WO2006067750A2 - Procede et appareil d'affichage pour systeme de panneau lumineux et systeme de panneau lumineux - Google Patents
Procede et appareil d'affichage pour systeme de panneau lumineux et systeme de panneau lumineux Download PDFInfo
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- WO2006067750A2 WO2006067750A2 PCT/IB2005/054346 IB2005054346W WO2006067750A2 WO 2006067750 A2 WO2006067750 A2 WO 2006067750A2 IB 2005054346 W IB2005054346 W IB 2005054346W WO 2006067750 A2 WO2006067750 A2 WO 2006067750A2
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- spotlights
- light
- color
- spotlight
- display area
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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
- G09G3/3406—Control of illumination source
- G09G3/342—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2310/00—Command of the display device
- G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
- G09G2310/0235—Field-sequential colour display
-
- 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
- G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
- G09G2310/024—Scrolling of light from the illumination source over the display in combination with the scanning of the display 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
- G09G2310/00—Command of the display device
- G09G2310/06—Details of flat display driving waveforms
- G09G2310/061—Details of flat display driving waveforms for resetting or blanking
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
- G09G3/3413—Details of control of colour illumination sources
Definitions
- the present invention relates to a backlight system display method and device, and backlight system.
- a display device using a backlight is constructed to display an image by guiding light emitted from the backlight into a transmissive type display panel, modulating the light in accordance with the image to be displayed and guiding the resultant modulated light out of the panel front.
- Patent Document 1 describes a liquid crystal display device which belongs to such a type and realizes a structure using a backlight and eliminating the necessity for a color filter in a display panel.
- This device is intended to constitute the backlight with R (red), G (green), B (blue) linear light sources along scanning lines on a screen and provide a color display by repeating operations of sequentially selecting (addressing) a scanning line on the display panel from top to bottom of the screen within a 1 -frame period and writing any 1 -color image signal corresponding to the selected scanning line into pixels of the scanning line while turning on the linear light source corresponding to the color of the image signal and the position of the selected scanning line in synchronization with the writing, with color to be displayed being changed for each frame.
- Patent Document 2 discloses a liquid crystal display device which also belongs to the same type and eliminates the necessity for providing any color filter in a display panel. This device is designed to be able to realize high-speed driving. [Patent Document 1]
- Patent Document 2 Japanese Patent Application Laid-Open No. 10997/98 (especially, see Paragraph Nos. [0001] and [0016] to [0019])
- color synthesis effect does not function, and it tends to provoke a situation in which the user recognizes image information of only one or two colors instantaneously and clearly, that is, the so-called color division.
- Patent Document 2 is designed to realize high-seed pixel driving using a low response liquid crystal material but to be merely able to display images with at most three colors in the display area, which is inadequate for countermeasures for the color division.
- the present invention has been made in view of such problems and an object thereof is to provide display method and device which can avoid the above-described color division, and a backlight system adapted to them.
- Another object of the invention is to provide a display method and a device and a backlight system, which can improve an efficiency of use of light from a backlight and an aperture ratio of a display panel satisfactorily without any problems such as color division.
- a first aspect of the present invention is a display method using a transmissive type matrix display panel in which a plurality of row electrodes and a plurality of column electrodes are arranged and pixels are driven based on signals applied to these row and column electrodes, wherein: a backlight system is used to individually generate at least first, second and third colors of bar-shaped spotlights formed along the row electrodes and to irradiate the display panel with the spotlights as backlight while moving the spotlights in a direction perpendicular to a longitudinal extending direction of the row electrodes over a display area of the display panel, each of the spotlights being repeatedly moved from one side of the display area to the other side opposed thereto with existence of respective first to third spotlights of at least the first to third colors and a fourth spotlight of at least one color chosen from at least the first to third colors in the display area; in accordance with moving of the spotlights, repetition is made of an addressing operation of selecting a row electrode associated with pixels corresponding to a
- Adopting such an aspect eliminates the necessity for providing any color filter in the display panel and improves an aperture ratio and transmission factor of light, that is, an efficiency of use of rear light from the backlight.
- the display panel need not be provided with subpixels corresponding to the first to third colors and can be constructed of only principal pixels, and therefore the number of column electrodes required is only 1/3 of that of the construction with subpixels, thereby contributing to simplification of the display panel structure and a reduction of the manufacturing cost.
- One principal pixel has a combined function of displaying pixels of the first to third colors, and therefore if the size of this principal pixel is reduced by applying processing of fine formation at a subpixel size level which is conventionally feasible, high resolution can also be achieved.
- the display area at least four spotlights exist simultaneously and their pixel information is effectively displayed, and therefore it is possible to make a color synthesis effect function fine and avoid above-described color division and also provide more advantages in displaying moving images.
- using the imaginary area can not only increase the number of spotlights appearing on the screen but also complicate moving pattern of the spotlights, and thereby further promote the color division prevention effect.
- a black spot or other spot for preventing light transmission may be formed between adjoining spotlights. This can prevent mixed-color parts which may appear in areas where the spotlights superimpose on one another and avoid displays of undesired light due to such mixed-color parts. Such spots for preventing light transmission are spatially small areas and also temporally transient, so that they have no substantial influence on the image to be displayed. Furthermore, a synchronous timing control may be applied to the moving of the spotlights and the addressing operation. This ensures the moving of the spotlights on the backlight side and the addressing operation on the panel side.
- the spotlight is preferably moved by changing a color of illumination light for pixels associated with at least one selected row electrode after completing the addressing operation and driving of the pixels based on the pixel information signals.
- the addressing operation and application of the pixel information that is, writing of pixels normally presents a transient state of pixels no matter what kind of the pixel driving active element or pixel driving structure is applied. Even if the pixels are irradiated with the corresponding spotlights during a period during which this transient state may be presented, pixel information is not displayed appropriately. According to this form, pixels of a selected row electrode are irradiated after pixel writing operation, and therefore spotlights can be modulated appropriately in accordance with appropriate pixel information.
- the pixels are not irradiated with light in the midst of the writing of the pixels and the pixels are placed in a dark state, making it possible to hide the pixel information which may present a transient variation.
- the addressing operation and provision of the pixel information signal may be performed for a row electrode associated with pixels at a location at which the spot for preventing light transmission is formed. This is because if a pixel information writing transient state is presented at the spot for preventing light transmission, inappropriate modulation due to the transient state does not influence the display.
- pixels corresponding to an overlap portion or boundary of the spotlights and/or its vicinity area are preferably driven with predetermined pixel information signals capable of preventing light transmission of the pixels. Since a so-called color mixture is likely to occur in areas of adjoining spotlights, it is possible to prevent light of mixed colors from passing and deteriorating the display quality by driving the pixels corresponding to this color mixture portion with pixel information (preferably the darkest pixel information) of e.g. a black level.
- driving of the pixels corresponding to an overlap portion or boundary of the spotlights and/or its vicinity area may be performed based on simultaneous selection of a plurality of row electrodes and simultaneous provision of the predetermined pixel information signals to these selected row electrodes, and it is thereby possible to realize efficient control.
- the spotlights may have their own widths, or a width of at least one of the spotlights may be made variable, or an intensity of at least one of the spotlights may be made variable, which amplifies the possibility of color balance adjustment.
- a range of pixels driven with the predetermined pixel information signals may correspond to a color mixture portion caused around a boundary of the spotlight and have a width no less than a width of the color mixture portion, and it is thereby possible to sufficiently shut off even a tiny amount of light leaking from the color mixture portion and further improve the display quality.
- the spotlights may be moved on the display area at substantially the same time or sequentially depending on the style of the backlight system. Furthermore, one cycle of moving of the spotlights on the display area may be made equivalent to one frame period of the images to be displayed, which ensures consistency with the original image information signal.
- a second aspect of the present invention is directed to backlight systems used in the above-described aspect and forms of display methods, one of which is a backlight system comprising construction in which a plurality of linear irradiating sections for selectively applying the first to third colors of light extend along the row electrodes and are arranged over the display area, the backlight system carrying out the moving of the spotlights by making control in which an irradiating section next to an irradiating section corresponding to the forefront of a spotlight is switched to make light irradiation of a color of that spotlight.
- a second one is a backlight system comprising: a linear light source; a reflector plate for condensing light rays from the light source to a linear illuminating face; coloring means having a color film and being capable of moving the color film in such a manner that the color film passes through above the illuminating face; and light distribution conversion means for converting linear light rays having been introduced from the illuminating face and colored through the color film into planar distributional light rays, wherein the color film has patterns in which the first to third colors of light, and the moving of the spotlights on the display area is performed by passing operation of the color film of the coloring means above the illuminating face.
- This can implement the present display method using a single light source.
- a further good form is obtaind in such a way that the color film has coloring areas corresponding to the first to third colors, respectively and a light shield area formed at a splice location between the coloring areas, and a more practical form is obtained in such a way that the coloring means are a cylindrical coloring drum which is provided around the linear light source and rotates about a predetermined center axis as a rotation axis and whose surface part is provided with the color film.
- a third one is a backlight system comprising: a light guide assembly plate having a plurality of light guide parts each extending along the row electrodes with a width in which the part can be overlapped on pixels associated with at least one row electrode, the light guide parts being lined up over the display area; and optical systems for selectively entering the first to third colors of light to a side face of the light guide part in the light guide assembly plate for each part, wherein the optical system next to an optical system corresponding to the forefront of a spotlight is switched to turn on the light of a color of that spotlight so as to move the spotlight.
- a so-called edge-light type light source can also realize the present display method satisfactorily.
- the light guide part may be adapted so as to have a groove extending in a direction perpendicular to a longitudinal extending direction of the part and having an incline for reflecting light from the optical systems toward the display area or the other equivalent reflecting structure to make uniform a light distribution in the longitudinal extending direction of the light guide part.
- a partition layer between the light guide parts in the light guide assembly plate the partition layer consisting of a material having a light reflective property or refractive index lower than a refractive index of the light guide parts so as to satisfactorily secure the independency of the linear shape of each sub-spotlight making up the spotlight.
- an optical condensing member between the optical system and the side face of the light guide part so as to construct a more efficient system.
- a further aspect of the present invention is also directed to a display device found in the above description and the following description, the display device having advantages specific to the apparatus with various advantages associated with the display method and backlight system.
- Fig. 1 is a block diagram showing a general conceptional configuration of a liquid crystal display device according to one embodiment of the invention.
- Fig. 2 is a schematic illustration showing illumination spotlights from a backlight unit and a driving manner of a display panel in a liquid crystal display device shown in Fig. 1.
- Fig. 3 is a flow chart showing operation of the liquid crystal display device, relating to Fig. 2.
- Fig. 4 is cross-sectional view and plan view showing one example of a backlight unit applied to the liquid crystal display device shown in Fig. 1 and illumination spotlights therefrom.
- Fig. 5 is a flow chat showing operation of a liquid crystal display device according to the other embodiment of the invention.
- Fig. 6 is an illustration showing illumination spotlights from a backlight and driving manner of a display panel, relating to Fig. 5.
- Fig. 7 is an illustration showing illumination spotlights from a backlight unit and driving manner of a display panel in a liquid crystal display device according to a further embodiment of the invention.
- Fig. 8 is a flow chart showing operation of the liquid crystal display device, relating to Fig. 7.
- Fig. 9 is a flow chart showing another style of operation of the liquid crystal display device, relating to Fig. 7.
- Fig. 10 is cross-sectional view and plan view showing another example of a backlight unit applied to the liquid crystal display device shown in Fig. 1 and illumination spotlights therefrom.
- Fig. 11 is a schematic section view showing a modification of backlight unit shown in Fig. 4.
- Fig. 12 is cross-sectional view and plan view showing a further example of a backlight unit applied to the liquid crystal display device shown in Fig. 1 and illumination spotlights therefrom.
- Fig. 13 is perspective view and plan view showing a further style of construction of a backlight unit applied to the liquid crystal display device shown in Fig. 1 and illumination spotlights therefrom.
- Fig. 14 is an outline showing a manufacturing method for a light pipe used in the backlight unit of Fig. 13.
- Fig. 15 is an illustration showing illumination spotlights from a backlight unit and driving manner of a display panel in a liquid crystal display device according to a modification.
- Fig. 16 is an illustration for explaining a configuration of a feature peculiar to a liquid crystal display device of an embodiment according to the invention and its representative preceding part of operation.
- Fig. 17 is an illustration for explaining a configuration of a feature peculiar to a liquid crystal display device of an embodiment according to the invention and its representative following part of operation.
- Fig. 18 is an illustration showing illumination spotlights from a backlight unit and driving manner of a display panel in a liquid crystal display device according to a further modification of the invention.
- Fig. 19 is an illustration showing a construction of pixels and row and column electrodes of a display panel according to a variation of the invention.
- Fig. 1 shows a basic general configuration of a liquid crystal display device according to one embodiment of the invention.
- this liquid crystal display device is constructed mainly of a transmissive type liquid crystal display panel 1, a backlight unit 2 disposed behind the panel 1 to irradiate the rear of the panel 1 with light and peripheral circuits that generate signals and voltages necessary to control or drive the panel 1 and backlight unit 2 and supply the signals and voltages to them.
- the liquid crystal display panel 1 is intended to cause a liquid crystal layer (not shown) interposed between two opposed transparent substrates to carry out optical modulation in accordance with an image to be displayed.
- the liquid crystal display panel 1 in this example adopts an active matrix type configuration, and one substrate 11 on its rear side is provided with, for example, field effect type thin film transistors (TFTs) 12 as pixel driving active elements within a predetermined display area, the TFTs being arranged in a matrix form and associated with the respective pixels.
- TFTs field effect type thin film transistors
- Drain electrodes of the TFTs 12 are individually connected to pixel electrodes 13.
- a front side substrate 14 which is the other substrate of the display panel 1 and disposed opposed to the rear substrate 11 with a certain gap is provided with a common electrode 15 formed over a principal surface (inner surface of the panel) facing the pixel electrodes 13.
- a liquid crystal medium (not shown) is sealed in the gap between the substrate 11 and the substrate 14 to form a liquid crystal layer.
- the TFTs 12 are selectively turned on for each row by a gate signal as a row electrode signal (or row selection signal) supplied through the gate line Gx, while the TFTs which have been turned on are driven in accordance with pixel information to be displayed depending on the levels of the source signals as column electrode signals (or pixel information signals) supplied through the source lines Sy.
- the pixel electrodes 13 are given an electric potential according to such a drive state by their drain electrodes.
- the orientation of the liquid crystal medium is controlled for each pixel electrode by the electric field of intensity defined by a difference between this pixel electrode potential and a level of the voltage supplied to the common electrode 15. Therefore, for each pixel in accordance with the pixel information, the liquid crystal medium can modulate rear illumination light from the backlight unit 2 and control the amount of the light transmitted to the front side. Since details of the basic configuration of such a liquid crystal display panel are publicly known with various documents, further description will be avoided here.
- the display panel 1 has no color filter layer which has customarily been used for full-color display. As will be clarified in the following explanations, this is because the backlight unit 2 will assume the function of such a color filter. Therefore, the display panel 1 can be a so-called monochrome display panel.
- the backlight unit 2 has a configuration for planar illumination at the latest ultimately and the illuminating range covers the effective display area of the display panel 1. Furthermore, the backlight unit 2 individually generates first to third bar-shaped spotlights 2R, 2G and 2B bearing all kinds of so-called primary color light of, in this example, red, green and blue in an elongated form in which the lightspots are arranged in parallel with each other along the gate lines Gx.
- the backlight unit 2 irradiates the display panel 1 with the spotlights as rear light rays while moving the spotlights in a direction (vertical direction in Fig. 1) perpendicular to a longitudinal extending direction (horizontal direction in Fig. 1) of the spotlights over a display area of the display panel 1.
- the backlight unit 2 is controlled so as to move each of the spotlights 2R, 2G and 2B from one side of the display area to the other side opposed thereto and repeat such moving pattern. It should be noted that only three spotlights 2R, 2G, 2B are here shown to explain the basic configuration and operation at first, but according to the present invention, at least four spotlights are used for the display panel 1. This respect will be described later. Details of the configuration and control of the backlight unit 2 will also be described later.
- peripheral circuits shown as components other than the display panel 1 and backlight 2 can be roughly divided into three systems; a display panel drive system 3, a backlight drive system 4 and a system control system 5.
- the display panel drive system 3 includes buffer memory 31 and image memory 32 as image signal processing means, a source driver 33 as column driving means, a gate driver 34 as row driving means and a voltage producing circuit 35 as common electrode driving means.
- the buffer memory 31 serially receives digital image signals of red (R), green (G), blue (B) for one frame from an image signal supply system (not shown) and temporarily stores or writes these digital image signals frame-sequentially, while reading the stored image signals for each scanning line based on a control signal from a timing controller 51 and transfers the image signals to the image memory 32.
- the image memory 32 stores the transferred image signals based on a control signal from the timing controller 51 and performs read control suitable for the control of the backlight unit 2, which will be described later. In a frame under this read control, an image signal for the next frame is written into the buffer memory 31.
- the image signals are read from the image memory 32 for each scanning line and the read image signals are transferred to and held in the source driver 33 based on a control signal from the timing controller 51.
- the source driver 33 supplies the held image signals for one scanning line to the respective source lines Sy as source signals (pixel information signals) corresponding to their respective pixels.
- the gate driver 34 performs control to select any of the scanning lines, that is, gate lines Gx based on a control signal from the timing controller 51 and this control will also be adapted to the control of the backlight unit 2 which will be described later.
- Such a selection of the gate line is performed by generating a gate signal for applying a predetermined, for example, high level to the gate line to be selected.
- the voltage producing circuit 35 supplies an appropriate voltage signal to the common electrode 15 based on a control signal from the timing controller 51.
- This voltage signal may be a direct current or may also be an alternating current conforming to a so-called AC drive method.
- the level of this voltage signal serves as a reference potential of the source signals supplied to the source lines Sy.
- the backlight drive system 4 is constructed of a backlight driver 41 and other necessary components (not shown).
- the backlight driver 41 drives the backlight unit 2 under the control specific to the present invention based on a control signal from the timing controller 51. Such control may be realized in various manners, and details thereof will be explained below.
- this example adopts the timing controller 51 which can be programmed with processing steps in advance.
- the timing controller 51 receives synchronization signals of image signals from an image signal supply system (not shown) and generates various control signals carrying necessary instructions on timings and operations for the above-described blocks 31 to 35 and 41.
- the synchronization signals received here may include a dot clock signal indicating a data transfer timing for each pixel, so-called horizontal and vertical synchronization signals and frame synchronization signal indicating a frame period or the like. Based on these synchronization signals, the timing controller 51 generates control signals to perform the control specific to the present invention, which will be described later.
- Fig. 2 shows movements of the spotlights 2R, 2G, 2B applied from the backlight unit 2 onto the display panel 1 and also shows a selection of a scanning line which is performed together with the movements of these spotlights.
- the spotlights 2R, 2G, 2B move in a direction (vertical direction in Fig. 2) perpendicular to the longitudinal direction of the spotlights on the display area, each of the spotlights is repeatedly moved from one side of the display area to the other side opposed thereto and the moving pattern is repeated.
- these patterns move from the top edge to the bottom edge of the screen.
- the red spotlight as a first spotlight exists divided into two portions at the top and bottom edges of the screen, and the green spotlight as a second spotlight and the blue spotlight as a third spotlight exist between these red portions.
- Each spotlight has a width obtained, in this example, by dividing the height of the screen by 3, and moves while maintaining its total width appearing on the screen.
- the same spotlight is divided and its portion sticking out of the bottom edge appears at an upper section of the screen, but the sum of the lower width and upper width of the spotlight is kept to 1/3 of the height of the screen.
- the display panel 1 is controlled so that the scanning lines corresponding to the irradiation positions of the respective spotlights of the red, green and blue are sequentially selected (addressing operation).
- a scanning line located close to an adjoining spotlight below the spotlight in the irradiation range of each spotlight is selected.
- the nth scanning line corresponding to the red spotlight, the (n+x)th scanning line corresponding to the green spotlight and the (n+y)th scanning line corresponding to the blue spotlight are selected.
- nth, “(n+x)th” and “(n+y)th” indicate ordering numbers when numbering the scanning lines downward starting from a scanning line (the first scanning line) located at the top of the display area, and the same applies to the following.
- x and y express, in the number of scanning lines, spacings between a scanning line selected with regard to the red spotlight and scanning lines selected with regard to the green and blue spotlights, and the same applies to the following.
- the backlight unit 2 changes to the situation in (B) of Fig. 2.
- the irradiating position of each spotlight in (A) of Fig. 2 is shifted downward by one line.
- the display panel 1 is likewise controlled so that the scanning lines associated with pixels corresponding to the specific irradiating positions of the respective spotlights of the red, green and blue are selected. Therefore, the (n+l)th scanning line corresponding to the red spotlight, the (n+x+l)th scanning line corresponding to the green spotlight and the (n+y+l)th scanning line corresponding to the blue spotlight are selected.
- the (n+2)th scanning line corresponding to the red spotlight, the (n+x+2)th scanning line corresponding to the green spotlight and the (n+y+2)th scanning line corresponding to the blue spotlight are selected.
- the scanning lines are selected for the respective spotlights on the display panel 1 in such a way as to follow the movements of the respective spotlights.
- a scanning line (gate line) to be selected is indicated in the "Gt" section by appending a line number to be selected every time the selection is changed. For example, if a line number "n+x" is appended to "Gt", it means that the (n+x)th scanning line is selected and a gate signal for turning on TFTs connected to this selected line is supplied from the gate driver 34.
- a source signal supplied to the mth source line Sm (see Fig. 2) numbered from the left of the display area is expressed by appending the number of the scanning line and the color (R, G, B) of the corresponding pixel information in the section of "Sm" in Fig. 3.
- a source signal (Gn+x, m) carrying pixel information for displaying the pixel as a green pixel is supplied to the source line Sm.
- a source signal is updated in a cycle of 1/3 of a horizontal scanning period (H). This corresponds to the supply operation of a pixel information signal.
- Fig. 3 shows the waveform of a gate signal supplied to the nth gate line Gt in a
- Gate-n section as a representative example.
- the gate signal becomes active (high level) with a slight delay from an update time point of the source signal in an update period of the source signal shown in "Sm” and becomes inactive (low level) a little ahead of the next update. While the gate signal is active, all TFTs to which the gate signal is applied are kept in an ON-state making it possible to give potentials to the respective drain and pixel electrodes in accordance with the source signal supplied via the respective source lines.
- Each irradiating section formed in the backlight unit 2 can selectively generate or transmit light of any one of red, green and blue, and the irradiating section associated with this nth line performs such switching that irradiation with the green light is turned off (Goff) and irradiation with the red light is turned on (Ron).
- This switching of G ⁇ R should be performed when a sufficient time elapses after the new data Rn,m is written into the above-described pixel Pn,m. This is because a pixel remains in a transient state after an actual writing operation of new data into the pixel until pixel information with the new data is held stably and therefore if the color of illumination light is switched in this transient state, the illumination light after the switching is inappropriately modulated.
- the "sufficient time” referred to here preferably exceeds the time after writing of the new data is started until the pixel stably holds the pixel information of the new data.
- the backlight unit 2 sequentially changes colors of the respective spotlights of R, G, B during each horizontal scanning period (H) so that each spotlight moves on the screen and selects a scanning line corresponding to the switching position in response to the switching, and pixel information on the selected scanning line is written.
- operation of changing the color of a spotlight at the position corresponding to the selected line is performed for each color.
- FIG. 2 shows a situation in which the movements of the spotlights further advance, the blue spotlight appears at the top and bottom edge sides of the screen at this time, and the red spotlight and the green spotlight are continued between them.
- This figure also shows a situation in which the (n-l)th, (n+x-l)th and (n+y-l)th scanning lines are selected. This corresponds to a situation of selecting the immediately preceding (spatially one step upper) scanning lines with respect to the scanning lines selected in the foregoing figure (A), respectively.
- FIG. 2 shows a situation in which the movements of the spotlights further advance, the nth scanning line corresponding to the blue spotlight, (n+x)th scanning line corresponding to the red spotlight and the (n+y)th scanning line corresponding to the green spotlight are selected.
- This corresponds to a situation of selecting the same scanning lines as those in the foregoing figure (A) respectively.
- (F) of Fig. 2 shows a situation as the next step in which the (n+l)th scanning line corresponding to the blue spotlight, the (n+x+l)th scanning line corresponding to the red spotlight and the (n+y+l)th scanning line corresponding to the green spotlight are selected, which shows the same selected lines as those in the foregoing figure (B).
- the switching period of an irradiation color of the irradiating section in this embodiment is basically a time T obtained by multiplying a width of a spotlight, that is, the number of lines (x or y-x) corresponding to the length of 1/3 of a height of the screen by H/3 (H is 1 horizontal scanning period), but the duration of the irradiation color is T- ⁇ .
- ⁇ corresponds to the amount of time shift perceived when timing at which specific color irradiation of the irradiating section is turned off is shifted to a time before data writing as referenced by Goff and Roff .
- the display panel 1 is provided with no color filter layer, and therefore no light loss in the color filter layer is produced, contributing to improvement of efficiency of use of light. Furthermore, the display panel 1 need not adopt a form in which one principal pixel is comprised of sub-pixels of three colors R, G, B but can be constructed of only principal pixels, thereby making it possible to reduce the number of pixels and increase the aperture ratio considerably, as well as to contribute to the simplification of the panel structure and the reduction of manufacturing cost.
- Fig. 4 shows a specific configuration and illumination manner of the backlight unit 2.
- the left side of Fig. 4 shows a cross-sectional structure of the backlight unit 2 and the right side shows a plan structure of the backlight unit 2 and its form of illumination light on a plan view when the backlight unit 2 is incorporated in the display panel 1.
- the backlight unit 2 has a transparent light guide plate 20 made of, for example, acrylic resin and a linear light source section 21 provided on the light guide plate 20.
- the light guide plate 20 is provided with many recess-sectional grooves 201 for housing principal light- emitting sections of the linear light source sections 21, which are formed on the principal surface on the light irradiation side at predetermined intervals, and these grooves extend linearly from left to right in parallel with each other over the display area.
- the linear light source section 21 is constructed on the basis of the recess-sectional grooves 201.
- a light-emitting diode layer 2OB capable of emitting blue light is formed at the bottom of the recess-sectional groove 201.
- a light-emitting diode layer 2OG capable of emitting green light
- a light-emitting diode layer 2OR capable of emitting red light are stacked in that order on the layer 2OB.
- a blue light emitting command signal is applied, the layer 2OB spontaneously emits blue light and this light passes through the other light-emitting layers 2OG and 2OR and is applied onto the display panel 1 as a linear spot along scanning lines.
- green and red light emitting command signals are applied, the layers 2OG and 2OR also spontaneously emit green light and red light respectively, and these light rays are applied as linear spots along scanning lines onto the display panel 1.
- Slits 202 extending in parallel in the longitudinal direction of the recess-sectional grooves are provided between the one and the other recess-sectional grooves 201.
- the slit 202 forms a narrow passage space which extends from the illuminating face side of the backlight unit 2 to generally the depth of the recess-sectional groove 201, and air or other medium exists in the space.
- Such a passage space of the slit may also be formed beyond the depth of the recess-sectional groove 201 or may reach the rear face of the light guide plate 20.
- a plurality of longitudinal optical diffusive reflecting films 203 are formed on the rear face of the light guide plate 20 for each linear light source section 21.
- the optical diffusive reflecting films 203 are formed in parallel along the recess-sectional grooves 201 and facing the bottom face of the respective recess-sectional grooves 201.
- the reflecting films 203 reflect light leaked from the light-emitting layers 2OR, 2OG, 2OB and returns the light to the front (illuminating face) to effectively use the light and diffuse the reflected light, thus contributing to equalization of brightness distribution of linear light spots projected onto the display panel 1.
- the slit 202 reflects light rays from the light-emitting layers 2OR, 2OG, 2OB based on the existence of air or the like within the passage space. This allows a longitudinal rectangular area along the scanning line with the slit 202 serving as a delimiting boundary to be used as an irradiation area of generally one linear light source section 21.
- Light rays from the light-emitting layers 2OR, 2OG, 2OB not only propagate directly or through internal refraction of the light guide plate 20 to the display panel 1 but also are reflected by the reflecting film 203 and then propagate to the display panel 1 or are reflected by the slit 202 and then propagate to the display panel 1. It acts so as to make uniform brightness of light over the rectangular irradiation area through propagation inside the light guide plate 20 except for the direct irradiation.
- the backlight unit 2 in such a configuration is controlled so as to change the light- emitting color of the linear light source section 21 in correspondence with the scanning line selected by the display panel 1. For example, in a situation shown in (A) of Fig. 2, after the nth scanning line is selected and the corresponding red pixel information is written, the light source section 2 In is switched to emit red light to be applied onto the position of the nth scanning line in the display area (Fig. 4(1)). Likewise, for the (n+x)th scanning line, the light source section 21n+x is switched to emit green light to be applied onto the position of the (n+x)th scanning line in the display area (Fig.
- the light source section 21n+y is switched to emit blue light to be applied onto the position of the (n+y)th scanning line in the display area (Fig. 4(3)).
- emission of light of any corresponding one of the colors of red, green and blue is continued so that the spotlights formed present bar-shaped spots 2R, 2G, 2B on the display panel 1 , respectively, as shown in Fig. 4.
- the light source sections 2 In, 21n+x, 21n+y are supplied with control signals (red, green or blue light emitting command signals) so as to change the light-emitting color as in (1) to (3) in response to a selection timing of the scanning lines corresponding to the positions to be irradiated with light. Details of selection of a scanning line and timing of changing the light-emitting color conform to those already described in Fig. 2.
- the light source section 21 has been explained so far assuming that its width W 21 is equal to a pitch of the scanning line of the display panel 1, but it is possible to simplify the configuration and manufacturing of the backlight unit 2 by setting the width to an integral multiple not smaller than 2 of the pitch.
- the width W 21 of the light source section 21 is set to a value, for example, three times the pitch of the scanning line, the light source section 21 is responsible for irradiation of the three consecutive scanning lines. In this case, if, for example, the light source section 2 In is responsible for irradiation relating to the nth to (n+2)th scanning lines, the light source section 2 In continues to emit and irradiate for the corresponding color as long as the nth to (n+2)th scanning lines are selected.
- Such wrong optical modulation is attributable to the fact that while scanning lines are selected line by line, colors of the illumination light of the irradiating section 21 of the backlight unit 2 are changed for every plurality of lines, which may cause the quality of the image to be displayed to deteriorate though instantaneously (in this embodiment, periods corresponding to one horizontal scanning period and two horizontal scanning periods for the (n+l)th and the (n+2)th lines, respectively), thereby leading to undesirable results.
- the nth to (n+2)th gate lines Gt-n, Gt-n+1, Gt-n+2 for which red pixel information should be presented are sequentially selected for every horizontal scanning period, but irradiation switching of G ⁇ R of red light of the corresponding irradiating section 2 In (Ln in Fig. 5) is carried out during a selection period Tn+2 of the last gate line Gt-n+2. Such irradiation of red light is turned on after the pixel information relating to the last gate line Gt-n+2 is captured, on the basis of the same purport as that described above.
- irradiation of light of all colors is turned off (Goff ) immediately before the first gate line Gt-n is selected (before the gate signal Gt-n rises) and pixel information is captured in a state of no irradiation.
- the light source section 2In(Ln) does not irradiate the corresponding positions with light until pixel information is written for all the three nth to (n+2)th scanning lines. It is not until writing is performed for the last scanning line Gt-n+2 for which the irradiating section 2In(Ln) is responsible that switching (Ron) of red light irradiation of the irradiating section 2 In is effected and optical modulation is started for the three scanning lines simultaneously.
- This can eliminate the above-mentioned problem (wrong optical modulation) of inconsistency between selection of a scanning line for each line and switching of irradiation color every plurality of lines.
- Fig. 6 shows the display screen in a vertically long size for the convenience of the space etc. of the drawing, but it is different from the actual size and is not drawin to scale. In this respect, the same applies to Fig. 2 and the following figures.
- Fig. 7 is depicted in the same format as that in Fig. 2 and shows an example of transition in order of (A), (A2), (B), (B2), (C), (C2).
- the display panel 1 is controlled so that the nth, (n+x)th and (n+y)th scanning lines corresponding to the irradiated positions of the respective spotlights of red, green and blue are selected sequentially.
- these selected scanning lines are located on the forefront of the spotlights, and therefore they are located close to the color mixture portion.
- the positions of the color mixture portions on the panel is expressed relative to the selected scanning line, they can be the positions of the (n+q)th, (n+x+q)th, (n+y+q)th scanning lines, q expresses a spacing from the scanning lines (n, n+x, n+y, • • • ) selected for an original image display to the scanning line corresponding to the color mixture portions with the number of lines.
- the width of the color mixture portion corresponds to one scanning line for clarity.
- the (n+q)th, (n+x+q)th, (n+y+q)th scanning lines corresponding to such color mixture portions are selected sequentially under the same situation of the spotlights as in Fig. 7(A).
- (A2) of Fig. 7 shows this situation, and in response to these selectings, pixel information from the source lines are written into the pixels associated with the selected lines, respectively.
- the pixel information written here is assumed to be information (darkest pixel information) having a value presenting the highest light- shielding rate (e.g., black). This causes the light in the color mixture portions to be shut off with the darkest pixel information of the display panel 1, and therefore it is possible to avoid influences of light of unnecessary colors on the displaying. In this way, it is possible to form a spatiotemporal black masks which hide the color mixture portions on the display panel 1 in the form of following the emerging color mixture portions.
- Fig. 7(B) selection of the (n+l)th, (n+x+l)th, (n+y+l)th scanning lines and writing of pixel information for display
- Fig. 7(B2) selection of the (n+l+q)th, (n+x+l+q)th, (n+y+l+q)th scanning lines corresponding to the color mixture portions adjacent thereto and writing of the darkest pixel information
- Fig. 8 expresses Fig. 7 in the form of a time chart and follows the same format as that of Fig. 3.
- the darkest pixel information is preferably, before the color mixture portion reaches a certain scanning line, written into the pixel on the scanning line. This is because writing the darkest pixel information into the pixel in question after the color mixture portion arrives prevents the mixed-color light from passing with the normal displaying pixel information written therein so far and a transient modulated state from this pixel information until it saturates with the darkest pixel information for the duration from the arrival of the color mixture portion to the completion of the writing.
- Fig. 9 shows an example with the other control and is drawn in a format similar to that in Fig. 8.
- selection of the (n+q)th, (n+x+q)th and (n+y+q)th scanning lines corresponding to the color mixture portions and capturing of the darkest pixel information (bk) for them are performed simultaneously in a single period of H/3. For this reason, the gate signals Gt- n+q, Gt-n+x+q and Gt-n+y+q corresponding thereto are made risen simultaneously.
- Fig. 10 shows another specific configuration example of the backlight unit and parts equivalent to those of Fig. 4 are assigned the same reference symbols.
- this backlight unit 2' is made up of an array of light-emitting diodes formed on a predetermined substrate 20', and red, green and blue light-emitting diodes 2OR, 2OG, 2OB are arranged in that order in stripe shape from the top end to the bottom end of the panel 1 along the principal surface of the substrate 20'.
- An irradiating section 21 made up of a set of light-emitting diodes of three colors is formed for every scanning line or every plurality of scanning lines, and each diode and irradiating section are formed in parallel, and longitudinally along scanning lines as in the case of those shown in Fig. 4.
- a light guide 2a having a principal surface and a diffuser 2b are disposed between the backlight unit 2' and display panel 1, each covering at least a display area of the display panel 1.
- the light guide 2a and diffuser 2b shown in Fig. 10 are shown in their cross-sectional views as in the case of the backlight unit 2'.
- the light guide 2a has a prism array structure condensing light from the diode array and guiding it to the diffuser 2b.
- the diffuser 2b diffuses the light from the light guide 2a, equalizes a light distribution mainly in the longitudinal direction of the scanning line and in a direction perpendicular thereto and guides the diffused light to the display panel 1 as a longitudinal square light spot.
- the light guide 2a may be omitted depending on a light distribution characteristic of the light-emitting diode.
- Fig. 10 shows the irradiation manner of light-emitting diodes in the same situation as that shown in Fig. 4 in a simplified manner, wherein light-emitting diodes 2OR, 2OG, 2OB which are turned off are expressed with shading in a cross-sectional view on the left.
- the light-emitting positions in the irradiating section 21 on the display area vary depending on the color of the spotlight to be formed, but the light condensing and diffusing functions of the light guide 2a and diffuser 2b can mitigate variations in the positions of irradiation onto the display panel 1.
- the backlight unit 2' in the structure shown in Fig. 10 has basically the same method of control of the irradiating sections 21 as that shown in Fig. 4.
- the layers of the light-emitting diodes are not overlapped in the direction perpendicular to the principal surface, and most of emitted light rays are applied without passing through the non- light-emitting diode layers, and therefore it has an aspect that loss in the efficiency of use of light is smaller than that in Fig. 4.
- the optical diffusive reflecting film 203 as shown in Fig. 4 or a reflecting film may be formed for each irradiating section 21 or over the entire surface on the rear of the substrate 20' in Fig. 10.
- a groove 2Ov having a V-figured cross section is provided on the rear of the substrate 20, and the bottom thereof faces an end of a slit 202.
- An optical diffusive reflecting film 203 is formed so as to fill the space within this groove 2Ov and cover the entire rear surface of the substrate 20. This causes the light arriving from the light- emitting diodes 2OR, 2OG, 2OB toward the rear to be rebounded on the slope of the groove 2Ov and returned to a side of the light-emitting source diode.
- this groove 2Ov can prevent light emitted in one irradiating section 21 from leaking to other irradiating sections 21, whereby the independency of illumination light for each irradiating section is enhanced and effective use of light is achieved. Furthermore, since a single reflecting layer can be formed over the entire rear surface of the substrate 20 without forming the optical diffusive reflecting film 203 for each irradiating section as shown in Fig. 4, advantageous manufacturing is attained.
- Such a change in this Fig. 11 is also applicable to the configuration in Fig. 10. That is, at the delimiting position of the irradiating section 21 shown in Fig. 10, the structure in Fig. 11 can be formed for the substrate 20'.
- Fig. 12 shows another configuration example of the backlight unit.
- the configuration shown in Fig. 12 is not based on surface irradiating means with an arrangement of a plurality of longitudinal light-emitting sources as shown in Figs. 4 and 10, but based on a concept of linealy guiding light from a single light source from one side of the display panel and forming spotlight which distributes over the display area.
- a light guide plate 2LG as optical distribution converting means covering the display area is disposed on the rear of the display panel 1 and a cylindrical illuminator 200 having an irradiation area is disposed facing the side of this light guide plate 2LG as the backlight unit.
- This cylindrical illuminator 200 has a so-called barber-pole-like structure and is principally provided with a fixed columnar Cold Cathode Fluorescent Lamp (CCFL) 25 arranged in parallel with one side, for example, the left end face of the light guide plate 2LG and a fixed reflector plate 26 fit surrounding the outside thereof at a predetermined distance and an optically transmissive coloring drum 27 wound around the outside thereof in a freely rotatable manner.
- CCFL Cold Cathode Fluorescent Lamp
- the fluorescent lamp 25 may be replaced by a Hot Cathode Fluorescent Lamp (HCFL). Although here is adopted a type used as a light source of white light, a light source of other color may also be used.
- the axis of the fluorescent lamp 25 is aligned with a straight line (center line) by which the end face of the light guide plate 2LG is halved along the longitudinal direction thereof.
- the reflector plate 26 is formed so as to surround the fluorescent lamp 25 except an outlet area (illuminating face) 26w from which light exits and has a substantially paraboloidal surface for reflecting light from the fluorescent lamp 25 and condensing the reflected light onto the illuminating face as efficiently as possible.
- the focus position of the paraboloidal surface is aligned with the axis of the fluorescent lamp 25 and the center line of the end face of the light guide plate 2LG.
- the coloring drum 27 involves a mechanism (not shown) rotatable around the axis of the fluorescent lamp 25 as a rotation axis at a predetermined speed.
- Light from the fluorescent lamp 25 passing through the illuminating face 26w defined by the aperture of the reflector plate 26 is colored at the surface section which appears outside the illuminating face of the coloring drum 27 and guided to the end face of the light guide plate 2LG.
- This guided light propagates in a planar shape through the light guide plate 2LG, principally in the lateral direction of the display area of the display panel 1 , and forms the above-described bar-shaped spotlights (2R, 2G, 2B) in the display area. Therefore, the end face light which has passed through the illuminating face 26w is converted to planar illumination light which enters from the rear of the display panel 1 and spreads over the display area.
- the coloring drum 27 includes coloring areas 27r, 27g, 27b which correspond to red, green and blue spotlights (2R, 2G, 2B), respectively, which continuously move from top to bottom of the display area in the display panel 1 as described above when the coloring drum 27 is rotated. These coloring areas can be formed with known coloring films of the corresponding colors.
- the coloring areas 27r, 27g, 27b of the coloring drum 27 are formed in such a way that when the coloring drum 27 makes one revolution, once cycle of the moving pattern of the spotlight is completed on the display panel 1.
- the coloring areas 27r, 27g, 27b of the drum 27 appear mainly consisting of slanted bars of red, green and blue.
- Black areas 2BK having a predetermined width are formed along boundaries between the coloring areas 27r, 27g, 27b, as required. As already described, this is intended to prevent mixed- color irradiation with different colors of red, green and blue that would be produced on the display panel 1 (that is, to form a black mask).
- the coloring areas 27r, 27g, 27b are made of red, green and blue color filter films, respectively, but it is possible to change the coloring characteristics of the color filters as appropriate in accordance with the characteristic of the light emitted from the fluorescent lamp 26. As a standard in this case, it is a common understanding that a white color can be realized when all colors are synthesized on the display panel, but this does not exclude the possibility of intentionally removing this standard.
- Fig. 13 shows the configuration of a backlight unit in a further form.
- the configuration in Fig. 13 is based on a concept based on a light stick that covers at least one scanning line of the display panel 1 as shown in the upper figure.
- the light stick 40 adopted has a rectangular parallelepiped-based appearance and has V- figured grooves 4v formed on the rear (a side opposite to the side from which light is applied). These grooves extend in a direction perpendicular to the longitudinal extending direction of the stick and formed so as to suitably reflect light incident on one end face of the stick 40 toward the illuminating face side on the slopes of the grooves in order.
- a 3-color light source 42 is provided facing the end face as a necessary optical system and a convex lens 44 is provided between the light stick 40 and the light source 42 as a light condensing member.
- the light source 42 is made up of, for example, red, green and blue light-emitting diodes and any one of these diodes is selectively turned on and can be driven to emit light.
- Fig. 13 shows an example where there are three grooves 4v, but this number can be arbitrarily set. It is also possible to arrange the light source and light-condensing system not only on one side but also on both sides of the light stick 40.
- the light reflected on the end face can be expected to have action similar to that in the above- described process with respect to the slope of the end face side of the groove 4v, and the efficiency of use of light improves.
- the configuration where a light source is disposed on only one side of the light stick 40 and no reflecting means is provided on an end face of the opposite side it is possible to adopt a structure not having V-figured grooves but having slopes only on the light source side.
- a light pipe 400 as a light guide assembly plate is configured by lining up a plurality of the sticks 40 having such a structure in a flat plate shape with their edge faces aligned with one another.
- Barrier layers 46 made of a material having high reflectivity or lower refractive index than the refractive index of the light stick 40 are formed between the light sticks 40 of this light pipe 400. This barrier layer 46 can prevent light propagating inside the light stick 40 from entering other light sticks 40. Therefore, it is possible to establish independency of light in the propagation path.
- the already-described light sources 42 and light-condensing lenses 44 are arranged on the side of the light pipe 400 in a one-to-one correspondence with the light sticks 40. How to control each light source 42 is based on the gist explained using Figs. 4 and 10.
- the light pipe 400 is disposed behind the display panel 1 in such a way that each illuminating face of the light stick 40 faces the rear of the display panel 1. Light propagating through the light pipe 400 is applied onto the display panel 1 for each light stick 40.
- Fig. 14 shows situations in which the light pipe 400 is manufactured.
- thin films 46' made up of a highly reflective thin film or reflector made of transparent resin having a low refractive index to form the above-described barrier layers 46 and light guide layers 40' made of resin or the like having extremely high optical transmittance to form the above-described light sticks 40 are stacked one atop another alternately on a manufacturing substrate (not shown).
- the thin films 46' are preferably of an adhesive type to improve adhesion between the light guide layers. As many light guide layers 40' as required to cover the number of scanning lines of the display panel applied are stacked. When stacking is completed, the structure is subjected to necessary stabilization processing such as heating, drying to transform it into a stable structure.
- the multilayered structure obtained in this way is sliced to a predetermined thickness. Such slicing is performed using a plane 4OC parallel to the direction in which the thin films 46' and light guide layers 40' are stacked as a slicing surface. In this way, an original form of one light pipe 400 shown on the right of Fig. 14 is created. Then, after the formation of the grooves 4v and other necessary post-processes, the light pipe 400 having a structure shown in the lower part of Fig. 13 is completed.
- the grooves 4v can be formed through, for example, grinding and emboss shaping or the like.
- the backlight unit 2 has a configuration (rear light source type) based on an array of linear irradiating sections extending from one end to the other end of the display area, but it is also possible to derive a modification example (edge light source type) using a light guide extending over the display area like the form shown in Fig. 13 instead of the linear irradiating section and introducing light from the edge thereof.
- a modification example edge light source type
- the fluorescent lamp 25 that is a light source always emits light in the same driving state, and therefore a variation in the power supply current is extremely small. This contributes to reduction of power consumption with less noise and ripple, which is advantageous in stabilization of the power supply of the entire display device.
- the present invention is not necessarily limited to such a spotlight configuration. That is, it is possible to narrow the width to increase the number of spotlights corresponding to the red, green and blue.
- spotlights are applied onto the display panel 1 and moved as shown in Fig. 15 (when there are two spotlights for each of the red, green and blue), but the observation is the same as that using three spotlights in the above-described basic examples. More specifically, during the horizontal scanning period "H" shown in the time charts in Figs.
- Figs. 16 and 17 are schematic diagrams representing such points and show a relationship between an imaginary area to be defined and a display area.
- An imaginary area (shown with a frame of dotted lines) 500 is intended to form a sequence of spotlights to be presented in the display area of the panel 1.
- a number of spotlights R 1 , G 1 , B 1 , R 2 , G 2 , B 2 , • • • which is greater than the number of spotlights (8 in this example) presented in the display area 510, and to which at least n (n is an integer equal to or greater than 2; here, 5) sets of first to third colors (R, G, B) are repeatedly assigned in order of the first to third colors, are each designed to repeatedly moved from start to end of the imaginary area 500.
- the situation of such movement is shown in (a) to (c) of Fig. 16 and (d) to (f) of Fig. 17 through some omitted processes in midstream, (f) of Fig. 17 is followed by the situation as shown in (a) of Fig. 16, and if the state in (a) of Fig. 16 is assumed to be a starting point, one cycle of spotlights in the imaginary area 500 completes by returning to the state in (a) of Fig. 16 again.
- An effective range 510 (shown by thick lines in the figure) of spotlights to be formed in the display area is defined in the imaginary area 500 and the spotlights within the effective range are applied onto the panel 1 as rear light.
- eight spotlights R 2 , G 2 , B 2 , R 3 , G 3 , B 3 , R 4 , G 4 enter the panel 1.
- the proportions of occupations of the R, G, B spotlights in the display area vary according to the situation of movement of the spotlights, and moreover the distribution of the R, G, B spotlights become uneven.
- the R, G, B spotlights in the display area remain in the same proportion and do not vary depending on the situation.
- using the imaginary area 500 can make the proportion and/or distribution of the spotlights to be formed in the display area arbitrarily adjustable and variable according to the situation of movement of spotlights. This means that it is possible not only to increase the number of spotlights appearing in the screen but also to make its moving pattern more complex, whereby the color division prevention effect can be further promoted.
- the number of spotlights in the imaginary area is 15 and the number of spotlights in the display area is 8, but it goes without saying that the present invention is not limited to these numbers.
- the number of spotlights in the display area is 4.
- this number is not limited to "3" which is the number of basic colors as the technique disclosed in the above-mentioned Patent Document 2.
- the number of spotlights in the display area is 4, the number of spotlights in the imaginary area becomes a multiple of the number of basic colors exceeding 4 (3 in the case of this embodiment), which exceeds 4.
- first to fourth spotlights mean spotlights of the first to fourth types (or genres). Considering it in the examples in Figs. 16 and 17, for example, the first spotlight refers to R 2 , R 3 , the second spotlight refers to G 2 , G 3 , the third spotlight refers to B 2 , B 3 and the fourth spotlight refers to R 4 , G 4 .
- the imaginary area 500 is occupied by light spots to which an integer number (5 in this example) of basic colors R, G, B are assigned respectively, but the present invention is not necessarily limited to this and the numbers of R spotlights, G spotlights and B spotlights need not be the same.
- the light spots to be formed in the imaginary area 500 can be composed so that a predetermined reference color is represented per unit time when the light spots appearing in the display area are synthesized.
- the imaginary area referred herein need not always be provided as a physical space such as memory in the backlight driver 41 or the like. Only existence of the concept recognized as such an imaginary area in the control of the backlight suffices. Furthermore, also when such control of movement of spotlights using the imaginary area is performed, pixel driving is performed for the panel 1 in accordance with the spotlights presented in the display area and their movement as in the case of the aforementioned basic example. Moreover, the aforementioned configuration and control are also applicable to those of the backlight system applied hereto. Therefore, the pixel driving and the form of the backlight system in this case should be referred to the above explanations.
- red, green and blue spotlights have the same width, but they may have their own different widths.
- red, green and blue spotlights have the same width, but they may have their own different widths.
- spotlights having smaller widths for green than blue or red than green.
- the pixel information storage time for a 1 -frame period of the pixel is shorter for a green display than for a blue display, and for a red display than for a green display. In this way, it is possible to make density of the display color differ in order of blue, green, red in images obtained consequently.
- the densities of the display colors are assumed to be balanced in order of blue, green, red, but it is also possible to adopt other color balances by using other width settings.
- a width setting may be variable irrespective of whether the setting is performed automatically or not, or performed intentionally or not.
- FIG. 18 shows a drive pattern on the display panel.
- the display panel has a sufficiently larger range of the scanning lines to be displayed black than the width of the color mixture portion when driving the pixel relating to the scanning line(s) at the position corresponding to the color mixture portion of the spotlights as shown in (B) with the darkest pixel information as described above and displaying it black.
- Fig. 19 shows a configuration of pixels and matrix electrodes of a display panel according to a modification example. This configuration is intended to simplify the control of the gate driver 34 and source driver 33 compared to the aforementioned examples.
- three gate lines GI R , GI G , GI B , • " for red, green and blue are arranged for each row of pixels and three source lines SI R , SI G , SI B , • " for red, green and blue are arranged for each column of pixels.
- One pixel electrode is assigned three TFTs for red, green and blue, the gate electrodes of these TFTs are connected to their respective gate lines and the source electrodes are connected to their respective source electrodes. All the drains of the TFTs are connected to the corresponding pixel electrodes.
- the nth scanning line to be selected is a row corresponding to the gate lines G2 R , G2 G , G2 B
- the (n+x)th scanning line is a row corresponding to the gate lines Gm2 R , Gir ⁇ c, Gm2 B
- the (n+y)th scanning line is a row corresponding to the gate lines Gz2 R , GZ2 G , GZ2 B
- the gate line G2 R , gate line Gm2c and gate line Gz2 B of these gate lines, that are respectively correspond to colors of the pixel information to be displayed are selected simultaneously.
- This simultaneous selection is performed by supplying the gate signals which become active at the same timing to these gate lines.
- the TFTs connected to the selected gate lines are turned on, and pixel information signals from the source lines are supplied to these TFTs which have been turned on.
- Red pixel information signals from the source lines SI R , S2 R , S3 R , • • • are supplied to the TFTs connected to the gate line G2 R
- green pixel information signals form the source lines SI G , S2 G , S3 G , • " are supplied to the TFTs connected to the gate line Gm2c
- blue pixel information signals from the source lines SIB, S2 B , S3B, "' are supplied to the TFTs connected to the gate line Gz2 B .
- the pixel information signals of the respective colors can be supplied simultaneously.
- the spotlights are three spotlights of red, green and blue
- selection of the three scanning lines for red, green and blue corresponding to the spotlights can be performed simultaneously, not on a time-division basis for one horizontal scanning period as explained so far. Therefore, the update period of pixel information can continue to be one horizontal scanning period, making it possible to avoid speed enhancement of selection control of gate lines and pixel information supply control of source lines.
- the configuration shown in Fig. 19 applies to the case where the number of spotlights is 3 of red, green and blue, but the same concept is also applicable to cases where the number of spotlights is greater.
- control can be repeated such that three gate lines of the respective colors of a first group of those corresponding to a selection target row are selected simultaneously, the corresponding pixel information signals are supplied thereto and then the remaining three gate lines of the respective colors of a second group are selected simultaneously and the corresponding pixel information signals are supplied.
- one more set of source lines of red, green and blue may be added so that six gate lines are selected simultaneously and the corresponding pixel information signals are supplied.
- double-tracked lines configuration for the gate lines and source lines as shown in Fig. 19 can be applied to the example in Fig. 18.
- the present invention is not limited to a from in which spotlights of red (R), green (G), blue (B) appear in that order from the start scanning line of the display area, but it is also possible to adopt, for example, a mode of recombination of color sequence in which R, G, B are followed by G, B, R and further B, R, G are presented, and then return to the sequence of R, G, B and repeat this process or adopt a more complex pattern of appearance of R, G, B.
- a mode of appearance of spotlights may be basically set in such a way that the sum total of all spotlights that have appeared in the display area in one frame of an image to be displayed or a predetermined unit display period becomes white color or becomes a reference color other than white color intentionally.
- the configuration having the features explained in Figs. 16 and 17 is extremely advantageous.
- the above description is directed to a form in which spotlights move from top to bottom of the display area, but it is also possible to move the spotlights from bottom to top or combine moving from top to bottom with moving from bottom to top as appropriate.
- the present invention is not limited to an active matrix type and the present invention is also basically applicable to a passive matrix type.
- optical diffusive reflecting film 2a ... light guide
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Abstract
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2004-370358 | 2004-12-22 | ||
JP2004370358A JP2006178126A (ja) | 2004-12-22 | 2004-12-22 | バックライト式表示方法及び装置並びにバックライトシステム |
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WO2006067750A2 true WO2006067750A2 (fr) | 2006-06-29 |
WO2006067750A3 WO2006067750A3 (fr) | 2006-12-07 |
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PCT/IB2005/054346 WO2006067750A2 (fr) | 2004-12-22 | 2005-12-21 | Procede et appareil d'affichage pour systeme de panneau lumineux et systeme de panneau lumineux |
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Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8564629B2 (en) | 2010-05-25 | 2013-10-22 | Semiconductor Energy Laboratory Co., Ltd. | Liquid crystal display device and driving method thereof |
US9047840B2 (en) | 2010-06-25 | 2015-06-02 | Semiconductor Energy Laboratory Co., Ltd. | Display device and electronic appliance |
US9165521B2 (en) | 2010-07-26 | 2015-10-20 | Semiconductor Energy Laboratory Co., Ltd. | Field sequential liquid crystal display device and driving method thereof |
CN105103215A (zh) * | 2013-04-15 | 2015-11-25 | 精工爱普生株式会社 | 电光装置及电子设备 |
US9269309B2 (en) | 2009-07-02 | 2016-02-23 | Dolby Laboratories Licensing Corporation | Dual modulation using concurrent portions of luminance patterns in temporal fields |
US9286848B2 (en) | 2010-07-01 | 2016-03-15 | Semiconductor Energy Laboratory Co., Ltd. | Method for driving liquid crystal display device |
JP2016053730A (ja) * | 2010-11-30 | 2016-04-14 | 株式会社半導体エネルギー研究所 | 表示装置の駆動方法 |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010125703A1 (fr) * | 2009-04-30 | 2010-11-04 | シャープ株式会社 | Module d'affichage à cristaux liquides, dispositif d'affichage à cristaux liquides, équipement mobile et procédé de commande pour modules d'affichage à cristaux liquides |
US8537086B2 (en) * | 2010-06-16 | 2013-09-17 | Semiconductor Energy Laboratory Co., Ltd. | Driving method of liquid crystal display device |
US8564529B2 (en) * | 2010-06-21 | 2013-10-22 | Semiconductor Energy Laboratory Co., Ltd. | Method for driving liquid crystal display device |
US8988337B2 (en) * | 2010-07-02 | 2015-03-24 | Semiconductor Energy Laboratory Co., Ltd. | Driving method of liquid crystal display device |
TW201305668A (zh) * | 2011-04-15 | 2013-02-01 | Semiconductor Energy Lab | 導光元件,背光單元,及顯示裝置 |
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EP1098536A2 (fr) * | 1999-11-05 | 2001-05-09 | Texas Instruments Incorporated | Récupération de couleur séquentielle pour systèmes de projection |
WO2003098329A1 (fr) * | 2002-05-17 | 2003-11-27 | Infocus Corporation | Source de lumiere d'imagerie a recuperation de polarisation et des couleurs |
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US5612753A (en) * | 1995-01-27 | 1997-03-18 | Texas Instruments Incorporated | Full-color projection display system using two light modulators |
TW536646B (en) * | 1999-12-24 | 2003-06-11 | Ind Tech Res Inst | Back-lighted auto-stereoscopic display |
KR100873070B1 (ko) * | 2002-06-05 | 2008-12-09 | 삼성전자주식회사 | 백라이트 어셈블리 및 이를 이용한 액정표시장치 |
-
2004
- 2004-12-22 JP JP2004370358A patent/JP2006178126A/ja active Pending
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2005
- 2005-12-21 WO PCT/IB2005/054346 patent/WO2006067750A2/fr active Application Filing
- 2005-12-22 TW TW94145966A patent/TWI401656B/zh not_active IP Right Cessation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
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EP1098536A2 (fr) * | 1999-11-05 | 2001-05-09 | Texas Instruments Incorporated | Récupération de couleur séquentielle pour systèmes de projection |
WO2003098329A1 (fr) * | 2002-05-17 | 2003-11-27 | Infocus Corporation | Source de lumiere d'imagerie a recuperation de polarisation et des couleurs |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9269309B2 (en) | 2009-07-02 | 2016-02-23 | Dolby Laboratories Licensing Corporation | Dual modulation using concurrent portions of luminance patterns in temporal fields |
US8564629B2 (en) | 2010-05-25 | 2013-10-22 | Semiconductor Energy Laboratory Co., Ltd. | Liquid crystal display device and driving method thereof |
US9047840B2 (en) | 2010-06-25 | 2015-06-02 | Semiconductor Energy Laboratory Co., Ltd. | Display device and electronic appliance |
US9286848B2 (en) | 2010-07-01 | 2016-03-15 | Semiconductor Energy Laboratory Co., Ltd. | Method for driving liquid crystal display device |
US9165521B2 (en) | 2010-07-26 | 2015-10-20 | Semiconductor Energy Laboratory Co., Ltd. | Field sequential liquid crystal display device and driving method thereof |
JP2016053730A (ja) * | 2010-11-30 | 2016-04-14 | 株式会社半導体エネルギー研究所 | 表示装置の駆動方法 |
CN105103215A (zh) * | 2013-04-15 | 2015-11-25 | 精工爱普生株式会社 | 电光装置及电子设备 |
Also Published As
Publication number | Publication date |
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TW200634407A (en) | 2006-10-01 |
TWI401656B (zh) | 2013-07-11 |
WO2006067750A3 (fr) | 2006-12-07 |
JP2006178126A (ja) | 2006-07-06 |
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