The present invention relates to a liquid crystal display device and in particular, relates to an arrangement of color layers on a color filter substrate.
Liquid crystal display (LCD) devices are widely used for LCD televisions and mobile terminals due to its high-quality image display ability together with thin and light-weight characteristics. The LCD devices can be classified into three types, one is a transparent type accompanied with a backlight module including a light source, a reflective type utilizing ambient light, and a transflective type having both of above-stated two types. Among these types, the transparent type is often used for the one which displays video signals as represented by LCD televisions. This is because the chromaticity area which is a color range of the LCD device can be changed to a desired range by designing for it.
However, the chromaticity area cannot be varied perfectly due to the fact that actual available light sources and material of color resist used for the color layer 22 are limited. For example, when a chromaticity area 301 in
In particular, in the case of the LCD television which requires a wide chromaticity area, the chromaticity area attained by the LCD device is generally set more widely than the requested chromaticity area. Moreover, it is general to operate the LCD device such that video signals supplied thereto are treated with data processing so that a displayed image is to be identical to the requested chromaticity area. For example, the technology which corrects the chromaticity by a correction circuit is disclosed In Japanese Patent Application Laid-Open No. 2002-44677 (patent document 1), and the chromaticity is being corrected in the linear summation of three colors of the input signal SG, SB and SR as shown in
In
This circuit carries out the following correction procedure.
SG′=SG+KBG·SB+KRG·SR
SB′=SB+KGB·SG+KRB·SR
SR′=SR+KGR·SG+KBR·SB
where,
KBG: Mixture coefficient of the B signal for the G signal
KRG: Mixture coefficient of the R signal for the G signal
KGB: Mixture coefficient of the G signal for the B signal
KRB: Mixture coefficient of the R signal for the B signal
KGR: Mixture coefficient of the G signal for the R signal
KBR: Mixture coefficient of the B signal for the R signal
When the above-mentioned processing is not performed, the color tone of the displayed image actually shifts and gives uneasiness. Therefore, the correction is needed by performing the above-mentioned signal processing. However, in order to add the data processing to the above-mentioned video signal, the arithmetic circuit which deals with the video signal at high speed is needed, and there is a problem which increases the cost of the LCD device.
On the other hand, Japanese Patent Application Laid-Open No. 2005-141180 (patent document 2) discloses a technology which adjusts the chromaticity of the transmissive region by changing the size of the chromaticity-adjusting region arranged in each sub-pixel and the film thickness of the color layer as shown in
In that technique, however, when the pixel size becomes small, its fabrication becomes difficult. As shown in
When the pixel size becomes smaller, the distance from the end of the chromaticity-adjusting region to the shielding region becomes relatively short. When a mating or a fitting deviates from a correct position that is, an overlapping error for a pair of substrates occurs, the shielding region on the TFT side is overlapped on the end of the chromaticity-adjusting region, and the proportion of the chromaticity-adjusting region in the sub-pixel may change. Therefore, a ratio of an area of the chromaticity-adjusting region and an area of the transmissive region is changed, and thus the chromaticity area changes.
Thus, changing the chromaticity area by adjusting the emission spectrum and the spectral transmission characteristic has enormous obstacle in view of the reality of the restriction of the kind of light sources and the material of the color resist.
In the method of applying a calculation to the video signal, the arithmetic circuit which deals with the video signal at high speed is needed, and there is a problem that it increases the cost of the LCD device.
In the method of providing the chromaticity-adjusting region in each sub-pixel, because the chromaticity-adjusting region is arranged alone, when the minute pattern formation with high definition is difficult, and when the fitting of a pair of substrates is deviated from the correction position, there is a problem that the proportion of the chromaticity-adjusting region to the transmissive region shifts and thus being deviated from an aimed chromaticity.
An exemplary object of the present invention is to provide an LCD device which can easily change the chromaticity area.
A liquid crystal display device according to an exemplary aspect of the present invention includes a liquid crystal layer sandwiched between a first substrate and a second substrate. The first substrate is provided with sub-pixels arranged in an array such that each sub-pixel is arranged in each partitioned area surrounded with wiring lines respectively extending in a direction so as to be crossed each other. The second substrate is provided with color layers such that three consecutive sub-pixels with three color layers as one unit are repeatedly arranged in a predetermined pattern, and a primary color layer for a first sub-pixel of the three sub-pixels and other color layer extended from an adjacent sub-pixel next to the first sub-pixel are arranged on an area opposing to an aperture of at least one sub-pixel among the three sub-pixels.
Exemplary features and advantages of the present invention will become apparent from the following detailed description when taken with the accompanying drawings in which:
In a preferred exemplary embodiment of the LCD device according to the present invention, a TFT substrate is provided with sub-pixels arranged in each partitioned area surrounded with wiring lines such as gate lines (scanning lines) and data lines (signal lines) each extending in a direction approximately crossing at right angles each other, while a CF substrate is provided with a consecutively arranged three sub-pixels as one pixel such that three color layers of red, green and blue are repeatedly arranged in a predetermined pattern. An LC layer is sandwiched between the TFT substrate and the CF substrate. On the CF substrate, a primary color layer for a first sub-pixel of sa id three sub-pixels and other color layer extended from an adjacent sub-pixel next to said first sub-pixel are arranged on an area opposing to an aperture portion of at least one sub-pixel among said three sub-pixels.
In order to describe the exemplary embodiment of the above-mentioned present invention more in detail, the LCD device according to the first exemplary embodiment of the present invention will be described with reference to
As shown in
In the conventional CF substrate, only one color layer is arranged in each sub-pixel. However, in this exemplary embodiment, two or more color layers are arranged in at least one sub-pixel among three sub-pixels forming one pixel. For example, in a G-cell 202, although only a green layer (hereinafter, referred to as a G-layer 222) is at least arranged in the aperture, a red layer (hereinafter, referred to as a R-layer 221) and the G-layer 222 are arranged in the R-cell 201, and a blue layer (hereinafter, referred to as a B-layer 223) and the G-layer 222 are arranged in the B-cell 203. That is, the R-cell 201 and the B-cell 203 include a first area (a first color region 22a) where the color layer arranged originally in the sub-pixel is arranged and a second area (a second color region 22b) where the G-layer 222 is arranged. In the R-cell 201 and the B-cell 203, the G-layer 222 is arranged so as to separate the R-layer 221 and the G-layer 223 within the aperture of the respective sub-pixels by crossing there with the same width. Here, its shape is made a rectangle, and a layout of those three color layers is shown in
In an aforementioned structure, when the second color region 22b is arranged in the aperture edge of the sub-pixel, when the TFT substrate 10 and the CF substrate 20 are overlapped and then the positional displacement occurs, (that is, the fitting difference in the structure where the TFT substrate 10 and the CF substrate 20 are overlapped and fitted in the frame so as to be adjusted, but deviated from correct position), the area ratio of the color layer 22 changes, and thus there is a case that the desired chromaticity area is not obtained. Accordingly, in this exemplary embodiment, the color layer (the G-layer 222 in
Thus, according to a structure of the first exemplary embodiment, the chromaticity area of the LCD device can be changed without changing the emission spectrum of the light source and the spectral transmission characteristic of the color resist forming the color layer 22. The reason will be described in the following. For example, in the LCD device using a certain light source and the color resist without correction, it is supposed that the red and the blue belong to the chromaticity areas of non-mixed colors shown in
According to a structure of the first exemplary embodiment, it is available for a high-definition pixel. The reason will be described in the followings. In the first exemplary embodiment, different color layers arranged in one transmissive region are same as the primary color layer arranged in an adjacent pixel. The pattern of the color layer is generally made by using photolithographic technique as shown in
According to the structure of the first exemplary embodiment, it is difficult to change the chromaticity area even if the fitting displacement occurs such that the overlapping error is produced between the TFT substrate 10 and the CF substrate 20. The reason will be described as follows.
The width of the color layer 22 which continues from the adjacent sub-pixel is preferably same as a width of the desired chromaticity area, but it is not limited to the indicated structure. In the above-mentioned exemplary embodiment, although the G-layer 222 is extend to the adjacent sub-pixels (R-cell 201 and the B-cell 203) any color layer would be arbitrarily acceptable for extending it to the adjacent sub-pixels such that the R-layer 221 or the B-layer 223 can be extended to the adjacent sub-pixel. In the above-mentioned exemplary embodiment, the G-layer 222 is extended to both of the sub-pixels (the R-cell 201 and the B-cell 203). However, it can be arranged so as to be extended to only one sub-pixel (either the R-cell 201 or the B-cell 203).
Next, the LCD device according to a second exemplary embodiment of the present invention will be described with reference to
Even in an aforementioned structure, when the second color region 22b is arranged in the aperture edge of the sub-pixel, and the TFT substrate 10 and the CF substrate 20 are overlapped and then the positional displacement occurs, the area ratio of the color layer 22 changes, and thus there is a case that the desired chromaticity area is not obtained. Accordingly, in this exemplary embodiment, minimum distance “c” from the short side of the aperture to the color layer end crossing the sub-pixel is set so as to be half or more of the distance which corresponds to the width of the smaller one of either a distance “2a” between the apertures in the sub-pixels adjacent to each other in a vertical direction and the distance “2b” between the apertures in the sub-pixels adjacent to each other in a lateral direction (that is, satisfying a relation of c>=a or c>=b).
As a result, even if the fitting displacement or overlapped error between the TFT substrate 10 and the CF substrate 20 occurs, the width of the color layer in the second color region 22b does not change. Therefore, the area ratio of the first color region 22a and the second color region 22b in the aperture does not change. Accordingly, the similar advantage as in the first exemplary embodiment can be obtained.
Next, the LCD device according to a third exemplary embodiment of the present invention will be described with reference to
Minimum distance “c” from the short side of the aperture to the color layer end crossing the sub-pixel is set so as to be half or more of the distance which corresponds to the width of the smaller one of either a distance “2a” between the apertures in the sub-pixels adjacent to each other in a vertical direction and the distance “2b” between the apertures in the sub-pixels adjacent to each other in a lateral direction (that is, satisfying a relation of c>=a or c>=b).
As a result, even if the fitting displacement or overlapped error between the TFT substrate 10 and the CF substrate 20 occurs, the width of the color layer in the second color region 22b does not change. Therefore, the area ratio of the first color region 22a and the second color region 22b in the aperture does not change. Accordingly, the similar advantage as in the first exemplary embodiment can be obtained.
Next, the LCD device according to a fourth embodiment of the present invention will be described with reference to
Minimum distance “c” from the short side of the aperture 216 to the color layer (closer to the short side) end crossing the sub-pixel 200 is set so as to be half or more of the distance which corresponds to the width of the smaller one of either a distance “2a” between the apertures in the sub-pixels adjacent to each other in a vertical direction and the distance “2b” between the apertures in the sub-pixels adjacent to each other in a lateral direction (that is, satisfying a relation of c>=a or c>=b).
Next, the LCD device according to a fifth embodiment of the present invention will be described with reference to
Thus, in a structure of the present invention, because the portion where three kinds of color layers 22 are located is produced inevitably, by laminating three color layers to form the columnar spacers 25, the manufacturing step can be simplified compared with the conventional method which forms the columnar spacers separately.
The present invention has a feature that the primary color layer and the color layer extended from the adjacent sub-pixel are arranged in at least one sub-pixel, and thus each color layer 22 can be arranged so as not to be overlapped or so as to be overlapped.
Since the feature of the present invention is the arrangement of the color layers on the CF substrate 20, the other arrangement of the members, structure and manufacturing method or the like are not limited to particular one. For example, the structure of the TFT substrate 10, the LC layer 30 and the polarizers 4a and 4b, the manufacturing method, the optical characteristic the drive system of the LCD and the lighting system of the backlight module are optional.
In each above-mentioned embodiment, although the transmissive type LCD device is indicated together with the CF substrate 20 according to the present invention, the present invention is not limited to the above-mentioned embodiments, and it can also be applied similarly to the transflective LCD device and the reflective type LCD device.
The present invention is available for not only the LCD device but also the terminal device using the LCD device.
According to the LCD device of the present invention, the LCD device includes a liquid crystal layer sandwiched between a first substrate and a second substrate. The first substrate is provided with sub-pixels arranged in an array such that each sub-pixel is arranged in each partitioned area surrounded with wiring lines respectively extending in a direction so as to be crossed each other. The second substrate is provided with color layers such that three consecutive sub-pixels with three color layers as one unit are repeatedly arranged in a predetermined pattern, and wherein a first color layer is arranged on an area opposing to an aperture of a first sub-pixel among the three sub-pixels, a second color layer and the first color layer extended from the first sub-pixels are arranged on an area opposing to an aperture of a second sub-pixel adjacent to one side of the first sub-pixel, and a third color layer and the first color layer extended from the first sub-pixels are arranged on an area opposing to an aperture of a third sub-pixel adjacent to other side of the first sub-pixel.
In the present invention, it is desirable to make a distance between an edge of the other color layer and a side of the aperture on the arrayed direction is set so as to be half or more of a distance which corresponds to a width of smaller one of either a distance between the apertures in the sub-pixels adjacent to each other in the arrayed direction and a distance between the apertures in the sub-pixels adjacent to each other in a direction normal to the arrayed direction.
According to the LCD device of the present invention, the chromaticity area of the LCD device can be changed without changing the emission spectrum of the backlight module light source and the spectral transmission characteristic of the material composing the color layers. This is because the chromaticity area can be easily adjusted by arranging the third color in the sub-pixel each having the first color and the second color, respectively.
According to the LCD device of the present invention, the chromaticity area of the LCD device can be changed without adding a new additional fabrication process of the CF substrate. Because only the ordinary color layers are sufficient for the adjustment of the chromaticity area.
According to the LCD device of the present invention, it is also available for the high-definition pixel. Because the isolated removing pattern does not exist in the pattern of each color layer, the pattern formation of the color layers becomes possible even if the pixel pitch becomes small.
According to the LCD device of the present invention, even if the fitting displacement or overlapped error between the TFT substrate 10 and the CF substrate 20 occurs, it is difficult for the chromaticity area to change. This is because the width and the area of the second color region crossing the primary color layer do not change.
According to the LCD device of the present invention, the columnar spacers can be made without adding a different process newly. Because there is a portion where three kinds of color layers are located inevitably in every one pixel including red, green and blue sub-pixels, and the columnar spacers can be formed by laminating all color layers in that portion.
While the invention has been particularly shown and described with reference to exemplary embodiments thereof, the invention is not limited to these embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the claims.
Number | Date | Country | Kind |
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86524/2008 | Mar 2008 | JP | national |