JP5029115B2 - Display device, display device driving method, and electronic apparatus - Google Patents

Description

  The present invention relates to a technique for displaying an image by a frame sequential method (field sequential method).

In a surface sequential display device that allows a viewer to perceive a color image by sequentially displaying each single color image of a plurality of primary color components (for example, red, green, and blue) in a time-sharing manner, a color mixture of the plurality of primary color components The phenomenon that each primary color component is separated and perceived at the edge of the image represented by (hereinafter referred to as “color breakup”) becomes a problem. Patent Document 1 discloses a technique for reducing color breakup by sequentially displaying single-color images of different colors in each of three areas obtained by dividing a display area by a predetermined number of rows.
Japanese Patent Laying-Open No. 2005-316092

  However, in the technique of Patent Document 1, the display of the other areas is stopped during the period in which the monochromatic image is displayed in one area (the period in which the monochromatic image is displayed in each area does not overlap). There is a problem that it is difficult to ensure the brightness of the image. In view of the above circumstances, an object of the present invention is to solve the problem of suppressing a decrease in brightness of an image when an image is displayed in each area within the display area by a frame sequential method.

  In order to solve the above problems, a display device according to the present invention includes a first unit display area (for example, one unit display area A in the group C1 in FIG. 2) and a second unit display area (for example, the group C2 in FIG. 2). A plurality of subfields in one frame so that the first unit display area and the second unit display area have different colors in the display means including one unit display area A) And a controller that sequentially displays each single color image of a plurality of colors in the first unit display area and the second unit display area. According to the above configuration, since the single color images of different colors are displayed in parallel in the first unit display area and the second unit display area, compared with the configuration in which the single color images are sequentially displayed in each display area. Therefore, the brightness of the image can be easily secured. The display means includes, for example, a liquid crystal device in which an OCB mode liquid crystal is sealed in a gap between the first substrate and the second substrate. The display device of the present invention is used for various electronic devices.

A display device according to a preferred aspect of the present invention generates a separated image signal that specifies gradations for a white component and a plurality of color components from an input image signal that specifies gradations of a plurality of primary color components for each pixel. The image processing means is provided, and the control means causes the display means to display each single color image of the white component and a plurality of color components (primary color component or a mixed color component of the plurality of primary color components) based on the separated image signal. According to the above aspect, in addition to the occurrence of color breakup in a monochromatic image of a white component, since the gradation of the color component that causes color breakup is reduced by extracting the white component, color breakup is effective. It is possible to suppress it.
In the first aspect (for example, the second embodiment) of the display device including the image processing means, the control means has different colors for the plurality of color components in the first unit display area and the second unit display area. A monochrome image is displayed in each subfield based on the separated image signal, while a white monochrome image is displayed in parallel in the same subfield in the first unit display area and the second unit display area based on the separated image signal. To display. In the second mode (for example, the third embodiment), the control unit converts each single color image of a plurality of colors including a white component and a plurality of color components into a single color image of the first unit display area and the second unit display area. Is displayed in each sub-field based on the separated image signal so that the colors become different colors.
A mode in which a plurality of white components are extracted from the display color of the pixel is also suitable. If a single color image of each of a plurality of white components is displayed in each subfield separated from each other on the time axis, the monochrome image of the white component is compared with a configuration in which the white component is displayed in only one subfield. Gradation (luminance) is suppressed. Therefore, it is possible to reduce flicker due to the display of the monochromatic image of the white component.
Further, in a specific aspect of the present invention, the display means displays the monochrome image of at least one white component among the plurality of white components in a subfield having a longer time than the subfield displaying the monochrome image of each color component. indicate. According to the above aspect, since a sufficient period for displaying the monochrome image of the color component and the white component is ensured, flicker can be effectively suppressed.
In a further preferred aspect, the display means displays a black image (that is, stops display) in a predetermined period within one frame. According to this aspect, color breakup is suppressed by shortening the period for displaying the single color image of the color component, and moving picture blurring is achieved by shortening the period for displaying the single color image of the color component and the white component. There is an advantage that it is suppressed. In a further preferred aspect, the period for stopping the display is set at the end of the frame.
In another aspect, the image processing means generates a separated image signal by including two color mixture components of the plurality of primary color components in the plurality of color components. According to the above aspect, color breakup can be made difficult to be perceived as compared with a configuration in which single-color images of primary color components are continuously displayed. In a further preferred aspect, the subfield that displays the monochromatic image of the mixed color component is interposed between the subfields that display the monochromatic image of the primary color component.

  In a preferred aspect of the present invention, the display means has a rectangular shape in which a plurality of unit display areas including a first unit display area and a second unit display area are arranged in a first direction and a second direction intersecting each other. The size of each unit display area along at least one of the first direction and the second direction is an isosceles triangle whose apex angle is 10 ° and whose height is six times the short side of the display area. Below the bottom dimension. In a further preferred aspect, the dimension along at least one of the first direction and the second direction in each unit display area is the base of an isosceles triangle whose apex angle is 10 ° and whose height is three times the short side of the display area. Or less than According to the above aspect, it is possible to suppress the occurrence of color breakup due to the movement of the viewpoint within one unit display area.

  The present invention is also specified as a method of driving a display device. A driving method according to the present invention is a method for driving a display device including a first unit display area and a second unit display area, and a monochromatic image in each subfield includes a first unit display area and a second unit display area. The multi-color single-color images are sequentially displayed in parallel in the first unit display area and the second unit display area in each of the plurality of subfields in one frame so that they become different colors. The same effect as the display device of the present invention can be obtained by the above driving method.

<A: First Embodiment>
FIG. 1 is a block diagram showing a configuration of a display device according to the first embodiment of the present invention. As shown in the figure, the display device 100 includes a lighting device 10, a liquid crystal device 20, and a control device 50. In FIG. 1, the illumination device 10 and the liquid crystal device 20 are illustrated apart from each other for convenience, but the illumination device 10 and the liquid crystal device 20 are actually close to each other.

  The liquid crystal device 20 includes a first substrate 21 and a second substrate 22 that face each other. Liquid crystal (not shown) is sealed in the gap between the first substrate 21 and the second substrate 22. A liquid crystal that responds at high speed such as an OCB (Optically Compensated Bend) mode is preferably used. A plurality of pixel electrodes 24 corresponding to each pixel of the image are arranged on the surface of the second substrate 22 facing the liquid crystal. The orientation of the liquid crystal sandwiched between the first substrate 21 and the second substrate 22 changes according to the potential difference between each pixel electrode 24 and the counter electrode (not shown) on the surface of the first substrate 21. Therefore, the ratio (transmittance) of the amount of light transmitted to the observation side in the irradiation light from the illumination device 10 is controlled for each pixel electrode 24.

  As shown in FIG. 1, a rectangular display area (area in which the pixel electrodes 24 are arranged) 25 in which an image is actually displayed in the liquid crystal device 20 is in a matrix form along the X direction and the Y direction intersecting each other. Are divided into a plurality of areas (hereinafter referred to as “unit display areas”) A. Each unit display area A is a rectangular area having a common size. In each unit display area A, a plurality of pixel electrodes 24 are arranged in a matrix along the X direction and the Y direction.

  FIG. 2 is a conceptual diagram illustrating a case where the display area 25 is divided into 25 unit display areas A of 5 rows × 5 columns in the X and Y directions. As shown in FIG. 2, the plurality of unit display areas A constituting the display area 25 are divided into three groups C (C1 to C3). Each group C includes a plurality of unit display areas A. The unit display areas A belonging to the same group C are not adjacent to each other in the X direction and the Y direction.

  The illumination device 10 in FIG. 1 is disposed on the back side of the liquid crystal device 20 to illuminate the liquid crystal device 20. The illumination device 10 includes a plurality of illumination units B each corresponding to a separate unit display area A. As shown in FIG. 1, each illumination unit B and the unit display region A corresponding to the illumination unit B overlap when viewed from the direction perpendicular to the display region 25 (XY plane). Therefore, the plurality of illumination units B are arranged in a matrix along the X direction and the Y direction.

  Each illumination section B has three light emitters 12 (12R, 12G, 12B) each corresponding to a different primary color component, and the light emitted from each light emitter 12 to the liquid crystal device 20 side (unit display area A). And a light guide 14 for guiding. The light emitter 12R outputs light having a wavelength corresponding to red (red light). Similarly, the light emitter 12G emits green light, and the light emitter 12B emits blue light. In practice, a reflecting plate or a scattering plate is attached to the light guide 14, but is omitted in FIG. 1 for convenience.

  The illumination device 10 and the liquid crystal device 20 cooperate to display a color image. FIG. 3 is a timing chart for explaining operations of the illumination device 10 and the liquid crystal device 20. A frame F illustrated in FIG. 3 is a period used for displaying one color image. The liquid crystal device 20 displays an image with a frame frequency of 120 Hz (double speed display). Therefore, the time length of the frame F is 1/120 seconds.

  As shown in FIG. 3, the frame F is divided into three subfields SF (SF1 to SF3). The illuminating device 10 and the liquid crystal device 20 display a plurality of single-color images each corresponding to a separate primary color component in parallel in a plurality of unit display areas A in each subfield SF (frame sequential method). The viewer perceives a color image in which each color is mixed by sequentially viewing the single-color images displayed for each subfield SF in each unit display area A. Therefore, a colored layer (color filter) is not necessary for the liquid crystal device 20.

  The control device 50 in FIG. 1 is a circuit that controls the lighting device 10 and the liquid crystal device 20. The control device 50 includes an illumination drive circuit 52 that drives the illumination device 10 and a liquid crystal drive circuit 54 that drives the liquid crystal device 20. Note that the control device 50 may be mounted in any manner. For example, a configuration in which the illumination drive circuit 52 is mounted on the illumination device 10 and the liquid crystal drive circuit 54 is mounted on the liquid crystal device 20 or a configuration in which the illumination drive circuit 52 and the liquid crystal drive circuit 54 are mounted on a single integrated circuit is adopted. Is done.

  The control device 50 is supplied with an input image signal S1 from an external device. The input image signal S1 is a signal that designates the display color of each pixel constituting the image. The input image signal S1 individually designates a gradation for each of the three types of primary color components (red, green and blue) constituting the display color of the pixel. That is, the input image signal S1 includes a gradation G1_R of a red component (hereinafter referred to as “R component”), a gradation G1_G of a green component (hereinafter referred to as “G component”), and a blue component (hereinafter referred to as “B component”). The key G1_B is designated for each pixel.

  The control device 50 controls the illumination device 10 and the liquid crystal device 20 based on the input image signal S1 so that the single color images of the respective primary color components are sequentially displayed in the unit display regions A of the display region 25. More specifically, the control device 50 causes each unit display area A to sequentially display single-color images of the three primary color components in the subfields SF1 to SF3 of one frame F. That is, in each unit display area A (groups C1 to C3), as shown in FIG. 3, each monochrome image of B component, R component, and G component is displayed once in order in one frame F. The

  Further, the control device 50 displays the monochromatic images in parallel for all the unit display areas A so that the display colors of the monochromatic images in the unit display areas A in one subfield SF are different for each group C. Therefore, the unit display area A in which a single color image of the same color is displayed is not adjacent in the X direction and the Y direction. Focusing on the subfields SF1 to SF3, it can be understood that the permutation of the display colors of the single-color images in each unit display area A is different for each group C.

  For example, as shown in FIG. 3, in the subfield SF1, a monochrome image of B component is displayed in each unit display area A of the group C1, and a monochrome image of R component is displayed in each unit display area A of the group C2. A monochrome image of the G component is displayed in each unit display area A of the group C3. In the subfield SF2, an R component monochromatic image is displayed in the unit display area A of the group C1, a G component monochromatic image is displayed in the unit display area A of the group C2, and the unit display area A of the group C3. A monochrome image of the B component is displayed.

  The liquid crystal driving circuit 54 uses the primary color component to be displayed in the unit display area A for the potential of the pixel electrode 24 in each unit display area A in the first period (hereinafter referred to as “writing period”) of each subfield SF. Is set to a potential corresponding to the gradation specified by the input image signal S1 (hereinafter referred to as “data potential”). For example, in the writing period of the subfield SF1, the liquid crystal driving circuit 54 supplies the data potential corresponding to the B component gradation G1_B to the pixel electrode 24 in each unit display area A of the group C1, and the R component level. A data potential corresponding to the key G1_R is supplied to the pixel electrode 24 in each unit display area A of the group C2, and a data potential corresponding to the gradation G1_G of the G component is supplied to the pixel electrode 24 in each unit display area A of the group C3. To supply. Similarly, in the writing period of the subfield SF2, the liquid crystal driving circuit 54 supplies the data potential corresponding to the R component gradation G1_R to each pixel electrode 24 of the group C1, and according to the G component gradation G1_G. The data potential is supplied to each pixel electrode 24 of the group C2, and the data potential corresponding to the B component gradation G1_B is supplied to each pixel electrode 24 of the group C3. In accordance with the data potential set in the pixel electrode 24 in the writing period of each subfield SF, the transmittance of the liquid crystal in the subfield SF (the gradation of each pixel of the monochromatic image) is set.

  The illumination drive circuit 52 sequentially controls light emission / extinction of each of the plurality of light emitters 12 (12R, 12G, 12B) in each subfield SF for each illumination unit B. More specifically, the illumination driving circuit 52 emits colored light having a wavelength corresponding to the primary color component from the illumination unit B corresponding to the unit display area A where a single-color image of one primary color component is to be displayed. To control. For example, as shown in FIG. 3, in the subfield SF1, the illumination driving circuit 52 causes the light emitter 12B to emit light for each illumination unit B corresponding to each unit display area A of the group C1, and each illumination corresponding to the group C2. For the part B, the light emitter 12R is caused to emit light, and for each illumination part B corresponding to the group C3, the light emitter 12G is caused to emit light.

  Since the illumination device 10 and the liquid crystal device 20 are controlled under the above conditions, in each subfield SF, a single color image of a different color is displayed in parallel in each unit display area A in each of the groups C1 to C3. The Therefore, there is an advantage that the brightness of the image can be easily ensured as compared with the configuration of Patent Document 1 in which a monochromatic image is exclusively displayed for each area into which the display area 25 is divided.

  Further, in this embodiment, since a single color image of a different color is displayed in each unit display area A dividing the display area 25, the single color image of the same color is displayed in the entire display area 25 in one subfield SF in the frame F. There is an advantage that color breakup is reduced compared to the configuration (hereinafter referred to as “proportional”) displayed on the screen. The reduction in color breakup will be described in detail as follows.

  4 and 5 are conceptual diagrams showing how an image is formed on the retina of an observer when a white subject P that is a mixed color of three kinds of primary color components is displayed. 4 corresponds to the proportionality, and FIG. 5 corresponds to the present embodiment. 4 and 5, it is assumed that the observer's viewpoint instantaneously moves to the right (a dramatic movement of the eyeball (saccade)). In FIG. 4 and FIG. 5, the symbol Y means a yellow component, the symbol C means a cyan component, and the symbol M means a magenta component. Further, the number of unit display areas A in FIG. 5 is different from the illustration in FIG. 2 for convenience.

  When the movement amount of the viewpoint in the subfield SF is smaller than the lateral width of the subject P, the images displayed in each subfield SF overlap on the viewer's retina. If the overlapping images on the retina are different colors, the observer perceives a color mixture of both display colors for the overlapping portion of the image. As shown in FIG. 4, in the contrast in which the entire subject P is a single color in one subfield SF, the color mixing of the two primary color components is performed over the width x1 corresponding to the movement amount of the viewpoint in the subfield SF. Perceive. For example, the observer is yellow, which is a color mixture of the R component and the G component, over a width x1 corresponding to the amount of movement of the viewpoint between the subfield SF1 in which the R component is displayed and the subfield SF2 in which the G component is displayed. The component (Y) is perceived.

  On the other hand, in the case of the present embodiment shown in FIG. 5, the display color of the single color image is different for each unit display area A. Therefore, compared with the case of FIG. The frequency at which the images overlap on the retina increases, and the width x2 at which the images overlap decreases as compared to the width x1 in FIG. Therefore, in this embodiment, it becomes difficult for the observer to perceive the distinction between the primary color component area and the mixed color component area on the retina. That is, according to this embodiment, it is possible to reduce the color breakup perceived by the observer as compared with the proportionality.

Next, selection of the size of each unit display area A will be described.
FIG. 6 is a graph showing the relationship between the speed at which the eyeball of the observer moves and the frame frequency at which the observer does not perceive color breakup. When the eyeball of the observer moves at a high speed (for example, in the case of a jumping movement (saccade)), the color breakup cannot be resolved unless the frame frequency is sufficiently increased. However, if the movement of the observer's eyeball is as low as the speed Vs in FIG. 6, no color break is perceived even if the frame frequency is 120 Hz (double speed display) as in this embodiment.

  FIG. 7 is a graph showing the relationship between the amount of eye movement (angle [°]) and the speed of eye movement. As shown in the figure, the speed of eye movement increases as the amount of movement of the line of sight increases. As shown in FIG. 7, when the movement amount of the line of sight is about 10 °, the movement speed of the eyeball is a speed Vs at which color breakup is not perceived under double speed display. That is, if the movement amount of the eyeball is within about 10 °, the observer hardly perceives color breakup. Therefore, in this embodiment, the size of each unit display area A is selected so that the amount of movement of the observer's line of sight within one unit display area A is within about 10 °.

  FIG. 8 is a schematic diagram showing the positional relationship between the display area 25 and the eyeball E of the observer. The normal distance between the display area 25 and the eyeball E of the observer is in a range up to about 6 times the short side dimension (typically height) H of the display area 25. Accordingly, the dimensions in the X direction and the Y direction in the unit display area A are isosceles triangles T1 having an apex angle of 10 ° (more preferably 5 °) and a height of 6 times the dimension H as shown in FIG. The dimension D1 of the bottom side of. Assuming that the distance between the display area 25 and the eyeball E of the observer approaches about three times the dimension H of the short side of the display area 25, the dimensions of the unit display area A are as shown in FIG. , The apex angle is 10 ° (more preferably 5 °), and the base D of the isosceles triangle T2 having a height three times the dimension H is required. That is, the dimension of the unit display area A along at least one of the X direction and the Y direction is preferably set to a dimension D1 or less, more preferably a dimension D2 or less in FIG.

  If the size of the unit display area A is selected as described above, the movement of the observer's line of sight within one unit display area A is prevented from exceeding 10 °. Therefore, there is an advantage that the color breakup can be effectively suppressed without excessively increasing the frame frequency. On the other hand, when the amount of movement of the observer's line of sight exceeds 10 °, the viewpoint moves to a separate unit display area A, so that a single color image of a different color is displayed for each unit display area A. Color breakup is suppressed by the configuration of the form.

<B: Second Embodiment>
Next, a second embodiment of the present invention will be described.
In the first embodiment, a configuration in which single-color images of three kinds of primary color components are sequentially displayed based on the input image signal S1 has been exemplified. On the other hand, in this embodiment, the display color designated by the input image signal S1 is separated into a plurality of primary color components and a plurality of white components. In addition, about the element which an effect | action and function are common in 1st Embodiment in this form, the same code | symbol as the above is attached | subjected and each detailed description is abbreviate | omitted suitably.

  FIG. 9 is a block diagram illustrating a configuration of the display device 100. As shown in the figure, the display device 100 of this embodiment includes an image processing device 40 in addition to the elements of the first embodiment. The image processing device 40 and the control device 50 may be installed in a single integrated circuit or may be installed separately in separate integrated circuits.

  The image processing device 40 generates and outputs a separated image signal S2 based on the input image signal S1 supplied from the external device. The separated image signal S2 is a signal that designates the gradation of each component for each pixel when the display color designated by the input image signal S1 is separated into a plurality of primary color components and a plurality of white components. As shown in FIG. 9, the separated image signal S2 of the present embodiment includes a first white component (hereinafter referred to as “W1”) in addition to the R component gradation G2_R, the G component gradation G2_G, and the B component gradation G2_B. The tone G2_W1 of the “component”) and the tone G2_W2 of the second white component (hereinafter referred to as “W2 component”) are designated.

  FIG. 10 is a flowchart for explaining the operation of the image processing apparatus 40. The process shown in FIG. 6 is executed for each pixel constituting the image. The image processing apparatus 40 specifies the minimum value Gmin from the gradations (G1_R, G1_G, and G1_B) of the three primary color components that the input image signal S1 designates for one pixel (step S1). Next, the image processing apparatus 40 determines whether or not the minimum value Gmin specified in step S1 is lower than the threshold value TH1 (step S2). The threshold value TH1 is typically a preset fixed value, but may be a variable value according to an instruction from a user or a host device, for example.

  Part (a) in FIG. 11 and part (a) in FIG. 12 show specific examples of gradations (G1_R, G1_G, and G1_B) that the input image signal S1 specifies for each primary color component. In the display color illustrated in part (a) of FIG. 11, the G component gradation G1_G of the three primary color components is the minimum value Gmin below the threshold TH1. When the minimum value Gmin is lower than the threshold value TH1 as shown in part (a) of FIG. 11, the image processing apparatus 40 designates the minimum value Gmin specified in step S1 as the gradation G2_W1 of the W1 component and the level of the W2 component. A separated image signal S2 designating the key G2_W2 to zero is generated (step S3). Further, the image processing apparatus 40 uses the numerical values obtained by subtracting the minimum value Gmin from the gradations (G1_R, G1_G, G1_B) of the three kinds of primary color components as the gradations (G2_R, G2_G, G2_B) of the respective primary color components. The signal S2 is designated (step S4).

  For example, when the display color of the part (a) in FIG. 11 is designated, the image processing apparatus 40, as shown in the part (b) in FIG. 11, the gradation G1_G (minimum value) of the G component in the input image signal S1. Gmin) is designated as the gradation G2_W1 of the W1 component. Further, the image processing apparatus 40 designates the difference value between the R component gradation G1_R and the minimum value Gmin as the gradation G2_R, and designates the difference value between the B component gradation G1_B and the minimum value Gmin as the gradation G2_B. To do. The G component gradation G2_G (G2_G = G1_G−Gmin) in the separated image signal S2 is zero.

  On the other hand, in the display color of the part (a) in FIG. 12, the G component gradation G1_G which is the minimum value Gmin among the gradations of the three primary color components exceeds the threshold value TH1. When the result of step S2 is negative as shown in part (a) of FIG. 12, the image processing apparatus 40 specifies the threshold value TH1 as the gradation G2_W1 of the W1 component and sets the difference value between the minimum value Gmin and the threshold value TH1. A separated image signal S2 designated as the W2 component gradation G2_W2 is generated (step S5). Further, the image processing apparatus 40 is a numerical value obtained by subtracting the minimum value Gmin (or the addition value of the gradation G2_W1 (TH1) and the gradation G2_W2) from the gradations (G1_R, G1_G, G1_B) of the three kinds of primary color components. Are designated in the separated image signal S2 as gradations (G2_R, G2_G, G2_B) of the respective primary color components (step S4).

  For example, when the display color of the part (a) in FIG. 12 is designated, the image processing apparatus 40 designates the threshold value TH1 as the gradation G2_W1 of the W1 component and G as shown in the part (b) in FIG. The difference value between the component gradation G1_G (minimum value Gmin) and the threshold value TH1 is designated as the W2 component gradation G2_W2. Further, the image processing apparatus 40 designates the difference value between the R component gradation G1_R and the minimum value Gmin as the gradation G2_R, and designates the difference value between the B component gradation G1_B and the minimum value Gmin as the gradation G2_B. To do. The gradation G2_G of the G component in the separated image signal S2 is zero. As described above, when the gradation of the white component (W1 + W2) in the display color specified by the input image signal S1 exceeds the threshold value TH1, the white component is separated into the W1 component and the W2 component with the threshold value TH1 as a boundary. The

  FIG. 13 is a timing chart for explaining the operation of the display device 100. As shown in the figure, the frame F is divided into six subfields SF1 to SF6. The operation of the illumination device 10 (illumination drive circuit 52) in the subfields SF2 to SF4 is the same as the operation in the subfields SF1 to SF3 of the first embodiment.

  The illumination drive circuit 52 causes all three light emitters 12 (12R, 12G, 12B) of the illumination sections B to emit light in each of the subfields SF1 and SF5. Therefore, in the subfields SF1 and SF5, white light is irradiated to all the unit display areas A of the liquid crystal device 20. In addition, the illumination drive circuit 52 turns off all three light emitters 12 of the illumination part B in the subfield SF6. Accordingly, the light irradiation to the liquid crystal device 20 is stopped in the subfield SF6.

  The liquid crystal driving circuit 54 should display the potential of the pixel electrode 24 in each unit display area A in the unit display area A in the writing period of each of the subfields SF2 to SF4 as in the first embodiment. The primary color component is set to a data potential corresponding to the gradation (G2_R, G2_G, G2_B) specified by the separated image signal S2. The liquid crystal driving circuit 54 supplies a data potential corresponding to the gradation G2_W1 of the W1 component to all the pixel electrodes 24 in the writing period of the subfield SF1 in which white light is irradiated to the liquid crystal device 20, and the same. A data potential corresponding to the gradation G2_W2 of the W2 component is supplied to all the pixel electrodes 24 in the subfield SF5 irradiated with white light. Further, the liquid crystal driving circuit 54 supplies a data potential for controlling the transmittance of the liquid crystal to the lowest value (for example, zero) to all the pixel electrodes 24 in the subfield SF6 where the lighting device 10 is turned off.

  With the above operation, for the primary color components, single color images of different colors in each group C are displayed in the unit display areas A in the subfields SF2 to SF4, while the subfields SF1 and SF5 before and after the subfields SF2 to SF4 are displayed. In each of these, monochromatic images of white components (W1, W2) are displayed in all unit display areas A. In the subfield SF6, the black image K is displayed for all the unit display areas A.

  As described above, in the present embodiment, since the white components (W1, W2) are extracted from the display colors of the respective pixels, the luminance of the single color image of each primary color component is reduced as compared with the first embodiment. . In addition, since color breakup does not occur in the monochromatic image of the white component, according to this embodiment, the color of the image perceived by the observer as compared with the first embodiment that displays only the monochromatic image of each primary color component. It is possible to suppress cracking. In the present embodiment, the black image K is not displayed because the subfield SF6 of the black image K is set in the frame F in addition to the subfield SF in which the monochrome images of the primary color components and the white components are displayed. Compared with the configuration, it is possible to suppress a phenomenon in which the outline of a moving image is perceived indefinitely (hereinafter referred to as “moving image blur”).

  By the way, in the configuration in which the white component single color image extracted from the display color designated by the input image signal S1 is displayed by only one subfield SF (hereinafter referred to as “proportional”), the display color of the image is particularly white. When they are close to each other, the monochromatic image of the white component has a significantly higher gradation than the monochromatic image of the other colors. Therefore, the flicker perceived by the observer becomes conspicuous by sequentially displaying the low-tone single-color image of each primary color component and the high-tone single-color image of the white component. In this embodiment, since the white component in the display color is separated into the W1 component and the W2 component, each monochrome image is displayed in a separate subfield SF (SF1, SF5). The gradation (luminance) of a monochromatic image is restricted to a range up to the threshold value TH1. That is, since the difference in gradation between the primary color component monochromatic image and the white component monochromatic image is suppressed, even when displaying an image close to white, flicker is reduced as compared with the comparative example. There are advantages.

  The flicker perceived by the observer is the frequency at which light is emitted to the observation side (hereinafter referred to as “light emission frequency”) and the ratio of the time during which light is emitted to the observation side in one frame F (hereinafter referred to as “light emission duty”). It depends on. That is, flicker is reduced as the emission frequency and emission duty are higher. If the black image subfield SF6 is inserted into the frame F to prevent motion blur, the light emission duty is reduced as compared with the configuration in which the subfield SF6 is not set. Therefore, the setting of the subfield SF6 causes the flicker to increase. It becomes. On the other hand, displaying the white component in the subfields SF (SF1, SF5) spaced apart from each other as in the present embodiment is equivalent to increasing the emission frequency, and thus acts to reduce flicker. That is, in this embodiment, it is possible to cancel the increase in flicker caused by the display of the black image by the dispersive display of the white component.

<C: Third Embodiment>
Next, a third embodiment of the present invention will be described. In the second embodiment, the configuration in which the monochromatic image of each white component is displayed in the subfield SF (SF1, SF5) different from the subfield SF in which the monochromatic image of each primary color component is displayed is exemplified. On the other hand, in the present embodiment, both the single-color image of the white component and the single-color image of the primary color component are converted into units in parallel in each subfield SF based on the separated image signal S2 generated by the image processing device 40. It is displayed in the display area A. In addition, about the element which an effect | action and function are equivalent to 2nd Embodiment in this form, the same code | symbol as the above is attached | subjected and each detailed description is abbreviate | omitted suitably.

  FIG. 14 is a conceptual diagram showing a state in which the display area 25 is divided into a plurality of unit display areas A. As shown in the figure, the plurality of unit display areas A constituting the display area 25 are divided into five groups C (C1 to C5). As in the first embodiment, the unit display areas A belonging to the same group C are not adjacent to either the X direction or the Y direction.

  FIG. 15 is a timing chart for explaining the operation of the display device 100 according to this embodiment. As shown in the figure, the control device 50 has sub-color images of a plurality of colors (five colors) including three kinds of primary color components (R, G, B) and two kinds of white components (W1, W2). The display of each unit display area A is sequentially controlled in each of the subfields SF1 to SF5 so as to be displayed in each unit display area A of a separate group C in the field SF. That is, the permutation of the single color image displayed in each unit display area A among the single color images including the primary color component and the white color component is different for each group C. For example, in the subfields SF1 to SF5, in the unit display area A of the group C1, monochrome images are displayed in the order of W1 component → G component → B component → W2 component → R component, whereas the group C2 In each unit display area A, monochrome images are displayed in the order of G component → B component → W 2 component → R component → W 1 component. The point that the black image K is displayed in all the unit display areas A in the subfield SF6 is the same as in the second embodiment.

  Also in this embodiment, the same effect as in the second embodiment can be obtained. In the second embodiment, subfields SF (SF2 to SF4) for displaying a primary color component monochromatic image are continuous on the time axis. In the present embodiment, each unit display area A has a single primary color component monochromatic color. A subfield SF in which an image is displayed and a subfield SF in which a white color monochromatic image is displayed are distributed on the time axis. As the primary color component monochromatic images continue on the time axis, the color breakup becomes more prominent. Therefore, according to the present embodiment, it is possible to make the color breakup less perceivable than in the second embodiment.

<D: Modification>
Various modifications can be made to each of the above embodiments. An example of a specific modification is as follows. Two or more aspects may be arbitrarily selected from the following examples and combined.

(1) Modification 1
In the second embodiment, the configuration in which the display color specified by the input image signal S1 is separated into a plurality of primary color components and a plurality of white color components is exemplified. However, the display colors of the pixels are mixed with two types of primary color components. A configuration in which a plurality of color components including a component (hereinafter referred to as “mixed color component”) and a plurality of white components are also employed. In the separated image signal S2, in addition to the three primary color component gradations and the two white component gradations as in the second embodiment, the yellow component level is a color mixture of the R component and the G component. A tone, a gradation of a cyan component that is a mixed color of the G component and the B component, and a gradation of a magenta component that is a mixed color of the B component and the R component are designated. For example, as shown in part (b) of FIG. 11, the R component and the B component remaining after the extraction of the W1 component are separated into the magenta component and the remaining R component, which are a mixture of both, and the respective gradations are separated. This is designated by the image signal S2. If the mixed-color component monochromatic image is displayed in the subfield SF in the gap of the subfield SF in which the monochromatic image of the primary color component is displayed, it is compared with the first and second embodiments in which the monochromatic image of the primary color component is continuous. Therefore, it is possible to further suppress color breakup.

(2) Modification 2
In the above embodiment, the configuration in which the W1 component and the W2 component are extracted from the display color is illustrated, but the number of white components separated can be arbitrarily changed. For example, a configuration in which only one white component is extracted from the display color is also employed. Also, three types of white components (W1 to W3) may be extracted from the display color designated by the input image signal S1. That is, when the input image signal S1 designates the display color of the part (a) in FIG. 16, as shown in the part (b) in FIG. 16, the threshold TH1 is designated as the gradation G2_W1 of the W1 component and the threshold TH2 ( The difference value between TH2> TH1) and the threshold value TH1 is designated as the gradation G2_W2 of the W2 component, and the difference value between the minimum gradation value Gmin (gradation G1_B in FIG. 15) and the threshold value TH2 is designated as the gradation value G2_W3 of the W3 component. Is specified.

  The plurality of unit display areas A constituting the display area 25 are divided into seven groups C (C1 to C7). As illustrated in FIG. 17, the control device 50 is a single color image of a plurality of colors (six colors) including three types of primary color components (R, G, B) and three types of white components (W1, W2, W3). Is displayed in each unit display area A of a separate group C in each subfield SF, and the display of each unit display area A is sequentially controlled in each of the subfields SF1 to SF6. As described above, as the number of white component separations is increased, the gradation of a single-color image of one white component is reduced, so that there is an advantage that flicker perceived by the observer can be effectively suppressed.

(3) Modification 3
Whether the white component is displayed in a subfield SF separate from the primary color component as in the second embodiment or whether the white component is displayed in each subfield SF together with the primary color component as in the third embodiment is displayed. Each of the plurality of white components extracted from the color is determined individually. For example, in the configuration in which two types of white components (W1, W2) are extracted from the input image signal S1, a monochrome image of the W1 component is displayed over a plurality of subfields SF together with the primary color component, as shown in FIG. A configuration is employed in which a single color image of a component is displayed in a subfield SF5 separate from the primary color component. Further, in the configuration in which three types of white components (W1, W2, W3) are extracted as shown in FIG. 16, as shown in FIG. 19, each monochrome image of the W1 component and the W2 component is divided into a plurality of subfields together with the primary color components. A configuration is adopted in which the display is performed over SF, and the monochrome image of the W3 component is displayed in a subfield SF6 separate from the primary color component.

(4) Modification 4
In each of the above embodiments, the case where all the subfields SF in the frame F have the same time length is illustrated, but the time length of each subfield SF is appropriately changed. For example, as shown in FIG. 20, a configuration is adopted in which the subfield SF6 in which the black image K is displayed in the second embodiment or the third embodiment is set to a longer period than the other subfields SF1 to SF5. The According to the above configuration, the time length for displaying a single color image (primary color component and white component) in the frame F is shortened by the increase in the subfield SF6 of the black image, so the second embodiment and the third embodiment. There is an advantage that moving image blur is suppressed as compared with the form.

  However, if the subfield SF6 displaying the black image K is too long, there is a problem that flicker perceived by the observer becomes conspicuous. Therefore, the subfield SF6 for displaying the black image K is desirably set to a time length of 50% or less of the frame F, and more preferably a time length of 30% or less of the frame F. When importance is placed on the suppression of flicker caused by the display of the black image K, the subfield SF6 of the black image K is set to the same length as the other subfields SF1 to SF5 as in the second embodiment. A configuration in which the subfield SF6 of the black image K is not provided in the frame F is preferable.

  In addition, as shown in FIG. 21, a configuration in which the subfield SF5 in which the W2 component monochromatic image is displayed is set to a longer period than the other subfield SF is also employed. According to the configuration of FIG. 21, the time length for displaying a single-color image of the primary color component in the frame F is shortened, so that color breakup is suppressed as compared with the second and third embodiments. Further, as shown in FIG. 21, extending the subfield SF5 of the W2 component (shortening the subfield SF6 of the black image K) acts equivalently to increasing the light emission duty, so that it is compared with the configuration of FIG. Therefore, there is an advantage that flicker is suppressed. The subfield SF1 for displaying the W1 component may be set to a longer time than the subfields SF2 to SF6.

(5) Modification 5
In the second embodiment and the third embodiment, in the last subfield SF6 of the frame F, the illumination device 10 is turned off and the black image K is displayed by controlling the transmittance of all the pixels to the lowest value (that is, The configuration in which the display is stopped) is exemplified, but a configuration in which only one of the lighting device 10 and the decrease in the transmittance of the liquid crystal is performed in the last subfield SF6 is also employed. Further, the black image K may be displayed in the first subfield SF1 of the frame F. In the preferred embodiment of the present invention, it is sufficient that the display is stopped in a predetermined period in the frame F, and the time when the black image K is displayed and the method of displaying the black image K are not limited. However, a configuration in which a period for stopping the display is not provided in the frame F is also employed in the present invention.

(6) Modification 6
In the second embodiment and the third embodiment, the configuration in which the liquid crystal device 20 is irradiated with white light by driving the light emitters 12 (12R, 12G, 12B) corresponding to the primary color components in an appropriate combination has been exemplified. Alternatively, the illuminating device 10 in which a light emitting body that emits white light is independently installed may be used.

<E: Application example>
Next, an electronic apparatus using the display device according to the present invention will be described. 22 to 24 show forms of electronic devices that employ the display device 100 according to any of the forms described above.

  FIG. 22 is a perspective view illustrating a configuration of a mobile personal computer that employs the display device 100. The personal computer 2000 includes a display device 100 that displays various images, and a main body 2010 on which a power switch 2001 and a keyboard 2002 are installed.

  FIG. 23 is a perspective view illustrating a configuration of a mobile phone to which the display device 100 is applied. A cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and a display device 100 that displays various images. By operating the scroll button 3002, the screen displayed on the display device 100 is scrolled.

  FIG. 24 is a perspective view showing a configuration of a personal digital assistant (PDA) to which the display device 100 is applied. The portable information terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the display device 100 that displays various images. When the power switch 4002 is operated, various information such as an address book and a schedule book are displayed on the display device 100.

  Note that examples of the electronic device to which the display device according to the present invention is applied include the digital still camera, the television, the video camera, the car navigation device, the pager, the electronic notebook, the electronic paper, in addition to the devices illustrated in FIGS. Examples include calculators, word processors, workstations, videophones, POS terminals, printers, scanners, copiers, video players, devices equipped with touch panels, and the like.

It is a block diagram which shows the structure of the display apparatus which concerns on 1st Embodiment of this invention. It is a conceptual diagram which shows a mode that the display area was divided into the several unit display area. 6 is a timing chart for explaining the operation of the display device. It is a conceptual diagram for demonstrating the color break which an observer perceives on the basis of contrast. It is a conceptual diagram for demonstrating the effect of 1st Embodiment. It is a graph which shows the relationship between the speed of an eyeball, and the frame frequency where a color break is not perceived. It is a graph which shows the relationship between the movement amount of a gaze, and the speed of an eyeball. It is a conceptual diagram for demonstrating the method to select the size of a unit display area. It is a block diagram which shows the structure of the display apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement which produces | generates a separated image signal. It is a conceptual diagram which shows the specific example of the operation | movement which produces | generates a separated image signal. It is a conceptual diagram which shows the specific example of the operation | movement which produces | generates a separated image signal. It is a timing chart for demonstrating operation | movement of the display apparatus in 2nd Embodiment. It is a conceptual diagram which shows the aspect of the division of the display area in 3rd Embodiment. 6 is a timing chart for explaining the operation of the display device. It is a conceptual diagram which shows the specific example of the production | generation of the separated image signal in a modification. It is a timing chart which shows operation of a display concerning a modification. It is a timing chart which shows operation of a display concerning a modification. It is a timing chart which shows operation of a display concerning a modification. It is a timing chart which shows operation of a display concerning a modification. It is a timing chart which shows operation of a display concerning a modification. It is a perspective view which shows the form (personal computer) of the electronic device which concerns on this invention. It is a perspective view which shows the form (cellular phone) of the electronic device which concerns on this invention. It is a perspective view which shows the form (mobile information terminal) of the electronic device which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Display apparatus, 10 ... Illumination apparatus, B ... Illumination part, 12 (12R, 12G, 12B) ... Luminescent body, 14 ... Light guide body, 20 ... Liquid crystal device, 21 ... 1st board | substrate , 22... Second substrate, 24... Pixel electrode, 25... Display area, A .. unit display area, 40... Image processing device, 50. Liquid crystal drive circuit, F ... Frame, SF (SF1, SF2, ...) ... Subfield.

Claims (5)

Display means including a first unit display area and a second unit display area ;
The gradation of the primary color components of multiple from the input image signal to be specified for each pixel, image processing means for generating separation images signals for designating a tone for a white component and a plurality of color components,
A first subfield for displaying the first unit display area and the second unit display area on the basis of a separated image signal designating gradation for the plurality of color components in one frame, and gradation for the white component A second subfield for displaying the first unit display area and the second unit display area based on the separated image signal designating the first unit display area and the second unit in the first subfield. while that presents on the basis of the separation image signal designating a gradation for the plurality of color components of a single color image of a different color in the display area, the second the first unit display area and the second unit display in the sub-field A display device comprising: a control unit configured to display a white single-color image in a region based on a separated image signal designating a gradation for the white component . The display means has a rectangular display area in which a plurality of unit display areas including the first unit display area and the second unit display area are arranged in a first direction and a second direction intersecting each other. And
The dimension along at least one of the first direction and the second direction in each unit display area is the dimension of the base of an isosceles triangle whose apex angle is 10 ° and whose height is six times the short side of the display area. The display device according to claim 1 . The display means, the display device according to claim 1 or claim 2 including a liquid crystal device sealing the liquid crystal in the OCB mode in a gap between the first substrate and the second substrate. An electronic device including any of the display apparatus of claims 1 to 3. A method of driving a display device including a first unit display area and a second unit display area,
From the input image signal that specifies the gradation of a plurality of primary color components for each pixel, a separated image signal that specifies the gradation for the white component and the plurality of color components is generated,
A first subfield for displaying the first unit display area and the second unit display area on the basis of a separated image signal designating gradation for the plurality of color components in one frame, and gradation for the white component A second subfield for displaying the first unit display area and the second unit display area based on the separated image signal designating the first unit display area and the second unit in the first subfield. While displaying a single-color image of a different color with respect to the display area based on a separated image signal designating gradations for the plurality of color components, the first unit display area and the second unit display area in the second subfield A display device driving method for displaying a white monochromatic image on the basis of a separated image signal designating a gradation for the white component .

Images