for example, 1/30 [sec]. Therefore, in this case, the frame period during the pause of driving becomes 1/20 [sec]. Of course, the value is an example, and may be other well-known values. However, since the Th period is set for low power consumption during the pause period, it is usually preferably a scan period or more (typically, several times to several tens of times For the length of the left and right or above, the frame period during the pause driving is usually preferably longer than 1/60 [sec].

In the above-described pause driving, in the present embodiment, in step S30, the control unit 110 determines whether or not the coordinate indicating the contact position of the finger or the like has been received from the coordinate processing circuit 120. When the coordinate of the contact is not received (in the case of No in step S30), the processing is repeated until the coordinate is received, and when the coordinate is received (Yes in step S30) In the case of ), the processing proceeds to step S40. Furthermore, the X coordinate sensor 130 and the Y coordinate sensor 140 for detecting the position (contact position) of the user's finger or the pen pressing the touch panel 150 can be used in the normal driving. The detection is performed in the same cycle as in the pause drive, and the detection cycle can be set longer in the pause drive. However, in this case, if the detection period in which the length of the period in which the detection is not performed is equivalent to the same length as the pause period is set, the user feels that the operation is unresponsive, which is not preferable.

Then, in step S40, the control unit 110 controls the display control circuit 200 to perform normal driving as shown in FIG. That is, the driving state of the liquid crystal panel shifts from the pause driving state to the normal driving state. Furthermore, the transfer is performed immediately upon detection of the coordinates, and is not performed after the end of the pause period for suspending the drive.

Fig. 7 is a view showing timings of a scanning signal and a driving image signal during normal driving. As shown in FIG. 7, the gate driver 400 in the normal driving sequentially outputs the effective scanning signals G(1) to G(N) in the entire frame period which coincides with the normal period Tn. In the normal period Tn, the source driver 300 (in the line sequential driving method) outputs the driving image signals S(1) to S(M) in which the polarity is reversed in units of columns. Further, similarly to the case of FIG. 6, the change in the pixel potential held by the pixel electrode Epix of the pixel formation portion P(1, 1) is also illustrated in FIG. Further, the length of the active period of each of the scanning signals G(1) to G(N) is approximately Tn/N, but is described in different lengths for convenience of observation in the drawing. Here, the frame period of one frame at the time of normal driving is, for example, 1/60 [sec], and is generally driven at a high speed so as not to cause flicker even when the moving image is displayed. As described above, in the normal driving, the driving system realized by the source driver 300 and the gate driver 400 is continuously performed.

In the normal driving as described above, in the present embodiment, in step S50, the control unit 110 determines whether or not the coordinates are received from the coordinate processing circuit 120. When the coordinates are received (in the case of Yes in step S50), the processing proceeds repeatedly until the coordinates are no longer received, and when the coordinates are not received (in the case of No in step S50), The process returns to step S20 to perform the pause drive, and the above process is repeated (S50 → S20 → ... → S50) until the device is stopped. Furthermore, in the case of the transition from the pause drive to the normal drive, or in the opposite case, the polarity inversion signal is preferably used. Reverse.

Here, in general, when the user's finger or pen is pressed by the touch panel 150, the pressing state generally continues for at least several times of the normal period Tn, regardless of the speed of the action. Therefore, the normal driving operation in the above step S40 continues for at least a plurality of frames. As described above, in the present liquid crystal panel, the operation is suspended until the finger or the like is brought into contact with the touch panel 150, and the normal driving is performed during the contact period, and once again, the driving is paused.

However, it is also considered that the transition from the pause drive to the normal drive should be performed immediately when the coordinates are detected. It cannot be said that the transition from the normal drive to the pause drive should be performed immediately when the coordinates cannot be detected. For example, when the user performs an operation of pressing the touch panel, if a process corresponding to the operation input (for example, corresponding to an input command) is performed, and then a process of displaying an appropriate screen is performed, there is a self-operation input. The time of passage is relatively long. At this time, if the input operation is completed and the finger is moved away from the touch panel, the screen is displayed during the pause driving, and thus there is There may be cases where the user feels that the display (reaction) is sluggish. Therefore, in the case of the step S50, the following situation is also considered: when the (detected) coordinate is not received, it is preferably from the time corresponding to the degree of the frame to a few seconds (or more) After the normal drive, the time shifts to the pause drive instead of immediately shifting to the pause drive. In this case, although the power consumption of the device is increased due to the shortening of the pause driving time, it takes time from the input operation to the display or when the display itself takes time (for example, when displaying an animation), etc. ), the display can be performed immediately (with good response) without waiting for the end of the pause period.

In this way, by setting a specific delay time when returning to the pause driving, even if the finger is separated from the touch panel, the normal driving of the delay time is performed in the liquid crystal panel, so that the screen is not overwritten until the next scanning period. The state of (unchanged). As a result, the reaction to the operation is not felt to be inferior, and the state in which the operation is in a bad state can be avoided.

<1.3 effect>

As described above, in the present embodiment, in the display device including the touch sensor, when the driving is performed in the driving mode (suspended driving) during the insertion of the scanning stop period (suspension period), there is a touch type. When the sensor is input, the drive mode is switched to the drive mode during which the scan stop is not inserted (normal drive). If the input disappears, the drive is switched to the pause drive, thereby suppressing the power consumption of the device and causing the screen display to be input. The reaction was good.

<2. Second embodiment> <2.1 Overall Configuration and Operation of Liquid Crystal Display Device>

The configuration of the liquid crystal display device of the present embodiment is the first shown in FIG. Since the configuration of the active matrix liquid crystal display device of the embodiment is the same, the description thereof is omitted.

In the present embodiment, unlike the case of the first embodiment, in the case of switching between the pause driving and the normal driving in the control unit 110, when the (content) material to be displayed is a still image, Perform different actions for the case of moving images. Hereinafter, the control operation of the display control circuit 200 by the control unit 110 having such characteristics will be described with reference to FIG. In addition, the moving image here refers to a moving image as a video content, and the person is described. However, not only such a moving image but also a wide range of still images may be widely included. Or intermittent changes (such as animation icons, etc.).

<2.2 Control action of the control unit>

Fig. 8 is a flow chart showing the flow of processing for switching the control unit of the normal drive and the pause drive. The processing of steps S10 to S50 shown in FIG. 8 is the same as the processing of steps S10 to S50 shown in FIG. 5. Therefore, the description thereof will be omitted, and the processing of the subsequent steps S60 and S70 will be described. However, here, unlike the case of the first embodiment, in the case where the (detected) coordinate is not received in step S50, the processing of the next step S60 is immediately shifted, and the normal driving is performed for a specific delay time. The processing in the case is set to be performed when it is determined as a non-moving image in the subsequent step S60. Further, instead of this configuration, the configuration may be the same as that in the case of the first embodiment.

In step S60 shown in FIG. 8, the control unit 110 determines whether the data being displayed or the data to be displayed immediately after (hereinafter referred to as display data) is dynamic. Image data. In the case of the non-moving image data (in the case of No in step S60), the process returns to step S20 to perform the pause driving, and the above processing is repeated (S60 → S20 → ... → S60) until the device is stopped. Or it is determined as a moving image in step S60. Furthermore, by setting a specific delay time when returning to the pause driving as described above, even if the finger is separated from the touch panel, the normal driving of the delay time is performed in the liquid crystal panel, and thus the next scanning period is not generated. The state of the screen is not overwritten (unchanged), so that it is possible to avoid a state in which the response to the operation is poor and the operation is also in a bad condition. Moreover, in the case where it is determined in the step S60 that the display material is the moving image data, the processing proceeds to a step S70.

Here, regarding the how the control unit 110 discriminates the display material as the moving image data in the above-described step S60, there are various well-known methods, and any method can be applied. For example, a method may be considered in which the control unit 110 includes a memory unit that stores image data during a frame period or a certain period of time, and a data comparison circuit that compares the saved image data with the current image data. When the data compared by the data comparison circuit is identical or substantially identical, it is determined as a still image, and if it does not match, it is determined as a moving image. Further, the function of determining whether or not the image is a moving image can be realized by a circuit or a component different from the control unit 110.

In the subsequent step S70, the control unit 110 determines whether or not the coordinates have been received from the coordinate processing circuit 120. When the coordinates are not received (in the case of No in step S70), the processing is repeated until the coordinates are received, and when the coordinates are received (in the case of Yes in step S70), the processing returns. Go to step S50, the process proceeds repeatedly until the coordinates are no longer received.

As described above, in the case of displaying the data non-moving image (in the case of No in step S60), the processing in the above-described step S70 is not performed, and as a result, the processing in the first embodiment is completely completed. In the case where the display data is a moving image, the configuration is such that after the determination is completed, the finger or the like is brought into contact with the touch panel 150, and the drive is normally driven, and the step is performed again when leaving. The judgment in S60. Therefore, as long as the contact is not detected, the above determination is not performed, so that the determination can be repeated in vain, thereby further reducing power consumption.

<2.3 effect>

As described above, in the present embodiment, in the display device including the touch sensor, when the driving is performed in the driving mode (suspended driving) during the insertion of the scanning stop period (suspension period), there is a touch type. When the sensor is input, it switches to the driving mode (normal driving) during which the scanning stop is not inserted. If the input disappears, it switches to the pause driving, thereby suppressing the power consumption of the device and allowing the screen display to be The response of the input operation is good, so that a smooth moving image display can be performed in a manner that does not suspend driving when a moving image is displayed.

<3. Third embodiment> <3.1 Overall Configuration and Operation of Liquid Crystal Display Device>

The configuration of the liquid crystal display device of the present embodiment is substantially the same as that of the active matrix liquid crystal display device of the first embodiment shown in FIG. 1. However, instead of the matrix type resistive film type touch panel 150, a matrix type electrostatic capacitor is used. The method or the light sensor method uses a touch panel that can detect an object such as a finger or a pen to a certain distance.

For example, in a touch panel using a matrix type electrostatic capacitance method, when the change in electrostatic capacitance exceeds a certain threshold value, it can be determined that the approach to a specific distance has been detected. Further, in the touch panel using the matrix type photosensor method, when the change in the amount of received light exceeds a certain threshold value, it can be determined that the approach to a specific distance is detected. In the present embodiment, a simple sensor structure and an operation principle using a sensor-incorporated liquid crystal panel using a photosensor method will be described with reference to FIGS. 9 and 10. Furthermore, as long as it is a capacitive touch panel or the like which can detect a proximity to a specific distance, the same can be applied.

In the method of detecting an image and detecting a reflected image (or both an image and a reflection image), the liquid crystal panel of the optical sensor of the present embodiment detects the touch position in the display screen. Either.

Fig. 9 is a view showing the principle of a method of detecting an image, and Fig. 10 is a view showing the principle of a method of detecting a reflected image. In the method of detecting an image (FIG. 9), a photo sensor including a photodiode 6 detects external light 51 that penetrates the glass substrate 41a, the liquid crystal layer 42, and the like. At this time, if the object 53 such as a finger is located near the surface of the liquid crystal panel 11, the external light 51 incident on the photosensor is blocked by the object 53. Therefore, an image of the object 53 formed by the external light 51 can be detected using a photo sensor. Further, the farther the distance from the object 53 such as a finger is, the brighter the image is due to the influence of the light diffraction or the like, and therefore the amount of current flowing through the photodiode 6 can be based on the corresponding amount of received light. The distance from the object 53 is detected.

Moreover, in the method of detecting a reflected image (FIG. 10), the photo sensor including the photodiode 6 detects the reflected light of the backlight light 52. More detail In other words, the backlight light 52 emitted from the backlight 15 passes through the liquid crystal panel 11 and is emitted to the outside from the surface of the liquid crystal panel 11. At this time, when the object 53 is located near the surface of the liquid crystal panel 11, the backlight light 52 is reflected by the object 53. For example, a person's finger belly will reflect light well. The reflected light of the backlight light 52 penetrates the glass substrate 41a or the liquid crystal layer 42 and the like and is incident on the photo sensor. Therefore, the reflected image of the object 53 generated by the backlight light 52 can be detected using the photo sensor. Further, the farther the distance from the object 53 such as a finger is, the darker the reflected image becomes. Therefore, the amount of current flowing through the photodiode 6 can be detected based on the amount of received light, and the distance from the object 53 can be detected.

Here, as described above, the distance to the object 53 can be measured according to the brightness of the image of the object 53 such as a finger or the reflected image, but the proximity of the object 53 is reliably detected in order to eliminate the detection of the noise. In the detection of the touch position, a threshold value of the current value flowing through the photodiode 6 corresponding to a predetermined input detection distance is defined. If the finger or the like approaches the distance within the input detection distance, the touch position can be detected.

Further, in the present embodiment, a proximity detection distance larger than the input detection distance is defined. The proximity detection distance should be such that the distance of the touch position detection can be substantially surely completed, specifically, the distance corresponding to the position through which the finger is continuously approached when the user inputs the operation. Similarly to the above-described input detection distance, the proximity detection distance defines a threshold value of the current value flowing through the photodiode 6 corresponding to the distance.

If the photo sensor detects the proximity of the object 53 such as a finger within the proximity detection distance, the control unit 110 continuously drives the source driver 300 and the gate driver 400 in the driving state of the normal driving. Way into Line control. Moreover, when the photo sensor does not detect the proximity of the object 53 such as a finger within the proximity detection distance, the control unit 110 causes the source driver 300 and the gate to be driven in a driving state in which the driving is suspended. The drive 400 is controlled in such a manner as to be intermittently driven.

In other words, in the steps S30 and S50 shown in FIG. 5, the control unit 110 determines whether or not the coordinate indicating the contact position of the finger or the like has been received from the coordinate processing circuit 120, and is not in the present embodiment. The control unit 110 determines whether a signal indicating the proximity of the object or the information indicating the proximity is detected from the photo sensor within the proximity detection distance. In this way, by performing the normal driving configuration by detecting the proximity of the distance detection object by the proximity of the input detection distance, the normal driving can be started up to the time when the finger actually approaches the touch position. Therefore, the normal drive can be started earlier than the configuration in which the normal drive is started after the actual start of the operation input is detected (the configuration of the first embodiment).

Further, when returning to the pause driving, the start of the pause driving is delayed after the actual operation input is completed until the object 53 such as the finger is moved farther than the approaching detection distance. Therefore, even if the finger leaves the touch panel, the normal driving of the delay time is performed in the liquid crystal panel, so that the screen is not overwritten (unchanged) until the next scanning period. As a result, it is possible to eliminate or reduce the feeling that the response to the operation is poor, so that the state in which the operation is in a bad condition can be avoided or reduced.

Furthermore, in order to start driving as early as possible, it is preferable that the proximity detection distance is large, but it is also considered that if it is set too large, erroneous detection may be caused by noise, or the proximity of a finger or the like that does not accompany the operation may be detected. So set it up like this The distance to which the erroneous detection is not performed and the appropriate distance greater than the input detection distance. Further, in the present embodiment, the setting of the delay time described above may be performed.

<3.2 effect>

As described above, in the present embodiment, in the display device including the touch sensor, the proximity detection distance is detected when the driving is performed in the driving mode (suspended driving) during the insertion scanning stop period (suspension period). When the finger or the like is approaching the touch sensor, the drive mode is switched to the drive mode during which the scan stop period is not inserted (normal drive), and if the approach is not detected, the drive is switched to the pause drive. The power consumption of the device can be suppressed, and the screen display can be further responsive to the input operation.

<4. Modifications>

Although the active matrix type liquid crystal display device has been described as an example, a display device other than the liquid crystal display device is provided as long as it is a display device based on active matrix type voltage control and a display device in which a scanning period and a pause period are provided. The invention can also be applied.

Moreover, although the display device includes an example including a touch panel, it may be, for example, a sensor that can detect proximity, contact, or pressing of a finger or an object. The image acquired by the camera outside the device is analyzed to detect the proximity of the finger or the object to the display device, and the like.

[Industrial availability]

The present invention is applied to a display device such as an active matrix type liquid crystal display device, and is particularly suitable for including a touch sensor or the like by proximity or contact. Or press the display device of the sensor circuit that implements the operational input.

6‧‧‧Photoelectric diode

10‧‧‧TFT (switching element)

11‧‧‧LCD panel

15‧‧‧Backlight

41a‧‧‧glass substrate

42‧‧‧Liquid layer

51‧‧‧External light

52‧‧‧Backlight light

53‧‧‧ objects

100‧‧‧With information terminal

110‧‧‧Control Department

120‧‧‧Coordinate processing circuit

130‧‧‧X coordinate sensor

140‧‧‧Y coordinate sensor

150‧‧‧ touch panel

200‧‧‧ display control circuit

300‧‧‧Source Driver

400‧‧‧gate driver

500‧‧‧Display Department

600‧‧‧Common electrode drive circuit

Ccs‧‧‧Auxiliary Capacitor

CsL‧‧‧Auxiliary Capacitor Line

Clc‧‧ liquid crystal capacitor (pixel capacitor)

DAT‧‧‧ Display data signal (image signal)

DV‧‧‧ digital image signal

Ecom‧‧‧Common electrode

Epix‧‧‧pixel electrode

G(1)~G(N)‧‧‧ scan signal

GCK‧‧‧ gate clock signal

GL(n)‧‧‧ scan signal line (n=1~N)

GSP‧‧‧ gate start pulse signal

LS‧‧‧Latch strobe signal

P(n,m)‧‧‧pixel forming part (n=1~N, m=1~M)

S(1)~S(M)‧‧‧ drive image signal

SCK‧‧‧ source clock signal

SL(m)‧‧‧image signal line (m=1~M)

SSP‧‧‧ source start pulse signal

TS‧‧‧ timing control signal

During the Ts‧‧‧ scan

During the suspension of Th‧‧

T1~t7, t11~t15‧‧‧

‧‧‧Polarity reversal signal

Fig. 1 is a perspective view showing the appearance of a portable information terminal device according to a first embodiment of the present invention.

Fig. 2 is a block diagram showing the overall configuration of a portable information terminal device of the above embodiment.

Fig. 3 is a block diagram showing the configuration of the display unit of the above embodiment.

Fig. 4 is a circuit diagram showing an equivalent circuit of the pixel formation portion of the above embodiment.

Fig. 5 is a flow chart showing the flow of processing of the control unit for switching the normal drive and the pause drive in the above embodiment.

Fig. 6 is a view showing timings of a scanning signal and a driving image signal when the driving is suspended in the above embodiment.

Fig. 7 is a view showing timings of a scanning signal and a driving image signal during normal driving in the above embodiment.

Fig. 8 is a flowchart showing a flow of a process of switching between a normal drive and a pause drive control unit in the second embodiment of the present invention.

Fig. 9 is a view showing the principle of a method of detecting an image in the display device according to the third embodiment of the present invention.

Fig. 10 is a view showing the principle of a method of detecting a reflected image in the display device of the above embodiment.

Claims (9)

A display device comprising: a sensor circuit for accepting an operation input using proximity or contact or pressing of a finger or an object; and comprising: a display panel comprising a plurality of pixel circuits arranged in two dimensions a driving circuit for continuously or intermittently performing an operation of writing a signal corresponding to display material for displaying an image into the plurality of pixel circuits; and a control unit receiving the above-mentioned sensor circuit to indicate the above The operation input information causes the drive circuit to continuously perform the above operation when it is determined that the operation input is present based on the information, and when the operation input is determined to be absent, the drive circuit intermittently performs the above operation. action. The display device according to claim 1, wherein the control unit determines whether the display material is moving image data, and when the display data is determined to be moving image data, causes the drive circuit to continuously perform the above operation. The display device of claim 2, wherein the control unit determines the display at a time point when it is determined that the operation input is determined based on the information, and a time point at which the operation input is not present or a specific time has elapsed since the time point Whether the data is dynamic image data. The display device of claim 1, wherein the control unit is in a period from a time point from when it is determined that the operation input is determined based on the information to determine that the operation input is not present, to a time point when a specific time has elapsed The drive circuit is continuously operated as described above. The display device of claim 1, wherein the sensor circuit detects proximity of the finger or the object within a predetermined first distance; and the control unit detects the approach period by the sensor circuit The above drive circuit continuously performs the above operation. A display device according to claim 5, wherein said sensor circuit accepts said operation input by a proximity or contact of said finger or said object within a second distance shorter than said first distance. The display device of claim 1, wherein the plurality of pixel circuits are arranged in a matrix corresponding to intersections of a plurality of image signal lines and a plurality of scanning signal lines crossing the plurality of image signal lines, the plurality of pixel circuits The image signal line is configured to transmit a plurality of image signals indicating an image to be displayed on the display panel to the plurality of pixel forming portions, and the plurality of pixel circuits respectively include: a switching element, which is applied to the connected Scanning a signal of the signal line to be in an on state or an off state; a pixel electrode connected to the connected image signal line via the switching element; and a common electrode disposed in the plurality of pixel circuits in common; the pixel capacitor The pixel electrode is formed by the pixel electrode and the common electrode, and the liquid crystal element displays a gray scale display pixel corresponding to a voltage held by the pixel capacitor. The display device of claim 7, wherein the switching element includes A thin film transistor of a semiconductor layer of an oxide semiconductor. A control method, characterized in that it is a method of controlling a display device, the display device comprising a sensor circuit for accepting an operation input using a finger or an object approaching or contacting or pressing, and a plurality of devices including a two-dimensional configuration a display panel of the pixel circuit; and the control method includes: a driving step of continuously or intermittently performing an operation of writing a signal corresponding to the display material for displaying the image into the plurality of pixel circuits; and driving control step, The sensor circuit receives information indicating the operation input, and when it is determined that the operation input exists according to the information, the operation is continuously performed in the driving step, and when it is determined that the operation input is not present, The above operation is intermittently performed in the above-described driving step.