Classifications

• • 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
  • G09G3/3607—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 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
  • G02F1/133509—Filters, e.g. light shielding masks
  • G02F1/133514—Colour filters
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
  • G02F1/1333—Constructional arrangements; Manufacturing methods
  • G02F1/1343—Electrodes
  • G02F1/134309—Electrodes characterised by their geometrical arrangement
  • G02F1/134345—Subdivided pixels, e.g. for grey scale or redundancy
• • G—PHYSICS
  • G02—OPTICS
  • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
  • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
  • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
  • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
  • G02F1/137—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
  • G02F1/139—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent
  • G02F1/1393—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells
• • 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
  • G09G2300/04—Structural and physical details of display devices
  • G09G2300/0439—Pixel structures
  • G09G2300/0452—Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• • 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
  • G09G2300/04—Structural and physical details of display devices
  • G09G2300/0469—Details of the physics of pixel operation
  • G09G2300/0478—Details of the physics of pixel operation related to liquid crystal pixels
  • G09G2300/0491—Use of a bi-refringent liquid crystal, optically controlled bi-refringence [OCB] with bend and splay states, or electrically controlled bi-refringence [ECB] for controlling the color
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G2310/00—Command of the display device
  • G09G2310/06—Details of flat display driving waveforms
• • 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
  • G09G2320/02—Improving the quality of display appearance
  • G09G2320/0242—Compensation of deficiencies in the appearance of colours
• • 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
  • G09G2320/02—Improving the quality of display appearance
  • G09G2320/0261—Improving the quality of display appearance in the context of movement of objects on the screen or movement of the observer relative to the screen
• • 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
  • G09G2320/103—Detection of image changes, e.g. determination of an index representative of the image change
• • 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
  • G09G2340/16—Determination of a pixel data signal depending on the signal applied in the previous frame
• • 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
  • G09G3/2007—Display of intermediate tones
  • G09G3/2011—Display of intermediate tones by amplitude modulation
• • 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
  • G09G3/2007—Display of intermediate tones
  • G09G3/2044—Display of intermediate tones using dithering
• • 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
  • G09G3/2007—Display of intermediate tones
  • G09G3/2074—Display of intermediate tones using sub-pixels

Definitions

• the present invention relates to a color display element. [Background technology]
• a color display device having a display element that performs color display according to three types of image signals of red, green, and blue.
• a color display device includes a CRT, a plasma display (PDP), and an organic display device.
• PDP plasma display
• organic display device There are various color display devices such as EL display (OLED) and liquid crystal display (LCD), which are already widely used.
• LCDs are characterized by their thinness, low power consumption, and high display quality, and have been applied to all kinds of color display devices, such as mobile phones, PC monitors, and home televisions.
• LCD color display methods use liquid crystal display elements capable of monochromatic modulation, divide one pixel into three sub-pixels, and provide red, blue, and green color filters for each sub-pixel.
• the micro color filter (MCF) method is adopted.
• Another color display method is to switch the display state of a liquid crystal display element capable of monochrome modulation at high speed, and synchronize the red, blue, and green light sources with the display element, so that the three primary colors can be divided by time division.
• a field sequential color (FSC) system that uses the color mixing effect of the above is known.
• this ECB-type liquid crystal display device (hereinafter referred to as ECB color LCD) uses the birefringence of liquid crystal and the polarization of a polarizing plate to color light. Therefore, a bright color display can be obtained by increasing the light transmittance.
• the birefringence of the liquid crystal layer changes according to the voltage, the color of the transmitted light or the reflected light can be changed by controlling the voltage applied to the liquid crystal cell. Colors can also be displayed.
• Fig. 15 shows the relationship between the birefringence (referred to as retardation R) of the liquid crystal display element used for the ECB color LCD and the coordinates on the chromaticity diagram. From 0 to around 250 nm, the color is almost achromatic in the center of the chromaticity diagram, but above that, the color changes according to the amount of birefringence.
• retardation R the birefringence
• liquid crystal When a liquid crystal is made of a material with negative dielectric anisotropy (denoted by ⁇ ) and is vertically aligned with the substrate when no voltage is applied, the liquid crystal molecules tilt with the voltage, and the birefringence of the liquid crystal accordingly. Will increase.
• the chromaticity changes along the curve in Fig. 15 under crossed Nicols.
• the state is dark (black state).
• the brightness (brightness) changes from black to gray to white. Will increase.
• the color changes to yellow, red, purple, blue, yellow, purple, light blue, green, and so on. Phase
• the ECB color LCD in the vertical alignment mode can change the brightness between the maximum brightness and the minimum brightness in the modulation region on the low voltage side, and can efficiently convert multiple hues in the higher voltage region. Can be changed by
• LCDs have achieved high display quality even in moving image display, and are being applied to large-screen TVs. Especially
• overdrive driving method (OD method) reported in H. Okumu r aeta 1., S ID'92, pp 601-604 (1992) is widely used for LCDs for displaying moving images.
• the OD method is used to improve the halftone response speed of the LCD. For example, in an LCD in a normally white mode (display mode in which white display is performed when no voltage is applied), assume that the previous state is white, and when switching this to a halftone level, one frame immediately after switching is performed. Is set slightly higher than the voltage value for displaying the original halftone level, thereby shortening the response time to reach the target halftone level. If the previous state is black, set it slightly lower than the original voltage value. From the second frame, a drive voltage for displaying the original halftone level should be applied as usual. With this method, the optical response of the LCD can be completed in about one frame or within one frame.
• red and green are on in the white state, and red and green are off in the blue halftone state In this state, blue has an intermediate brightness state.
• red and green are in a transient response state from the on state to the off state, and the blue pixels are from the on state of blue to blue. In a transient response state leading to a halftone state.
• red and green are in their respective halftone states, and blue is in a halftone state brighter than the desired halftone state after the switching. If you look at this, it can be said that the color purity is low and the display is a little lighter blue.
• the hue does not change significantly as described above, so even when displaying an intense moving image like a currently commercialized LCD television, there is no significant discomfort. It is thought that it is possible to view.
• an ECB color LCD for example, when switching from white to blue, a transient response accompanied by a change in hue is observed in the first frame immediately after switching. In other words, in the transitional state from white to blue, the middle line along the curve shown in Figure 15 The display color of yellow ⁇ red ⁇ purple appears, and after that, blue display will be performed. In other words, in a transient response state, a display color different from blue, such as magenta, is observed. When such display colors having different system colors are observed, coloring is observed at the edge of the moving object in the moving image display, giving a sense of discomfort to the moving image display.
• the binary gradation control is performed at the unit pixel, but the gradation display is performed by the spatial color mixing effect. Even if the image changes only, the binary information for display will change greatly. Therefore, when displaying an image in which a natural image is displayed by dither as a moving image, the color balance of the entire image is lost, not only at the edge of the moving object.
• the present invention has been made in view of such circumstances, and a color display element (liquid crystal display) that reduces an undesirable coloring phenomenon that occurs in an edge portion of a moving object or an entire image when switching images such as a moving image display.
• Display element and a driving method thereof.
• the present invention provides a medium in which a unit pixel is composed of a plurality of sub-pixels including a first sub-pixel and a second sub-pixel provided with a color filter, and the optical property of each of the sub-pixels is changed according to an applied voltage.
• a color display element arranged,
• the optical properties of the medium arranged in the first sub-pixel are determined by the range in which the brightness of light passing through the medium changes and the light passing through the medium exhibiting a chromatic color and the hue of the chromatic color Changing range Means for applying to the first sub-pixel the light modulated in the surroundings;
• the correction voltage of the second sub-pixel is determined from the applied voltage to the first sub-pixel before switching and the voltage applied to the first sub-pixel after switching.
• the correction voltage is a voltage that mixes a chromatic color that transiently occurs in the first sub-pixel when the display is switched with the color of the second pixel to make it achromatic.
• the pixel includes a first sub-pixel and a second sub-pixel provided with at least one type of color filter of red, green, and blue, and the first sub-pixel.
• FIG. 1 is a diagram showing the structure of one pixel of a liquid crystal display device (color display device) used in the color display device of the present invention.
• FIG. 2 is a diagram showing the relationship between retardation and color of the liquid crystal display device of FIG.
• FIG. 3 is a diagram showing another structure of one pixel of the liquid crystal display element used in the color display device of the present invention.
• FIG. 4 is a diagram showing a relationship between retardation and color of the liquid crystal display device of FIG.
• FIG. 5 is a diagram showing still another structure of one pixel of the liquid crystal display element used in the color display device of the present invention.
• FIG. 6 is a diagram showing a change over time in applied voltage and retardation of the color display device of the present invention.
• FIG. 7 is a diagram showing a change over time in applied voltage and retardation of the color display device of the present invention.
• FIG. 8 is a diagram showing a change over time in applied voltage and retardation of the color display device of the present invention.
• FIG. 9 is a system block diagram of the color display device of the present invention.
• FIG. 10 is another system block diagram of the color display device of the present invention.
• FIG. 11 is a diagram showing a structure of one pixel in Embodiment 1 of the present invention.
• FIG. 12 is a diagram showing a structure of one pixel in Embodiment 2 of the present invention.
• FIG. 13 is a diagram showing a structure of one pixel in Embodiment 3 of the present invention.
• FIG. 14 is a diagram showing a structure of one pixel in the fourth embodiment of the present invention.
• FIG. 15 is a diagram showing the relationship between retardation and color of a liquid crystal display element.
• FIG. 1 shows a color display device used in a color display device according to the best mode for carrying out the present invention.
• FIG. 2 is a diagram showing a structure of one pixel of a display element. A color display element having the same structure has been proposed by the present inventors in WO2004 / 042687.
• one pixel 50 is divided into a plurality (two) of sub-pixels 51 and 52, One of the sub-pixels 51 is overlaid with a green color filter indicated by the symbol G, and the other sub-pixel 52 is adjusted for retardation to change the achromatic brightness change from black to white and the red to red. Display any color from magenta to blue.
• a unit pixel is composed of the second sub-pixel 51 that displays a color (green).
• subpixels that display green with high visibility (hereinafter referred to as green subpixels) 51 use a green color filter G without using ECB coloring, and use ECB only for red and blue. Use the coloring phenomenon.
• the green sub-pixel 51 By setting the green sub-pixel 51 with the color filter to the ⁇ state and the sub-pixel without the color filter (hereinafter referred to as the transparent sub-pixel) 52 to white (the maximum luminance state of the achromatic color change area), White is displayed as the whole pixel.
• the green sub-pixel 51 may be set to the maximum transmission state
• the transparent sub-pixel 52 may be set to the magenta color of the chromatic region.
• the magenta color includes both red (R) and blue (B) colors, so that a white display is obtained as a result of the combination.
• the green sub-pixel 51 In order to display green (G) in a single color, the green sub-pixel 51 is set to the maximum transmission state, 5 Put 2 in the dark state. Further, in order to display a single color of red (R) (or a single color of blue (B)), the green sub-pixel 51 is set to a dark state, and the retardation value of the transparent sub-pixel 52 is set to 450 nm (or! /, Is
• both the green sub-pixel 51 and the transparent sub-pixel 52 are set to the ⁇ state with the retardation set to 0, black display can be obtained.
• the retardation is the amount of retardation of the liquid crystal layer itself when used in a transmission type, and in the case of use in a reflection type, light passes through the liquid crystal layer twice. Use the value that is twice the amount of retardation.
• the transmission type uses a crossed Nicols configuration and the reflection type uses a circular polarizer.
• the green sub-pixel 51 changes the retardation in the range of 0 to 250 nm
• the transparent sub-pixel 52 changes the retardation in the range of 0 to 250 nm and 450 nm to 6 nm. Change in the range of 00 nm. Since the liquid crystal material is commonly used for both the sub-pixels 51 and 52, the driving voltage range is set to be different.
• Green has a high luminosity factor, so if a color filter is used to create a highly pure color, a high-quality image can be obtained.
• the present invention can be applied to other than liquid crystal. That is, in general, a medium is used in which the optical properties are changed by externally applied modulation means, and the medium has a modulation area in which the lightness is changed by the modulation means and a modulation area in which the hue is changed.
• the retardation for red display is about 450 nm, and the retardation for blue is about 600 nm. Therefore, the thickness of the senor is set to achieve a retardation of 600 nm.
• the cell thickness is about 10 microns.
• the response speed is about the same as the transmissive LCD currently on the market because the cell thickness is halved, and moving images can be displayed.
• the green sub-pixel 51 having high luminosity characteristics can perform continuous gradation display, but the transparent sub-pixel 52 has a chromatic state, that is, blue and red are based on the ECB. Since coloring is used, gradation display cannot be performed.
• the transparent sub-pixel 52 is divided into two sub-pixels 52a and 52b, and the gradation is digitally expressed by changing the area ratio. Since the sub-pixels 52a and 52b have different areas, four levels of halftones are displayed according to the area of the sub-pixels 52a and 52b which are lit to display the color.
• a color filter such as magenta, having a relationship between green and neon color is provided in the first sub-pixel 52 that is colored by a change in retardation. This enhances the color purity of red and blue, and improves color reproducibility.
• FIG. 3A shows the case where the first sub-pixel is one
• FIG. 3B shows the case where the first sub-pixel is divided into two (2: 1).
• Figure 4 shows the calculated values of the color change due to the retardation.
• the retardation amount increases from zero, the brightness changes in chromatic colors ranging from black display to magenta (halftone of magenta) to bright magenta display.
• third and fourth sub-pixels 55 and 56 having red and blue color filters are added.
• these sub-pixels 55 and 56 make continuous brightness changes of blue and red, respectively. Color can be displayed.
• FIG. 5 (b) shows such an example, in which only a sub-pixel 56 having a red color filter is added.
• green with high visibility is treated independently, and the other primary colors are displayed in pixels other than green using the coloring effect of birefringence.
• this is the most advantageous for the display performance of natural images, but it is not necessarily limited to green, but red is treated as an independent pixel and blue and green are colored by birefringence. It is also acceptable to use a display method or a method in which blue is treated as an independent pixel and red and green are displayed using the coloring effect of birefringence.
• Fig. 1 (a) one pixel is divided into two types of sub-pixels, a green color filter is provided in the second sub-pixel 51, and a color filter is provided in the first sub-pixel 52.
• the display is monochrome and red / blue with interference colors due to birefringence. This pixel may be divided into a plurality of sub-pixels as necessary.
• the first sub-pixel displays blue before switching, and becomes white by switching.
• the second sub-pixel displays black both before and after the switching.
• V52 in FIG. 6 indicates the applied voltage of the first subpixel at this time
• R52 indicates the response of the retardation of the first subpixel.
• purple (550 nm) ⁇ Red (450 nm) ⁇ Yellow (350 nm) are observed sequentially.
• the value in parentheses indicates the approximate value of the retardation at that time.
• a system color close to magenta is displayed for these mixed colors.
• the edge of the moving object will be colored magenta instead of blue or white.
• Such a phenomenon is visible not only at the edges when a moving object is displayed, but also when a still image is switched, for example, when the entire screen is switched from blue to white.
• a pixel which performs image switching in a hue change region such as an edge portion of a moving object, is used.
• the above-mentioned unintended display color is canceled for the first sub-pixel 52 at the same time, that is, an achromatic color is obtained by mixing. Outputs the display color.
• the voltage should be applied so that the second sub-pixel 52 is in the on state or the halftone state.
• V51 in FIG. 6 indicates the voltage applied to the second subpixel at this time, and R51 indicates the retardation of the second subpixel.
• the transitional color of the first sub-pixel and the transitional green of the second sub-pixel appear to be mixed. If you adjust the value of VI, it looks almost gray as a whole.
• the voltage for display after switching is not V0 but another value V2.
• the value of V1 is superimposed on V2 and applied, so that green that is brighter than the original green display is displayed for one frame period. That At this time, a grayish green mixed with the transient response of the first pixel is visible only for one frame period.
• Figure 7 shows the response of @] £ and retardation.
• FIG. 8 shows the voltage and retardation response of the first and second sub-pixels when the first sub-pixel changes from purple to white.
• the difference from FIG. 6 is that the and the retardation of the first sub-pixel before switching are smaller than those in FIG. 6, and the voltage at which the retardation becomes 550 nm corresponding to purple is marked.
• the transitional color appearing in the first sub-pixel is, on average, visible as a color closer to red than in FIG.
• a color obtained by averaging the transient response of the first sub-pixel is represented by two components of pure blue and pure red, and green equal to the average value is displayed on the second sub-pixel.
• the voltage of the second sub-pixel may be determined in advance so that the color looks almost achromatic.
• the voltage of the first sub-pixel before and after the display switching and the voltage value of the second sub-pixel determined to be close to achromatic visually are stored in a table.
• the voltage of the pixel may be calculated.
• the display color at the time of the transient response is yellow, and red and yellow are the same warm color system and are close to the system colors. Coloring may not be bothersome.
• the voltage correction of the second sub-pixel 51 may forcefully increase the sense of incongruity. In such cases the second The sub-pixel 51 may be left in black display and the voltage correction as described above may not be performed.
• the present invention can be applied to a conventional OD method. In the first sub-pixel 52, even if the OD method is used, display of a hue different from a desired display color is performed for one frame. In order to make it achromatic, the voltage is further superimposed on the second sub-pixel, which is determined by the OD method.
• a control circuit 2 is a circuit that controls the display panel 1 in which the pixels in FIG. 1A are arranged on a matrix based on an input image signal.
• the RGB input image signals are converted to digital signals by the A / D converter 3 respectively, and the red and blue input image signals enter the signal conversion circuit 4 and correspond to the voltage for driving the first sub-pixel 52 It is converted to the signal S1.
• the converted signal S 1 of the first sub-pixel is input to the correction signal calculation circuit 6 together with the signal S 1 ′ of the first sub-pixel which has been read out from the memory 5.
• the newly input signal S 1 of the first sub-pixel is replaced with the signal S 1 ′ of the first sub-pixel up to that time and stored in the memory 5.
• the correction signal calculation circuit 6 has a built-in lookup table 7, and calculates the second sub-pixel from the signal S 1 ′ of the first sub-pixel up to that point and the signal S 1 of the newly entered first sub-pixel. Calculates and outputs the correction signal C2 to
• the output correction signal C 2 and the digitally converted G image signal are added by an adder 8 and output as a signal S 2 of the second sub-pixel.
• the signal S 1 of the first sub-pixel and the signal S 2 of the second sub-pixel are converted by the DA converter 9 and then sent to the display unit 1 as drive voltage signals of the first and second sub-pixels. It is.
• FIG. 10 is an example of another control circuit.
• the signal conversion circuit 4 in the control circuit 2 in FIG. 9 forms the image processing unit 10.
• the motion detection unit 11 is placed in place of the memory 5 and the correction signal calculation circuit 6, and generates a correction signal from the signal of the first sub-pixel and the amount of change.
• the correction signal is added by the adding circuit 7 to the input image signal.
• the gamma correction unit 12 performs gamma correction on each of the signal of the first subpixel and the signal of the second subpixel, performs DZA conversion, and outputs the result to the display element for a predetermined period.
• a predetermined amount may be obtained from the change amount using a lookup table, or a calculation may be performed for each frame using a formula that has been formulated. Is also good.
• an overdrive processing unit (not shown) may be provided to perform processing based on the OD method.
• the phenomena that occur are the same as those in the above basic configuration. Therefore, the countermeasure is the same, and when the edge during moving image display, the switching of still images, or the coloring phenomenon that is superimposed on the entire image during dither processing occurs, the second sub-pixel is compensated to compensate for it. 5 1 should be controlled.
• a green color filter is used for the second sub-pixel 51
• a magenta color filter is used for the first sub-pixel 52 (see FIG. 3).
• the first sub-pixel 52 displays a magenta color in a brightness change region from black to the maximum brightness, and displays a red, magenta, and blue display in a hue change region exceeding the maximum brightness. Therefore, in such a pixel configuration, for example, when switching from blue to black, blue ⁇ magenta ⁇ red is observed in the hue change region, and halftone display of magenta in the lightness change region is observed. It will be. In other words, although the display is momentarily red, magenta is displayed in most frame periods.
• the entire image at the edge of the moving object when switching between still images, or during dither processing is not a blue or monochromatic image but a magenta image. Will be colored.
• a driving method that outputs a display color that cancels the unintended display color to the first sub-pixel 52 is adopted.
• the second sub-pixel 51 when switching from blue to black as described above, the second sub-pixel 51 remains black and the display state is displayed only by the first sub-pixel 52. Instead of changing the color, the magenta system color is displayed in the transient response state of the first sub-pixel 52, so that the second sub-pixel 51 is turned on or in the halftone state during the transient response Voltage as described above.
• the transient response of the transition state from red to black is magenta for most of the frame period, and the transition state from blue to red is also magenta, so as a countermeasure, a display color close to achromatic was observed by the same processing.
• the method (3) in addition to the method (2), at least one of red and blue color filters is added as the second sub-pixel 51 (see FIG. 5). This makes it possible to achromaticize any transitional color of the first sub-pixel.
• compensation is attempted only with green pixels.
• magenta is displayed for most of the frame period, but red is displayed for a moment.
• This red cannot be achromatic by green alone, but can be achromatic by using a blue color filter.
• the ECB color LCD is controlled by appropriately controlling the primary color filter pixels arranged in the second sub-pixel 51 in accordance with the hue change situation in the first sub-pixel 52. It is possible to reduce discomfort when displaying a moving image.
• green is mainly used as the primary color filter.
• FIGS. 6 to 8 the discussion has been made on the assumption that the response is performed within one frame period.
• the voltage correction method of the present invention is effective even when the liquid crystal response is performed over a plurality of frames.
• the common configuration of the liquid crystal display element as an example of the color display element used in this embodiment is as follows.
• the liquid crystal material is a liquid crystal material with a negative dielectric anisotropy ⁇ (menoletane: hS3 ⁇ 4, model name ML C-6 0 8) is used.
• a substrate structure to be used an active matrix substrate in which TFT is disposed on one substrate is used, and a substrate on which color filters are disposed is used as the other substrate.
• the pixel shape and the color filter configuration are changed according to the embodiment.
• the number of TFT pixels is 800 ⁇ 3 horizontally and 600 ⁇ long.
• a reflection type configuration using an aluminum electrode is used for the pixel electrode on the TFT side.
• a broadband ⁇ / 4 plate (a phase compensator that can almost satisfy the 1Z4 wavelength condition in the visible light region) is disposed between the upper substrate (color filter substrate) and the polarizing plate as a phase compensator. .
• a normally black configuration is obtained in which the display becomes a state when no voltage is applied and a light state is obtained when voltage is applied in a reflective display.
• the pixel configuration of the liquid crystal display element used in the first embodiment is such that, as shown in FIG. 11, one unit pixel is divided into two sub-pixels, and a green color filter is provided only in one of the second sub-pixels 51. It is arranged.
• the liquid crystal display element has unit pixels of horizontal 1200 and vertical 600, and the cell thickness is 5 microns.
• transparent without a unit pixel color filter In the first sub-pixel 52, which is a sub-pixel, the retardation amount when a voltage of ⁇ 5 V is applied is about 300 nm.
• the applied voltage value of the second sub-pixel 51 having a green color filter is reduced in a region of 3 V or less.
• the transmittance changes accordingly, and continuous tone characteristics can be obtained.
• the first sub-pixel 52 which is a transparent sub-pixel without a green power filter, displays blue when 5 V is applied, and displays red when 3.8 V is applied. It can be seen that the liquid crystal panel has three primary colors.
• the continuous gray scale of the monochrome opening according to the magnitude of the applied voltage is displayed.
• the threshold voltage of this liquid crystal display element is about 2 V, and monochrome continuous tone display is in the range of 2-3 V.
• black, white, halftone, and red are selected as background colors, and a blue color having a size of 200 pixels horizontally and 100 pixels vertically is used as a moving object. Create a square window and move it from left to right so that it shifts by one unit pixel per frame (1 / 60th of a second).
• the pixel configuration of the liquid crystal display element used in the second embodiment is such that one unit pixel is divided into two sub-pixels and a green color filter is provided in the second sub-pixel 51 as shown in FIG.
• the first sub-pixel 52 is provided with a magenta color filter.
• the liquid crystal display element has unit pixels of width 1200 and height 600 as in Example 1, and the cell thickness is 5 microns.
• the liquid crystal panel of this embodiment is a display of three primary colors.
• a continuous gradation of magenta is displayed according to the magnitude of the applied voltage.
• the threshold voltage of this element is about 2 V, and the continuous tone display area is in the range of 2-3 V.
• black, halftone, and red are selected as background colors, and a blue color of a size of 200 pixels horizontally and 100 pixels vertically is set as a moving object. Create a square window and move it from left to right by one unit pixel per frame (1 / 60th of a second).
• the first By applying 2.2 V to the element 52, the response speed from blue to white at the left end can be rapidly changed, and a response within one frame can be realized.
• this alone will cause the left and right edges to become magenta when the window moves, so for one unit pixel at the left and right ends of the window, the green By applying 2.7 V to increase the lightness and performing observations, the coloring of the edges does not matter.
• red is selected as the background color
• 3.8 V is applied to the first sub-pixel 52 on the background
• 0 V is applied to the second sub-pixel 51.
• 5 V is applied to the first sub-pixel 52 and 0 V is applied to the second sub-pixel 51. In this state, when the window moves, the response speed is slow, a tailing phenomenon occurs, and the left and right edges become magenta.
• the pixel configuration of the liquid crystal display element used in the third embodiment is such that, as shown in FIG. 13, one unit pixel is divided into three sub-pixels, and one second sub-pixel 51 is provided with a green color filter.
• the remaining two first sub-pixels 52a and 52b are provided with magenta color filters, each having an area ratio of 1: 2.
• the liquid crystal display element has a width of 800, It has 600 vertical unit pixels and a cell thickness of 5 microns. Further, at this time, the amount of retardation when the ⁇ 5 V voltage is applied to the magenta pixel in the first sub-pixel 52 provided with the magenta color filter is about 300 nm.
• the applied voltage value of the second sub-pixel 51 having a green color filter is reduced in a region of 3 V or less.
• the transmittance changes accordingly, and continuous tone characteristics can be obtained.
• the first sub-pixels 52 a and 52 b having magenta color filters display blue when 5 V is applied and red when 3.8 V is applied. You can see that it is a display.
• the first sub-pixels 52 a and 52 b display a continuous magenta tone corresponding to the magnitude of the applied flH in an area of 3 V or less. Also, since the first sub-pixels 52a and 52b are divided into areas, it is possible to represent four gray levels as blue or red digital gray levels by appropriately adjusting the display pixels. . Further, the threshold voltage of the liquid crystal display element of this embodiment is about 2 V, and the continuous tone display area is in the range of 2 to 3 V. Further, in this embodiment, red can be displayed in four gradations, and the display state is expressed as black ⁇ red halftone 1 ⁇ red halftone 2 ⁇ red from the ⁇ ⁇ side.
• a red halftone 1 and a red halftone 2 are selected as background colors, and a moving body having a size of 200 pixels horizontally and 100 pixels vertically is selected. Create a blue square window and move it from left to right so that it shifts by one unit pixel per frame (1 / 60th of a second).
• red halftone 1 when red halftone 1 is selected as the background color, 3.8 V is applied to the smaller sub-pixel 52 b of the first sub-pixel 52 in the background, The larger of the sub-pixels of 5 2 OV is applied to the sub-pixels 52a of the. Further, 0 V is applied to the second sub-pixel 51. Further, in the moving window, 5 V is applied to the first sub-pixel 52, and 0 V is applied to the second sub-pixel 51. In this state, when the window moves, the response speed is slow, a tailing phenomenon occurs, and the left and right edges become magenta.
• the pixel configuration of the liquid crystal display element used in the fourth embodiment is such that one unit pixel is divided into six as shown in FIG. 14, and three first sub-pixels 52a, 52b, 52c and three
• the second sub-pixels 51 a, 51 b, and 51 c are formed, and the three first sub-pixels 52 a, 52 b, and 52 c have an area ratio of 4: 2: 1, and magenta A color filter is provided.
• the area of the two sub-pixels 51 b and 51 c among the three second sub-pixels 51 a, 51 b and 51 c has the smallest area among the first sub-pixels 52 a, 52 b and 52 c It has the same area as the sub-pixel 52c, and has blue and red color filters, respectively.
• a green color filter is provided for the remaining one sub-pixel 51a.
• the area of the green sub-pixel 51a is defined as S, where S is the sum of the areas of the first sub-pixels 52a, 52b, 52c, and Smin is the pixel area of the sub-pixel 52c having the minimum area. , S + Smin.
• the liquid crystal display element of the present embodiment has unit pixels of 400 (horizontal) and 600 (vertical). Same as ⁇ 3. With this configuration, analog full color can be displayed as described above.
• a 50% red halftone is selected as the background color, and a blue square window with a size of 100 horizontal pixels and 100 vertical pixels is created as the moving object. Move from left to right so that it is shifted by one unit pixel per frame (1 / 60th of a second).
• 5 V is applied to all of the first sub-pixels 52 a, 52 b, and 52 c, and the blue color of the second sub-pixels 51 a, 51 b, and 51 c is further applied.
• 3 V is applied to the sub-pixel 51c having the filter, and 0 V is applied to the other sub-pixels 51a and 51b.
• the sub-pixel 51a with the green color filter is used for each of the second sub-pixels 51a, 51b, and 51c.
• the coloring power S at the edge part is almost uninteresting.
• Example 5 A study is performed using a liquid crystal display element having the same configuration as that of the second embodiment. At this time, when the entire screen is switched from blue display to black, magenta color is observed for a moment. Therefore, if observation is performed by applying 2.5 V to the second sub-pixels 51 on the entire panel surface only in one frame immediately after the image switching, the magenta coloring is not bothersome.
• a study is performed using a liquid crystal display element having the same configuration as that of the second embodiment. At this time, a rectangle of 100 ⁇ 100 pixels, which is 50% halftone of blue display, is displayed using dither with black as a background. As the dither matrix used at this time, a Bayer type 4 ⁇ 4 matrix represented by Equation 1 is used.
• the display image is divided into blocks of 4 pixels x 4 pixels, consisting of 25 vertical blocks and 25 horizontal blocks.
• the display status of each block is f ON OFF ON OFF
• the whole rectangle is colored magenta during the switching process.
• a study is performed using a liquid crystal display element having the same configuration as that of the sixth embodiment. At this time, a rectangle of 100 ⁇ 100 pixels, which is 25% halftone of blue display, is displayed using dither with black as a background. At this time, the display status of each block is f ON OFF ON OFF,
• ON is blue and OFF is black.
• blue is displayed at 25% halftone due to the spatial color mixing effect.
• pulse width modulation When gradation display is performed by performing pulse width modulation, such as when using an M I ⁇ substrate, pulse width modulation may be used. Further, in this embodiment, V V liquid crystal is used. However, by using the OCB mode, higher-speed response can be realized, which is preferable for alleviating the edge coloring phenomenon.
• the same driving method as that of the present embodiment is used even when a mode in which the air gap as the medium of the interference layer is changed by mechanical modulation is used instead of the liquid crystal element having the ECB effect. Can be used. Further, the same driving method as that of the present embodiment can be used even when a particle-moving display element that moves a plurality of particles, which is a medium based on the structure described in the embodiment, by applying a voltage is used as the display device. is there. Further, in the present embodiment, the combination of green and magenta described as a color filter is also applicable to the combination of red and cyan and blue and yellow.
• a TFT is used as a drive substrate.
• a substrate configuration is changed such as using a switching element formed on a semiconductor substrate, or a simple matrix drive or a plasma dressing drive is used. Such a driving method can be obvious.
• the substrate used to form the TFT is formed by transferring an amorphous silicon TFT substrate, a low-temperature polysilicon TFT substrate, a high-temperature polysilicon TFT substrate, a semiconductor substrate (LCOS), or a semiconductor layer onto a glass or plastic substrate. Any substrate such as the obtained active substrate can be used. [Industrial applicability]
• the present invention provides a color display element (liquid crystal display element) that reduces an undesirable coloring phenomenon that occurs on an edge portion of a moving object or an entire image when switching an image such as a moving image display, and a drive thereof. Can be used for the method.
• a color display element liquid crystal display element

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