JP5658699B2 - 4 color drive liquid crystal display device and display board used therefor - Google Patents

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having a pixel arrangement structure for displaying an image with high resolution and a driving device thereof.

  In general, a liquid crystal display device injects a liquid crystal material between two substrates having electrodes for generating an electric field, and forms electric fields by applying different potentials to the two electrodes to form liquid crystal molecules. This is an apparatus for expressing an image by changing the arrangement and thereby adjusting the light transmittance.

  Such a liquid crystal display device has a plurality of pixels on which pixel electrodes and red (R), green (G), and blue (B) color filters are formed, and each pixel is driven by a signal applied through a wiring. Then, the display operation is performed. The wiring includes a gate line (or scanning signal line) for transmitting a scanning signal and a data line (or image signal line) for transmitting an image signal. Each pixel is connected to one gate line and one data line. The image signal transmitted to the pixel electrode formed in the pixel is controlled through the thin film transistor.

  However, the conventional liquid crystal display device that displays one dot based on the three color pixels of red (R), green (G), and blue (B) has a disadvantage that the light efficiency is lowered. Specifically, each of the red (R), green (G), and blue (B) pixels has a color filter. Such a color filter transmits only about 1/3 of the applied light. , Overall light efficiency falls.

  On the other hand, various colors can be displayed by arranging various color filters of red (R), green (G), and blue (B) in each pixel. Stripe type arranged in column units, mosaic type in which red (R), green (G), and blue (B) color filters are arranged in sequence in the column and row directions, zigzag form so that unit pixels intersect in the column direction And a delta type in which red (R), green (G), and blue (B) color filters are sequentially arranged. In the case of the delta type, when displaying three unit pixels including red (R), green (G), and blue (B) color filters with one dot, a circular or diagonal line is expressed on the screen display. Has an advantageous expression ability.

In addition, “ClairVoyante Laboratories” proposes a pixel array structure called “The Pen Tile Matrix ^™ color pixel arrangement” that has a high-resolution representation capability that is more advantageous when displaying images and at the same time minimizes design costs. did. In such a pixel array structure of a pen tile matrix, the blue unit pixels adjacent to each other are transmitted with data signals by one data driving integrated circuit and driven by different gate driving integrated circuits. By using such a pen tile matrix pixel structure, it is possible to realize a resolution of UXGA (Ultra Extended Graphics Array) using a display device of the SVGA (Super Video Graphics Array) class. Furthermore, although the number of low-cost gate driving integrated circuits increases, the number of relatively expensive data driving integrated circuits can be reduced, so that the production cost of the display device can be reduced.

  However, since the size of the blue pixel is different from the size of the red and green pixels in the pen tile matrix pixel structure, it is necessary to change the storage capacity due to the difference in the liquid crystal charging rate, and the two blue pixels are connected by one wiring. Therefore, problems such as non-uniform pixel characteristics occur.

  In particular, since the blue pixels are arranged in the existing stripe format, when the resolution is not sufficient, the vertical line pattern by the blue pixels is easily visually recognized, which causes a problem of deteriorating the overall image quality.

  The technical problem of the present invention is to provide a liquid crystal display device having high light efficiency.

Arranged in a matrix, comprising a plurality of pixels defined by a black matrix,
One pixel includes a red sub-pixel indicating red, a green sub-pixel indicating green, a blue sub-pixel indicating blue, and a fourth color sub-pixel indicating fourth color,
The fourth color is different from red, green, and blue,
A liquid crystal display device is provided in which the opening area of the red sub-pixel is larger than the opening area of the blue sub-pixel.

1 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention. 1 is a color filter layout diagram of a liquid crystal display device according to a first embodiment of the present invention. FIG. 6 is a color filter layout diagram of a liquid crystal display device according to a second embodiment of the present invention. FIG. 7 is a color filter layout diagram of a liquid crystal display device according to a third embodiment of the present invention. The graph which compared the emission spectrum of the backlight used in the 1st thru | or 3rd Example of this invention with that of the past. FIG. 7 is a layout diagram of color filters and a black matrix of a liquid crystal display device according to a fourth embodiment of the present invention. FIG. 7 is a cross-sectional view of a color filter display panel for a liquid crystal display device according to a fifth embodiment of the present invention. FIG. 10 is a cross-sectional view of a color filter display panel for a liquid crystal display device according to a sixth embodiment of the present invention. Sectional drawing of the liquid crystal display device by 7th Example of this invention. The response time graph with the cell gap of a liquid crystal display device. FIG. 10 is a diagram illustrating an example of a pixel arrangement of a liquid crystal display device according to an eighth embodiment of the present invention. 14 is a diagram illustrating a pixel structure of a thin film transistor substrate of a liquid crystal display according to an eighth embodiment of the present invention. FIG. 13 is a cross-sectional view of the thin film transistor substrate for a liquid crystal display device, taken along line XIII-XIII ′ in FIG. 12. The enlarged view of the example of pixel arrangement | positioning of the liquid crystal display device by 8th Example of this invention. FIG. 10 is a diagram illustrating an example of a pixel arrangement of a liquid crystal display device according to a ninth embodiment of the present invention. 14 is a diagram illustrating a pixel structure of a thin film transistor array substrate of a liquid crystal display according to a ninth embodiment of the present invention. FIG. 17 is a cross-sectional view of the thin film transistor array substrate for a liquid crystal display device, taken along line XVII-XVII ′ in FIG. 16. FIG. 10 is a diagram illustrating an example of pixel arrangement of a liquid crystal display device according to a tenth embodiment of the present invention.

  Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily carry out the embodiments. However, the present invention can be implemented in various and different forms and is not limited to the embodiments described herein.

  In order to clearly express various layers and regions on the drawing, the thickness is shown enlarged. Throughout the specification, similar parts are denoted by the same reference numerals. When a layer, membrane, region, plate, etc. is “on top” of another part, this is not only “on top” of the other part, but also other parts in the middle Including. On the other hand, when a part is “directly above” another part, it means that there is no other part in the middle.

  Hereinafter, the structure of a liquid crystal display according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention, and FIGS. 2 to 4 are color filter layout diagrams of the liquid crystal display device according to first to third embodiments of the present invention.

  A liquid crystal display according to a first embodiment of the present invention includes a lower display panel, an upper display panel facing the lower display panel, liquid crystal molecules filled between the lower display panel and the upper display panel, and oriented in a predetermined direction. The liquid crystal layer 3, upper and lower polarizing plates 22 and 12, upper and lower compensators 23 and 13, a backlight unit 350, and the like. The orientation of liquid crystal molecules changes with the application of an electric field, but the amount of transmitted light changes depending on the degree of change in orientation.

  The lower display panel is connected to a lower substrate 110 made of a transparent insulating material such as glass, a thin film transistor TFT formed thereon, and a pixel electrode made of a transparent conductive material such as ITO or IZO. 190 included. At this time, the thin film transistor TFT switches the image signal voltage applied to the pixel electrode 190.

  A lower compensation plate 13 and a lower polarizing plate 12 are attached to the lower surface of the lower substrate 110. Here, the lower compensation plate 13 may be a biaxial compensation film or a uniaxial compensation film, and may be omitted in some cases.

  A backlight unit 350 is disposed below the lower polarizing plate 12. The backlight unit 350 includes a light source 351 using a cold cathode tube, a light guide plate 352, and the like. At this time, light emitted from the light source 351 is light having a value between 0.31 and 0.34 in the x coordinate on the color coordinate and a value between 0.32 and 0.35 in the y coordinate. is there. Such light is a backlight for a liquid crystal display device, and contains a greater amount of blue component than light emitted from a commonly used light source. In order to obtain such a light source, the blue light emitting material included in the light source 351 may be increased by a certain amount.

  FIG. 5 is a graph comparing the emission spectrum of the backlight used in the example of the present invention with that of the conventional one.

  As can be seen from the graph, in the backlight used in the present invention, red light having a wavelength of 620 to 650 nm was weakened instead of blue light having a wavelength of 440 to 470 nm as compared with the conventional backlight. Here, it is assumed that the conventional blue light is “blue 1” and the enhanced blue light is “blue 1.09” or “blue 1.18”.

  The upper display panel is formed on a lower substrate 210 made of a transparent insulating material such as glass, a black matrix 220 defining pixels in a matrix form, and red and green formed on pixels defined by the black matrix 220. A blue color filter (230R, 230G, 230B) and a reference electrode 270 made of a transparent conductive material such as ITO or IZO are formed.

  Here, red, green, and blue filters (230R, 230G, and 230B) are repeatedly formed in the pixels defined by the black matrix 220, but red, green, and blue filters (230R, 230G, and so on) are formed in the pixels. 230B) is not formed. This pixel is a white pixel (W), which blocks or passes almost all components of the light emitted by the backlight.

  The number of red, green, blue and white pixels on which red, green and blue filters (230R, 230G, 230B) are formed is the same, and the red, green, blue and white pixels are sequentially arranged along the pixel row. It is arranged repeatedly. At this time, the areas of the blue pixel and the white pixel are smaller than the areas of the red pixel and the green pixel, and are about ½. Therefore, if the areas of one white pixel and one blue pixel are combined, they are almost the same as the area of one red pixel and one green pixel.

  On the other hand, since the white pixel (W) has no color filter, the cell gap in this portion is larger than that in the other color pixel portions.

  An upper compensation plate 23 and an upper polarizing plate 22 are attached to the upper surface of the upper substrate 210. Here, a biaxial compensation film or a uniaxial compensation film can be used as the upper compensation plate 23, and may be omitted depending on the case.

  If an image is displayed by using red, green, blue and white pixels as one dot (color display unit pixel group) as in the present invention, the overall light efficiency is improved. For example, the amount of light passing through the TFT substrate side polarizer (lower polarizing plate: 12) of the liquid crystal display device is “1”. When a dot is displayed with three pixels of red, green and blue, it is 1/3 of the area of each pixel and the transmittance is 1/3 by the color filter, so the overall transmittance of one dot is [1/3 * 1/3 (R)] + [1/3 * 1/3 (G)] + [1/3 * 1/3 (B)] = 1/3 = 33.3%.

  However, in the embodiment of the present invention, the area of each pixel is ¼ of the area of one dot and the transmittance of the white pixel is 1 (since the white pixel has no color filter), The total transmittance is [1/4 × 1/3 (R)] + [1/4 × 1/3 (G)] + [1/4 × 1/3 (B)] + [1/4 × 1 ( W)] = 1/2 = 50%. Thus, according to the embodiment of the present invention, it can be seen that the luminance is further increased by about 1.5 times as compared with the conventional liquid crystal display device.

  Further, by making the area of the blue pixel and the white pixel smaller than that of the red pixel or the green pixel, it is possible to prevent the area occupied by one dot from being added by adding the white pixel. At this time, the white pixel exhibits a brightness three or more times higher than that of the red, green, and blue pixels, so that only about 30% of the area exhibits a sufficient function as one pixel. In addition, since blue is the color most insensitive to changes in the amount of light among the three colors of red, green, and blue, the reduction in area has the least effect on image quality. However, if the area of the blue pixel is reduced, a slight change in image quality, for example, a yellowing phenomenon appears even if it is insignificant. The yellowing phenomenon is a phenomenon in which an image is biased to the yellow side. This is caused by a shortage of the blue component. In order to replenish the shortage of the blue component, the present invention uses a backlight that generates light containing a larger amount of the blue component.

  On the other hand, since the white pixel has no color filter, the cell gap is larger than that of other pixels. However, when the cell gap is large, the light emitted from the white pixel also tends to be biased to the yellow side. In such a case, it is possible to prevent the light emitted from the white pixel from being blue due to the backlight component containing a large amount of blue component.

  In the first embodiment, red, green, blue and white pixels are arranged so as to appear repeatedly in sequence along the row. However, the arrangement of these pixels can be variously modified. Examples of such modifications will be described below in the second and third embodiments.

  FIG. 3 is a layout diagram of color filters of the liquid crystal display device according to the second embodiment of the present invention.

  A pixel matrix of 2 rows and 3 columns forms one dot, red, blue, and green pixels are sequentially arranged in the first row, and green, white, and red pixels are sequentially arranged in the second row. .

  FIG. 4 is a layout diagram of color filters of the liquid crystal display device according to the third embodiment of the present invention.

  The third embodiment has the same arrangement structure as the second embodiment except that the size of blue pixels is enlarged and the size of white pixels is reduced. Since the brightness of the white pixel is three times higher than that of the red, green, and blue pixels, a sufficient function can be exhibited even if the area is only about 1/3 that of the other pixels. Therefore, the current level of yellowing can be reduced by enlarging the blue pixels instead of reducing the white pixels.

  FIG. 6 is a layout view of color filters and a black matrix of a liquid crystal display device according to a fourth embodiment of the present invention.

  The fourth embodiment has the same pixel arrangement as that of the second embodiment, and is characterized in that the width of the black matrix (BM) around the white pixel is expanded as compared with other portions. This is to block the disclination line (disclination line) that appears due to a step height that is high because no color filter is formed on the white pixel.

  The white pixel cell gap is different from that of other pixels, so that the black line is used to block the gyration lines caused by steps. In the following example, the white pixel cell gap is the same as that of the other pixels. Present how to do.

  FIG. 7 is a cross-sectional view of a color filter display panel for a liquid crystal display device according to a fifth embodiment of the present invention.

  The color filter display panel according to the fifth embodiment includes a transparent insulating substrate 210, a black matrix 220 formed on the lower surface of the insulating substrate 210, and red, green, and blue formed for each pixel defined by the black matrix 220. Transparent color filters (230R, 230G, 230B, 230W) that transmit all colors, an overcoat film 250 formed on the lower surface of these color filters (230R, 230G, 230B, 230W), and a lower surface of the overcoat film 250 And a reference electrode 270 formed on the substrate.

  The feature of the color filter display panel according to the fifth embodiment is that the generation of a step is prevented by forming an all-color transmission filter (230W) in a white pixel. As the all-color transmission filter (230W), it is preferable to use a transparent organic substance and a photosensitive agent to which no dye is added. An organic filter containing a red pigment is used for the red filter 230R, an organic filter containing a green pigment is used for the green filter 230G, and an organic filter containing a blue pigment is used for the blue filter 230B. The overcoat film 250 is preferably formed of the same material as the all-color transmission filter (230W) of the white pixel, for example, because the manufacturing process can be simplified.

  If the generation of the step is prevented by using the all-color transmission filter (230W) in this way, the cell gap of the liquid crystal display device can be formed uniformly, so that the yellowing phenomenon of the white pixel and the distortion generated in the step portion. Generation of lines can be prevented, and the response speed can be optimized.

  The response speed optimization will be specifically described with reference to FIG.

  FIG. 10 is a response time graph according to the cell gap of the liquid crystal display device.

  “On” in FIG. 10 is a response time at the moment when a voltage is applied between the pixel electrode and the common electrode (response time at a moment when the voltage is switched from Black to White), and “Off” is the pixel electrode and the common electrode. "On + Off" is the sum of the response times of "On" and "Off". The response time at the moment when the voltage applied during the period is removed (the response time at the moment of switching from White to Black). As shown in FIG. 10, the response time gradually decreases (response speed increases) as the cell gap increases, and exhibits a minimum value when the cell gap is about 3.7 μm along the way. If the cell gap increases beyond 3.7 μm, it increases again. Therefore, it is preferable to set the cell gap to about 3.7 μm. However, when the white pixel has no color filter, the cell gap is about 1.5 to 1.6 μm larger than the other pixels, so the response speed of the white pixel is slow.

  FIG. 8 is a cross-sectional view of a color filter display panel for a liquid crystal display according to a sixth embodiment of the present invention.

  In the color filter display panel for the liquid crystal display device according to the sixth embodiment, a thick overcoat film 250 is used to make the cell gaps of white pixels uniform. The overcoat film 250 covering the color filters (230R, 230G, 230B) is formed to be sufficiently thick so that the level difference in the white pixel portion is within 0.2 μm. As a material for the overcoat film 250, it is preferable to use a transparent organic substance and a photosensitive agent to which no dye is added.

  In this way, the process of forming the all-color transmission filter (230W) can be omitted compared to the fifth embodiment, which is advantageous in terms of process simplification.

  FIG. 9 is a cross-sectional view of a liquid crystal display device according to a seventh embodiment of the present invention.

  In the seventh embodiment, the step of the white pixel on the color filter display plate is left as it is, and instead, a protrusion is formed on the protective film of the thin film transistor display plate to make the cell gap of the white pixel uniform.

  The liquid crystal display device according to the seventh embodiment will be described more specifically.

  First, the color filter display panel is formed on an upper substrate 210 made of a transparent insulating material such as glass, a black matrix 220 formed on the lower surface thereof to define pixels in a matrix form, and pixels defined by the black matrix 220. Red, green and blue color filters (230R, 230G, 230B), an overcoat film 250 covering the color filters (230R, 230G, 230B), and a transparent conductive material such as ITO or IZO. A reference electrode 270 having an incision 271 is formed.

  Here, red, green, and blue filters (230R, 230G, and 230B) are repeatedly formed in the pixels defined by the black matrix 220, but red, green, and blue filters (230R, 230G, and so on) are formed in the pixels. 230B) is not formed. This pixel is a white pixel (W), which blocks or passes almost all components of the light emitted by the backlight. Since there is no color filter in the white pixel (W), this portion forms a recess.

  The thin film transistor array panel includes a lower substrate 110 made of a transparent insulating material such as glass, a thin film transistor formed thereon, and a pixel electrode 190 connected to the thin film transistor and made of a transparent conductive material such as ITO or IZO. Including. At this time, the thin film transistor switches the image signal voltage applied to the pixel electrode 190. The pixel electrode 190 has an incision 191.

  More specifically, a gate electrode 123 formed on the insulating substrate 110, a gate insulating film 140 covering the gate electrode 123, an amorphous silicon layer 154 formed on the gate insulating film 140, The resistive contact layers 163, 165 formed on the amorphous silicon layer 154, the source electrode 173 and the drain electrode 175 formed on the resistive contact layers 163, 165, the source electrode 173, and the drain electrode The thin film transistor array panel includes a protective film 180 that covers 175, a pixel electrode 190 that is connected to the drain electrode 175 through a contact hole 181 of the protective film 180, and the like. At this time, although not shown, the gate line is connected to the gate electrode 123 to transmit the scanning signal and the source electrode 173, and the data line to transmit the image signal is also formed.

  Here, the protective film 180 protrudes from a region corresponding to a white pixel to form a convex portion.

  As described above, the concave portions of the color filter display panel and the convex portions of the thin film transistor panel correspond to each other so that the white pixel has almost the same cell gap as the other color pixels.

  In order to manufacture the thin film transistor array panel having such a structure, a photoetching process is performed using an optical mask having a transflective region. That is, when the protective film 180 is stacked on the source electrode 173 and the drain electrode 175 and the contact hole 181 is formed in the protective film 180, the photomask having a transparent region, a semi-transmissive region, and an opaque region is used. The light mask is arranged so that the transparent region corresponds to the contact hole 181 portion, the semi-transmissive region corresponds to the portion excluding the contact hole 181 and the white pixel, and the opaque region corresponds to the white pixel portion. If the photomask is thus disposed and the photosensitive film on the protective film 180 is exposed and developed, the entire photosensitive film is removed at the portion where the contact hole 181 is formed, and the protective film 180 is exposed. The photosensitive film remains as it is, and in other portions, the photosensitive film is partially removed and only a part of the entire thickness remains. A contact hole 181 is formed using such a photosensitive film as an etching mask, and the photosensitive film is ashed to remove the photosensitive film portion where only a part of the entire thickness remains. In this way, the photosensitive film remains only in the white pixel portion, but the protective film 180 is etched using this as an etching mask, and the plateau is formed in the white pixel portion by cutting off the other portions except the white pixel portion. .

  Meanwhile, a process of manufacturing a thin film transistor array panel includes a plurality of photolithography processes, and efforts are being made to reduce this. As one of the efforts, a photosensitive film pattern having a thick portion and a thin portion is formed by using a light mask having a transparent region, a semi-transmissive region, and an opaque region as mentioned above. A method of etching so that the layers have different patterns is used. A typical one is a four-photomask process in which an amorphous silicon layer, a resistive contact layer, and a data metal layer are etched using one photosensitive film pattern. Usually, the pixel electrode is patterned once when the gate wiring is patterned, once when the amorphous silicon layer and the resistive contact layer are patterned, once when the data wiring is patterned, and once when the protective film is patterned. The photo etching process is used once and all five times, and this is referred to as a five-sheet photomask process. The four-sheet photomask process includes an amorphous silicon layer, a resistive contact layer, and a data metal layer. The number of optical masks is reduced by one by simultaneously patterning using only one optical mask. In this case, the data wiring and the resistive contact layer pattern have substantially the same planar pattern, and the amorphous silicon layer also has substantially the same planar pattern as the data wiring except for the channel portion.

  If the thin film transistor array panel and the color filter display panel having the above-described structure are aligned and bonded, and a liquid crystal material is injected between them and vertically aligned, the basic structure of the liquid crystal display device according to the present invention is constructed. The pixel region is divided into a plurality of small domains by the cut-out portion 191 of the pixel electrode 190 and the cut-out portion 271 of the reference electrode 270, and each small domain is divided into four types according to the direction in which the liquid crystal contained therein is inclined by an electric field. It is done. The incisions 191 and 271 are formed to obtain a wide viewing angle.

  As described above, if the cell gap of the liquid crystal display device is formed uniformly, the yellowing phenomenon of the white pixels can be prevented and the response speed of the liquid crystal display device can be optimized.

  On the other hand, in order to prevent the appearance of the vertical line pattern due to the arrangement of blue pixels in a row, the liquid crystal display devices as in the eighth to tenth embodiments are provided.

  FIG. 11 is a pixel arrangement example of the liquid crystal display device according to the eighth embodiment of the present invention.

  In the liquid crystal display device according to the eighth embodiment of the present invention, red, blue and green pixels (R, B, G) are arranged in a pen tile matrix form as shown in FIG. 11, and white pixels (W ) Are arranged adjacent to the blue pixel (B).

  Red, blue, green, red, white and green pixels (R, B, G, R, W, G) are sequentially arranged in the row direction. Then, blue and white pixels (... B, W,...) Are alternately arranged in one column direction, and red and green pixels (... R, G...) Are arranged on both sides of the blue and white pixel columns. Red and green pixel rows are alternately arranged. At this time, the blue pixels (B) and the white pixels (W) arranged in the same column in two adjacent rows are centered so that the red and green pixels (R, G) face each other diagonally. Is done.

  That is, in one pixel row, the first pixel unit (R, B, G) in which red, blue, and green are sequentially arranged and the second pixel unit (R, B, in which red, white, and green are sequentially arranged) W, G) are alternately arranged, and in a pixel row adjacent to this pixel row, a third pixel unit (G, W, R) in which green, white, and red are sequentially arranged, and green, blue, red Are alternately arranged in fourth pixel units (G, B, R).

  Here, for convenience of explanation, the pixels are divided into first to fourth pixel units, but such first to fourth pixel units are used for displaying one dot in image display. It is not meant to be used as a thing.

  Thus, a pixel structure in which the first and second pixel units and the third and fourth pixel units are alternately arranged in two adjacent pixel rows is arranged in two pixel row units.

  Therefore, the four pixels (R, G) of red and green are arranged so as to face each other in the diagonal direction centering on the blue pixel and the white pixel located in the same column of two adjacent pixel rows.

  For example, four pixels (R, G) of red and green are opposed to each other in the diagonal direction centering on a blue pixel (B) and a white pixel (W) located in the same column of two adjacent pixel rows. When the arrangement is referred to as one pixel region, such pixel regions are sequentially arranged in the row direction and the column direction, and the positional relationship (up and down) of the blue and white pixels changes for each column of one pixel region. For example, if a blue pixel is arranged on a white pixel in each pixel area arranged in one pixel area column, a white pixel is arranged on the blue pixel in each pixel area in the adjacent pixel area column. The

  With such a structure, the blue, red and green pixels in the liquid crystal display device according to the eighth embodiment of the present invention are arranged in a zigzag manner in two adjacent pixel rows, and the white pixels are also arranged in a zigzag manner. The

  Next, the structure of the thin film transistor substrate of the liquid crystal display device according to the eighth embodiment of the present invention having the pixel arrangement structure will be described in more detail with reference to FIGS.

  FIG. 12 is a specific pixel arrangement diagram of the thin film transistor substrate of the liquid crystal display device according to the eighth embodiment of the present invention having such a pixel arrangement, and FIG. 13 is cut along the line XIII-XIII ′ in FIG. It is sectional drawing of the shown thin-film transistor substrate for liquid crystal display devices.

  As shown in FIG. 12, in the liquid crystal display device having the pixel arrangement of the pen tile structure according to the eighth embodiment of the present invention, red, blue, green, red, white and green pixels (R, B, G) are arranged in the row direction. , R, W, G) are sequentially arranged. In addition, blue and white pixels (... B, W,...) Are alternately arranged in one column direction, and red and green pixels (... R, G. Red and green pixel rows are alternately arranged.

  At this time, as shown in FIG. 12, one gate line (or scanning signal line) 121 that transmits a scanning signal or a gate signal in the row direction is formed for each pixel row in the pixel row direction. In the column direction, a data signal 171 that transmits a data signal and intersects the gate line 121 to define a unit pixel is insulated from the gate line 121 and is separated from the pixel (..., R, B, G, W, R, B. ) Is formed for each row. Here, at a portion where the gate line 121 and the data line 171 intersect, a gate electrode 123 connected to the gate line 121, a source electrode 173 connected to the data line 171, and a source electrode 173 with respect to the gate electrode 123. A thin film transistor including a drain electrode 175 and a semiconductor layer 154 formed on the opposite side is formed, and each pixel has a pixel electrode 190 electrically connected to the gate line 121 and the data line 171 through the thin film transistor. Is formed.

  Further, a storage capacitor conductive pattern 177 that forms a storage capacitor is connected to the pixel electrode 190 so as to face the gate line 121 or the storage capacitor wiring formed in the same layer as the storage capacitor. The conductive pattern 177 is formed on the gate line 121 and is connected to the pixel electrode 190 through the contact hole 187. The width of the portion of the gate line 121 where the storage capacitor conductive pattern 177 is formed is wider than the width of the portion where the storage capacitor conductive pattern 177 is not formed in order to secure a sufficient storage capacity. .

  Further, the data wiring (data line 171, source electrode 173, drain electrode 175, and data line end (pad) 179) is connected to a transistor and an external circuit. Contact holes 185 (or 181) and contact holes 187 (see FIGS. 12 and 13) for connecting the pixel electrode 190 to the drain electrode 175 and the storage capacitor conductor pattern 177 are formed in the protective film 180, respectively. The width of the end portion 179 of the data line 171 is expanded for connection to an external circuit. With this structure, each pixel column receives an image signal through a data pad connected to the data line 171.

  More specifically, the structure of the thin film transistor substrate of the liquid crystal display device is described. A gate wiring is formed on the insulating substrate 110. The gate wiring is a general term for a gate line 121 formed for each pixel row in the pixel row direction, and a gate electrode 123 and an end portion 125 of the thin film transistor connected to the gate line 121. 125 is expanded in width for connection with an external circuit.

  A gate wiring and a gate insulating film 140 are sequentially formed on the substrate 110, and the gate insulating film 140 made of silicon nitride (SiNx) or the like covers the gate wiring.

  A semiconductor layer 154 made of a semiconductor such as amorphous silicon is formed in an island shape on the gate insulating film 140 of the gate electrode 123, and silicide or n-type impurities are doped at a high concentration on the semiconductor layer 154. Resistive contact layers 163 and 165 made of a material such as n + hydrogenated amorphous silicon are formed. In contrast, the semiconductor layer 154 may be formed along the pattern of the data line 171.

  Data lines are formed on the resistive contact layers 163 and 165 and the gate insulating film 140. The data lines cross the gate lines 121 and define the pixels, and the data lines 171 are formed in the column direction, and the source lines 173 are convex portions of the data lines 171 and extend to the top of the resistive contact layer 163. A data pad 179 connected to one end of the data line 171 and receiving an external image signal; and a resistive contact layer 165 opposite to the source electrode 173 with respect to the gate electrode 123 and separated from the source electrode 173. And a drain electrode 175 formed on the upper portion.

  A protective film 180 is formed on the data wiring and the semiconductor layer 154 not covered with the data wiring. The protective film 180 is formed with contact holes 185 and 189 exposing the drain electrode 175 and the end portion 179 whose width of the data line is expanded, and the end portion whose width of the gate line is expanded together with the gate insulating film 140. A contact hole 182 that exposes 125 is formed.

  A pixel electrode 190 that is electrically connected to the drain electrode 175 through the contact hole 185 (or 181) and located in the pixel is formed on the protective film 180. Further, auxiliary contact members 95 and 97 connected to the gate line end 125 and the data line end 179 through the contact holes 182 and 189 are formed on the protective film 180.

  Here, as shown in FIGS. 12 and 13, the pixel electrode 190 overlaps with the gate line 121 to form a storage capacitor, and when the storage capacity is insufficient, the storage capacitor is formed in the same layer as the gate wirings 121, 125, and 123. Additional wiring can be added.

  In the liquid crystal display device according to the eighth embodiment of the present invention having such a structure, W (white) data is extracted from R, G, B data provided from an external data source (for example, a graphic controller), and this Each pixel is driven by R, G, B, and W data reconstructed based on the above.

  Therefore, four red (R) and green colors formed adjacent to both sides symmetrically with respect to the blue pixel (B) and the white pixel (W) located in the same column in two adjacent pixel rows. The dots in which the pixel (G) is included in one pixel area can be displayed in Table 1 or Table 2 below.

In addition, by applying a rendering technique, red and green pixels (only one column on one side) with a blue pixel (B) and a white pixel (W) positioned in the same column in two adjacent pixel rows as a reference position. R, G) are arranged adjacent to each other and one dot is shown in Table 3 below.
Or it can display like Table 4.

Alternatively, with the blue pixel (B) and the white pixel (W) as reference positions, the green and red pixels (G, R) are arranged adjacent to each other only in the other column, and one dot is as shown in Table 5 or Table 6 below. Can be displayed.

  FIG. 14 is a view showing a pixel viewing state when driving the pixel structure of the liquid crystal display device according to the eighth embodiment of the present invention having such a structure.

  As shown in FIG. 14, according to the eighth embodiment of the present invention, not only the red pixel (R) and the green pixel (G) but also the blue pixel (B) are arranged in a zigzag form, Since the pixels (W) are not arranged adjacent to each other but are arranged in a zigzag shape, an undesirable vertical line pattern due to a specific pixel (for example, a blue pixel) is not visually recognized even when the resolution is not sufficient. Therefore, a liquid crystal display device having a pen tile matrix structure with improved image quality characteristics can be provided.

  Next explained is a liquid crystal display device according to the ninth embodiment of the invention.

  FIG. 15 shows a pixel arrangement example of the liquid crystal display device according to the ninth embodiment of the present invention.

  As shown in FIG. 15, the substrate of the liquid crystal display device according to the ninth embodiment of the present invention is in the same manner as the eighth embodiment in the form of a pen tile matrix, and red, blue, green, red in the row direction. , White and green pixels (R, B, G, R, W, G) are sequentially arranged. Blue and white pixels (... B, W,...) Are alternately arranged in one column direction, and red and green pixels (... R, G...) Are arranged on both sides of the blue and white pixel columns. Alternatingly arranged red and green pixel rows are arranged. Accordingly, the red and green pixels (R, G) are arranged to face each other diagonally with the blue pixel (B) and the white pixel (W) positioned in the same column in two adjacent pixel rows as the center. The

  However, unlike the eighth embodiment, the blue and white pixels located at the center form one diamond shape as a whole. That is, the blue pixel (B) and the white pixel (W) formed adjacent to the same column in two adjacent rows each have a triangular shape whose bottom is formed parallel to the row direction, as shown in FIG. Are arranged so that their bases correspond to each other to form a diamond shape. This appears to be a form in which one rhombus generated including two pixel rows is separated in the row direction.

  In addition, four pixels (R, G) of red and green are arranged opposite to each other in the diagonal direction on four sides of such a rhombus blue pixel and white pixel (B, W). At this time, the two red pixels (R) are arranged so as to face each other diagonally with the blue and white pixels (B, W) as the centers, and the two green pixels (G) are also arranged in the blue and white pixels (B). , W) are arranged so as to face each other in the diagonal direction.

  Accordingly, in the ninth embodiment, the blue, red, and green pixels are arranged in a zigzag manner in two adjacent pixel rows (that is, a line connecting pixels of the same color becomes a zigzag), and the white pixels are also in a zigzag manner. Placed in.

  Further, as in the eighth embodiment, four pixels (R, G) of red and green are centered on a blue pixel (B) and a white pixel (W) located in the same column of two adjacent pixel rows. When one pixel region is arranged so as to face each other in the diagonal direction, such pixel regions are sequentially arranged in the row direction and the column direction, and the positions of the blue and white pixels are arranged for each pixel region column. It changes alternately.

  Next, the structure of the thin film transistor substrate of the liquid crystal display device according to the ninth embodiment of the present invention having the above pixel arrangement structure will be described in more detail with reference to FIGS.

  FIG. 16 is a specific pixel arrangement diagram of the thin film transistor substrate of the liquid crystal display device according to the ninth embodiment of the present invention having such a pixel arrangement, and FIG. 17 is cut along the line XVII-XVII ′ in FIG. It is sectional drawing of the shown thin-film transistor substrate for liquid crystal display devices.

  In the thin film transistor substrate of the liquid crystal display device according to the ninth embodiment of the present invention, red, blue, green, red, white and green pixels (R, B, G, R, W, G) are arranged in sequence. Blue and white pixels (... B, W,...) Are alternately arranged in one column direction, and red and green pixels (... R, G...) Are arranged on both sides of the blue and white pixel columns. Red and green pixel rows are alternately arranged.

  At this time, as shown in FIG. 16, one gate line (scanning signal line) 121 for transmitting a scanning signal (gate signal) to each pixel row is formed for each pixel row in the row direction. The gate lines 121 formed in the two adjacent pixel rows are arranged so as to face each other with the pixel in each pixel row as the center.

  In the column direction, a data line 171 that transmits a data signal to the pixel column is insulated from the gate line 121 and intersects the pixel line (row direction arrangement: R, B, G, R, W, G,...) Each is formed.

  Here, at the intersection of the gate line 121 and the data line 171, the gate electrode 123 connected to the gate line 121, the source electrode 173 connected to the data line 171, and the source electrode 173 to the gate electrode 123 A thin film transistor including a drain electrode 175 and a semiconductor layer 154 formed on the opposite side is formed, and each pixel has a pixel electrode 190 electrically connected to the gate line 121 and the data line 171 through the thin film transistor. Is formed.

  In the same layer as the gate line 121, a storage capacitor is formed to face the pixel electrode 190 and extend in the row direction. The storage capacitor line 131 is a part of the storage capacitor line, and is arranged in two rows so as to overlap with the pixel electrodes 190 corresponding to the red, blue, green, and white pixels respectively formed in two adjacent rows. Is formed on the boundary line between.

  On the other hand, the data line 171 is connected to the drain electrode 175, and a data pad 179 for receiving a video signal from the outside and transmitting it to the data line 171 is connected to the end of each data line 171. . With this structure, each pixel column receives an image signal through the data pad 179 connected to the data line 171.

  The structure of the thin film transistor substrate for a liquid crystal display according to the ninth embodiment of the present invention will be described in detail. A gate wiring and a storage capacitor wiring are formed on the transparent insulating substrate 110. The gate wiring includes a scanning signal line or gate line 121 extending in the row direction, and a gate electrode 123 of a thin film transistor which is a part of the gate line 121. An end portion 125 of the gate line 121 has a width for connection with an external circuit. Has been extended. At this time, a gate electrode 123 connected to one gate line 121 is formed in each blue pixel column.

  The storage capacitor line, that is, the storage capacitor line 131 is a storage capacitor having a storage capacitor for improving the charge storage capability of the pixel facing each pixel electrode 190 of the pixel (R, B, G, W) described later. Configure.

  A data line made of a low-resistance conductive material is formed on the gate insulating film 140 covering the gate line and the sustain line. The data lines are formed in the column direction and arranged one by one in the pixel column unit, the source electrode 173 of the thin film transistor connected to the data line 171 and the gate electrode 123 or the semiconductor layer 154 of the thin film transistor. A drain electrode 175 of the thin film transistor located on the opposite side of the electrode 173 is included, and the width of the one end 179 of the data line 171 is expanded.

  Since the data lines 171 are arranged apart from each other in each pixel column, a short circuit between the data lines 171 can be prevented, and interference between data signals transmitted to the data lines 171 can be prevented.

  Here, the data wiring can be formed of a single layer similarly to the gate wiring, but may be formed of a double layer or a triple layer. Of course, in the case of forming with two or more layers, it is preferable that one layer is made of a material having low resistance and the other layer is made of a material having good contact characteristics with other materials.

  A protective film 180 made of an organic insulating material such as acrylic or silicon nitride is formed on the data wiring and the semiconductor layer 154 that is not covered with these, and a drain electrode is formed on the protective film 180 through the contact hole 185. A pixel electrode 190 connected to 175 is formed on each pixel (R, B, G, W) along the pixel pattern.

  Even in the structure according to the ninth embodiment of the present invention, as in the eighth embodiment, when arranged in the same column of two adjacent pixel rows, both sides of the blue and white pixels forming one rhombus are centered. One red dot and four red pixels formed adjacent to each other can be displayed in Table 7 or Table 8 below.

  In addition, red and green pixels (which are positioned in the same column in two adjacent pixel rows by applying a rendering technique) and positioned in a column adjacent to one side centering on a blue pixel and a white pixel that form an overall rhombus shape ( An image can be displayed with R, G) as one dot in Table 9 or Table 10 below.

  Alternatively, it is possible to display an image with the green and red pixels (G, R) positioned in columns adjacent to the other side centered on the color pixel and the white pixel as one dot Table 11 or Table 12 below.

  On the other hand, unlike the ninth embodiment of the present invention, triangular blue and white pixels can be arranged differently in adjacent pixel rows to realize a diamond shape.

  FIG. 18 is a pixel arrangement example of the liquid crystal display device according to the tenth embodiment of the present invention.

  As shown in FIG. 18, the liquid crystal display device according to the tenth embodiment of the present invention is formed adjacent to two rows adjacent to each other in the form of a pen tile matrix as in the ninth embodiment. The blue pixel (B) and the white pixel (W) thus formed form one diamond shape as a whole.

  At this time, the blue pixels (B) and the white pixels (W) each have a triangular shape, but unlike the ninth embodiment, the bases of the triangles are formed parallel to the column direction. That is, one blue pixel (B) and white pixel (W) are formed in a triangular shape whose vertex is located on a boundary line between two pixel rows over two adjacent pixel rows. The blue and white pixels are arranged so that their bases correspond to each other to form one rhombus. This seems to be a form in which one diamond generated over two pixel rows is separated in the column direction.

  Also, as in the ninth embodiment, four pixels (R, G) of red and green are respectively provided on four sides of the rhombus blue pixel (B) and the white pixel (W) generated over two adjacent rows. Are arranged so as to face each other in the diagonal direction.

  On the other hand, unlike the ninth embodiment, four pixels (R, G) of red and green are diagonally arranged around a blue pixel (B) and a white pixel (W) arranged over two adjacent pixel rows. Are arranged in a row direction and a column direction, and the positions of blue and white pixels are alternately arranged in each pixel area row. change.

  That is, as shown in FIG. 18, if the blue pixel (B) of each pixel region is positioned on the right side of the white pixel (W) in one pixel region row, each pixel region in another adjacent pixel region row. The blue pixel (B) is located on the left side of the white pixel (W).

  The structure of the thin film transistor substrate of the liquid crystal display device according to the tenth embodiment of the present invention having such a pixel arrangement can be easily obtained by those skilled in the art from the pixel arrangement described above and the structure and cross section described in the ninth embodiment. Since it can be devised, detailed description is omitted here.

  Also in the tenth embodiment of the present invention, as in the eighth embodiment, the blue, red, and green pixels are arranged in a zigzag form over two adjacent pixel rows, and the white pixels are also arranged in a zigzag form.

  Therefore, the structure according to the tenth embodiment of the present invention is formed adjacent to both sides around the blue and white pixels that form a diamond shape as a whole in two adjacent pixel rows, as in the ninth embodiment. The four red and green pixels can be displayed as one dot in Table 13 or Table 14 below.

  In addition, by applying the rendering technique, red and green pixels (R, G) positioned in adjacent columns on only one side centering on blue and white pixels that are generally rhombus-shaped in two adjacent pixel rows are combined. Two dots can be displayed in Table 15 or Table 16 below.

  Alternatively, the green and red pixels (G, R) positioned in the adjacent column on the other side with the blue and white pixels as the center can be displayed in one dot below Table 17 or Table 18.

  On the other hand, when the rendering driving technique is performed to display a high-resolution image through the liquid crystal display device having the pen tile pixel arrangement structure according to the eighth to tenth embodiments of the present invention, the existing driving algorithm is used. The same can be applied.

  According to the embodiment of the present invention, not only the red and green pixels but also the blue pixels are arranged in a zigzag form, and the white pixels are arranged in a zigzag form without being arranged adjacent to each other. Therefore, even when the resolution is not sufficient, the vertical line pattern due to the pixel set of the specific color is not visually recognized.

  Further, it is possible to drive the white pixels to increase the overall luminance. At this time, since the white pixels are arranged in a zigzag pattern, only the luminance of the specific area does not increase, and the luminance increases uniformly over the entire screen. In addition, the luminance can be adjusted by adjusting the white pixel to, for example, white, gray, or black.

  The preferred embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the claims. Forms are also within the scope of the present invention.

  As described above, the use of a backlight with an enhanced blue component can prevent yellowing phenomenon during four-color driving, and can uniformly form a cell gap of a liquid crystal display device and In addition to preventing the occurrence of disclination lines (disclination lines) generated at the stepped portion, the response speed can be optimized.

  In addition, even when the resolution is not sufficient, it is possible to prevent the vertical line pattern from appearing due to the pixel group of the specific color, so that the image quality of the liquid crystal display device is improved.

3: Liquid crystal layer 12: Lower polarizing plate 13: Lower compensation plate 22: Upper polarizing plate 23: Upper compensation plate 95, 97: Contact auxiliary member 110: Lower substrate 121: Gate line 123: Gate electrode 125: Gate line end ( pad)
131: storage capacitor line 140: gate insulating film 145: pixel electrode via (connection portion)
154: Amorphous silicon layers 163, 165: Resistive contact layers 171, 173, 175, 179: Data wiring 171: Data line 173: Source electrode 175: Drain electrode 177: Conductor pattern for storage capacitor 179: End of data line Part (pad)
180: Protective films 181 and 185: Pixel electrode and drain electrode contact holes 182, 187, 189: Contact hole 190: Pixel electrode 191: Pixel electrode cut-out portion 210: Upper substrate 220: Black matrix 230R, 230G, 230B: RGB color Filter 230W: All color transmission filter 250: Overcoat film 270: Reference electrode 271: Reference electrode incision 350: Backlight unit 351: Light guide plate 352: Light source

Claims (8)

A plurality of pixels arranged in a matrix and defined by a black matrix ;
a backlight unit that diverges light having an x color coordinate between 0.31 and 0.34 and a y color coordinate between 0.32 and 0.35 ,
One pixel includes a red sub-pixel indicating red, a green sub-pixel indicating green, a blue sub-pixel indicating blue, and a white sub-pixel indicating white,
The size of the opening area of one red subpixel is larger than the opening area of one blue subpixel.   The liquid crystal display device according to claim 1, wherein the size of the opening area of the red subpixel is twice the size of the opening area of the blue subpixel.   The liquid crystal display device according to claim 1, wherein a size of an opening area of the green subpixel is larger than a size of an opening area of the blue subpixel.   The liquid crystal display device according to claim 3, wherein the size of the opening area of the green subpixel is twice the size of the opening area of the blue subpixel.   The liquid crystal display device according to claim 1, wherein an opening area size of the blue subpixel is the same as an opening area size of the white subpixel.   The sum of the opening area size of the blue subpixel and the opening area size of the white subpixel is the same as the opening area size of the green subpixel or the opening area size of the red subpixel. Item 2. A liquid crystal display device according to item 1.   The liquid crystal display device according to claim 1, wherein the red subpixel, the green subpixel, the blue subpixel, and the white subpixel are arranged in order along a row direction. A black matrix surrounding the red subpixel, the green subpixel, the blue subpixel, and the white subpixel;
The width of a black matrix surrounding the white subpixel is wider than a black matrix surrounding at least one of the red subpixel, the green subpixel, and the blue subpixel. Liquid crystal display device.

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