JP2008102220A - Video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a video display device that can improve the display quality of moving picture display while suppressing blur in a moving picture and generation of flicker. <P>SOLUTION: The video display device is equipped with: an LCD panel 11 composed of a plurality of horizontal lines comprising a plurality of pixels; gate driving circuits (first gate driver 13a, second gate driver 13b) repeatedly processing in a predetermined cycle to display inputted video information in a video information display period and to display a non-video signal in a non-video display period in a grayscale number different from that of the video information, to each horizontal line of the LCD panel 11; and a control circuit 15 controlling the time ratio of the non-video information display period to the predetermined cycle time according to predetermined information obtained from video information, as well as controlling the grayscale number of the non-video information according to the time ratio. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video display device provided with a period for inserting a non-image signal in one frame period in order to suppress moving image blur.

  In an impulse-type display device such as a CRT (Cathode Ray Tube), focusing on individual pixels, a lighting period in which an image is displayed and a light-off period in which no image is displayed are alternately repeated. For example, even when a moving image is displayed, since an extinguishing period is inserted when an image for one screen is rewritten, an afterimage of an object moving in human vision does not occur. For this reason, the background and the object are clearly distinguished, and the moving image is visually recognized without a sense of incongruity.

  On the other hand, in a hold-type display device such as a liquid crystal display device using TFT (Thin Film Transistor), the luminance of each pixel is determined by the voltage held in each pixel capacitor, and the holding voltage in the pixel capacitor is Is maintained for one frame period once rewritten. In this way, in the hold-type display device, the voltage to be held in the pixel capacitance as pixel data is held until it is rewritten once, so that the image of each frame is the same as the image of the previous frame and the time. Will be close to each other. As a result, when a moving image is displayed, an afterimage of a moving object occurs in human vision.

  As a method for reducing such an afterimage, in a hold-type display device such as a liquid crystal display device, a period for performing black display (non-image display) is inserted in one frame period (hereinafter referred to as black insertion). Thus, there is known a method in which the display on the liquid crystal display device is (pseudo-) impulsed (for example, Patent Document 1).

  However, in the case of the pseudo impulse driving as described above, an image display period and a non-image display (black display) period are mixed in one frame period, and an image display period and a non-image display period in one frame period are mixed. Depending on the ratio (display time ratio), when moving images are displayed, there is a possibility that moving image blur caused by an afterimage may occur.

Therefore, for example, in Patent Document 2, the display time ratio between the image display period and the non-image display period in one frame period is adjusted in accordance with the amount of movement of the image in the moving image, thereby displaying the moving image. A technique for reducing moving image blur caused by an afterimage is disclosed.
JP 2003-066918 A (published on March 05, 2003) JP 2002-323876 A (published November 08, 2002)

  By the way, in Patent Document 2, if the amount of motion of an image in a moving image increases, that is, the motion becomes faster, the afterimage is reduced by improving the time ratio of the non-image display period to improve the motion blur.

  However, in moving image display, when the time ratio of the non-image display period is increased, afterimages can be reduced to improve moving image blur for fast moving images, but flicker phenomenon occurs and display quality in moving image display is improved. This causes a problem of lowering.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a video display device capable of improving the display quality of moving image display by suppressing the occurrence of flicker while suppressing moving image blur. Is to realize.

  In order to solve the above problems, a video display device according to the present invention includes a display unit composed of a plurality of horizontal lines composed of a plurality of pixels, and video information input to each horizontal line of the display unit. Display processing in which a first display process for displaying the image information within the video information display period and a second display process for displaying the non-video signal with a different number of gradations from the video information within the non-video display period are repeated in a predetermined cycle. And controlling the time ratio of the non-video information display period with respect to the predetermined period according to predetermined information obtained from the video information and controlling the number of gradations of the non-video information according to the time ratio. The display control means is provided.

  According to the above configuration, the display control unit controls the time ratio of the non-video information display period with respect to the predetermined cycle according to the predetermined information obtained from the video information, and the non-display according to the time ratio. By controlling the number of gradations of the video information, the difference between the maximum luminance and the minimum luminance in the predetermined cycle is controlled.

  Thereby, the ratio when the difference between the maximum luminance and the minimum luminance in the predetermined cycle is divided by the luminance in the display means, that is, the flicker rate is changed according to the time ratio of the non-video information display period with respect to the predetermined cycle. be able to.

  For example, when the time ratio of the non-video information display period with respect to a predetermined cycle increases, that is, when the amount of motion included in the video information increases, the difference between the maximum luminance and the minimum luminance in the predetermined cycle is reduced. Control may be performed to increase the number of gradations of non-images. In this case, since the numerator of the formula for calculating the flicker rate is small, the flicker rate is small, the amount of motion included in the video information is large, and the time ratio of the non-video information display period is used to suppress the motion blur. Even if this increases, it is possible to suppress the occurrence of flicker. That is, it is possible to provide a video display device capable of suppressing flicker while suppressing moving image blur even when the non-video display period in which flicker phenomenon is likely to occur is long, that is, when the moving image speed is high. it can.

  The display processing means includes a first scanning means for selecting any one of the horizontal lines each time a horizontal synchronization signal is input in order to display the input video information within a video information display period; First holding means for holding video information for the one horizontal line to perform a first display process on the horizontal line selected by the first scanning means; and non-video information within the non-video display period. Second scanning means for selecting a horizontal line different from the horizontal line selected by the first scanning means when the horizontal synchronization signal is input in order to display with a different number of gradations from the information; Second holding means for holding the non-video information to be displayed on the horizontal line selected by the scanning means, the display control means according to predetermined information obtained from the video information, Scanning hand And the second scanning means controls the time ratio by controlling the number of lines between the horizontal lines selected within the same horizontal period, and the second holding means holds the time ratio according to the time ratio. The number of gradations of the non-video information may be controlled.

  Here, the number of horizontal lines selected by the second scanning unit increases because the number of lines between the horizontal lines selected within the same horizontal period by the first scanning unit and the second scanning unit decreases. It shows that. That is, the smaller the number of lines between the horizontal lines selected within the same horizontal period in the first scanning means and the second scanning means, the greater the ratio of inserting non-video information within the horizontal period. Indicates.

  Therefore, as in the above configuration, the number of lines between each horizontal line selected within the same horizontal period is controlled by the first scanning unit and the second scanning unit in accordance with predetermined information obtained from the video information. The ratio of inserting non-video information in one horizontal period by controlling the time ratio by controlling the number of gradations of non-video information held in the second holding means according to the time ratio It is possible to set the number of gradations of the non-video information in accordance with.

  Accordingly, the display control means may perform display processing so as to improve the number of gradations of non-video information displayed during the non-video information display period as the time ratio increases.

  As a result, the number of lines is reduced, and the rate at which non-video information is inserted within the horizontal period, that is, the time ratio is increased. In this case, the number of gradations of the non-video information should be set high. Thus, the difference between the maximum luminance and the minimum luminance, which is the numerator of the formula for calculating the flicker rate, can be reduced. As a result, the occurrence of flicker can be suppressed.

  The predetermined information obtained from the video signal is information regarding the amount of motion of the video information, and in the display control described above, the number of gradations of the non-video information is controlled according to the amount of motion of the video information. Is possible.

  If the time ratio is controlled to increase as the amount of motion increases, a moving image with high display quality that suppresses flickering while suppressing motion blur due to an increase in the amount of motion of video information. Can be displayed.

  The number of gradations of the non-video information may be determined in association with information on the luminance of the video information in addition to the information on the amount of motion.

  In this case, the contrast ratio can be controlled by setting the number of gradations of the non-video signal to the number of gradations considering the luminance information of the video signal.

  Further, the display control means may perform control so that the number of gradations of the non-video information decreases as the amount of movement increases or the luminance decreases.

  In this case, it is possible to prevent the contrast ratio from being lowered more than necessary by controlling so that the number of gradations of the non-video information decreases as the amount of motion increases or the brightness decreases.

  As described above, the video display device according to the present invention includes a display unit composed of a plurality of horizontal lines composed of a plurality of pixels, and the video information input to each horizontal line of the display unit is displayed as video information. Display processing means for performing display processing within a display period and display processing for displaying a non-video signal with a gradation number different from that of the video information within a non-video display period at a predetermined cycle; Display control means for controlling a time ratio of the non-video information display period with respect to the predetermined cycle according to the predetermined information, and controlling the number of gradations of the non-video information according to the time ratio. As a result, a video display device capable of suppressing flickering while suppressing moving image blur even when the non-video display period in which flicker phenomenon is likely to occur, that is, when the moving image speed of the image is high is provided. An effect that can be.

  An embodiment of the present invention will be described as follows. Note that in this embodiment, a liquid crystal display device is described as an example of a video display device.

  As shown in FIG. 1, the liquid crystal display device according to the present embodiment includes an LCD (Liquid Crystal Display) panel (display means) 11, a first source driver 12a and a second source driver 12b as source drive circuits, and gate drive. The circuit includes a first gate driver (first scanning means) 13a and a second gate driver (second scanning means) 13b as circuits, and is external to the first source driver 12a and the second source driver 12b. A video processing circuit 14 for supplying a video signal and a non-video signal input from a frame unit and supplying a horizontal synchronization signal and a vertical synchronization signal to the first gate driver 13a and the second gate driver 13b; And a control circuit 15 for supplying a control signal such as a start pulse signal to each driver, and during one frame period A microcomputer 16 for setting a ratio of inserting a non-video signal and the number of gradations of the non-video signal, and a memory 17 for storing data used by the microcomputer 16 are provided.

  The LCD panel 11 is composed of a plurality of horizontal lines made up of a plurality of picture elements or pixels, and displays a video signal sent from the video processing circuit 14.

  Further, the source driving circuit and the gate driving circuit display a display process for displaying the video information input from the video processing circuit 14 for each horizontal line of the LCD panel 11 within a video information display period, and a non-video signal. It functions as a display processing means for repeatedly performing display processing for displaying with different gradation numbers from the video information within a non-video display period at a predetermined cycle.

  The video processing circuit 14 includes a frame memory 141 that stores video signals sequentially input frame by frame from a tuner (not shown) in units of frames, and a synchronization that separates a horizontal synchronizing signal and a vertical synchronizing signal from the video signal. The signal separation circuit 142 includes a motion amount determination circuit 143 that determines the motion amount of a moving image included in the video signal from the video signals sequentially input for each frame.

  The motion amount determination circuit 143 is a circuit that determines a motion amount by comparing a difference in motion between two or more consecutive frames from a video signal sequentially input for each frame via a tuner or the like. .

  The motion amount determination circuit 143 determines the motion amount by, for example, the following calculation. That is, i is a pixel number arbitrarily selected from pixels existing in each frame among a plurality of frames sent continuously, and Pm i is the number of gradations of the i-th pixel included in the m-th frame. , Where the number of gradations of the i-th pixel included in the (m + 1) th frame is P (m + 1) i, the difference between Pmi and P (m + 1) i is changed from the minimum value of i to the maximum value ( The amount of motion is determined from an integrated value (Σ | Pm i −P (m + 1) i |) obtained by integrating up to 0 to MAX). Specifically, it is determined whether or not the integrated value is within a certain range, and when it is determined that the integrated value is within the range, the amount of motion is determined according to the range. Here, four types of ranges are prepared in order to classify the amount of movement into four levels of minimum, small, medium, and large.

  The motion amount determination circuit 143 sends data of the motion amounts determined in the above-described manner (four levels of minimum, small, medium, and large) to the microcomputer 16.

  The microcomputer 16 instructs the control circuit 15 to output a voltage corresponding to the number of gradations associated with the amount of motion stored in the memory 17 from the transmitted amount of motion data.

  In the memory 17, the number of motion amounts obtained by classifying a memory area including a set of a non-video signal insertion rate of a predetermined value and a gradation number of a non-video signal of a predetermined value with respect to the motion amount. It is saved as a memory map 17a. In this memory map 17a, setting values are stored so that the non-video signal insertion rate is higher as the amount of motion is larger and the number of gradations of the non-video signal is increased.

  Here, the non-video signal insertion rate indicates a time ratio for performing non-video display in one frame period. That is, a non-video signal insertion rate of 0 indicates that there is no period for non-video display in one frame period. Therefore, when the non-video signal insertion rate is 0, the number of gradations is not set.

  The control circuit 15 supplies a latch strobe LS signal to the first source driver 12a and a count value control signal to the first gate driver 13a and the second gate driver 13b. As a result, a video signal is written from the first source driver 12a to the target pixel of the LCD panel 11 at a predetermined timing during the video display period of one frame period.

  The control circuit 15 controls the time ratio of the non-video information display period with respect to the predetermined period according to predetermined information obtained from video information, and the non-video information according to the time ratio. It has a function as display control means for controlling the number of gradations. The control circuit 15 supplies a control signal for setting the number of gradations of the signal output as a non-video signal to the second source driver 12b based on an instruction from the microcomputer 16. ing. Thereby, the non-video signal is written from the second source driver 12b to the target pixel of the LCD panel 11 at a predetermined timing during the non-video display period of one frame period.

  The liquid crystal display device having the above configuration will be described in detail as follows.

  As shown in FIG. 2, the LCD panel 11 includes a plurality of first source bus lines 101a... Connected to the first source driver 12a and a plurality of second sources connected to the second source driver 12b. A plurality of first gate bus lines 102a connected to the first gate driver 13a and a plurality of second gate bus lines 102b connected to the second gate driver 13b. Are arranged so as to be orthogonal to each other, and a first TFT 111a as a switching element is provided at the intersection of the first source bus line 101a and the first gate bus line 102a, and the second source bus line 101b and the second gate A second TFT 111b as a switching element is provided at the intersection with the bus line 102b.

  A common electrode 113 is connected to each drain electrode of the first TFT 111a and the second TFT 111b via a common pixel capacitor 112. Thereby, signals can be separately supplied to the same pixel capacitor 112 from the first source driver 12a and the second source driver 12b.

  As shown in FIG. 2, the first source driver 12 a includes a reference voltage generation circuit 120, a sampling memory 121, a hold memory 122, a DA converter (DAC) 123, and an output circuit 124.

  The reference voltage generation circuit 120 is a circuit that generates a reference voltage for outputting an analog voltage value suitable for an appropriate number of gradations among RGB gradations expressed as a data signal. Is supplied to the DA converter 123. For example, when performing display processing such as dot inversion and line inversion, voltage data is held so that both positive and negative analog gradation voltages can be output for each number of gradations in accordance with an inversion signal generated for each line. For example, in the case of 256 gradations, 256 × 2 pieces of voltage data are held.

  The sampling memory (first holding means) 121 is a memory for reading and storing one line of the video data (RGB) signal sent from the video processing circuit 14 (FIG. 1) before writing it to the LCD panel 11. It is. That is, it is a memory that holds video information for one horizontal line in order to perform a first display process (video display process) on the horizontal line selected by the first gate driver 13a.

  The hold memory 122 is a memory for writing the same data after a data signal for one line is written in the sampling memory 121. The timing of writing data to the DA converter 123 by the hold memory 122 is controlled by a latch strobe LS signal.

  The DA converter 123 is a circuit that converts the data signal for one line stored in the hold memory 122 in a digital format into an analog voltage value according to the voltage value for each gradation output from the reference voltage generation circuit 120.

  The output circuit 124 is a circuit that outputs an analog voltage value signal converted by the DA converter 123 to each source bus line 101a.

  As shown in FIG. 2, the second source driver 12b includes an APL detection circuit 125, a black level control circuit 126, a DA converter (DAC) 127, and an output circuit 128.

  The APL detection circuit 125 is a circuit that detects APL (average luminance level) from video data (RGB) signals.

  The black level control circuit 126 determines the black level, that is, the number of gradations of the non-video signal from the APL detected by the APL detection circuit 125, and outputs a voltage signal corresponding to the determined number of gradations to the DA converter 127. To output. The black level control circuit 126 also has a function as second holding means for holding non-video information to be displayed on a horizontal line selected by a second gate driver 13b as second scanning means to be described later. Yes.

  The DA converter 127 is a circuit that converts an input voltage signal into an analog voltage value according to the voltage value output from the black level control circuit 126.

  The output circuit 128 is a circuit that outputs an analog voltage value signal converted by the DA converter 127 to each source bus line 101b.

  The first gate driver 13a functions as a first scanning unit that selects any one of the horizontal lines each time a horizontal synchronization signal is input in order to display the input video information within a video information display period. ing. In order to realize this function, the first shift register 131, the level shifter 132, and the output circuit 133 are included as shown in FIG. An example of a specific circuit configuration of the first gate driver 13a is shown in FIG.

  The first shift register 131 connects the plurality of first gate bus lines 102a... Of the LCD panel 11 via the level shifter 132 and the output circuit 133 in the subsequent stage each time a horizontal synchronization signal (Hsync) is input. The first gate voltage is applied line-sequentially by switching and selecting sequentially. As a result, the data signal for one line stored in the first source driver 12a is written to the first source bus line 101a line-sequentially, thereby performing line-sequential scanning.

  The second gate driver 13b displays the non-video information with a gray scale different from that of the video information within the non-video display period by the first gate p driver 13a when the horizontal synchronization signal is input. It has a function of selecting a horizontal line different from the selected horizontal line. In order to realize this function, the second gate driver 13b includes a counter 134, a second shift register 135, a level shifter 136, and an output circuit 137, as shown in FIG. An example of a specific circuit configuration of the second gate driver 13b is shown in FIG.

  The counter 134 performs horizontal synchronization for several tens to several hundreds of lines in order to generate a gate pulse for black writing processing with a delay of several tens to several hundreds of lines with respect to a gate bus line selected once. A circuit intended to measure a signal.

  Further, a black insertion gate pulse is added to the counter 134 by comparing the count upper limit data (digital format) included in the count value control signal sent from the microcomputer or the like with the count number measured by the counter. The display timing ratio (black insertion rate) between the video signal and the black signal output in one vertical period can be controlled.

  The second shift register 135 selects a gate bus line that performs black writing processing with a delay of several tens to several hundred lines counted by the counter 134 with respect to the first shift register 131 of the first gate driver 13a. It is a circuit for doing.

  Further, in the second shift register 135, by connecting a logic circuit such as an OR circuit to the input terminal of the output of each flip-flop, a plurality of gate lines can be simultaneously selected within one horizontal synchronization period. Yes, if the black gradation (zero gradation ≒ common voltage) cannot be completely reduced by selecting the gate line once, the above OR circuit can select the gate pulse twice or more to reliably write black. It is possible to execute processing.

  In accordance with the scanning of the black writing gate pulse, the second source driver 12b outputs a specific gradation signal expressing a specific gradation number different from the data signal output from the first source driver 12a. The darkness at the time of actual black writing can be adjusted by the tone value.

  That is, the second shift register 135 sequentially switches the plurality of second gate bus lines 102b... Of the LCD panel 11 via the level shifter 136 and the output circuit 137 in the subsequent stage in accordance with the scanning of the gate pulse for black writing. The second gate voltage is applied line-sequentially. As a result, a black write signal is written line-sequentially from the second source driver 12b to the second source bus line 101b.

  The operation of each driver having the above configuration will be described below with reference to FIGS.

  Here, a case where one frame period is composed of a video signal display period and a non-video signal display period will be described.

First, the flow of the data signal scanning process in the normal time, that is, in the video signal display period will be described.
(1): First, a horizontal synchronization signal (Hsync) is input to the first gate driver 13a and the second gate driver 13b.
(2): In the first shift register 131 of the first gate driver b13a, the gate pulse of the Nth line (LineN) rises by the input of Hsync until the next Hsync signal is input, and at the same time the latch strobe (LS) The signal rises for a period shorter than the gate pulse.
(3): When the LS signal is turned off in (2) above, the start pulse (SP) signal rises.
(4): The rising edge of the SP signal in (3) above turns on the TFT element of each pixel on the Nth line, and the first source driver 12a analogizes the data signal of the desired gradation number with its drain voltage. The converted voltage value is supplied.

Next, the flow of the data signal scanning process in the non-video signal period (black writing period) will be described.
(5): An Hsync signal for selecting a gate line ((N + m) th line) preceding the Nth line by M lines is input.
(6): As a result, the first gate driver 13a selects the (N + m) th line, and at the same time, the second gate driver 13b selects the Nth line with a delay of m lines.

  (7) (8): After that, the data signal for one line stored in the first source driver 12a is output to the (N + m) th line to which the start pulse signal is input, and at the same time the Nth line A predetermined gradation voltage signal corresponding to a predetermined gradation number for one line stored in the second source driver 12b is output to the line. In FIG. 4, a voltage signal of the number of gradations (number of gradations = 0) for black display is output.

  At this time, it is possible to control the number of m lines, which is the difference between the lines selected by the first gate driver 13a and the second gate driver 13b, by an instruction from the microcomputer 16 (FIG. 1). The non-video signal insertion rate is controlled by adjusting this number. The predetermined number of gradations stored in the second source driver 12b can be rewritten in accordance with the value of the number of lines m. For example, the number of lines m is reduced, the non-video signal insertion rate is improved, and flicker occurs. Even under easy conditions, flicker can be prevented by rewriting the predetermined number of gradations output from the second source driver 12b from zero to a halftone of, for example, around 32 gradations.

  That is, the non-video signal insertion rate is controlled according to the value of the number of lines m, and further, the non-video signal held by the black level control circuit 126 functioning as the second holding means is controlled according to the non-video signal insertion rate. By controlling the number of gradations of the video signal, for example, even if the number of lines m is reduced and the non-video signal insertion rate is improved and flicker is likely to occur, the number of gradations of the non-video signal is increased, By reducing the difference between the maximum brightness and the minimum brightness, flicker can be prevented.

  Details of the above effect will be described below.

  FIG. 5A is a diagram illustrating an example of drive control when the time ratio (non-video signal insertion rate) of the non-video display period in one frame period (1 V period) is 20%.

  In this case, the drain voltage in the non-video display period in one frame period is set to a voltage V20 higher than the common voltage Vcom = + 7V. In other words, if the drain voltage is the same voltage as the common voltage, black display with a gradation number of 0 is obtained. If the drain voltage is a voltage higher than the common voltage, gradation display with a gradation number greater than 0 is performed. Become. Here, from the data stored in the memory 17 shown in FIG. 1, the drain voltage is set such that the non-video signal insertion rate can be displayed with the number of gradations 16 corresponding to 20%.

  FIG. 5A shows an example in which the non-video signal insertion rate is 20%. However, when the amount of motion increases and the non-video signal insertion rate becomes 30%, FIG. As shown, the drain voltage in the non-video display period is set to a voltage V30 higher than the common voltage Vcom = + 7V. The drain voltage V30 in this case is set to a drain voltage that can be displayed with the number of gradations 32 corresponding to a non-video signal insertion rate of 30% from the data stored in the memory 17 shown in FIG.

  As described above, in the non-video display period of one frame period, the drain voltage V20 or V30 corresponding to the gradation number 16 or 32 having a gradation number larger than 0 according to the amount of motion of the moving image is larger than the common voltage. Therefore, the value of the AC component, which is the numerator of the formula for obtaining the flicker rate, can be made smaller than 14V-7V = 7V when the number of gradations is 0. As a result, the flicker rate can be made smaller than in the case of the number of gradations of 0, so that the occurrence of flicker can be suppressed.

  Therefore, since the flicker rate can be reduced while maintaining the non-video signal insertion rate, it is possible to display a moving image with high display quality without moving image blur and flicker.

  As described above, when the non-video signal insertion rate is determined so as to eliminate moving image blur according to the amount of motion of the moving image, non-video is generated according to the non-video signal insertion rate so that flicker does not occur. The number of gradations of the signal may be adjusted.

  That is, in the liquid crystal display device having the above-described configuration, the control circuit 15 includes the first gate driver 13a as the first scanning means and the second scanning means according to the amount of movement that is predetermined information obtained from the video information. The second gate driver 13b controls the time ratio by controlling the number of lines between each horizontal line selected within the same horizontal period, and functions as the second holding means according to the time ratio. It is only necessary to control the number of gradation levels of the non-video information held in the black level control circuit 126.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

  The present invention relates to a liquid crystal display device provided with a period for inserting a non-image signal in one frame period in order to suppress moving image blur. If the display device is a hold-type display device, it is within the technical scope of the present invention.

1, showing an embodiment of the present invention, is a block diagram illustrating a main configuration of a liquid crystal display device. FIG. FIG. 2 is a block diagram illustrating a main configuration of each driver of the liquid crystal display device illustrated in FIG. 1. FIG. 3 is a circuit diagram illustrating an example of a gate driver illustrated in FIG. 2. It is a wave form diagram of the output signal of each driver of the liquid crystal display shown in FIG. (A) is a waveform diagram of the output signal of each driver shown in FIG. 2 when the non-video signal insertion rate is 20%, and (b) is a diagram of FIG. 2 when the non-video signal insertion rate is 30%. It is a wave form diagram of the output signal of each driver shown.

Explanation of symbols

11 LCD panel (display means)
12a First source driver (display processing means)
12b Second source driver (display processing means)
13a First gate driver (display processing means, first scanning means)
13b Second gate driver (display processing means, second scanning means)
14 Video processing circuit 15 Control circuit (display control means)
16 microcomputer 17 memory 17a memory map 101a first source bus line 101b second source bus line 102a first gate bus line 102b second gate bus line 111a first TFT
111b 2nd TFT
112 pixel capacity 113 common electrode 120 reference voltage generation circuit 121 sampling memory (first holding means)
122 hold memory 123 DA converter 124 output circuit 125 APL detection circuit 126 black level control circuit (first holding means)
127 DA converter 128 Output circuit 131 First shift register 132 Level shifter 133 Output circuit 134 Counter 135 Second shift register 136 Level shifter 137 Output circuit 141 Frame memory 142 Synchronization signal separation circuit 143 Motion amount determination circuit LS Latch strobe signal

Claims (7)

A display means composed of a plurality of horizontal lines composed of a plurality of pixels;
A first display process for displaying input video information within a video information display period for each horizontal line of the display means, and displaying a non-video signal with a different number of gradations from the video information within a non-video display period Display processing means for repeatedly performing the second display processing in a predetermined cycle;
A display for controlling the time ratio of the non-video information display period with respect to the predetermined cycle according to predetermined information obtained from video information and for controlling the number of gradations of the non-video information according to the time ratio. A video display device comprising control means. The display processing means includes
First scanning means for selecting any one of the horizontal lines each time a horizontal synchronization signal is input in order to display input video information within a video information display period;
First holding means for holding video information for the one horizontal line in order to perform a first display process on the horizontal line selected by the first scanning means;
A horizontal line different from the horizontal line selected by the first scanning means when the horizontal synchronization signal is input to display the non-video information with a gradation number different from that of the video information within the non-video display period. Second scanning means for selecting
Second holding means for holding the non-video information to be displayed on the horizontal line selected by the second scanning means;
The display control means includes
The time ratio is controlled by controlling the number of lines between each horizontal line selected within the same horizontal period by the first scanning means and the second scanning means in accordance with predetermined information obtained from the video information. The video display apparatus according to claim 1, wherein the number of gradations of the non-video information held in the second holding unit is controlled in accordance with the time ratio.   3. The display control unit according to claim 1, wherein the display control unit performs display processing so as to improve the number of gradations of non-video information displayed in the non-video information display period as the time ratio increases. The video display device described.   The video display apparatus according to claim 1, wherein the predetermined information obtained from the video signal is information relating to a motion amount of the video information.   The video display apparatus according to claim 4, wherein the display control unit performs control so that the time ratio increases as the movement amount increases.   6. The video display device according to claim 4, wherein the number of gradations of the non-video information is determined in association with information on luminance of the video information in addition to information on the amount of motion. .   The video display device according to claim 6, wherein the display control unit performs control so that the number of gradations of the non-video information decreases as the amount of movement increases or the luminance decreases.

Images