WO2012165234A1 - Multi-display device - Google Patents

Multi-display device Download PDF

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Publication number
WO2012165234A1
WO2012165234A1 PCT/JP2012/063088 JP2012063088W WO2012165234A1 WO 2012165234 A1 WO2012165234 A1 WO 2012165234A1 JP 2012063088 W JP2012063088 W JP 2012063088W WO 2012165234 A1 WO2012165234 A1 WO 2012165234A1
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WO
WIPO (PCT)
Prior art keywords
liquid crystal
display device
backlight
crystal panel
crystal display
Prior art date
Application number
PCT/JP2012/063088
Other languages
French (fr)
Japanese (ja)
Inventor
上野　雅史
宮田　英利
小もう 張
Original Assignee
シャープ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by シャープ株式会社 filed Critical シャープ株式会社
Publication of WO2012165234A1 publication Critical patent/WO2012165234A1/en

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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/02—Composition of display devices
    • G09G2300/026—Video wall, i.e. juxtaposition of a plurality of screens to create a display screen of bigger dimensions
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/10—Special adaptations of display systems for operation with variable images
    • G09G2320/106—Determination of movement vectors or equivalent parameters within the image
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/021—Power management, e.g. power saving
    • G09G2330/022—Power management, e.g. power saving in absence of operation, e.g. no data being entered during a predetermined time
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2340/00—Aspects of display data processing
    • G09G2340/04—Changes in size, position or resolution of an image
    • G09G2340/0407—Resolution change, inclusive of the use of different resolutions for different screen areas
    • G09G2340/0435—Change or adaptation of the frame rate of the video stream
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/3406—Control of illumination source

Definitions

  • the present invention relates to a multi-display device in which a multi-screen is configured by arranging a plurality of liquid crystal display devices including a liquid crystal panel.
  • a multi-display device in which a multi-screen is configured by arranging a plurality of liquid crystal display devices including a liquid crystal panel is known.
  • a multi-display device as disclosed in, for example, Japanese Patent Laid-Open No. 2009-169196, a multi-screen is configured by arranging a plurality of video display units at least in the vertical direction or the horizontal direction.
  • the multi-display device includes a backlight unit having a plurality of light sources for displaying images on each image display unit.
  • An object of the present invention is to reduce power consumption while preventing deterioration in display quality of the entire multi-screen in a multi-display device.
  • a multi-display device includes a plurality of liquid crystal display devices arranged to form a multi-screen, and a drive control unit that controls the liquid crystal display device. And a backlight, and the drive control unit has a character graphic display region for displaying at least one of characters and figures among the plurality of liquid crystal display devices.
  • the liquid crystal display device is configured to reduce at least one of the luminance of the backlight and the driving frequency of the liquid crystal panel.
  • a multi-display device in a multi-display device, it is possible to reduce power consumption while preventing deterioration of display quality of the entire multi-screen.
  • FIG. 1 is a diagram illustrating a schematic configuration of a multi-display apparatus according to the first embodiment.
  • FIG. 2 is a block diagram showing the relationship between the control device and each liquid crystal display device.
  • FIG. 3 is a flowchart showing an example of the operation of the histogram analysis unit.
  • FIG. 4 is a diagram showing an example when a character or figure is subjected to histogram analysis.
  • FIG. 5 is a flowchart showing an example of the operation of the difference analysis unit.
  • FIG. 6 is a flowchart illustrating an example of the operation of the region determination unit.
  • FIG. 1 is a diagram illustrating a schematic configuration of a multi-display apparatus according to the first embodiment.
  • FIG. 2 is a block diagram showing the relationship between the control device and each liquid crystal display device.
  • FIG. 3 is a flowchart showing an example of the operation of the histogram analysis unit.
  • FIG. 4 is a diagram showing an example when a character or figure is subjected to hist
  • FIG. 7 is a diagram illustrating an example of the relationship between the gradation of the input signal and the gradation of the output signal when the gradation of the liquid crystal panel is adjusted according to the luminance of the backlight.
  • FIG. 8 is a block diagram showing the relationship between the control device and each liquid crystal display device in the multi-display device according to the second embodiment.
  • FIG. 9 is a block diagram showing the relationship between the control device and each liquid crystal display device in the multi-display device according to the third embodiment.
  • a multi-display device includes a plurality of liquid crystal display devices arranged to form a multi-screen, and a drive control unit that controls the liquid crystal display device, and the liquid crystal display device includes: A liquid crystal panel in which a plurality of pixels are arranged in a matrix and a backlight, and the drive control unit includes a character graphic display region for displaying at least one of characters and drawings among the plurality of liquid crystal display devices.
  • the liquid crystal display device having the above configuration is configured to reduce at least one of the luminance of the backlight and the driving frequency of the liquid crystal panel (first configuration).
  • a liquid crystal display device having a character graphic display region for displaying at least one of characters and drawings among a plurality of liquid crystal display devices constituting a multi-screen.
  • a liquid crystal display device that displays at least one of characters and drawings has few gradations for image display. Therefore, even if the brightness of the backlight is lowered or the driving frequency of the liquid crystal panel is lowered, the display quality of the entire multi-screen is not greatly affected.
  • the characters are not only ideographic characters, written characters and hieroglyphs used to represent various languages such as kanji, kana and alphabet, but also information transmission such as numbers, braille, symbols and symbols. Includes all notations for.
  • a figure is not only a drawn picture, figure, or chart, but also a figure that is composed of a set of lines and dots, such as patterns and icons, a figure that depicts the shape or state of an object, CG drawn by a computer or the like is also included.
  • the drive control unit includes a gradation control unit that increases a gradation of a video signal input to each pixel of a liquid crystal panel of the liquid crystal display device having the character graphic display area, and the character.
  • a backlight luminance adjusting unit for reducing the luminance of the backlight of the liquid crystal display device having the graphic display area (second configuration).
  • the luminance of the video signal input to each pixel of the liquid crystal panel is increased while the luminance of the backlight is lowered.
  • the power consumption of the multi-display device as much as the luminance of the backlight is reduced while preventing the display quality from being lowered in the entire multi-screen.
  • the gradation control unit is configured such that each pixel of the liquid crystal panel of the liquid crystal display device having the character graphic display region according to the luminance of the backlight lowered by the backlight luminance adjusting unit. Is configured to increase the gradation of the video signal input to the video signal (third configuration).
  • the brightness on the viewing side can be prevented from changing greatly by increasing the gradation of the image displayed on the liquid crystal panel as much as the brightness of the backlight decreases. Therefore, it is possible to more reliably prevent the display quality from being lowered over the entire multi-screen.
  • the drive control unit includes a drive frequency adjusting unit that reduces a drive frequency of a liquid crystal panel of a liquid crystal display device that displays at least one of characters and drawings. (Fourth configuration).
  • an image determination unit that determines the character graphic display area based on a video signal input to each pixel of the liquid crystal panel (fifth) Configuration).
  • the image determination unit is configured to analyze a histogram of a video signal input to each pixel of the liquid crystal panel and determine the character graphic display region based on the analysis result.
  • the character graphic display area can be more reliably determined by the above-described configuration. Thereby, the power consumption of the liquid crystal display device having the character graphic display area can be reduced by the first to fourth configurations described above.
  • the image determination unit calculates a difference between display frames of a video signal input to each pixel of the liquid crystal panel, and displays a still image based on the difference.
  • the liquid crystal display device that is configured to determine an image display area and has the character graphic display area and the still image display area, the luminance of the backlight and the driving frequency of the liquid crystal panel Is reduced (seventh configuration).
  • the power consumption of the liquid crystal display device having the character graphic display area and the still image display area can be reduced by the above-described configuration.
  • the dimension of the structural member in each figure does not represent the dimension of an actual structural member, the dimension ratio of each structural member, etc. faithfully.
  • FIG. 1 shows a schematic configuration of a multi-display device 1 according to the first embodiment of the present invention.
  • the multi-display device 1 is a display device in which a multi-screen is configured by arranging a plurality of liquid crystal display devices 2 vertically and horizontally.
  • the multi-display device 1 of the present embodiment includes a display unit 3 configured by arranging a plurality of liquid crystal display devices 2 and a control device 4 that inputs video signals and various control signals to the display unit 3.
  • Each signal output from the control device 4 may be input to each liquid crystal display device 2 constituting the display unit 3 or may be input to one liquid crystal display device 2 and then another liquid crystal display device.
  • a signal may be input to
  • the multi-display device 1 is configured to display images, characters and the like on the multi-screen of the display unit 3 based on each signal input from the control device 4.
  • the multi-display device 1 can display one image as the entire multi-screen, and can also display different information for each liquid crystal display device 2.
  • the multi-display device 1 displays information such as characters and figures on the shaded liquid crystal display device 2 in FIG. 1, while the white portion liquid crystal display device 2 in FIG. Can be displayed.
  • the plurality of liquid crystal display devices 2 of the multi-display device 1 are divided into a liquid crystal display device 2 that displays information such as characters and figures, and a liquid crystal display device 2 that displays images such as moving images.
  • a single liquid crystal display device 2 may include a display area for displaying information such as characters and drawings and a display area for displaying an image such as a moving image.
  • each liquid crystal display device 2 of the display unit 3 includes a liquid crystal panel 11, a backlight 12, and a liquid crystal panel control unit that controls driving of the liquid crystal panel 11, as in a general liquid crystal display device. 13 and a backlight control unit 14 that controls driving of the backlight 12.
  • the liquid crystal panel 11 is an active matrix substrate in which a large number of pixels are arranged in a matrix, a counter substrate disposed to face the active matrix substrate, and a liquid crystal formed between these substrates. And a layer.
  • the liquid crystal panel 11 may be, for example, a transmissive liquid crystal panel, or a reflective or semi-reflective liquid crystal panel. That is, the liquid crystal panel 11 may have any configuration as long as it can display video.
  • the active matrix substrate includes a thin film transistor as a switching element, a pixel electrode, and a plurality of rows of gate lines and a plurality of columns of source lines arranged in a grid so as to surround them. Yes.
  • the counter substrate is disposed at a position facing at least the pixel electrode of the active matrix substrate.
  • the counter substrate is provided with a counter electrode.
  • Each pixel includes a counter electrode, a pixel electrode of the active matrix substrate, and a liquid crystal layer disposed therebetween.
  • the gate electrode of the thin film transistor in the active matrix substrate is connected to the liquid crystal panel control unit 13 through a gate line. Therefore, when a gate voltage is output from the liquid crystal panel control unit 13 to the gate line, the thin film transistor connected to the gate line is selected.
  • the liquid crystal panel control unit 13 outputs a gate voltage with reference to the vertical synchronization signal.
  • the source electrode of the thin film transistor is connected to the liquid crystal panel control unit 13 via the source line.
  • the liquid crystal panel control unit 13 generates a gradation display signal necessary for gradation display of the video based on the input video signal. Therefore, when a gradation display signal is output as a driving voltage from the liquid crystal panel control unit 13 to the source line, the liquid crystal of each pixel is supplied to the liquid crystal through the thin film transistor connected to the gate line selected by the liquid crystal panel control unit 13. A voltage is applied. That is, the liquid crystal panel control unit 13 enables gradation display of each pixel by outputting a drive voltage to each gate line based on the video signal.
  • the backlight 12 is disposed on one side of the liquid crystal panel 11 in the thickness direction.
  • the backlight 12 for example, a direct type, an edge light type, or a planar light source type can be used.
  • a light source of the backlight 12 a cold cathode tube, a light emitting diode, etc. can be used, for example.
  • a backlight that lights in white using light sources of three colors of RGB may be used.
  • the backlight 12 may be constantly turned on or a part thereof may be turned off.
  • the liquid crystal panel control unit 13 generates and outputs a video signal to be output to each pixel of the liquid crystal panel 11 based on the input signal. That is, as described above, the liquid crystal panel control unit 13 outputs a gate voltage to the liquid crystal panel 11 and outputs a gradation display signal to each pixel.
  • the liquid crystal panel control unit 13 receives a video level adjustment signal output from the gradation control unit 42 as described later. The liquid crystal panel control unit 13 outputs a gradation display signal corresponding to the input video level adjustment signal.
  • the backlight control unit 14 is configured to control the luminance of the backlight 12 based on the input backlight adjustment signal.
  • the control device 4 is configured to control image display on the multi-screen of the display unit 3 in the multi-display device 1. That is, the control device 4 divides an image to be displayed on the entire multi-screen of the display unit 3 in the multi-display device 1 into an image to be displayed on each liquid crystal display device 2 constituting the display unit 3, and displays each liquid crystal display. A signal is output to the device 2.
  • FIG. 2 shows the relationship between each liquid crystal display device 2 and the control device 4. Also, the input video signal in FIG. 2 is a video signal generated for each liquid crystal display device 2 in the control device 4.
  • the control device 4 is configured to reduce the luminance of the backlight 12 and increase the gradation of the liquid crystal panel 11.
  • the control device 4 determines an image to be displayed on the liquid crystal display device 2 based on an input video signal, and the determination result of the image determination unit 21. Accordingly, a drive control unit 22 that controls the backlight 12 and the liquid crystal panel 11 is provided.
  • the image determination unit 21 determines whether the image displayed on the liquid crystal display device 2 is a still image of a character or a figure based on the input video signal generated for each liquid crystal display device 2 constituting the display unit 3. To do.
  • the image determination unit 21 determines whether or not the display image is a character or a still image by performing a histogram analysis of the image to be displayed and obtaining a difference between input video signals between display frames.
  • the characters are not only ideographic characters, written characters and hieroglyphs used to represent various languages such as kanji, kana and alphabet, but also information transmission such as numbers, braille, symbols and symbols. Includes all notations for.
  • the figure is not only drawn pictures, figures and charts, but also forms that are composed of sets of lines and dots, such as patterns and icons, those that depict the shape and state of things, Also included are computer graphics (CG) drawn by a computer or the like.
  • CG computer graphics
  • the image determination unit 21 performs histogram analysis of the input video signal to determine whether the display image is a character or a figure, and based on the difference of the input video signal between display frames, And a difference analysis unit 32 for determining whether the display image is a still image. Furthermore, the image determination unit 21 is a still image display region in which the liquid crystal display device 2 displays a still image of a character or a figure in a multi-screen according to the determination results of the histogram analysis unit 31 and the difference analysis unit 32. An area determination unit 33 is provided for determining whether or not.
  • the histogram analysis unit 31 is configured to execute the flow shown in FIG. 3 when an input video signal is input to the image determination unit 21 for each display frame. The flow of FIG. 3 will be described below.
  • FIG. 4 shows an example of the result of histogram analysis of the input video signal.
  • FIG. 4 is an example of a histogram when displaying characters or diagrams. From FIG. 4, it can be seen that when a character or a figure is displayed, a steep peak exists only in a specific gradation.
  • step SA1 After the input video signal is subjected to histogram analysis (step SA1), based on the analysis result, whether or not the gradation of the image to be displayed is only a specific gradation, that is, at a specific gradation. It is determined whether or not there is a peak (step SA2). The determination of the peak may be performed based on whether a specific gradation appears with a frequency equal to or higher than a threshold or whether the appearance frequency of a specific gradation is higher than the preceding and subsequent gradations. .
  • the liquid crystal display device 2 When it is determined that the appearance frequency is high only for a specific gradation (in the case of YES), the liquid crystal display device 2 is a character graphic display area for displaying characters or figures in the multi-screen of the multi-display device 1. A determination signal is output (step SA3), and this flow ends (end). On the other hand, when it is determined that the peak of the appearance frequency is not seen in the specific gradation (in the case of NO), the liquid crystal display device 2 determines that the normal video area is in the multi-screen, and the normal video Display (normal display) is performed (step SA4), and this flow is ended (END).
  • the histogram analysis unit 31 performs determination using the result of the histogram analysis, not only a still image of a character or a figure but also an area displaying a moving character or a moving figure is determined as a character graphic display area.
  • the difference analysis unit 32 is configured to execute the flow shown in FIG. 5 when an input video signal is input to the image determination unit 21 for each display frame. The flow of FIG. 5 will be described below.
  • a difference between input video signals between display frames is calculated (step SB1).
  • the difference between the input video signals may be calculated for each pixel or may be calculated for each block including a plurality of pixels.
  • the specified value is set to a value that determines that the difference of the input video signal between the display frames is the difference of the input video signal in the case of a still image.
  • the liquid crystal display device 2 displays a still image in the multi-screen of the multi-display device 1 A signal for determining that it is the display area is output (step SB3), and this flow is ended (END).
  • the liquid crystal display device 2 is the moving image display area in the multi-screen, Normal video display (normal display) is performed (step SB4), and this flow ends (END).
  • the difference analysis unit 32 obtains a difference between input video signals for each display frame. Therefore, the difference analysis unit 32 determines not only characters and drawings but also still images such as photographs and landscape images as still image display areas.
  • the region determination unit 33 is configured to execute the flow illustrated in FIG. 6 when an input video signal is input to the image determination unit 21 for each display frame. .
  • the flow of FIG. 6 will be described below.
  • step SC1 the liquid crystal display device 2 determines whether it is a character graphic display area and a still image display area in the multi-screen.
  • step SC2 When the liquid crystal display device 2 is a character graphic display region and a still image display region (in the case of YES), the drive control unit 22 performs power saving display described later (step SC2) and ends this flow. (End). On the other hand, when the liquid crystal display device 2 is not a character graphic display area or a still image display area (in the case of NO), normal video display (normal display) is performed (step SC3), and this flow is terminated (step SC3). End).
  • the image determination unit 21 can determine whether the liquid crystal display device 2 is a still image display region and a character graphic display region in the multi-screen of the multi-display device 1. In this embodiment, the image determination unit 21 determines whether or not the liquid crystal display device 2 is a still image display area and a character / graphic display area. You may determine only. That is, the image determination unit 21 may include only the histogram analysis unit 31.
  • the drive control unit 22 When the image determination unit 21 determines that the image displayed on the liquid crystal display device 2 is a character or figure still image, the drive control unit 22 reduces the luminance of the backlight 12 as compared with the normal display. At the same time, a signal is output so as to increase the gradation of the liquid crystal panel 11. The drive control unit 22 performs power-saving display that reduces the power consumption of the liquid crystal display device 2 by the amount that the luminance of the backlight 12 is reduced.
  • the drive control unit 22 controls the luminance of the backlight 12, and performs the luminance control of the backlight 12 and the gradation control of the liquid crystal panel 11 as described above.
  • a gradation control unit 42 for controlling the gradation of the image on the liquid crystal panel 11.
  • the backlight brightness adjustment unit 41 is more effective than the normal display when the image determination unit 21 determines that the liquid crystal display device 2 is a still image display region and a character / graphic display region in the multi-screen. Is also configured to reduce the luminance of the backlight 12. Specifically, the backlight luminance adjustment unit 41 outputs a backlight adjustment signal for reducing the luminance of the backlight 12 to the backlight control unit 14 of the liquid crystal display device 2.
  • the gradation control unit 42 adjusts the gradation of the image displayed on the liquid crystal panel 11 in accordance with the backlight adjustment signal.
  • An adjustment signal is output.
  • the gradation control unit 42 increases the gradation of the liquid crystal panel 11 as much as the luminance of the backlight 12 is reduced so that the luminance of the image displayed on the display screen of the liquid crystal display device 2 does not change much. Thereby, even when the luminance of the backlight 12 is lowered, it is possible to prevent the display quality of the liquid crystal display device 2 from being lowered.
  • the gradation of the video signal (input signal) input to the drive control unit 22 and the gradation of the video signal (output signal) output from the drive control unit 22 Is proportional.
  • the luminance of the image displayed on the screen of the liquid crystal display device 2 changes so as to draw a curve with respect to the gradation of the input signal, as indicated by the solid line in the center diagram of FIG.
  • the gradation control unit 42 displays the screen of the liquid crystal display device 2 corresponding to the luminance reduction. Gradation control is performed so as to increase the brightness.
  • the gradation control unit 42 adjusts the gradation so that the luminance of the image displayed on the screen of the liquid crystal display device 2 increases with respect to the gradation of the input signal as indicated by the thick broken line in the center diagram of FIG. Perform key conversion.
  • the gradation control unit 42 performs gradation conversion so that the gradation of the input signal and the gradation of the output signal have a relationship as shown in the bottom diagram of FIG.
  • FIG. 7 shows, as an example, a case where the gradation control unit 42 obtains a video level adjustment signal when the luminance of the backlight 12 is reduced to 80%. Therefore, in the center diagram of FIG. 7, the gradation of the output signal is increased with respect to the gradation of the input signal so that the luminance of the video displayed on the screen of the liquid crystal display device 2 is increased by 125%.
  • the luminance of the backlight 12 of the liquid crystal display device 2 that is a still image display region and a character graphic display region is lower than that in the normal display.
  • the gradation of the liquid crystal panel 11 is increased accordingly.
  • the display quality of the liquid crystal display device 2 is not greatly affected. Therefore, the display quality of the entire multi-screen is increased by increasing the gradation of the display image on the liquid crystal panel 11 by reducing the brightness of the backlight 12 so that the brightness of the display image on the liquid crystal display device 2 does not change significantly. Can be prevented.
  • the power consumption of the multi-display device 1 can be reduced by reducing the luminance of the backlight 12 while preventing the display quality of the multi-screen device 1 from being lowered.
  • the histogram analysis unit 31 determines whether a character or a figure is displayed from the result of the histogram analysis, and the difference analysis unit 32 determines whether a still image is displayed from the difference of the input video signal.
  • the character graphic display area and the still image display area can be easily and more reliably determined in the multi-screen.
  • FIG. 8 shows a schematic configuration of the control device 51 and the liquid crystal display device 2 in the multi-display device according to the second embodiment of the present invention.
  • the control device 51 is different in configuration from the above-described first embodiment in that the control device 51 is configured to be able to adjust the drive frequency of the liquid crystal panel 11 of the liquid crystal display device 2.
  • the same components as those in the first embodiment will be denoted by the same reference numerals, and only the differences will be described below.
  • the drive control unit 52 that controls the driving of the liquid crystal panel 11 according to the image determination result of the image determination unit 21 includes a drive frequency adjustment unit 53.
  • the drive frequency adjusting unit 53 is more effective than the normal display when the image determining unit 21 determines that the liquid crystal display device 2 is a multi-screen still image display region and a character graphic display region of the multi-display device. Is also configured to output a drive frequency adjustment signal for lowering the drive frequency of the liquid crystal panel 11.
  • the drive frequency adjusting unit 53 changes the drive frequency (60 Hz as an example) during normal display to 15 Hz. That is, the drive control unit 52 performs power saving display for reducing the power consumption by the amount that the drive frequency of the liquid crystal panel 11 is reduced.
  • the power consumption can be reduced by reducing the drive frequency.
  • the display quality is not significantly lowered even if the video is not frequently rewritten unlike a moving image. Therefore, with the above-described configuration, it is possible to reduce the power consumption of the multi-display device without reducing the display quality.
  • the driving frequency of the liquid crystal panel 11 is set so that the viewer does not feel the flickering of the change in display gradation due to the fluctuation of the charge of each pixel. It is preferable to set the driving frequency.
  • the control device 51 sets the drive frequency of the liquid crystal panel 11 to a liquid crystal display device determined to be a still image display region and a character graphic display region on a multi-screen of the multi-display device, compared with a normal display time. Reduce. Thereby, the power consumption of the multi-display device can be reduced while preventing the display quality of the multi-display device from deteriorating.
  • FIG. 9 shows a schematic configuration of the control device 61 and the liquid crystal display device 2 in the multi-display device according to the third embodiment.
  • the control device 61 is configured to be capable of adjusting the driving frequency of the liquid crystal panel 11 while performing the luminance reduction of the backlight 12 and the gradation control of the liquid crystal panel 11, and is different from the first embodiment described above.
  • the configuration is different.
  • the same components as those in the first embodiment will be denoted by the same reference numerals, and only the differences will be described below.
  • the control device 61 includes both the configuration of the first embodiment and the configuration of the second embodiment. That is, the drive control unit 62 that controls the liquid crystal panel 11 and the backlight 12 based on the determination result by the image determination unit 21 includes the backlight luminance adjustment unit 41 and the gradation control unit 42 similar to those in the first embodiment, A drive frequency adjustment unit 53 similar to that of the second embodiment is provided.
  • the backlight luminance adjustment unit 41 is used for the liquid crystal display device 2 determined by the image determination unit 21 to be a still image display region and a character graphic display region, as compared with the case of normal display. Also outputs a backlight adjustment signal for reducing the luminance of the backlight 12.
  • the gradation control unit 42 when the backlight adjustment signal is output from the backlight luminance adjustment unit 41, the gradation control unit 42 also displays the display image on the liquid crystal panel 11 so as to compensate for the luminance decrease of the backlight 12. A video level adjustment signal for increasing the gradation of the image is output.
  • the drive frequency adjustment unit 53 applies the drive frequency of the liquid crystal panel 11 to the liquid crystal display device 2 determined by the image determination unit 21 as the still image display region and the character graphic display region.
  • a drive frequency adjustment signal for lowering is output.
  • the luminance of the backlight 12 can be lowered and the driving frequency of the liquid crystal panel 11 can also be lowered. Therefore, the power consumption of the multi-display device can be further reduced as compared with the configurations of the first and second embodiments described above.
  • the liquid crystal display device 2 that lowers the brightness of the backlight 12 and the drive frequency of the liquid crystal panel 11 is a still image display region and a character graphic display region in the multi-display device. Therefore, even when the backlight 12 and the liquid crystal panel 11 are controlled as described above, the display quality of the multi-screen is not greatly affected.
  • the gradation control of the liquid crystal panel 11 is performed according to the decrease in the luminance of the backlight 12, so that the viewer can be prevented from feeling as a large luminance change.
  • the control device 61 reduces the luminance of the backlight 12 and the liquid crystal panel for the liquid crystal display device 2 determined to be a still image display region and a character graphic display region on a multi-screen of the multi-display device. 11 drive frequency is reduced. Thereby, the power consumption of the multi-display device can be reduced as compared with the configurations of the first and second embodiments without significantly reducing the display quality of the multi-display device.
  • the gradation of the display image on the display panel 11 as much as the luminance of the backlight 12 is reduced, it is possible to prevent the viewer from perceiving a large luminance change. Therefore, it is possible to more reliably prevent the display quality of the multi-display device from deteriorating.
  • whether the image is a still image display area or a character graphic display area is determined in the control devices 4, 51, 61 based on the input video signal.
  • these determinations may be made in the liquid crystal display device 2.
  • the image determination unit 21 and the drive control units 22, 52, 62 may be provided in the liquid crystal display device 2.
  • a signal indicating that the image display area is a still image display area or a character graphic display area may be input as tag information (meta information) to the control device or the liquid crystal display device together with the input video signal. In this case, it is not necessary to provide the image determination unit 21 in the multi-display device.
  • each liquid crystal display device 2 of the multi-display device may be set according to user settings.
  • the control shown in each of the above embodiments can be performed.
  • control devices 4, 51, 61 based on the input video signal input for each display frame, whether it is a still image display area or a character graphic display area, Judgment.
  • the input video signal is stored in the control devices 4, 51, 61, and after the determination is completed in the control devices 4, 51, 61, the signal is output to the multi-display device. Good.
  • the image determination unit 21 determines whether a character or a figure is displayed by histogram analysis, and determines whether a still image is displayed based on a difference between input video signals.
  • the character / graphic display area or the still image display area may be determined by other methods.
  • the drive control units 22 and 62 are configured to perform luminance reduction of the backlight 12 and gradation control of the liquid crystal panel 11.
  • the drive control units 22 and 62 may be configured to only reduce the luminance of the backlight 12.
  • the driving frequency of the liquid crystal display device 2 determined to display a character or a figure as a still image is reduced.
  • the present invention is not limited to this, and it is determined to display a character or a figure other than a still image.
  • the driving frequency of the liquid crystal display device 2 may be reduced.
  • the drive control units 22 and 62 perform the brightness control of the backlight 12 and the gradation control of the liquid crystal panel 11 according to the determination result of the image determination unit 21 for each liquid crystal display device 2. Yes.
  • image determination, luminance control of the backlight 12, and gradation control of the liquid crystal panel 11 may be performed for each display area in the display screen.
  • a plurality of light sources are provided in the backlight 12, and the control devices 4 and 61 may generate a backlight adjustment signal and a video level adjustment signal for each display region. .
  • each of the above embodiments may be applied to a so-called field sequential type liquid crystal display device in which backlights of three colors of RGB are arranged and sequentially lit.
  • the multi-display device according to the present invention can be used for a display device that forms a multi-screen by a plurality of liquid crystal display devices.

Abstract

In a multi-display device, power consumption is reduced while preventing a reduction in the quality of appearance of the multi-screen as a whole. A multi-display device (1) is provided with a plurality of liquid crystal display devices (2) arranged so as to constitute a multi-screen and a drive control section (22) that controls the liquid crystal display devices (2). The liquid crystal display devices (2) have liquid crystal panels (11) in which a plurality of pixels are arranged in a matrix form and backlights (12). The drive control section (22) is constituted such that, in the liquid crystal display devices (2) that have character and graphic display areas that at least display one of characters and graphics among the plurality of liquid crystal display devices (2), either one or both of brightness for the backlights (12) and drive frequency for the liquid crystal panels (11) is reduced.

Description

マルチディスプレイ装置Multi display device
　本発明は、液晶パネルを備えた複数の液晶表示装置を配置することによって、マルチ画面が構成されたマルチディスプレイ装置に関する。 The present invention relates to a multi-display device in which a multi-screen is configured by arranging a plurality of liquid crystal display devices including a liquid crystal panel.
　従来より、液晶パネルを備えた複数の液晶表示装置を配置することによって、マルチ画面が構成されたマルチディスプレイ装置が知られている。このようなマルチディスプレイ装置では、例えば特開２００９－１６９１９６号公報に開示されるように、複数の映像表示部を少なくとも縦方向または横方向に配列することにより、マルチ画面を構成している。また、前記マルチディスプレイ装置は、各映像表示部に映像を表示するための複数の光源を有するバックライトユニットを備えている。 Conventionally, a multi-display device in which a multi-screen is configured by arranging a plurality of liquid crystal display devices including a liquid crystal panel is known. In such a multi-display device, as disclosed in, for example, Japanese Patent Laid-Open No. 2009-169196, a multi-screen is configured by arranging a plurality of video display units at least in the vertical direction or the horizontal direction. In addition, the multi-display device includes a backlight unit having a plurality of light sources for displaying images on each image display unit.
　ところで、前記特開２００９－１６９１９６号公報に開示されているマルチディスプレイ装置の場合、マルチ画面を構成する各映像表示部で電力を消費する。そのため、装置全体として多くの電力を消費する。しかも、このようなマルチディスプレイ装置では、マルチ画面全体の表示品位を維持するために、光源の輝度の確保や液晶パネルの駆動などに或る程度の電力が必要となる。そのため、マルチディスプレイ装置では、表示品位を保ちながら電力消費量を低減することは困難であった。 By the way, in the case of the multi-display device disclosed in Japanese Patent Application Laid-Open No. 2009-169196, power is consumed in each video display unit constituting the multi-screen. For this reason, the entire apparatus consumes a large amount of power. Moreover, in such a multi-display device, in order to maintain the display quality of the entire multi-screen, a certain amount of power is required for securing the luminance of the light source and driving the liquid crystal panel. For this reason, it has been difficult for the multi-display device to reduce power consumption while maintaining display quality.
　本発明の目的は、マルチディスプレイ装置において、マルチ画面全体の表示品位の低下を防止しつつ、消費電力の低減を図ることにある。 An object of the present invention is to reduce power consumption while preventing deterioration in display quality of the entire multi-screen in a multi-display device.
　本発明の一側面にかかるマルチディスプレイ装置は、マルチ画面を構成するように配列された複数の液晶表示装置と、前記液晶表示装置を制御する駆動制御部とを備え、前記液晶表示装置は、複数の画素がマトリクス状に配置された液晶パネルと、バックライトとを有し、前記駆動制御部は、前記複数の液晶表示装置のうち、文字及び図の少なくとも一方を表示する文字図形表示領域を有する液晶表示装置において、前記バックライトの輝度及び前記液晶パネルの駆動周波数の少なくとも一方を低下させるように構成されている。 A multi-display device according to an aspect of the present invention includes a plurality of liquid crystal display devices arranged to form a multi-screen, and a drive control unit that controls the liquid crystal display device. And a backlight, and the drive control unit has a character graphic display region for displaying at least one of characters and figures among the plurality of liquid crystal display devices. The liquid crystal display device is configured to reduce at least one of the luminance of the backlight and the driving frequency of the liquid crystal panel.
　本発明の一実施形態により、マルチディスプレイ装置において、マルチ画面全体の表示品位の低下を防止しつつ、消費電力の低減を図ることができる。 According to an embodiment of the present invention, in a multi-display device, it is possible to reduce power consumption while preventing deterioration of display quality of the entire multi-screen.
図１は、第１の実施形態に係るマルチディスプレイ装置の概略構成を示す図である。FIG. 1 is a diagram illustrating a schematic configuration of a multi-display apparatus according to the first embodiment. 図２は、制御装置と各液晶表示装置との関係を示すブロック図である。FIG. 2 is a block diagram showing the relationship between the control device and each liquid crystal display device. 図３は、ヒストグラム解析部の動作の一例を示すフローである。FIG. 3 is a flowchart showing an example of the operation of the histogram analysis unit. 図４は、文字または図をヒストグラム解析した場合の一例を示す図である。FIG. 4 is a diagram showing an example when a character or figure is subjected to histogram analysis. 図５は、差分解析部の動作の一例を示すフローである。FIG. 5 is a flowchart showing an example of the operation of the difference analysis unit. 図６は、領域判定部の動作の一例を示すフローである。FIG. 6 is a flowchart illustrating an example of the operation of the region determination unit. 図７は、バックライトの輝度に応じて液晶パネルの階調を調整する場合に、入力信号の階調と出力信号の階調との関係の一例を示す図である。FIG. 7 is a diagram illustrating an example of the relationship between the gradation of the input signal and the gradation of the output signal when the gradation of the liquid crystal panel is adjusted according to the luminance of the backlight. 図８は、第２の実施形態に係るマルチディスプレイ装置における制御装置と各液晶表示装置との関係を示すブロック図である。FIG. 8 is a block diagram showing the relationship between the control device and each liquid crystal display device in the multi-display device according to the second embodiment. 図９は、第３の実施形態に係るマルチディスプレイ装置における制御装置と各液晶表示装置との関係を示すブロック図である。FIG. 9 is a block diagram showing the relationship between the control device and each liquid crystal display device in the multi-display device according to the third embodiment.
　本発明の一実施形態に係るマルチディスプレイ装置は、マルチ画面を構成するように配列された複数の液晶表示装置と、前記液晶表示装置を制御する駆動制御部とを備え、前記液晶表示装置は、複数の画素がマトリクス状に配置された液晶パネルと、バックライトとを有し、前記駆動制御部は、前記複数の液晶表示装置のうち、文字及び図の少なくとも一方を表示する文字図形表示領域を有する液晶表示装置において、前記バックライトの輝度及び前記液晶パネルの駆動周波数の少なくとも一方を低下させるように構成されている（第１の構成）。 A multi-display device according to an embodiment of the present invention includes a plurality of liquid crystal display devices arranged to form a multi-screen, and a drive control unit that controls the liquid crystal display device, and the liquid crystal display device includes: A liquid crystal panel in which a plurality of pixels are arranged in a matrix and a backlight, and the drive control unit includes a character graphic display region for displaying at least one of characters and drawings among the plurality of liquid crystal display devices. The liquid crystal display device having the above configuration is configured to reduce at least one of the luminance of the backlight and the driving frequency of the liquid crystal panel (first configuration).
　上記の構成により、マルチ画面を構成する複数の液晶表示装置のうち、文字及び図の少なくとも一方を表示する文字図形表示領域を有する液晶表示装置では、消費電力を低減することができる。しかも、文字及び図の少なくとも一方を表示する液晶表示装置では、画像表示のための階調が少ない。そのため、バックライトの輝度を低下させたり、液晶パネルの駆動周波数を低下させたりしても、マルチ画面全体の表示品位に大きな影響を与えることはない。 With the above-described configuration, power consumption can be reduced in a liquid crystal display device having a character graphic display region for displaying at least one of characters and drawings among a plurality of liquid crystal display devices constituting a multi-screen. Moreover, a liquid crystal display device that displays at least one of characters and drawings has few gradations for image display. Therefore, even if the brightness of the backlight is lowered or the driving frequency of the liquid crystal panel is lowered, the display quality of the entire multi-screen is not greatly affected.
　よって、上述の構成により、マルチ画面全体の表示品位の低下を防止しつつ、消費電力を低減することができるマルチディスプレイ装置を実現することができる。 Therefore, with the above-described configuration, it is possible to realize a multi-display device capable of reducing power consumption while preventing deterioration in display quality of the entire multi-screen.
　ここで、文字とは、漢字、仮名及びアルファベット等の各種言語を表記するために用いられる、表意文字、表記文字及び象形文字等だけでなく、数字、点字、記号及び符号などのような情報伝達のための表記を全て含む。また、図とは、描画された絵、図形及び図表だけでなく、模様及びアイコンなどのように線及び点等の集合によって形を構成しているもの、物の形または状態を描いたもの、及び、コンピュータ等によって描かれたＣＧなども含む。 Here, the characters are not only ideographic characters, written characters and hieroglyphs used to represent various languages such as kanji, kana and alphabet, but also information transmission such as numbers, braille, symbols and symbols. Includes all notations for. Also, a figure is not only a drawn picture, figure, or chart, but also a figure that is composed of a set of lines and dots, such as patterns and icons, a figure that depicts the shape or state of an object, CG drawn by a computer or the like is also included.
　前記第１の構成において、前記駆動制御部は、前記文字図形表示領域を有する液晶表示装置の液晶パネルの各画素に対して入力する映像信号の階調を増大させる階調制御部と、前記文字図形表示領域を有する液晶表示装置のバックライトの輝度を低下させるバックライト輝度調整部とを有する（第２の構成）。 In the first configuration, the drive control unit includes a gradation control unit that increases a gradation of a video signal input to each pixel of a liquid crystal panel of the liquid crystal display device having the character graphic display area, and the character. A backlight luminance adjusting unit for reducing the luminance of the backlight of the liquid crystal display device having the graphic display area (second configuration).
　このように、文字図形表示領域を有する液晶表示装置では、バックライトの輝度を低下させる一方、液晶パネルの各画素に対して入力する映像信号の階調を増大させる。これにより、視認側での明るさの変化を抑制することが可能となる。したがって、マルチ画面全体で表示品位の低下を防止しつつ、バックライトの輝度が低下する分、マルチディスプレイ装置の消費電力を低減できる。 As described above, in the liquid crystal display device having the character graphic display area, the luminance of the video signal input to each pixel of the liquid crystal panel is increased while the luminance of the backlight is lowered. Thereby, it is possible to suppress a change in brightness on the viewing side. Therefore, it is possible to reduce the power consumption of the multi-display device as much as the luminance of the backlight is reduced while preventing the display quality from being lowered in the entire multi-screen.
　特に、前記第２の構成において、前記階調制御部は、前記バックライト輝度調整部によって低下した前記バックライトの輝度に応じて、前記文字図形表示領域を有する液晶表示装置の液晶パネルの各画素に入力する映像信号の階調を増大させるように構成されている（第３の構成）。 In particular, in the second configuration, the gradation control unit is configured such that each pixel of the liquid crystal panel of the liquid crystal display device having the character graphic display region according to the luminance of the backlight lowered by the backlight luminance adjusting unit. Is configured to increase the gradation of the video signal input to the video signal (third configuration).
　バックライトの輝度が低下した分、液晶パネルに表示する画像の階調を増大させることにより、視認側での明るさが大きく変化するのを防止できる。したがって、マルチ画面全体での表示品位の低下をより確実に防止できる。 The brightness on the viewing side can be prevented from changing greatly by increasing the gradation of the image displayed on the liquid crystal panel as much as the brightness of the backlight decreases. Therefore, it is possible to more reliably prevent the display quality from being lowered over the entire multi-screen.
　前記第１から第３の構成のうちいずれか一つの構成において、前記駆動制御部は、文字及び図の少なくとも一方を表示する液晶表示装置の液晶パネルの駆動周波数を低下させる駆動周波数調整部を有する（第４の構成）。 In any one of the first to third configurations, the drive control unit includes a drive frequency adjusting unit that reduces a drive frequency of a liquid crystal panel of a liquid crystal display device that displays at least one of characters and drawings. (Fourth configuration).
　これにより、文字及び図の少なくとも一方を静止画像で表示する液晶表示装置の消費電力を低減できる。しかも、このように、文字及び図の少なくとも一方を表示する画面では、動画と同程度のフレーム数がなくても表示品位にはあまり影響しない。そのため、上述のような構成とした場合でも、マルチディスプレイ装置におけるマルチ画面の表示品位の低下を防止できる。 This makes it possible to reduce the power consumption of a liquid crystal display device that displays at least one of characters and drawings as a still image. Moreover, in this way, on the screen displaying at least one of characters and drawings, the display quality is not significantly affected even if the number of frames is not the same as that of moving images. For this reason, even when the above-described configuration is adopted, it is possible to prevent deterioration in display quality of a multi-screen in the multi-display device.
　前記第１から第４の構成のうちいずれか一つの構成において、前記文字図形表示領域を、前記液晶パネルの各画素に入力される映像信号に基づいて判定する画像判定部をさらに備える（第５の構成）。 In any one of the first to fourth configurations, an image determination unit that determines the character graphic display area based on a video signal input to each pixel of the liquid crystal panel (fifth) Configuration).
　これにより、文字及び図の少なくとも一方を表示する文字図形表示領域を判定することができる。そして、この判定結果をもとに、上述の第１から第４の構成によって、文字図形表示領域を有する液晶表示装置の消費電力を低減することができる。 Thereby, it is possible to determine a character graphic display area for displaying at least one of a character and a figure. Based on the determination result, the power consumption of the liquid crystal display device having the character / graphic display area can be reduced by the first to fourth configurations described above.
　前記第５の構成において、前記画像判定部は、前記液晶パネルの各画素に入力される映像信号のヒストグラムを分析し、その分析結果に基づいて前記文字図形表示領域を判定するように構成されている（第６の構成）。 In the fifth configuration, the image determination unit is configured to analyze a histogram of a video signal input to each pixel of the liquid crystal panel and determine the character graphic display region based on the analysis result. (Sixth configuration).
　こうすることで、文字及び図の少なくとも一方を表示する文字図形表示領域をより確実に判定することができる。すなわち、文字及び図のような特定の階調だけで表現される画像の場合には、それらのヒストグラムを分析することにより、文字及び図の少なくとも一方が表示されていることを検出できる。 In this way, it is possible to more reliably determine a character graphic display area that displays at least one of a character and a figure. That is, in the case of an image expressed only with a specific gradation such as a character and a figure, it is possible to detect that at least one of the character and the figure is displayed by analyzing the histogram.
　したがって、上述の構成によって、文字図形表示領域をより確実に判定できる。これにより、上述の第１から第４の構成によって、文字図形表示領域を有する液晶表示装置の消費電力を低減することができる。 Therefore, the character graphic display area can be more reliably determined by the above-described configuration. Thereby, the power consumption of the liquid crystal display device having the character graphic display area can be reduced by the first to fourth configurations described above.
　前記第５または第６の構成において、前記画像判定部は、前記液晶パネルの各画素に入力される映像信号の表示フレーム間の差分を算出し、該差分に基づいて、静止画像を表示する静止画像表示領域を判定するように構成されていて、前記駆動制御部は、前記文字図形表示領域で且つ前記静止画像表示領域を有する液晶表示装置において、前記バックライトの輝度及び前記液晶パネルの駆動周波数の少なくとも一方を低下させる（第７の構成）。 In the fifth or sixth configuration, the image determination unit calculates a difference between display frames of a video signal input to each pixel of the liquid crystal panel, and displays a still image based on the difference. In the liquid crystal display device that is configured to determine an image display area and has the character graphic display area and the still image display area, the luminance of the backlight and the driving frequency of the liquid crystal panel Is reduced (seventh configuration).
　これにより、静止画像を表示する静止画像表示領域をより確実に判定することができる。すなわち、静止画像は、表示フレーム間の映像信号の差分がほとんどないため、この差分を算出することによって、静止画像を表示しているかどうかをより確実に判定することができる。 This makes it possible to more reliably determine a still image display area for displaying a still image. That is, since the still image has almost no difference in the video signal between the display frames, it is possible to more reliably determine whether or not the still image is displayed by calculating this difference.
　しかも、上述の構成により、文字図形表示領域で且つ静止画像表示領域を有する液晶表示装置の消費電力を低減することができる。 In addition, the power consumption of the liquid crystal display device having the character graphic display area and the still image display area can be reduced by the above-described configuration.
　以下、本発明のマルチディスプレイ装置の好ましい実施形態について、図面を参照しながら説明する。なお、各図中の構成部材の寸法は、実際の構成部材の寸法及び各構成部材の寸法比率等を忠実に表したものではない。 Hereinafter, preferred embodiments of the multi-display device of the present invention will be described with reference to the drawings. In addition, the dimension of the structural member in each figure does not represent the dimension of an actual structural member, the dimension ratio of each structural member, etc. faithfully.
　［第１の実施形態］
　＜全体構成＞
　図１に、本発明の第１の実施形態に係るマルチディスプレイ装置１の概略構成を示す。このマルチディスプレイ装置１は、複数の液晶表示装置２を縦横に配列することによりマルチ画面が構成された表示装置である。本実施形態のマルチディスプレイ装置１は、複数の液晶表示装置２を配置することによって構成されるディスプレイ部３と、該ディスプレイ部３に映像信号及び各種制御信号を入力する制御装置４とを備える。なお、制御装置４から出力される各信号は、ディスプレイ部３を構成する各液晶表示装置２にそれぞれ入力されてもよいし、一つの液晶表示装置２に入力された後、他の液晶表示装置に信号入力されてもよい。 [First Embodiment]
<Overall configuration>
FIG. 1 shows a schematic configuration of a multi-display device 1 according to the first embodiment of the present invention. The multi-display device 1 is a display device in which a multi-screen is configured by arranging a plurality of liquid crystal display devices 2 vertically and horizontally. The multi-display device 1 of the present embodiment includes a display unit 3 configured by arranging a plurality of liquid crystal display devices 2 and a control device 4 that inputs video signals and various control signals to the display unit 3. Each signal output from the control device 4 may be input to each liquid crystal display device 2 constituting the display unit 3 or may be input to one liquid crystal display device 2 and then another liquid crystal display device. A signal may be input to
　マルチディスプレイ装置１は、制御装置４から入力される各信号に基づいて、ディスプレイ部３のマルチ画面上に画像及び文字等を表示するように構成されている。すなわち、マルチディスプレイ装置１は、マルチ画面全体として一つの画像を表示できる一方、液晶表示装置２毎に、異なる情報を表示することもできる。例えば、マルチディスプレイ装置１は、図１における網掛け部分の液晶表示装置２には、文字及び図等の情報を表示しつつ、図１における白部分の液晶表示装置２には、動画等の画像を表示することができる。なお、本実施形態では、マルチディスプレイ装置１の複数の液晶表示装置２を、文字及び図等の情報を表示する液晶表示装置２と、動画等の画像を表示する液晶表示装置２とに分けている。しかしながら、１つの液晶表示装置２内に、文字及び図等の情報を表示する表示領域と動画等の画像を表示する表示領域とが混在していてもよい。 The multi-display device 1 is configured to display images, characters and the like on the multi-screen of the display unit 3 based on each signal input from the control device 4. In other words, the multi-display device 1 can display one image as the entire multi-screen, and can also display different information for each liquid crystal display device 2. For example, the multi-display device 1 displays information such as characters and figures on the shaded liquid crystal display device 2 in FIG. 1, while the white portion liquid crystal display device 2 in FIG. Can be displayed. In the present embodiment, the plurality of liquid crystal display devices 2 of the multi-display device 1 are divided into a liquid crystal display device 2 that displays information such as characters and figures, and a liquid crystal display device 2 that displays images such as moving images. Yes. However, a single liquid crystal display device 2 may include a display area for displaying information such as characters and drawings and a display area for displaying an image such as a moving image.
　ディスプレイ部３の各液晶表示装置２は、図２に示すように、一般的な液晶表示装置と同様、液晶パネル１１と、バックライト１２と、該液晶パネル１１の駆動を制御する液晶パネル制御部１３と、バックライト１２の駆動を制御するバックライト制御部１４と、を有する。 As shown in FIG. 2, each liquid crystal display device 2 of the display unit 3 includes a liquid crystal panel 11, a backlight 12, and a liquid crystal panel control unit that controls driving of the liquid crystal panel 11, as in a general liquid crystal display device. 13 and a backlight control unit 14 that controls driving of the backlight 12.
　液晶パネル１１は、特に図示しないが、多数の画素がマトリクス状に配列されたアクティブマトリクス基板と、該アクティブマトリクス基板に対向して配置される対向基板と、これらの基板の間に形成される液晶層とを備える。なお、この液晶パネル１１は、例えば透過型の液晶パネルであってもよいし、反射型または半反射型の液晶パネルであってもよい。すなわち、液晶パネル１１は、映像を表示可能な構成であれば、どのような構成であってもよい。 Although not particularly shown, the liquid crystal panel 11 is an active matrix substrate in which a large number of pixels are arranged in a matrix, a counter substrate disposed to face the active matrix substrate, and a liquid crystal formed between these substrates. And a layer. The liquid crystal panel 11 may be, for example, a transmissive liquid crystal panel, or a reflective or semi-reflective liquid crystal panel. That is, the liquid crystal panel 11 may have any configuration as long as it can display video.
　前記アクティブマトリクス基板には、特に図示しないが、スイッチング素子としての薄膜トランジスタと、画素電極と、それらを囲むように格子状に配置される複数行のゲート線及び複数列のソース線とが設けられている。 Although not particularly shown, the active matrix substrate includes a thin film transistor as a switching element, a pixel electrode, and a plurality of rows of gate lines and a plurality of columns of source lines arranged in a grid so as to surround them. Yes.
　前記対向基板は、前記アクティブマトリクス基板の少なくとも画素電極と対向する位置に配置されている。この対向基板には、対向電極が設けられている。各画素は、それぞれ、対向電極と、前記アクティブマトリクス基板の画素電極と、両者の間に配置される液晶層とを備える。 The counter substrate is disposed at a position facing at least the pixel electrode of the active matrix substrate. The counter substrate is provided with a counter electrode. Each pixel includes a counter electrode, a pixel electrode of the active matrix substrate, and a liquid crystal layer disposed therebetween.
　前記アクティブマトリクス基板における薄膜トランジスタのゲート電極は、ゲート線を介して液晶パネル制御部１３に接続されている。よって、液晶パネル制御部１３からゲート線に対してゲート電圧を出力すると、該ゲート線に接続された薄膜トランジスタは選択状態になる。なお、液晶パネル制御部１３は、垂直同期信号を参照して、ゲート電圧を出力する。 The gate electrode of the thin film transistor in the active matrix substrate is connected to the liquid crystal panel control unit 13 through a gate line. Therefore, when a gate voltage is output from the liquid crystal panel control unit 13 to the gate line, the thin film transistor connected to the gate line is selected. The liquid crystal panel control unit 13 outputs a gate voltage with reference to the vertical synchronization signal.
　一方、薄膜トランジスタのソース電極は、ソース線を介して、液晶パネル制御部１３に接続されている。この液晶パネル制御部１３は、入力される映像信号に基づいて、映像の階調表示に必要な階調表示信号を生成する。よって、液晶パネル制御部１３からソース線に対して階調表示信号を駆動電圧として出力すると、前記液晶パネル制御部１３によって選択されたゲート線に接続された薄膜トランジスタを介して、各画素の液晶に電圧が印加される。すなわち、液晶パネル制御部１３は、映像信号に基づいて、各ゲート線に駆動電圧を出力することにより、各画素の階調表示を可能にする。 On the other hand, the source electrode of the thin film transistor is connected to the liquid crystal panel control unit 13 via the source line. The liquid crystal panel control unit 13 generates a gradation display signal necessary for gradation display of the video based on the input video signal. Therefore, when a gradation display signal is output as a driving voltage from the liquid crystal panel control unit 13 to the source line, the liquid crystal of each pixel is supplied to the liquid crystal through the thin film transistor connected to the gate line selected by the liquid crystal panel control unit 13. A voltage is applied. That is, the liquid crystal panel control unit 13 enables gradation display of each pixel by outputting a drive voltage to each gate line based on the video signal.
　バックライト１２は、液晶パネル１１の厚み方向の一側に配置されている。バックライト１２としては、例えば、直下型、エッジライト型または平面光源型を用いることができる。また、バックライト１２の光源としては、例えば、冷陰極管または発光ダイオード等を用いることができる。さらに、バックライト１２として、ＲＧＢの三色の光源を用いて白色に点灯するバックライトを用いてもよい。なお、バックライト１２は、以下の実施形態の説明において、常時点灯していてもよいし、一部が消えていてもよい。 The backlight 12 is disposed on one side of the liquid crystal panel 11 in the thickness direction. As the backlight 12, for example, a direct type, an edge light type, or a planar light source type can be used. Moreover, as a light source of the backlight 12, a cold cathode tube, a light emitting diode, etc. can be used, for example. Furthermore, as the backlight 12, a backlight that lights in white using light sources of three colors of RGB may be used. In the following description of the embodiment, the backlight 12 may be constantly turned on or a part thereof may be turned off.
　液晶パネル制御部１３は、入力される信号に基づいて液晶パネル１１の各画素に対して出力する映像信号等を生成し、出力する。すなわち、上述のとおり、液晶パネル制御部１３は、液晶パネル１１に対してゲート電圧を出力するとともに、各画素に対して階調表示信号を出力する。なお、液晶パネル制御部１３には、後述するように階調制御部４２から出力される映像レベル調整信号が入力される。この液晶パネル制御部１３では、入力された映像レベル調整信号に応じた階調表示信号を出力する。 The liquid crystal panel control unit 13 generates and outputs a video signal to be output to each pixel of the liquid crystal panel 11 based on the input signal. That is, as described above, the liquid crystal panel control unit 13 outputs a gate voltage to the liquid crystal panel 11 and outputs a gradation display signal to each pixel. The liquid crystal panel control unit 13 receives a video level adjustment signal output from the gradation control unit 42 as described later. The liquid crystal panel control unit 13 outputs a gradation display signal corresponding to the input video level adjustment signal.
　バックライト制御部１４は、入力されるバックライト調整信号に基づいて、バックライト１２の輝度を制御するように構成されている。 The backlight control unit 14 is configured to control the luminance of the backlight 12 based on the input backlight adjustment signal.
　＜制御装置の構成＞
　制御装置４は、マルチディスプレイ装置１におけるディスプレイ部３のマルチ画面での画像表示を制御するように構成されている。すなわち、制御装置４は、マルチディスプレイ装置１におけるディスプレイ部３のマルチ画面全体で表示する画像を、該ディスプレイ部３を構成する各液晶表示装置２で表示する画像に分割して、該各液晶表示装置２に対して信号出力する。なお、図２は、各液晶表示装置２と制御装置４との関係を示している。また、図２における入力映像信号は、制御装置４内で、各液晶表示装置２用に生成された映像信号である。 <Configuration of control device>
The control device 4 is configured to control image display on the multi-screen of the display unit 3 in the multi-display device 1. That is, the control device 4 divides an image to be displayed on the entire multi-screen of the display unit 3 in the multi-display device 1 into an image to be displayed on each liquid crystal display device 2 constituting the display unit 3, and displays each liquid crystal display. A signal is output to the device 2. FIG. 2 shows the relationship between each liquid crystal display device 2 and the control device 4. Also, the input video signal in FIG. 2 is a video signal generated for each liquid crystal display device 2 in the control device 4.
　また、制御装置４は、液晶表示装置２で表示する画像が、文字または図の静止画像である場合には、バックライト１２の輝度を低下させるとともに、液晶パネル１１の階調を上げるように構成されている。具体的には、図２に示すように、制御装置４は、液晶表示装置２で表示する画像を、入力映像信号に基づいて判定する画像判定部２１と、該画像判定部２１の判定結果に応じてバックライト１２及び液晶パネル１１を制御する駆動制御部２２とを備えている。 In addition, when the image displayed on the liquid crystal display device 2 is a still image of a character or a figure, the control device 4 is configured to reduce the luminance of the backlight 12 and increase the gradation of the liquid crystal panel 11. Has been. Specifically, as illustrated in FIG. 2, the control device 4 determines an image to be displayed on the liquid crystal display device 2 based on an input video signal, and the determination result of the image determination unit 21. Accordingly, a drive control unit 22 that controls the backlight 12 and the liquid crystal panel 11 is provided.
　＜画像判定部の構成＞
　画像判定部２１は、ディスプレイ部３を構成する各液晶表示装置２用に生成された入力映像信号に基づいて、液晶表示装置２で表示する画像が文字または図の静止画像であるかどうかを判定する。この画像判定部２１は、表示する画像のヒストグラム解析を行うとともに、表示フレーム間での入力映像信号の差分を求めることにより、表示画像が文字または図の静止画像であるかどうかを判定する。 <Configuration of image determination unit>
The image determination unit 21 determines whether the image displayed on the liquid crystal display device 2 is a still image of a character or a figure based on the input video signal generated for each liquid crystal display device 2 constituting the display unit 3. To do. The image determination unit 21 determines whether or not the display image is a character or a still image by performing a histogram analysis of the image to be displayed and obtaining a difference between input video signals between display frames.
　ここで、文字とは、漢字、仮名及びアルファベット等の各種言語を表記するために用いられる、表意文字、表記文字及び象形文字等だけでなく、数字、点字、記号及び符号などのような情報伝達のための表記を全て含む。また、図とは、描画された絵、図形及び図表だけでなく、模様及びアイコンなどのように線及び点等の集合によって形を構成しているもの、物の形及び状態を描いたもの、及び、コンピュータ等によって描かれたコンピュータグラフィックス（ＣＧ）なども含む。 Here, the characters are not only ideographic characters, written characters and hieroglyphs used to represent various languages such as kanji, kana and alphabet, but also information transmission such as numbers, braille, symbols and symbols. Includes all notations for. In addition, the figure is not only drawn pictures, figures and charts, but also forms that are composed of sets of lines and dots, such as patterns and icons, those that depict the shape and state of things, Also included are computer graphics (CG) drawn by a computer or the like.
　画像判定部２１は、入力映像信号のヒストグラム解析を行うことによって、表示画像が文字または図であるかどうかを判定するヒストグラム解析部３１と、表示フレーム間での入力映像信号の差分に基づいて、表示画像が静止画像であるかどうかを判定する差分解析部３２とを備える。さらに、画像判定部２１は、ヒストグラム解析部３１及び差分解析部３２の判定結果に応じて、液晶表示装置２がマルチ画面の中で、文字または図の静止画像を表示する静止画像表示領域であるかどうかを判定する領域判定部３３を備える。 The image determination unit 21 performs histogram analysis of the input video signal to determine whether the display image is a character or a figure, and based on the difference of the input video signal between display frames, And a difference analysis unit 32 for determining whether the display image is a still image. Furthermore, the image determination unit 21 is a still image display region in which the liquid crystal display device 2 displays a still image of a character or a figure in a multi-screen according to the determination results of the histogram analysis unit 31 and the difference analysis unit 32. An area determination unit 33 is provided for determining whether or not.
　ヒストグラム解析部３１は、表示フレーム毎に入力映像信号が画像判定部２１に入力されると、図３に示すフローを実行するように構成されている。以下で図３のフローについて説明する。 The histogram analysis unit 31 is configured to execute the flow shown in FIG. 3 when an input video signal is input to the image determination unit 21 for each display frame. The flow of FIG. 3 will be described below.
　図３のフローがスタートすると（スタート）、まず、入力映像信号のヒストグラム解析を行う（ステップＳＡ１）。図４に、入力映像信号をヒストグラム解析した結果の一例を示す。なお、この図４は、文字または図を表示する場合のヒストグラムの一例である。この図４から、文字または図を表示する場合には、特定の階調のみに急峻なピークが存在していることが分かる。 When the flow of FIG. 3 starts (start), first, histogram analysis of the input video signal is performed (step SA1). FIG. 4 shows an example of the result of histogram analysis of the input video signal. FIG. 4 is an example of a histogram when displaying characters or diagrams. From FIG. 4, it can be seen that when a character or a figure is displayed, a steep peak exists only in a specific gradation.
　図３に示すように、入力映像信号をヒストグラム解析（ステップＳＡ１）した後、その解析結果に基づいて、表示する画像の階調が特定の階調のみ大きいかどうか、すなわち、特定の階調でピークを有するかどうかを判定する（ステップＳＡ２）。このピークの判別は、特定の階調が閾値以上の頻度で出現するかどうか、または、特定の階調の出現頻度が前後の階調に比べて高いかどうかによって判別を行うようにすればよい。 As shown in FIG. 3, after the input video signal is subjected to histogram analysis (step SA1), based on the analysis result, whether or not the gradation of the image to be displayed is only a specific gradation, that is, at a specific gradation. It is determined whether or not there is a peak (step SA2). The determination of the peak may be performed based on whether a specific gradation appears with a frequency equal to or higher than a threshold or whether the appearance frequency of a specific gradation is higher than the preceding and subsequent gradations. .
　特定の階調のみ出現頻度が高いと判定された場合（ＹＥＳの場合）には、液晶表示装置２がマルチディスプレイ装置１のマルチ画面の中で文字または図を表示する文字図形表示領域であると判定する信号を出力して（ステップＳＡ３）、このフローを終了する（エンド）。一方、特定の階調に出現頻度のピークが見られないと判定された場合（ＮＯ場合）には、液晶表示装置２はマルチ画面の中で通常映像領域であると判断して、通常の映像表示（通常表示）を行い（ステップＳＡ４）、このフローを終了する（エンド）。 When it is determined that the appearance frequency is high only for a specific gradation (in the case of YES), the liquid crystal display device 2 is a character graphic display area for displaying characters or figures in the multi-screen of the multi-display device 1. A determination signal is output (step SA3), and this flow ends (end). On the other hand, when it is determined that the peak of the appearance frequency is not seen in the specific gradation (in the case of NO), the liquid crystal display device 2 determines that the normal video area is in the multi-screen, and the normal video Display (normal display) is performed (step SA4), and this flow is ended (END).
　なお、ヒストグラム解析部３１では、ヒストグラム解析の結果を用いて判定を行うため、文字または図の静止画像だけでなく、動く文字または動く図を表示する領域も、文字図形表示領域として判別する。 Since the histogram analysis unit 31 performs determination using the result of the histogram analysis, not only a still image of a character or a figure but also an area displaying a moving character or a moving figure is determined as a character graphic display area.
　差分解析部３２は、ヒストグラム解析部３１と同様、表示フレーム毎に入力映像信号が画像判定部２１に入力されると、図５に示すフローを実行するように構成されている。以下で図５のフローについて説明する。 Similar to the histogram analysis unit 31, the difference analysis unit 32 is configured to execute the flow shown in FIG. 5 when an input video signal is input to the image determination unit 21 for each display frame. The flow of FIG. 5 will be described below.
　図５のフローがスタートすると（スタート）、まず表示フレーム間での入力映像信号の差分を算出する（ステップＳＢ１）。このとき、入力映像信号の差分は、画素毎に算出してもよいし、複数の画素からなるブロック毎に算出してもよい。そして、その差分が規定値以下となる画素等の数が、表示画像が静止画像であると判断される基準以上であるかどうかを判定する（ステップＳＢ２）。なお、規定値は、表示フレーム間での入力映像信号の差分が、静止画像の場合の入力映像信号の差分であると判断されるような値に設定される。 When the flow of FIG. 5 starts (start), first, a difference between input video signals between display frames is calculated (step SB1). At this time, the difference between the input video signals may be calculated for each pixel or may be calculated for each block including a plurality of pixels. Then, it is determined whether or not the number of pixels or the like whose difference is equal to or less than a specified value is equal to or greater than a reference for determining that the display image is a still image (step SB2). The specified value is set to a value that determines that the difference of the input video signal between the display frames is the difference of the input video signal in the case of a still image.
　差分が規定値以下の画素等の数が基準以上であると判定された場合（ＹＥＳの場合）には、液晶表示装置２がマルチディスプレイ装置１のマルチ画面の中で静止画像を表示する静止画像表示領域であると判定する信号を出力して（ステップＳＢ３）、このフローを終了する（エンド）。一方、差分が規定値以下の画素等の数が基準以上ではないと判定された場合（ＮＯの場合）には、液晶表示装置２がマルチ画面の中で動画表示領域であると判断して、通常の映像表示（通常表示）を行い（ステップＳＢ４）、このフローを終了する（エンド）。 When it is determined that the number of pixels having a difference equal to or less than a specified value is equal to or greater than the reference (in the case of YES), the liquid crystal display device 2 displays a still image in the multi-screen of the multi-display device 1 A signal for determining that it is the display area is output (step SB3), and this flow is ended (END). On the other hand, when it is determined that the number of pixels or the like whose difference is less than or equal to the predetermined value is not the reference or more (in the case of NO), it is determined that the liquid crystal display device 2 is the moving image display area in the multi-screen, Normal video display (normal display) is performed (step SB4), and this flow ends (END).
　なお、差分解析部３２は、表示フレーム毎の入力映像信号の差分を求める。そのため、差分解析部３２は、文字及び図だけでなく、写真及び風景画像などの静止画像も静止画像表示領域として判別する。 The difference analysis unit 32 obtains a difference between input video signals for each display frame. Therefore, the difference analysis unit 32 determines not only characters and drawings but also still images such as photographs and landscape images as still image display areas.
　領域判定部３３は、ヒストグラム解析部３１及び差分解析部３２と同様、表示フレーム毎に入力映像信号が画像判定部２１に入力されると、図６に示すフローを実行するように構成されている。以下で図６のフローについて説明する。 Similar to the histogram analysis unit 31 and the difference analysis unit 32, the region determination unit 33 is configured to execute the flow illustrated in FIG. 6 when an input video signal is input to the image determination unit 21 for each display frame. . The flow of FIG. 6 will be described below.
　図６のフローがスタートすると（スタート）、ヒストグラム解析部３１から文字図形表示領域の判定信号が、差分解析部３２から静止画像表示領域の判定信号が、それぞれ出力されたかどうかを判定する（ステップＳＣ１）。すなわち、液晶表示装置２が、マルチ画面の中で文字図形表示領域であり且つ静止画像表示領域であるかどうかを判定する。 When the flow of FIG. 6 is started (start), it is determined whether the determination signal for the character / graphic display region is output from the histogram analysis unit 31 and the determination signal for the still image display region is output from the difference analysis unit 32 (step SC1). ). That is, the liquid crystal display device 2 determines whether it is a character graphic display area and a still image display area in the multi-screen.
　液晶表示装置２が文字図形表示領域であり且つ静止画像表示領域である場合（ＹＥＳの場合）には、駆動制御部２２によって、後述する省電力表示を行い（ステップＳＣ２）、このフローを終了する（エンド）。一方、液晶表示装置２が文字図形表示領域ではない若しくは静止画像表示領域ではない場合（ＮＯの場合）には、通常の映像表示（通常表示）を行い（ステップＳＣ３）、このフローを終了する（エンド）。 When the liquid crystal display device 2 is a character graphic display region and a still image display region (in the case of YES), the drive control unit 22 performs power saving display described later (step SC2) and ends this flow. (End). On the other hand, when the liquid crystal display device 2 is not a character graphic display area or a still image display area (in the case of NO), normal video display (normal display) is performed (step SC3), and this flow is terminated (step SC3). End).
　上述のような判定により、画像判定部２１によって、液晶表示装置２がマルチディスプレイ装置１のマルチ画面の中で静止画像表示領域且つ文字図形表示領域であるかどうかを判定することができる。なお、この実施形態では、画像判定部２１によって、液晶表示装置２が静止画像表示領域且つ文字図形表示領域であるかどうかを判定しているが、この限りではなく、文字図形表示領域であることのみを判定してもよい。すなわち、画像判定部２１は、ヒストグラム解析部３１のみを備える構成であってもよい。 By the above determination, the image determination unit 21 can determine whether the liquid crystal display device 2 is a still image display region and a character graphic display region in the multi-screen of the multi-display device 1. In this embodiment, the image determination unit 21 determines whether or not the liquid crystal display device 2 is a still image display area and a character / graphic display area. You may determine only. That is, the image determination unit 21 may include only the histogram analysis unit 31.
　＜駆動制御部の構成＞
　次に、駆動制御部２２について説明する。駆動制御部２２は、画像判定部２１において、液晶表示装置２で表示する画像が文字または図の静止画像であると判定された場合に、通常表示の場合よりもバックライト１２の輝度を低下させるとともに、液晶パネル１１の階調を上げるように、信号を出力する。駆動制御部２２は、バックライト１２の輝度を低下させる分、液晶表示装置２の電力消費量を低下させる省電力表示を行う。 <Configuration of drive control unit>
Next, the drive control unit 22 will be described. When the image determination unit 21 determines that the image displayed on the liquid crystal display device 2 is a character or figure still image, the drive control unit 22 reduces the luminance of the backlight 12 as compared with the normal display. At the same time, a signal is output so as to increase the gradation of the liquid crystal panel 11. The drive control unit 22 performs power-saving display that reduces the power consumption of the liquid crystal display device 2 by the amount that the luminance of the backlight 12 is reduced.
　駆動制御部２２は、上述のようなバックライト１２の輝度制御及び液晶パネル１１の階調制御を行うために、図２に示すように、バックライト１２の輝度を制御するバックライト輝度調整部４１と、液晶パネル１１の画像の階調を制御する階調制御部４２とを備える。 As shown in FIG. 2, the drive control unit 22 controls the luminance of the backlight 12, and performs the luminance control of the backlight 12 and the gradation control of the liquid crystal panel 11 as described above. And a gradation control unit 42 for controlling the gradation of the image on the liquid crystal panel 11.
　バックライト輝度調整部４１は、上述の画像判定部２１によって、液晶表示装置２が、マルチ画面の中で静止画像表示領域且つ文字図形表示領域であると判定された場合に、通常表示の場合よりもバックライト１２の輝度を低下させるように構成されている。詳しくは、バックライト輝度調整部４１は、液晶表示装置２のバックライト制御部１４に対して、バックライト１２の輝度を低下させるバックライト調整信号を出力する。 The backlight brightness adjustment unit 41 is more effective than the normal display when the image determination unit 21 determines that the liquid crystal display device 2 is a still image display region and a character / graphic display region in the multi-screen. Is also configured to reduce the luminance of the backlight 12. Specifically, the backlight luminance adjustment unit 41 outputs a backlight adjustment signal for reducing the luminance of the backlight 12 to the backlight control unit 14 of the liquid crystal display device 2.
　階調制御部４２は、バックライト輝度調整部４１からバックライト調整信号が出力された場合に、該バックライト調整信号に応じて、液晶パネル１１で表示される画像の階調を調整する映像レベル調整信号を出力するように構成されている。すなわち、階調制御部４２は、液晶表示装置２の表示画面に表示される画像の輝度があまり変わらないように、バックライト１２の輝度が低下した分、液晶パネル１１の階調を大きくする。これにより、バックライト１２の輝度を低下させた場合でも、液晶表示装置２の表示品位の低下を防止することができる。 When the backlight adjustment signal is output from the backlight luminance adjustment unit 41, the gradation control unit 42 adjusts the gradation of the image displayed on the liquid crystal panel 11 in accordance with the backlight adjustment signal. An adjustment signal is output. In other words, the gradation control unit 42 increases the gradation of the liquid crystal panel 11 as much as the luminance of the backlight 12 is reduced so that the luminance of the image displayed on the display screen of the liquid crystal display device 2 does not change much. Thereby, even when the luminance of the backlight 12 is lowered, it is possible to prevent the display quality of the liquid crystal display device 2 from being lowered.
　以下で、階調制御部４２において映像レベル調整信号を求める方法について図７を用いて簡単に説明する。 Hereinafter, a method of obtaining the video level adjustment signal in the gradation control unit 42 will be briefly described with reference to FIG.
　図７の一番上に示す図のように、駆動制御部２２に入力される映像信号（入力信号）の階調と、該駆動制御部２２から出力される映像信号（出力信号）の階調とは比例している。しかしながら、液晶表示装置２の画面に表示される映像の輝度は、図７の中央の図に実線で示すように、入力信号の階調に対して曲線を描くように変化する。そして、階調制御部４２は、上述のとおり、バックライト輝度調整部４１からバックライト１２の輝度を低下させるバックライト調整信号が出力されると、その輝度低下分だけ、液晶表示装置２の画面の輝度を増大させるように階調制御を行う。すなわち、階調制御部４２は、入力信号の階調に対して、液晶表示装置２の画面に表示される映像の輝度が図７の中央の図における太破線で示すとおり増大するように、階調変換を行う。実際には、階調制御部４２は、入力信号の階調と出力信号の階調とが図７の一番下の図に示すような関係になるように、階調変換を行う。 As shown at the top of FIG. 7, the gradation of the video signal (input signal) input to the drive control unit 22 and the gradation of the video signal (output signal) output from the drive control unit 22 Is proportional. However, the luminance of the image displayed on the screen of the liquid crystal display device 2 changes so as to draw a curve with respect to the gradation of the input signal, as indicated by the solid line in the center diagram of FIG. Then, as described above, when the backlight adjustment signal for reducing the luminance of the backlight 12 is output from the backlight luminance adjustment unit 41, the gradation control unit 42 displays the screen of the liquid crystal display device 2 corresponding to the luminance reduction. Gradation control is performed so as to increase the brightness. That is, the gradation control unit 42 adjusts the gradation so that the luminance of the image displayed on the screen of the liquid crystal display device 2 increases with respect to the gradation of the input signal as indicated by the thick broken line in the center diagram of FIG. Perform key conversion. Actually, the gradation control unit 42 performs gradation conversion so that the gradation of the input signal and the gradation of the output signal have a relationship as shown in the bottom diagram of FIG.
　なお、図７は、一例として、バックライト１２の輝度を８０％に低下させたときに、階調制御部４２で映像レベル調整信号を求める場合を示している。そのため、図７の中央の図では、液晶表示装置２の画面に表示される映像の輝度が１２５％上昇するように、入力信号の階調に対して出力信号の階調を増大させている。 FIG. 7 shows, as an example, a case where the gradation control unit 42 obtains a video level adjustment signal when the luminance of the backlight 12 is reduced to 80%. Therefore, in the center diagram of FIG. 7, the gradation of the output signal is increased with respect to the gradation of the input signal so that the luminance of the video displayed on the screen of the liquid crystal display device 2 is increased by 125%.
　（第１の実施形態の効果）
　この実施形態では、複数の液晶表示装置２が配置されたマルチディスプレイ装置１において、静止画像表示領域且つ文字図形表示領域である液晶表示装置２のバックライト１２の輝度を通常表示の場合よりも低下させる一方、その分、液晶パネル１１の階調を大きくする。このように、液晶表示装置２が文字または図の静止画像を表示している場合には、動画等の画像を表示する場合に比べて少ない階調しか使わない。そのため、液晶パネル１１で表示する画像の階調を入力映像信号の階調から変更しても、液晶表示装置２の表示品位には大きな影響を与えない。よって、液晶表示装置２の表示画像の輝度が大きく変化しないように、バックライト１２の輝度を低下させた分、液晶パネル１１の表示画像の階調を大きくすることで、マルチ画面全体の表示品位の低下を防止できる。 (Effects of the first embodiment)
In this embodiment, in the multi-display device 1 in which a plurality of liquid crystal display devices 2 are arranged, the luminance of the backlight 12 of the liquid crystal display device 2 that is a still image display region and a character graphic display region is lower than that in the normal display. On the other hand, the gradation of the liquid crystal panel 11 is increased accordingly. As described above, when the liquid crystal display device 2 displays still images of characters or figures, fewer gradations are used than when displaying images such as moving images. Therefore, even if the gradation of the image displayed on the liquid crystal panel 11 is changed from the gradation of the input video signal, the display quality of the liquid crystal display device 2 is not greatly affected. Therefore, the display quality of the entire multi-screen is increased by increasing the gradation of the display image on the liquid crystal panel 11 by reducing the brightness of the backlight 12 so that the brightness of the display image on the liquid crystal display device 2 does not change significantly. Can be prevented.
　したがって、上述の構成により、マルチディスプレイ装置１におけるマルチ画面の表示品位の低下を防止しつつ、バックライト１２の輝度を低下させる分、マルチディスプレイ装置１の消費電力を低減することができる。 Therefore, with the above-described configuration, the power consumption of the multi-display device 1 can be reduced by reducing the luminance of the backlight 12 while preventing the display quality of the multi-screen device 1 from being lowered.
　また、ヒストグラム解析部３１によってヒストグラム解析の結果から文字または図を表示しているかどうかを判定するとともに、差分解析部３２によって入力映像信号の差分から静止画像を表示しているかどうかを判定する。これにより、マルチ画面の中で文字図形表示領域及び静止画像表示領域を容易に且つより確実に判定することができる。 Further, the histogram analysis unit 31 determines whether a character or a figure is displayed from the result of the histogram analysis, and the difference analysis unit 32 determines whether a still image is displayed from the difference of the input video signal. Thereby, the character graphic display area and the still image display area can be easily and more reliably determined in the multi-screen.
　［第２の実施形態］
　図８に、本発明の第２の実施形態に係るマルチディスプレイ装置における制御装置５１及び液晶表示装置２の概略構成を示す。この制御装置５１は、液晶表示装置２の液晶パネル１１の駆動周波数を調整可能に構成されている点で、上述の第１の実施形態とは構成が異なる。以下の説明において、第１の実施形態と同一の構成には同一の符号を付して、構成が異なる点についてのみ以下で説明する。 [Second Embodiment]
FIG. 8 shows a schematic configuration of the control device 51 and the liquid crystal display device 2 in the multi-display device according to the second embodiment of the present invention. The control device 51 is different in configuration from the above-described first embodiment in that the control device 51 is configured to be able to adjust the drive frequency of the liquid crystal panel 11 of the liquid crystal display device 2. In the following description, the same components as those in the first embodiment will be denoted by the same reference numerals, and only the differences will be described below.
　具体的には、図８に示すように、画像判定部２１の画像判定結果に応じて液晶パネル１１の駆動を制御する駆動制御部５２は、駆動周波数調整部５３を有している。この駆動周波数調整部５３は、画像判定部２１によって、液晶表示装置２が、マルチディスプレイ装置のマルチ画面の静止画像表示領域且つ文字図形表示領域であると判定された場合に、通常表示の場合よりも液晶パネル１１の駆動周波数を低下させる駆動周波数調整信号を出力するように構成されている。例えば、駆動周波数調整部５３は、通常表示時の駆動周波数（一例として６０Ｈｚ）を、１５Ｈｚに変更する。すなわち、駆動制御部５２は、液晶パネル１１の駆動周波数を低下させる分、電力消費量を低下させる省電力表示を行う。 Specifically, as shown in FIG. 8, the drive control unit 52 that controls the driving of the liquid crystal panel 11 according to the image determination result of the image determination unit 21 includes a drive frequency adjustment unit 53. The drive frequency adjusting unit 53 is more effective than the normal display when the image determining unit 21 determines that the liquid crystal display device 2 is a multi-screen still image display region and a character graphic display region of the multi-display device. Is also configured to output a drive frequency adjustment signal for lowering the drive frequency of the liquid crystal panel 11. For example, the drive frequency adjusting unit 53 changes the drive frequency (60 Hz as an example) during normal display to 15 Hz. That is, the drive control unit 52 performs power saving display for reducing the power consumption by the amount that the drive frequency of the liquid crystal panel 11 is reduced.
　これにより、マルチディスプレイ装置のマルチ画面において静止画像表示領域且つ文字図形表示領域である液晶表示装置２では、駆動周波数を低下させる分、消費電力を低減することができる。マルチ画面の静止画像表示領域且つ文字図形表示領域では、動画のように頻繁に映像を書き換えなくても、表示品位を大幅に低下させることがない。よって、上述の構成により、表示品位を低下させることなく、マルチディスプレイ装置の消費電力の低減を図れる。 Thereby, in the liquid crystal display device 2 which is a still image display area and a character graphic display area in the multi-screen of the multi-display apparatus, the power consumption can be reduced by reducing the drive frequency. In the multi-screen still image display area and the character graphic display area, the display quality is not significantly lowered even if the video is not frequently rewritten unlike a moving image. Therefore, with the above-described configuration, it is possible to reduce the power consumption of the multi-display device without reducing the display quality.
　なお、上述のように液晶パネル１１の駆動周波数を低下させる場合には、液晶パネル１１の駆動周波数を、各画素の電荷の変動に伴う表示階調の変化を視認者がフリッカとして感じない程度の駆動周波数に設定するのが好ましい。 When the driving frequency of the liquid crystal panel 11 is lowered as described above, the driving frequency of the liquid crystal panel 11 is set so that the viewer does not feel the flickering of the change in display gradation due to the fluctuation of the charge of each pixel. It is preferable to set the driving frequency.
　（第２の実施形態の効果）
　この実施形態では、制御装置５１は、マルチディスプレイ装置のマルチ画面において静止画像表示領域且つ文字図形表示領域であると判定された液晶表示装置に対し、液晶パネル１１の駆動周波数を通常表示時よりも低下させる。これにより、マルチディスプレイ装置の表示品位の低下を防止しつつ、該マルチディスプレイ装置の消費電力の低減を図ることができる。 (Effect of 2nd Embodiment)
In this embodiment, the control device 51 sets the drive frequency of the liquid crystal panel 11 to a liquid crystal display device determined to be a still image display region and a character graphic display region on a multi-screen of the multi-display device, compared with a normal display time. Reduce. Thereby, the power consumption of the multi-display device can be reduced while preventing the display quality of the multi-display device from deteriorating.
　［第３の実施形態］
　図９に、第３の実施形態に係るマルチディスプレイ装置における制御装置６１及び液晶表示装置２の概略構成を示す。この制御装置６１は、バックライト１２の輝度低下及び液晶パネル１１の階調制御を行いつつ、該液晶パネル１１の駆動周波数を調整可能に構成されている点で、上述の第１の実施形態とは構成が異なる。以下の説明において、第１の実施形態と同一の構成には同一の符号を付して、構成が異なる点についてのみ以下で説明する。 [Third Embodiment]
FIG. 9 shows a schematic configuration of the control device 61 and the liquid crystal display device 2 in the multi-display device according to the third embodiment. The control device 61 is configured to be capable of adjusting the driving frequency of the liquid crystal panel 11 while performing the luminance reduction of the backlight 12 and the gradation control of the liquid crystal panel 11, and is different from the first embodiment described above. The configuration is different. In the following description, the same components as those in the first embodiment will be denoted by the same reference numerals, and only the differences will be described below.
　具体的には、制御装置６１は、図９に示すように、第１の実施形態の構成と第２の実施形態の構成とを両方、備える。すなわち、画像判定部２１による判定結果に基づいて液晶パネル１１及びバックライト１２を制御する駆動制御部６２は、第１の実施形態と同様のバックライト輝度調整部４１及び階調制御部４２と、第２の実施形態と同様の駆動周波数調整部５３とを備える。 Specifically, as shown in FIG. 9, the control device 61 includes both the configuration of the first embodiment and the configuration of the second embodiment. That is, the drive control unit 62 that controls the liquid crystal panel 11 and the backlight 12 based on the determination result by the image determination unit 21 includes the backlight luminance adjustment unit 41 and the gradation control unit 42 similar to those in the first embodiment, A drive frequency adjustment unit 53 similar to that of the second embodiment is provided.
　バックライト輝度調整部４１は、上述の第１の実施形態と同様、画像判定部２１によって静止画像表示領域且つ文字図形表示領域であると判定された液晶表示装置２に対し、通常表示の場合よりもバックライト１２の輝度を低下させるバックライト調整信号を出力する。 Similar to the first embodiment, the backlight luminance adjustment unit 41 is used for the liquid crystal display device 2 determined by the image determination unit 21 to be a still image display region and a character graphic display region, as compared with the case of normal display. Also outputs a backlight adjustment signal for reducing the luminance of the backlight 12.
　階調制御部４２も、上述の第１の実施形態と同様、バックライト輝度調整部４１からバックライト調整信号が出力されると、バックライト１２の輝度低下を補うように液晶パネル１１の表示画像の階調を大きくする映像レベル調整信号を出力する。 Similarly to the first embodiment described above, when the backlight adjustment signal is output from the backlight luminance adjustment unit 41, the gradation control unit 42 also displays the display image on the liquid crystal panel 11 so as to compensate for the luminance decrease of the backlight 12. A video level adjustment signal for increasing the gradation of the image is output.
　駆動周波数調整部５３は、上述の第２の実施形態と同様、画像判定部２１によって静止画像表示領域且つ文字図形表示領域であると判定された液晶表示装置２に対し、液晶パネル１１の駆動周波数を低下させる駆動周波数調整信号を出力する。 Similarly to the second embodiment described above, the drive frequency adjustment unit 53 applies the drive frequency of the liquid crystal panel 11 to the liquid crystal display device 2 determined by the image determination unit 21 as the still image display region and the character graphic display region. A drive frequency adjustment signal for lowering is output.
　これにより、バックライト１２の輝度を低下させるとともに、液晶パネル１１の駆動周波数も低下させることができる。よって、上述の第１及び第２の実施形態の構成に比べて、マルチディスプレイ装置の消費電力をさらに低減することができる。しかも、このようなバックライト１２の輝度低下や液晶パネル１１の駆動周波数低下を行う液晶表示装置２は、マルチディスプレイ装置において静止画像表示領域且つ文字図形表示領域である。よって、上述のようなバックライト１２及び液晶パネル１１の制御を行っても、マルチ画面の表示品位にはあまり大きく影響しない。さらに、上述の第１の実施形態と同様、バックライト１２の輝度低下に応じて液晶パネル１１の階調制御を行うことにより、視認者が大きな輝度変化として感じるのを防止できる。 Thereby, the luminance of the backlight 12 can be lowered and the driving frequency of the liquid crystal panel 11 can also be lowered. Therefore, the power consumption of the multi-display device can be further reduced as compared with the configurations of the first and second embodiments described above. Moreover, the liquid crystal display device 2 that lowers the brightness of the backlight 12 and the drive frequency of the liquid crystal panel 11 is a still image display region and a character graphic display region in the multi-display device. Therefore, even when the backlight 12 and the liquid crystal panel 11 are controlled as described above, the display quality of the multi-screen is not greatly affected. Further, similarly to the first embodiment described above, the gradation control of the liquid crystal panel 11 is performed according to the decrease in the luminance of the backlight 12, so that the viewer can be prevented from feeling as a large luminance change.
　（第３の実施形態の効果）
　この実施形態では、制御装置６１は、マルチディスプレイ装置のマルチ画面において静止画像表示領域且つ文字図形表示領域であると判定された液晶表示装置２に対し、バックライト１２の輝度を低下させるとともに液晶パネル１１の駆動周波数を低下させる。これにより、マルチディスプレイ装置の表示品位を大幅に低下させることなく、該マルチディスプレイ装置の消費電力を、第１及び第２の実施形態の構成よりも低減することができる。しかも、バックライト１２の輝度を低下させた分、表示パネル１１の表示画像の階調を大きくすることにより、視認者が大きな輝度変化として感じないようにすることができる。したがって、マルチディスプレイ装置の表示品位の低下をより確実に防止できる。 (Effect of the third embodiment)
In this embodiment, the control device 61 reduces the luminance of the backlight 12 and the liquid crystal panel for the liquid crystal display device 2 determined to be a still image display region and a character graphic display region on a multi-screen of the multi-display device. 11 drive frequency is reduced. Thereby, the power consumption of the multi-display device can be reduced as compared with the configurations of the first and second embodiments without significantly reducing the display quality of the multi-display device. In addition, by increasing the gradation of the display image on the display panel 11 as much as the luminance of the backlight 12 is reduced, it is possible to prevent the viewer from perceiving a large luminance change. Therefore, it is possible to more reliably prevent the display quality of the multi-display device from deteriorating.
　［その他の実施形態］
　以上、本発明の実施の形態を説明したが、上述した実施の形態は本発明を実施するための例示に過ぎない。よって、本発明は上述した実施の形態に限定されることなく、その趣旨を逸脱しない範囲内で上述した実施の形態を適宜変形して実施することが可能である。 [Other Embodiments]
While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.
　前記各実施形態では、入力映像信号に基づいて、制御装置４，５１，６１内で、静止画像表示領域であるか、及び、文字図形表示領域であるかを、それぞれ判定している。しかしながら、液晶表示装置２内でこれらの判定を行うようにしてもよい。この場合には、画像判定部２１及び駆動制御部２２，５２，６２を、液晶表示装置２内に設ければよい。 In each of the above-described embodiments, whether the image is a still image display area or a character graphic display area is determined in the control devices 4, 51, 61 based on the input video signal. However, these determinations may be made in the liquid crystal display device 2. In this case, the image determination unit 21 and the drive control units 22, 52, 62 may be provided in the liquid crystal display device 2.
　また、画像を表示する領域が静止画像表示領域または文字図形表示領域であることを示す信号を、タグ情報（メタ情報）として、入力映像信号とともに制御装置または液晶表示装置に入力してもよい。この場合には、マルチディスプレイ装置に画像判定部２１を設ける必要がなくなる。 Also, a signal indicating that the image display area is a still image display area or a character graphic display area may be input as tag information (meta information) to the control device or the liquid crystal display device together with the input video signal. In this case, it is not necessary to provide the image determination unit 21 in the multi-display device.
　さらに、ユーザーの設定により、マルチディスプレイ装置の各液晶表示装置２の表示モード（動画表示領域、文字・図の静止画像表示領域等）を設定できるようにしてもよい。これにより、静止画像表示領域且つ文字図形表示領域に設定された液晶表示装置において、前記各実施形態に示す制御を行うことが可能になる。 Furthermore, the display mode (moving image display area, character / figure still image display area, etc.) of each liquid crystal display device 2 of the multi-display device may be set according to user settings. As a result, in the liquid crystal display device set in the still image display area and the character graphic display area, the control shown in each of the above embodiments can be performed.
　前記各実施形態では、制御装置４，５１，６１内で、表示フレーム毎に入力される入力映像信号に基づいて、静止画像表示領域であるか、及び、文字図形表示領域であるかを、それぞれ判定している。しかしながら、この制御装置４，５１，６１内に入力映像信号を記憶しておいて、該制御装置４，５１，６１内で判定が完了した後、マルチディスプレイ装置に信号を出力するようにしてもよい。 In each of the embodiments, in the control devices 4, 51, 61, based on the input video signal input for each display frame, whether it is a still image display area or a character graphic display area, Judgment. However, the input video signal is stored in the control devices 4, 51, 61, and after the determination is completed in the control devices 4, 51, 61, the signal is output to the multi-display device. Good.
　前記各実施形態では、画像判定部２１は、ヒストグラム解析によって文字または図を表示しているかどうかを判別するとともに、入力映像信号の差分によって静止画像を表示しているかどうかを判別している。しかしながら、文字図形表示領域または静止画像表示領域の判別を他の方法によって行ってもよい。 In each of the above embodiments, the image determination unit 21 determines whether a character or a figure is displayed by histogram analysis, and determines whether a still image is displayed based on a difference between input video signals. However, the character / graphic display area or the still image display area may be determined by other methods.
　前記実施形態１，３では、駆動制御部２２，６２が、バックライト１２の輝度低下と液晶パネル１１の階調制御とを行うように構成されている。しかしながら、駆動制御部２２，６２を、バックライト１２の輝度低下のみを行うように構成してもよい。 In the first and third embodiments, the drive control units 22 and 62 are configured to perform luminance reduction of the backlight 12 and gradation control of the liquid crystal panel 11. However, the drive control units 22 and 62 may be configured to only reduce the luminance of the backlight 12.
　前記実施形態２では、文字または図を静止画像で表示すると判定された液晶表示装置２の駆動周波数を低減するようにしているが、この限りではなく、静止画像以外でも文字または図を表示すると判定された液晶表示装置２の駆動周波数を低減してもよい。 In the second embodiment, the driving frequency of the liquid crystal display device 2 determined to display a character or a figure as a still image is reduced. However, the present invention is not limited to this, and it is determined to display a character or a figure other than a still image. The driving frequency of the liquid crystal display device 2 may be reduced.
　前記実施形態１，３では、液晶表示装置２毎に、駆動制御部２２，６２によって、画像判定部２１の判定結果に応じてバックライト１２の輝度制御及び液晶パネル１１の階調制御を行っている。しかしながら、各液晶表示装置２において、表示画面内の表示領域毎に、画像判定、バックライト１２の輝度制御及び液晶パネル１１の階調制御を行ってもよい。この場合には、各液晶表示装置２において、バックライト１２内に複数の光源を設けるとともに、制御装置４，６１が、表示領域毎に、バックライト調整信号及び映像レベル調整信号を生成すればよい。 In the first and third embodiments, the drive control units 22 and 62 perform the brightness control of the backlight 12 and the gradation control of the liquid crystal panel 11 according to the determination result of the image determination unit 21 for each liquid crystal display device 2. Yes. However, in each liquid crystal display device 2, image determination, luminance control of the backlight 12, and gradation control of the liquid crystal panel 11 may be performed for each display area in the display screen. In this case, in each liquid crystal display device 2, a plurality of light sources are provided in the backlight 12, and the control devices 4 and 61 may generate a backlight adjustment signal and a video level adjustment signal for each display region. .
　また、別の実施形態として、上述の各実施形態の構成を、ＲＧＢの３色のバックライトを配置して順に点灯させる、いわゆるフィールドシーケンシャル方式の液晶表示装置に適用してもよい。 As another embodiment, the configuration of each of the above embodiments may be applied to a so-called field sequential type liquid crystal display device in which backlights of three colors of RGB are arranged and sequentially lit.
　本発明によるマルチディスプレイ装置は、複数の液晶表示装置によってマルチ画面を構成する表示装置に利用可能である。 The multi-display device according to the present invention can be used for a display device that forms a multi-screen by a plurality of liquid crystal display devices.

Claims (7)

  1. 　マルチ画面を構成するように配列された複数の液晶表示装置と、
    　前記液晶表示装置を制御する駆動制御部とを備え、
    　前記液晶表示装置は、
    　複数の画素がマトリクス状に配置された液晶パネルと、
    　バックライトとを有し、
    　前記駆動制御部は、前記複数の液晶表示装置のうち、文字及び図の少なくとも一方を表示する文字図形表示領域を有する液晶表示装置において、前記バックライトの輝度及び前記液晶パネルの駆動周波数の少なくとも一方を低下させるように構成されている、マルチディスプレイ装置。     A plurality of liquid crystal display devices arranged to form a multi-screen;
    A drive control unit for controlling the liquid crystal display device,
    The liquid crystal display device
    A liquid crystal panel in which a plurality of pixels are arranged in a matrix;
    Having a backlight,
    In the liquid crystal display device having a character graphic display region for displaying at least one of a character and a figure among the plurality of liquid crystal display devices, the drive control unit is at least one of the luminance of the backlight and the drive frequency of the liquid crystal panel. A multi-display device configured to reduce
  2. 　前記駆動制御部は、
    　　前記文字図形表示領域を有する液晶表示装置の液晶パネルの各画素に対して入力する映像信号の階調を増大させる階調制御部と、
    　　前記文字図形表示領域を有する液晶表示装置のバックライトの輝度を低下させるバックライト輝度調整部とを有する、請求項１に記載のマルチディスプレイ装置。     The drive control unit
    A gradation control unit for increasing the gradation of a video signal input to each pixel of a liquid crystal panel of a liquid crystal display device having the character graphic display area;
    The multi-display device according to claim 1, further comprising: a backlight luminance adjusting unit that reduces a luminance of a backlight of the liquid crystal display device having the character graphic display region.
  3. 　前記階調制御部は、前記バックライト輝度調整部によって低下した前記バックライトの輝度に応じて、前記文字図形表示領域を有する液晶表示装置の液晶パネルの各画素に入力する映像信号の階調を増大させるように構成されている、請求項２に記載のマルチディスプレイ装置。 The gradation control unit adjusts the gradation of the video signal input to each pixel of the liquid crystal panel of the liquid crystal display device having the character graphic display area according to the luminance of the backlight lowered by the backlight luminance adjustment unit. The multi-display device according to claim 2, configured to increase.
  4. 　前記駆動制御部は、
    　　文字及び図の少なくとも一方を表示する液晶表示装置の液晶パネルの駆動周波数を低下させる駆動周波数調整部を有する、請求項１から３のいずれか一つに記載のマルチディスプレイ装置。     The drive control unit
    4. The multi-display device according to claim 1, further comprising a drive frequency adjusting unit that reduces a drive frequency of a liquid crystal panel of a liquid crystal display device that displays at least one of characters and drawings.
  5. 　前記文字図形表示領域を、前記液晶パネルの各画素に入力される映像信号に基づいて判定する画像判定部をさらに備える、請求項１から４のいずれか一つに記載のマルチディスプレイ装置。 The multi-display device according to any one of claims 1 to 4, further comprising an image determination unit that determines the character graphic display area based on a video signal input to each pixel of the liquid crystal panel.
  6. 　前記画像判定部は、前記液晶パネルの各画素に入力される映像信号のヒストグラムを分析し、その分析結果に基づいて前記文字図形表示領域を判定するように構成されている、請求項５に記載のマルチディスプレイ装置。 The said image determination part is comprised so that the histogram of the video signal input into each pixel of the said liquid crystal panel may be analyzed, and the said character figure display area may be determined based on the analysis result. Multi-display device.
  7. 　前記画像判定部は、前記液晶パネルの各画素に入力される映像信号の表示フレーム間の差分を算出し、該差分に基づいて、静止画像を表示する静止画像表示領域を判定するように構成されていて、
    　前記駆動制御部は、前記文字図形表示領域で且つ前記静止画像表示領域を有する液晶表示装置において、前記バックライトの輝度及び前記液晶パネルの駆動周波数の少なくとも一方を低下させる、請求項５または６に記載のマルチディスプレイ装置。     The image determination unit is configured to calculate a difference between display frames of a video signal input to each pixel of the liquid crystal panel and determine a still image display area for displaying a still image based on the difference. And
    The liquid crystal display device having the character graphic display area and the still image display area, wherein the drive control unit reduces at least one of the luminance of the backlight and the drive frequency of the liquid crystal panel. The multi-display device as described.
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