JP6004344B2 - Hold-type image display system - Google Patents

Description

  The present invention relates to an image display device, an image display method thereof, and an image display device drive controller, and more particularly to a hold-type image display device, an image display method thereof, and an image display device drive controller.

  Conventionally, a liquid crystal display (LCD) is widely used because it is thinner than a CRT (cathode ray tube) display and does not occupy an installation area. However, in the hold type display device such as an LCD, unlike the impulse type display device such as a CRT display, since the image is maintained within the frame period, there is a problem that the moving image is unclear.

  In the case of an impulse type display device, an image is displayed as a pulse at an early stage in a frame and black display is performed until the next frame, so that an afterimage of the user's eyes is adjusted. On the other hand, in the case of a hold-type display device, an image is held and displayed as a still image within a frame period, and a moving image is displayed by switching the screen every frame. Therefore, the still image is switched from frame to frame seamlessly. Therefore, for the user, the previous frame image becomes an afterimage, and a double image obtained by superimposing the shifted images is perceived and a moving image blur is recognized. In order to improve such moving image blur in the hold-type display device, Patent Document 1 discloses a hold-type display device that is driven in a pseudo impulse-type display.

  However, since the liquid crystal display device of Patent Document 1 switches between black display and video display every ½ frame period of the input signal, the black insertion rate per frame is limited to ½. As a result, the device disclosed in Patent Document 1 cannot set the optimal black insertion rate according to individual usage conditions, taking into account the balance between the improvement in moving image blur, which is a merit of black insertion, and the decrease in luminance, which is a demerit. There wasn't.

  In addition, there are several liquid crystal driving methods for the liquid crystal panel, and different liquid crystal driving methods such as a TN panel, an IPS panel, a VA panel, and an OCB panel have different response characteristics and different optimal black insertion rates. In the device of Patent Document 1, it is difficult to apply the black insertion drive optimal for all these methods. Further, the liquid crystal display device disclosed in Patent Document 1 requires a frame memory for doubling the drive frequency of the device and temporarily storing video information, resulting in an increase in circuit scale and an increase in cost.

  On the other hand, Patent Document 2 discloses an apparatus that increases the degree of freedom of the black insertion rate and avoids an increase in circuit scale. In the liquid crystal display device of Patent Document 2, as shown in FIGS. 14 to 16, a start pulse signal (VSP) is individually input to each gate driver, and an enable signal (VOE) that is a control signal is half of a plurality of gate drivers. And an enable signal whose polarity is inverted by an inverter is input to the other half of the gate drivers. Then, one gate line is selected from each of the gate drivers divided in half, and a video signal is written to the pixels on one gate line in accordance with the enable signal, and the polarity is applied to the pixels on the other gate line. By adopting a configuration in which a black signal is written in accordance with the inverted enable signal, the black insertion rate of the gate driver can be changed.

Japanese Patent Laid-Open No. 9-18814 JP 2001-166280 A

  However, when commercializing the resolution used in the TV, if a gate driver that is widely available on the market is used, for example, VA (Video Graphics Array) has two gate drivers, XGA (Extended Graphics Array) and WXGA (Wide XGA). ), In general, three gate drivers are used. However, in the device configuration of Patent Document 2, since the number of gate drivers is limited to an even number, the degree of freedom in selecting the number of gate drivers is reduced when the product is applied. In some cases, an extra gate driver IC is required, resulting in unnecessary costs.

  Further, in the apparatus of Patent Document 2, since one gate driver starts scanning of video display and another gate driver specified in advance starts scanning of black display, the black insertion rate is the gate driver. Since the black insertion rate for one frame is fixed and the operation is performed, it is difficult to variably set the optimal black insertion rate in accordance with each use situation.

  Furthermore, the apparatus disclosed in Patent Document 2 does not consider continuous holding of a blanking period for writing a black image across a plurality of frames. For this reason, as shown in FIG. 15, when the black signal writing spans the next frame, the time interval for the blanking period is vacant, and a difference in the black image holding time occurs at the top and bottom of the screen. There is also a disadvantage that a luminance difference as shown in FIG.

[the purpose]
Therefore, the present invention improves the above-described disadvantages of the prior art, and in a hold-type display device, a black image is inserted in one frame, and motion blur due to overlap recognition between the current frame image and the afterimage of the previous frame is reduced. It is an object of the present invention to improve the image quality of moving images and to variably set the black insertion rate for one frame in accordance with individual usage conditions.

In order to achieve the above object, a hold-type image display system of the present invention is a hold-type image display system that displays a video on a display panel by controlling a video signal input to a source line and a gate line of the display panel. A source driver that outputs a video signal to the source line; a gate driver that outputs a scanning signal to the gate line; and a controller that drives and controls the source driver and the gate driver by receiving an input video signal; A backlight on the back of the display panel, and the controller independently controls an output enable signal input to each gate driver, and a video signal in which a black or halftone line is inserted between the video lines. Output to the source driver and a start pulse signal for writing one or more video lines; Means for outputting a start pulse signal for writing one or more black or halftone lines to the gate driver within one frame period and scrolling the black band on the display panel screen within one frame period; Black or halftone insertion rate is determined according to the display, and black or halftone is input to the input of the start pulse signal to the gate driver for video line writing based on the determined black or halftone insertion rate. A means for changing the timing of input of the start pulse signal to the gate driver for line writing, and dividing one frame into a plurality of preset blocks, and an image of any one block from the previous frame to the current frame calculating a distance traveled between the switches the black image insertion rate depending on the maximum value of the moving distance of each block calculated, before Means for luminance by switching the black image insertion rate adjusts the backlight dimming the brightness to be constant, characterized in that it comprises a.

  According to such an image display device, it is possible to execute black insertion driving for writing a black signal so as to straddle continuous video frames, and the video display time and the black image display time are determined according to the timing of starting the black image display scanning. The ratio (hereinafter referred to as black image insertion rate) can be arbitrarily set.

  Further, in the above image display device, the above-described black scanning execution unit may have a function of variably controlling the start timing of the black image display scanning with respect to the video display scanning by the video scanning execution unit. In this way, the black image insertion rate for each frame can be arbitrarily changed.

  Further, the image display device may include a black insertion rate setting unit that arbitrarily sets a black image display scanning start timing by the black scanning execution unit in accordance with an operating environment. In this way, it is possible to set the black image insertion rate for each frame from a larger range according to individual use situations.

  In addition, the image display device of the present invention includes a display panel having a configuration in which a plurality of gate lines and a plurality of source lines intersect with each other and are arranged in a lattice pattern, and pixels are formed at intersections of the gate lines and the source lines, respectively. A source driver that supplies black source video signals containing line image portions and black image portions alternately to each source line, and a gate line group obtained by dividing a plurality of gate lines into several groups. A plurality of gate drivers that sequentially supply a gate-on signal to each corresponding gate line, and a controller that drives and controls the source driver and the gate driver. The controller individually supplies an output enable signal to each gate driver. A function to control the gate output of each gate driver independently and to output a video start pulse for writing a line image part Function and, characterized in that a function of outputting the black display start pulse for the black image portion written to the first gate driver to an arbitrary timing within one video frame period.

  According to such an image display device, a gate driver is provided for each group of gate lines divided into a plurality of gate lines, and the enable of each gate driver is individually controlled. Since the black display start pulse is input to the gate driver at a different timing from the start pulse, the ratio between the video display time and the black image display time in the black insertion drive (hereinafter referred to as the black image insertion rate) can be It was possible to adjust continuously. Since two or more gate drivers may be used, an odd number may be used, so that the degree of freedom in selecting the gate driver is increased when the product is applied, and the black insertion rate can be freely set with the minimum necessary gate driver.

  In the above image display device, the drive control unit described above may have a function of variably controlling the timing of the black display start pulse output with respect to the video start pulse output. In this way, the black image insertion rate for each frame can be arbitrarily changed by changing the timing of outputting the black display start pulse.

  Further, in the above image display device, the above-described controller may include a video display enable signal that enables the gate output of the gate driver only during a period in which the line image portion of the black insertion video signal is supplied to the source line, or black insertion. A function may be provided in which a black display enable signal for enabling the gate output of the gate driver only during a period in which the black image portion of the video signal is supplied to the source line is individually supplied to each gate driver. In this way, it is possible to individually control the execution of video display scanning or black image display scanning for each gate driver.

  In the above image display device, each gate driver described above supplies a video display gate-on signal for writing only the line image portion of the black insertion video signal to the pixel in accordance with the video display enable signal to the corresponding gate line. In addition, a function of supplying a black display gate-on signal for writing only the black image portion of the black insertion video signal to the pixel in accordance with the black display enable signal may be provided to the corresponding gate line.

  In this way, each gate driver can switch and execute video display scanning or black image display scanning.

  In the above image display device, the above-described controller may have a function of arbitrarily setting the timing of the black display start pulse output by the drive control unit in accordance with the operating environment. In this way, it is possible to set the black image insertion rate for each frame from a larger range according to individual use situations.

  In the above image display device, the controller described above determines the black image insertion rate for each frame period based on the input video signal, and the timing of the black display start pulse output based on the determined black image insertion rate. May be provided with a function of setting. In this way, the black image insertion rate can be set according to the content of the display video.

  In the above image display device, the controller described above temporarily stores information for one frame of the input video signal sequentially input every frame, and temporarily stores the video signal of one frame of the input video signal. A function may be provided in which a black image insertion rate is determined based on data that is compared with the stored video signal of the previous frame. In this way, the optimum black image insertion rate can be determined according to the content of the display video.

  In addition, the image display device includes a backlight disposed on the back surface of the display panel, and the controller described above temporarily stores information for one frame of the input video signal sequentially input every frame. Compares the video signal of one frame of the input video signal with the video signal of the previous frame temporarily stored, and determines the black image insertion rate and the dimming brightness of the backlight based on the changed data May have a function to

  In this way, since the backlight is dimmed in accordance with the black insertion, it is possible to execute the black insertion driving while preventing a change in luminance due to the switching of the black insertion.

  Further, in the above image display device, the controller described above outputs a video display enable signal to the gate driver that shifts and outputs a gate-on signal to each corresponding gate line in accordance with a video start pulse input until the shift output is completed. And a function of supplying a black display enable signal to other gate drivers. In this way, it is possible to input a black display start pulse to the gate driver at a timing with a high degree of freedom, and the black image insertion rate can be continuously adjusted.

  In the above image display device, the controller described above may have a function of inserting a black image signal between line image portions in the input image signal and outputting the black image signal as a black inserted video signal to the source driver. In this way, it is possible to obtain a black insertion video signal for the source driver to alternately output a line image portion and a black image portion for each source line.

  Further, in the above image display device, the controller described above may have a function of outputting a black insertion video signal including a black image signal to the source driver even during a blanking period of the input video signal. In this way, black signal writing across multiple video frames is performed without blackout during the blanking period between frames, so the in-plane luminance due to the difference in the black image holding period in the display panel The difference can be eliminated.

  In the above image display device, the controller described above may have a function of outputting a black insertion video signal including a halftone signal to the source driver instead of the black image signal. In this way, it is possible to reduce a decrease in luminance due to black insertion driving.

  Next, the driving method of the image display device of the present invention has a configuration in which a plurality of gate lines and a plurality of source lines intersect with each other and are arranged in a lattice pattern, and pixels are formed at each intersection of the gate lines and the source lines. A display panel, a source driver that supplies a video signal to each source line, and a gate line group that includes a plurality of gate lines divided into several groups, and sequentially supplies a gate-on signal to each gate line. A driving method of an image display device comprising a plurality of gate drivers and a drive control unit for individually supplying an output enable signal to each gate driver, wherein the black image portion includes a line image portion and a black image portion alternately. Black insertion video signal supply process in which the source driver starts supplying the insertion video signal to each source line, and video for partial line image writing in synchronization with this black insertion video signal supply process A video start pulse input process in which the first gate driver inputs a start pulse from the drive control unit and a video display gate-on signal for writing only the line image portion of the black insertion video signal to the pixels are sequentially applied to each gate line. The first gate driver drives a black display start pulse for writing a black image part at an arbitrary timing within one video frame period, and a video scanning process in which the supplied video display scan is sequentially performed from the first gate driver. A black display start pulse input process input from the control unit and a black image display scan for sequentially supplying a black display gate-on signal for writing only the black image portion of the black insertion video signal to the pixels to the respective gate lines. And a black scanning process executed sequentially from the gate driver.

  Further, in the above driving method, in the above-described video scanning process, each gate driver is for video display that makes the gate driver's gate output effective only during a period in which the line image portion of the black insertion video signal is supplied to the source line. A gate-on signal for video display is output in response to the enable signal, and in the black scanning process, each gate driver enables the gate output of the gate driver only during the period when the black image portion of the black insertion video signal is supplied to the source line. A black display gate-on signal may be output in accordance with the black display enable signal to be generated.

  In the above driving method, a black insertion rate setting step of arbitrarily setting the timing of the black display start pulse output by the drive control unit according to the operating environment may be provided.

  In the above driving method, in the above black insertion rate setting step, information of one frame of the input video signal sequentially input every frame is temporarily stored, and the video of one frame of the input video signal is stored. The signal is compared with the temporarily stored video signal of the previous frame, and the black image insertion rate is determined based on the changed data. Based on the determined black image insertion rate, the black display start pulse output is determined. The timing may be set.

  In the above driving method, in the above black insertion rate setting step, information of one frame of the input video signal sequentially input every frame is temporarily stored, and the video of one frame of the input video signal is stored. The signal is compared with the temporarily stored video signal of the previous frame, and based on the changed data, the black image insertion rate and the dimming brightness of the backlight mounted on the back of the display panel in advance are determined. Based on the determination, the black display start pulse output timing and the dimming luminance of the backlight may be set.

  Further, the above driving method is a black insertion signal conversion in which a black image signal is inserted between line image portions of an input image signal and output to a source driver as a black insertion video signal before the black insertion video signal supplying step described above. A process may be provided.

  In the driving method of the image display device, the black insertion video signal described above includes a black image signal also in a blanking period in the input video signal.

  In the driving method of the image display device, the black insertion video signal described above includes a halftone signal instead of the black image signal.

  According to such a driving method of the image display device, similarly to the above image display device, the black image insertion rate is finely set in consideration of the balance between the effect of improving the motion blur and the demerit of the luminance reduction. be able to.

  Next, the controller for driving the image display device according to the present invention has a configuration in which a plurality of gate lines and a plurality of source lines intersect with each other and are arranged in a lattice pattern, and pixels are formed at the intersections of the gate lines and the source lines. A display panel, a source driver for supplying a video signal to each source line, and a gate-on signal are sequentially supplied to each corresponding gate line provided for each of the gate lines divided into a plurality of groups. An image display device comprising a gate driver, and a controller for controlling the operation of the image display device, wherein a black insertion video signal including a line image portion and a black image portion alternately is transmitted from the source driver to each source. A function to output to the line, and a function to independently control the gate output of each gate driver by supplying an output enable signal to each gate driver individually A function of outputting a video start pulse for writing a line image portion to the first gate driver, and a first gate for a black display start pulse for writing a black image portion at an arbitrary timing within one video frame period And a function of outputting to a driver.

  Also, the image display device drive controller described above is a video display enable signal or a black insertion video signal that enables the gate output of the gate driver only during a period when the line image portion of the black insertion video signal is supplied to the source line. The black display enable signal for enabling the gate output of the gate driver only during the period when the black image portion is supplied to the source line is individually supplied to each gate driver.

  Further, the image display device driving controller arbitrarily sets the timing of the black display start pulse output according to the operating environment.

  Further, the controller for driving the image display device temporarily stores information for one frame of the input video signal sequentially input for each frame, and is temporarily stored with the video signal of one frame of the input video signal. The black image insertion rate for each frame period is determined on the basis of the changed data by comparing with the video signal of the immediately previous frame, and the black display start pulse output timing is determined based on the determined black image insertion rate. Set.

  Further, the controller for driving the image display device temporarily stores information for one frame of the input video signal sequentially input for each frame, and is temporarily stored with the video signal of one frame of the input video signal. The black image insertion rate and the dimming brightness of the backlight mounted on the back of the display panel in advance are determined based on the number of data changed by comparing the video signal of the previous frame, and based on this determination You may comprise so that the timing of black display start pulse output and the light control brightness | luminance of a backlight may be set.

  The image display device driving controller inserts a black image signal between the line image portions in the input image signal and outputs the black image signal as a black insertion video signal to the source driver.

  In addition, the image display device driving controller outputs a black inserted video signal into which the black image signal is inserted during the blanking period in the input video signal to the source driver.

  Further, the image display device driving controller outputs a black insertion video signal in which a halftone signal is inserted into the input image signal instead of the black image signal to the source driver.

  According to such an image display device drive controller, the black image insertion rate is finely set in consideration of the balance between the effect of improving the motion blur and the demerit of the luminance reduction, as in the above image display device. be able to.

  Since the present invention is configured and functions as described above, in the hold type display device, the black insertion rate for one frame period is finely adjusted in consideration of the balance between the effect of improving moving image blur and the disadvantage of luminance reduction. The image quality of the moving image can be improved.

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

  FIG. 1A is a diagram showing the configuration of the image display apparatus according to the first embodiment of the present invention. As shown in FIG. 1, the image display apparatus according to the first embodiment includes a grid in which m (m is a natural number) gate lines V1 to Vm and n (n is a natural number) source lines H1 to Hn intersect. The display panel 1 having a configuration in which pixels 6 are formed at intersections of the gate lines V1 to Vm and the source lines H1 to Hn, and a source driver connected to each of the source lines H1 to Hn and supplying a video signal 4 and a plurality of gate drivers 5A to 5A that divide a plurality of gate lines V1 to Vm into several groups and sequentially supply a gate-on signal (Vg) to the corresponding gate lines V1 to Vm. 5N.

  As shown in FIG. 1, the i gate lines V1 to Vi from the top are connected to the gate driver 5A, and the (i + 1) th to jth gate lines V (i + 1) to Vj are connected to the gate driver 5B. The gate lines V (l + 1) to Vm from the (1 + 1) th to the mth line are connected to the gate driver 5N (not shown from the j + 1st to the 1st line).

  FIG. 1B is an enlarged view of the circuit of one pixel 6 shown in FIG. In the circuit of the pixel 6 forming the display panel 1 in the first embodiment, the source electrode of the thin film transistor (TFT) 12 is connected to the source lines H1 to Hn, the gate electrode of the TFT 12 is connected to the gate lines V1 to Vm, The drain electrode of the TFT 12 is connected to the pixel electrode 13 formed on one glass substrate, and between the pixel electrode 13 formed on one glass substrate and the common electrode 15 placed on the other glass substrate. In this configuration, the liquid crystal layer 14 is sandwiched.

  The video display is performed by controlling the light transmittance of the liquid crystal layer 14 by the potential difference between the pixel electrode 13 and the common electrode 15, but when the video signal is written to the pixel 6, it is transmitted through the gate lines V 1 to Vm. A gate-on signal (Vg1 to Vgm) turns on the TFT 12, so that a gradation voltage corresponding to the video signal from the source lines H1 to Hn is applied to the pixel electrode 13, and the common electrode is set to a constant voltage. The light transmittance of the liquid crystal layer 14 is controlled by the potential difference between the pixel electrode 13 to which the gradation voltage 15 is applied and the image voltage display based on the video signal is realized.

  Furthermore, the image display apparatus of the first embodiment includes a controller 7 that controls the operations of the source driver 4 and the gate drivers 5A to 5N. The controller 7 inserts a black image signal into the input video signal and displays the video. A black insertion signal conversion unit 8 that generates and outputs a black insertion video signal including a signal portion and a black image signal portion within a horizontal scanning period, and outputs the black insertion video signal from the black insertion signal conversion unit 8 to the source driver 4 And a drive control unit 9 for performing the above operation.

  As shown in FIG. 2, one frame period is divided into the same number of writing periods (horizontal scanning periods) as the number (m) of the gate lines V1 to Vm, and the part corresponding to the writing period of the input video signal is the line image part. Assuming (horizontal scanning period portion), the black insertion signal conversion unit 8 inserts a black image signal between the line image portions in the input video signal, and similarly applies the black image signal during the blanking period in the input video signal. Has the function of inserting. Although FIG. 2 shows a case where a black image signal is inserted into an input video signal that has a dummy signal output during the blanking period, the black insertion signal conversion unit 8 is not limited thereto, and the black insertion signal conversion unit 8 performs the dummy signal during the blanking period. Even in the case of an input video signal with no output, a black image signal is similarly inserted. In general, there are various methods for video signals, such as output of a dummy signal during the blanking period, or output of nothing.

  The source driver 4 functions as source line driving means by alternately outputting a line image portion and a black image portion to the source lines H1 to Hn according to the black insertion video signal.

  Here, in the first embodiment, the source driver 4 inputs the black insertion image signal created by the black insertion signal conversion unit 8 and outputs the black insertion image signal to the source lines H1 to Hn by double speed driving. Not limited to this, the source driver 4 has a function of converting the output charges to the source lines H1 to Hn into gradation charges corresponding to black display, and as shown in FIG. The input video signal may be output to the source lines H1 to Hn while switching to the gradation charge. In this way, the black insertion signal conversion unit 8 need not be provided, that is, the line memory necessary for black image insertion can be reduced, and the drive frequency of the source driver 4 accompanying the black image insertion need not be doubled. .

  The drive control unit 9 has a function of individually supplying output enable signals for controlling the gate outputs of the gate drivers 5A to 5N to the gate drivers 5A to 5N. The video display enable signal (VOE_i) that enables the output of the gate-on signal only during the period when the line image portion of the signal is supplied to the source lines H1 to Hn, or the black image portion of the black insertion video signal is the source lines H1 to Hn. The black display enable signal (VOE_b) for enabling the output of the gate-on signal only during the period supplied to the gate driver 5A to 5N is individually supplied.

  Thereby, each of the gate drivers 5A to 5N has a function of collectively controlling outputs to the connected gate lines V1 to Vi, V (i + 1) to Vj,..., V (l + 1) to Vm. In response to VOE_i from the drive control unit 9, the gate lines V1 to Vi, V (i + 1) are converted into a gate display signal having a pulse width that causes only the line image portion of the black insertion video signal to be written to the pixel 6 in accordance with VOE_i. ) To Vj,..., V (l + 1) to Vm, and a function as image scanning means for sequentially executing image display scanning, and according to VOE_b, only the black image portion of the black insertion image signal is set as the gate-on signal. A black display gate-on signal with a pulse width to be written to the gate lines V1 to Vi, V (i + 1) to Vj,... And a function as a black scanning means for sequentially executed.

  In addition, the drive control unit 9 cooperates with the gate output control by the output enable signal for the gate driver 5A, and for the video display scanning start pulse (VSP_i) for writing the video signal and the black image signal writing. The black display scanning start pulse (VSP_b) is output once at different timings in one frame period. The drive control unit 9 outputs VSP_i to the gate driver 5A at the start of video display scanning, and simultaneously starts supplying VOE_i to the gate driver 5A. When the video display scanning is completed in the gate driver 5A, supply of VOE_b to the gate driver 5A is started, and VSP_b is output to the gate driver 5A at an arbitrary timing within one video frame period specified by VSP_i.

  Furthermore, the controller 7 includes a black insertion rate setting unit 10 that arbitrarily sets the timing of the black display start pulse (VSP_b) output by the drive control unit 9 according to the operating environment.

  This black insertion rate setting unit 10 has a function of determining a black image insertion rate for each frame period with reference to an input video signal, and the timing of VSP_b output by the drive control unit 9 corresponding to the determined black image insertion rate. Has a function to set. Specifically, the black insertion rate setting unit 10 includes a frame memory (not shown) that temporarily stores information for one frame of the input video signal sequentially input for each frame, and one frame of the input video signal. A determination unit (not shown) for comparing the video signal of the first frame and the video signal of the previous frame stored in the frame memory and determining an optimum black image insertion rate based on the changed data; It is configured with.

  As a result, it is possible to determine the black image insertion rate for each frame period suitable for the driving method and usage of the display panel 1, and to set the VSP_b output timing that can realize the determined black image insertion rate. The timing set here is a timing at which the pixel lines for video signal writing and black image signal writing are not simultaneously selected by one gate driver.

  As a result, the gate driver 5A inputs VSP_b from the drive control unit 9 at the timing set by the black insertion rate setting unit 10, and based on VOE_b supplied in advance, VSP_b is used as a black display gate-on signal for the gate line V1. Are sequentially supplied to Vi, and when this scanning is completed, VSP_b is shifted to the gate driver 5B. The gate drivers 5A to 5N sequentially perform such scanning, thereby realizing the black image insertion rate for each frame determined by the black insertion rate setting unit 10.

  The drive control unit 9 also supplies a black start video signal (data) to the source driver 4 and a signal start pulse (HSP), a horizontal clock signal (HCK), and a latch, which are signals for controlling the drive of the source driver 4. A signal (DLP) and a polarity inversion control signal (POL) are supplied, and a scan start pulse (VSP_i or VSP_b), which is a signal for driving and controlling the gate drivers 5A to 5N with respect to the gate drivers 5A to 5N, a vertical clock signal (VCK) and an enable signal (VOE_i or VOE_b) are supplied.

  The source driver 4 has the same function as that generally used. For example, the acquisition of the data signal is started by the input of the HSP, and the data signal is sequentially stored in the internal shift register in synchronization with the HCK. Then, the data signal is determined by the input of DLP, and at the same time, the positive / negative from the reference voltage is determined according to POL, and the gradation voltage according to the data signal is output to the source lines H1 to Hn.

  The polarity inversion control signal (POL) is a control signal for inverting the voltage polarity of the gradation voltage output from the source driver 4 to the source lines H1 to Hn. By controlling the POL, a DC voltage is prevented from being applied to the liquid crystal.

  Here, the black insertion signal conversion unit 8, the drive control unit 9, and the black insertion rate setting unit 10 in the controller 7 described above may be configured such that the function content is programmed and executed by a computer.

  FIG. 3 is a timing chart of signals propagated through the image display apparatus according to the first embodiment.

  In FIG. 3A, a line image signal is supplied to the pixels 6 on the gate lines V1 to Vi corresponding to the gate driver 5A, and a black image is applied to the pixels 6 on the gate lines V (i + 1) to Vj corresponding to the gate driver 5B. FIG. 3B is a timing chart illustrating an example in which a signal is supplied. FIG. 3B is a diagram illustrating a black image signal applied to the pixels 6 on the gate lines V1 to Vi corresponding to the gate driver 5A, contrary to FIG. And a line image signal is supplied to the pixels 6 on the gate lines V (i + 1) to Vj corresponding to the gate driver 5B.

  As shown in FIG. 3A, VOE_i is input to the gate driver 5A in the case of supplying a line image signal to the pixels 6 on the corresponding gate lines V1 to Vi, and thereby the gate driver 5A The gate-on signal is converted to a video display gate-on signal having the same pulse width as the line image signal output period of the source driver 4 and sequentially supplied to the gate lines V1 to Vi.

  On the other hand, VOE_b is input to the gate driver 5B in the case of supplying a black image signal to the pixels 6 on the gate lines V (i + 1) to Vj, whereby a gate-on signal is transmitted from the gate driver 5B to the source driver 4. Are converted into a black display gate-on signal having the same pulse width as that of the black image signal output period and sequentially supplied to the gate lines V (i + 1) to Vj.

  Thus, in the first embodiment, a video signal or a black image signal can be written to different pixel lines in the 1H period (one horizontal scanning period).

  Next, the operation of the image display apparatus according to the first embodiment will be described. FIG. 4 is a diagram for explaining the operation of the image display apparatus according to the present embodiment. Here, the driving method of the image display apparatus of the present invention will be described simultaneously with showing each step.

  First, the black image insertion rate for each frame period is determined and set based on the video signal input by the black insertion rate setting unit 10 (black insertion rate setting step). On the other hand, in the black insertion signal conversion unit 8, a black image signal is inserted between the line image portions of the input video signal, and is output to the drive control unit 9 as a black insertion video signal (black insertion signal conversion step).

  When the black insertion video signal is output from the drive control unit 9 to each source driver 4, various drive control signals are output to the gate drivers 5 </ b> A to 5 </ b> N and each source driver 4 in synchronization with this.

  Here, in the first embodiment, a plurality of gate drivers that can collectively enable gate outputs are used, and the gate drivers 5A to 5N are controlled by independent output enable signals (VOE_i or VOE_b) from the drive control unit 9. Is done.

  As shown in FIG. 2, the black insertion video signal is input from the drive control unit 9 to the source driver 4. The source driver 4 alternately outputs a video signal and a black image signal to the source lines H1 to Hn based on the input black insertion video signal (black insertion video signal supply step).

  As shown in FIG. 4, VSP_i indicating the start of a frame is input to the gate driver 5A from the drive control unit 9 together with VOE_i (video start pulse input step), and this VSP_i is similarly input to the clock signal ( The gate lines V1 to Vi are shifted as gate-on signals in synchronization with VCK), and the TFTs 12 of the pixels 6 on the gate lines V1 to Vi are turned on. During this time, VOE_i is input to the gate driver 5A.

  Subsequently, when scanning with the gate driver 5A is completed, VSP_i is shifted into the gate driver 5B, and VOE_i is input from the drive controller 9 to the gate driver 5B simultaneously with this input. In the gate driver 5B, VSP_i shifts the corresponding gate lines V (i + 1) to Vj as gate-on signals, and VOE_i is also input to the gate driver 5B during this shift period. Thereafter, similarly, VSP_i is shift-inputted to the gate driver 5N, and at the same time VOE_i is inputted from the drive control unit 9. Also in the gate driver 5N, VSP_i shifts the corresponding gate lines V (l + 1) to Vm as gate-on signals, and VOE_i is input during this shift period (video scanning process). Further, VOE_b is input to the gate drivers 5A to 5N other than this period.

  Also, VSP_b from the drive control unit 9 is input to the gate driver 5A once in the frame period according to the timing determined by the black insertion rate setting unit 10 (black display start pulse input process), and the gate driver 5A In response to the clock signal (VCK), VSP_b shifts the corresponding gate lines V1 to Vi as a gate-on signal, and turns on the TFTs of the pixels 6 on the gate lines V1 to Vi. During such black image display scanning, VOE_b is input to the gate driver 5A.

  When the black image display scanning by the gate driver 5A is completed, VSP_b is shifted into the gate driver 5B, and VSP_b shifts the corresponding gate lines V (i + 1) to Vj as gate-on signals. During this shifting period, VOE_b is also input to the gate driver 5B. Thereafter, similarly, VSP_b is shift-input to the gate driver 5N, and the black image display scanning by the gate driver 5N is started (black scanning process).

  As described above, in the first embodiment, the video display scanning start pulse (VSP_i) is input for one video signal writing within one frame period, and the black display scanning is performed for one black image signal writing. A start pulse (VSP_b) is input to the gate driver 5A.

  By adopting such a configuration, as shown in FIG. 5B, it is possible to realize a black image insertion drive in which the black band scrolls the screen between one frame as shown in FIG. The width of the black band is determined by the timing of the black display scanning start pulse (VSP_b) input with respect to the video display scanning start pulse (VSP_i) input. Further, in the first embodiment, as shown in FIG. 4, by continuing to write the black image signal during the blanking period between the frames, the holding time of the video signal and the black image are obtained in all the pixels 6 on the screen. The signal holding time is constant, and the in-plane luminance difference due to the holding time difference can be eliminated.

  Here, VSP_b is an arbitrary timing as long as the pixel lines of the video signal and the black image signal are not simultaneously selected by one gate driver as in the black VSP settable range shown in FIG. Input is possible at the timing, and there is no restriction such as the timing of the break of the gate driver as in the conventional display device. For this reason, the black insertion rate can be finely adjusted, and the optimal black insertion according to the operating environment is taken into consideration, taking into account the effect of improving the motion blur, which is the merit of black image insertion, and the balance of luminance reduction, which is a disadvantage. The rate can be set.

  In the first embodiment, the optimum black insertion driving can be applied regardless of the liquid crystal driving method such as the TN panel, the IPS panel, the VA panel, and the OCB panel.

  Here, in the first embodiment, the moving image blur is reduced by inserting a black image display between the display frame images in the image display device. However, the present invention is not limited to the black display. A halftone display such as the above may be inserted. In this case, in addition to the improvement of moving image blur, a decrease in luminance can be suppressed, but a decrease in chromaticity region and contrast occurs. Therefore, an optimum halftone insertion rate is set in consideration thereof.

  In the first embodiment, the controller 7 includes a black insertion rate setting unit 10, which determines the black image insertion rate for each frame period with reference to the input video signal, The timing for starting the supply of the black image display gate-on signal in the gate drivers 5A to 5N is set in accordance with the determined black image insertion rate. However, the present invention is not limited to this, and as shown in FIG. 7 sets the timing of starting the output of the black display gate-on signal in the gate drivers 5A to 5N, that is, the timing of the VSP_b output to the gate driver 5A, in accordance with the timing data externally input by the user's operation or the like. A black insertion rate setting unit 10 a that outputs to the drive control unit 9 may be provided in place of the black insertion rate setting unit 10.

  In the first embodiment as described above, the black image insertion rate can be changed by changing the timing at which VSP_b is input to the gate driver 5A. Further, the black image insertion is not performed unless VSP_b is input. It is also possible to drive, and it is possible to easily switch the black image insertion rate. Therefore, when using it for a monitor application, a bright screen with less flicker is provided without black insertion, and in the case of video display such as TV, a black insertion is provided to provide a screen with less moving blur, etc. It is possible to provide a display according to the condition.

  Furthermore, it is possible to apply an application such as continuously switching the black image insertion rate depending on a video scene such as a scene such as a sports screen where a motion is intense, such as a landscape.

  Next, a second embodiment according to the present invention will be described.

  FIG. 8 is a diagram showing the configuration of the image display apparatus according to the second embodiment of the present invention. Constituent elements similar to those in the first embodiment shown in FIG. As shown in FIG. 8, in the second embodiment, in addition to the same configuration as that of the first embodiment described above, a backlight 21 is installed on the back as viewed from the user of the display panel 1. Then, the black insertion rate setting unit 20 temporarily stores information for one frame of the input video signal sequentially input for each frame, and temporarily stores the video signal of one frame of the input video signal. The drive control unit 29 has a function of comparing the video signal of the previous frame and determining the black image insertion rate and the dimming luminance of the backlight based on the number of changed data. A function of adjusting the dimming luminance of the backlight 21 based on the determination is provided.

  FIG. 9 is a flowchart showing the operation of the black insertion setting unit 20 in the image display apparatus according to the second embodiment.

  The black insertion setting unit 20 compares the current frame data data (n) with the previous frame data data (n−1), and counts the changed data for one frame (FIG. 9: Steps S91 to S93). ). The counted information is smoothed by, for example, moving average for several frames (FIG. 9: Step S95), and by determining a threshold value (FIG. 9: Step S96), it is determined whether the image is a static image or a dynamic image.

  When the determination result is a static video, for example, black insertion is not performed, and the dimming luminance of the backlight 21 is set to 50% (FIG. 9: Step S98). Is reduced to 50% to improve motion blur, and the dimming luminance of the backlight 21 is switched to 100% (FIG. 9: Step S97).

  With such a configuration, it is possible to switch the black insertion rate depending on the video scene and improve the moving image blur as necessary. The reason why the backlight 21 is dimmed in accordance with the insertion of the black image is that, as shown in FIG. 10, the black image insertion reduces the transmission efficiency of the panel in exchange for the improvement of the motion blur. In this way, a change in luminance due to switching of black insertion is prevented, and in the case of a static video that does not require black image insertion, power consumption can be reduced by dimming the backlight 21. Is possible.

  Another example of the operation of the black insertion setting unit 20 in the second embodiment is shown in FIGS.

  As another method for the black insertion setting unit 20 to determine the black image insertion rate and the dimming brightness of the backlight, first, as shown in FIG. 11, one frame is divided into a plurality of preset blocks. Then, as shown in FIG. 12, the distance that the image of an arbitrary block has moved from the previous time to the current frame is calculated.

  The distance calculation method may be, for example, by detecting the block position of the previous frame and the block position with the smallest average absolute value error from the current frame using a tree search method or the like, and obtaining the distance moved by the block. .

  The maximum value of the calculated movement distance of each block, the black insertion rate at that time, and the dimming luminance of the backlight 21 are shown in FIG. With this configuration, the power consumption of the backlight can be reduced by continuously switching the black insertion rate according to the movement of the video scene and inserting the minimum required black image according to the intensity of movement. Can also be reduced.

(A) is a figure which shows the structure of the image display apparatus of 1st Embodiment concerning this invention, (b) is sectional drawing which shows the structure of a pixel, (c) is a figure which shows another structural example of a controller. . It is explanatory drawing which shows the preparation process of the black insertion image signal in embodiment disclosed in FIG. 2 is a timing chart of signals propagated through the image display device according to the embodiment disclosed in FIG. 1. It is explanatory drawing which shows operation | movement of the image display apparatus of embodiment disclosed in FIG. It is explanatory drawing shown about the moving image display in the image display apparatus of embodiment disclosed in FIG. It is explanatory drawing which shows operation | movement of the image display apparatus of embodiment disclosed in FIG. It is explanatory drawing which shows another example of the production process of the black insertion image signal in embodiment disclosed in FIG. It is a figure which shows the structure of the image display apparatus of 2nd Embodiment concerning this invention. It is a flowchart which shows operation | movement of the black insertion setting part in embodiment disclosed in FIG. It is a figure which shows the relationship characteristic of the black image insertion rate in a display panel concerning this invention, a moving image blur, and transmission efficiency. It is a figure which shows operation | movement of the black insertion setting part in embodiment disclosed in FIG. It is a figure which shows operation | movement of the black insertion setting part in embodiment disclosed in FIG. It is a figure which shows the relational characteristic of the movement distance maximum value of each block which the black insertion setting part in embodiment disclosed in FIG. 8 calculated, the black insertion rate, and the light control brightness | luminance of a backlight. It is a figure which shows the structure of the conventional image display apparatus. It is explanatory drawing which shows operation | movement of the conventional image display apparatus. It is explanatory drawing which shows the display screen in the conventional image display apparatus.

DESCRIPTION OF SYMBOLS 1 Display panel 4 Source driver 5A-5N Gate driver 6 Pixel 7, 27 Controller 8 Black insertion signal conversion part 9, 29 Drive control part 10, 10a, 20 Black insertion rate setting part 12 Thin film transistor (TFT)
13 Pixel electrode 14 Liquid crystal layer 15 Common electrode 21 Backlight

Claims (2)

A hold-type image display system for displaying a video on a display panel by controlling a video signal input to a source line and a gate line of the display panel, the source driver outputting a video signal to the source line, and the gate A gate driver that outputs a scanning signal to a line, a controller that drives and controls the source driver and the gate driver by receiving an input video signal, and a backlight on the back of the display panel,
The controller is
The output enable signal input to each gate driver is controlled independently, and a video signal in which a black or halftone line is inserted between video lines is output to the source driver, and a start pulse for writing one or more video lines A signal and a start pulse signal for writing one or more black or halftone lines are output to the gate driver within one frame period, and the black band is scrolled on the display panel screen within one frame period. Means,
Black or halftone insertion rate is determined according to the display, and black or halftone is input to the input of the start pulse signal to the gate driver for video line writing based on the determined black or halftone insertion rate. Means for changing the timing of input of the start pulse signal to the gate driver for line writing;
Divide one frame into a plurality of preset blocks, calculate the distance that the image of one arbitrary block moved from the previous frame to the current frame, and calculate the maximum value of the calculated movement distance of each block hold-type image display system characterized by switching the black image insertion rate, and means for adjusting the dimming brightness of the backlight so that the brightness becomes constant due to the switching of the black image insertion rate in accordance with the . A control device for a hold-type image display system that drives and displays video on the display panel by controlling the video signal to the source line of the display panel with the source driver and controlling the signal to the gate line of the display panel with the gate driver. There,
The output enable signal input to each gate driver is controlled independently, and a video signal in which a black or halftone line is inserted between video lines is output to the source driver, and a start pulse for writing one or more video lines A signal and a start pulse signal for writing one or more black or halftone lines are output to the gate driver within one frame period, and the black band is scrolled on the display panel screen within one frame period. Means,
Black or halftone insertion rate is determined according to the display, and black or halftone is input to the input of the start pulse signal to the gate driver for video line writing based on the determined black or halftone insertion rate. Means for changing the timing of input of the start pulse signal to the gate driver for line writing;
Divide one frame into a plurality of preset blocks, calculate the distance that the image of one arbitrary block moved from the previous frame to the current frame, and calculate the maximum value of the calculated movement distance of each block depending on the switching of the black image insertion rate, the hold-type image display system characterized by comprising a means for adjusting the dimming brightness of the backlight so that the brightness becomes constant due to the switching of the black image insertion rate Control device.

Images