JP2005275113A - Color display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color display device that prevents a white light, obtained through additive color mixing of colored light beams transmitted through respective color elements constituting color filters, from being colored. <P>SOLUTION: Red elements 10r, green elements 10g, and blue elements 10b are arranged in order along the width while made to correspond to respective display electrodes 6 to form a color filter layer, and an island-shaped red element 10r' and a blue element 10b' are arranged in one pixel region where a display electrode 6 and a scanning electrode 12 of a green element 10g cross each other. The ratio of the area Ag of the green element 10g in a reflection display area where an opening 9a is not provided in one pixel region to areas Ar and Ab of the island-shaped red element 10r' and blue element 10b' is set so that Ar:Ag:Ab=0.05:0.86:0.09. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color display device having a color filter composed of a plurality of color elements.

  In a display device that requires an external light source such as a liquid crystal display panel, a color filter is used to change the light source light into colored light of a desired color when performing color display. This color filter is formed by arranging a plurality of color elements having different spectral characteristics in a predetermined arrangement. In this case, normally, as shown in Patent Document 1, each color element is formed in the same area.

However, for example, in the case of a display device that colors light using a color filter in which all color elements of red, green, and blue are formed in the same area, white light obtained by additively mixing colored light of red, green, and blue However, it tends to be colored green.
JP-A-5-5876

  The subject of this invention is providing the color display apparatus which prevented the coloring of the white light obtained by the additive color mixture of the colored light which permeate | transmitted each color element which comprises a color filter.

  In order to solve the above problems, the color display device of the present invention has a color filter composed of a plurality of color elements having different spectral characteristics, and appropriately color-mixes each colored light transmitted through each color element for color display. The color display device is characterized in that the area ratio between the color elements is set so that the white light obtained by additive color mixing of the colored light transmitted through the color elements is not colored. .

  According to the color display device of the present invention, the spectral ratio of each color element is set so that the area ratio of each color element constituting the color filter is not colored in white light obtained by additively mixing colored light transmitted through each color element. Since it is set according to the characteristics, the coloring of white light is eliminated, and a clear and high-quality color display quality can be obtained.

  In the color display device of the present invention, a plurality of pixels of the same area are arranged in parallel in a predetermined arrangement to form a display region, and the color filter is composed of red, green, and blue color elements, and each color element is a pixel. It is preferable to be installed corresponding to the arrangement of the above, whereby an accurate color display based on the additive color mixture of the three primary colors of light can be obtained. In this case, a reflection color display device is provided by reflecting a light incident from the front side which is the observation side of the display and is emitted to the front side, and the color filter is installed on the front side of the light reflection film In this way, it is possible to obtain a high-quality color reflective display in which the occurrence of color mixing is suppressed.

  Further, in the above-described reflective color display device, a red element and a blue element are disposed in one pixel in which a green element is disposed, and red on a light reflecting film in one green element pixel. The area ratio of each of the green, blue and blue color elements is preferably 0.01 to 0.50: 0.50 to 0.99: 0.01 to 0.50, whereby white light is colored greenish The degree to which it is performed can be remarkably reduced, and high-quality color display quality can be obtained by this high-purity white light.

  In addition, the color display device of the present invention is a liquid crystal display device in which a liquid crystal is sealed between a pair of substrates arranged opposite to each other, and the regions facing the electrodes respectively installed on the opposed surfaces of the pair of substrates are pixels. A transflective color liquid crystal display device in which a reflective display area in which a light reflective film is disposed and a transmissive display area in which a light reflective film is not disposed are formed in one pixel Preferably, according to this color liquid crystal display device, high-quality color display quality can be obtained by white light with higher purity even in reflective display.

Hereinafter, preferred embodiments of the present invention will be described.
FIG. 1 is an explanatory view showing the entire configuration of a transflective liquid crystal display device as a first embodiment of the present invention, FIG. 2 is a partially enlarged plan view thereof, and FIGS. 3 and 4 are respectively III-III in FIG. It is a line sectional view and a IV-IV line sectional view.

  As shown in FIG. 1, the transflective liquid crystal display device of the present embodiment is roughly composed of a liquid crystal display panel LP and a backlight BL.

  The backlight BL is a side-light type surface emitting illumination device, and includes a light guide plate 1 made of a transparent resin plate, a cold cathode tube 2 as a light source disposed opposite to one end surface thereof, and a liquid crystal display of the light guide plate 1. The light reflecting plate 3 is disposed on the back surface 1b opposite to the light emitting surface 1a opposed to the panel LP. According to this backlight BL, the light emitted from the cold cathode tube 2 is incident on the light guide plate 1 and then diffusely reflected by the back surface 1b processed on the diffuse reflection surface, as shown by the two-dot chain line. The light is emitted in a planar shape from the emission surface 1a toward the liquid crystal display panel LP.

  As shown in FIG. 3, the liquid crystal display panel LP has a pair of glass substrates 4 and 5 joined together by a frame-shaped sealing material (not shown) with a predetermined gap therebetween, and surrounded by a sealing material. The liquid crystal L is sealed between the five.

  The front glass substrate 4 disposed on the front side, which is the display observation side, of the pair of glass substrates 4 and 5 is formed of a transparent conductive film having a plurality of stripes on the inner surface facing the rear glass substrate 5. The display electrodes 6 are arranged in parallel in a predetermined direction (in this example, a direction perpendicular to the paper surface). The alignment film 7 is uniformly deposited so as to cover the exposed surface of the front glass substrate 4 on which the display electrodes 6 and the display electrodes 6 are not provided. The surface of the alignment film 7 is subjected to an alignment process in a predetermined direction.

  A front polarizing plate 8 is attached to the outer surface (front surface) of the front glass substrate 4 with its transmission axis positioned in a predetermined direction.

  On the other hand, a light reflecting film 9 having a single film shape is provided on the inner surface of the rear glass substrate 5. The light reflecting film 9 is a metal thin film formed by vapor deposition using a metal material such as aluminum or an alloy of silver, palladium, and copper, and the surface facing the liquid crystal layer L as a light reflecting surface is a smooth surface. It is finished. On the inner surface side of the light reflecting film 9, a color filter layer 10 made up of red, green and blue color elements 10r, 10g and 10b is laminated. As shown in FIG. 2, the color filter layer 10 of the present embodiment has the color elements 10r, 10g, and 10b formed in a stripe shape, and the stripe-shaped color elements 10r, 10g, and 10b are on the front glass substrate 4 side described above. The display electrodes 6 are arranged corresponding to 1: 1. In this case, the red, green, and blue striped color elements 10r, 10g, and 10b are repeatedly arranged in the width direction in the order of red, green, and blue without any gap.

  Returning to FIG. 3, the color filter layer 10 is laminated with a transparent protective layer 11 made of a transparent resin material such as an acrylic resin. On the flat surface of the transparent protective layer 11, scanning electrodes 12 made of a transparent conductive film having a plurality of stripes extend in parallel to a direction (paper surface direction) perpendicular to the extending direction of the display electrodes 6 described above. Are arranged side by side. Then, the alignment film 13 is uniformly applied so as to cover the scanning electrodes 12 and the surface of the transparent protective layer 11 exposed therebetween. The alignment film 13 is also subjected to an alignment process in a predetermined direction.

  In this embodiment, a pair of liquid crystal layers L facing each other with the liquid crystal layer L interposed therebetween so that the liquid crystal molecules of the liquid crystal layer L are twisted and aligned by 230 ° ± 20 ° from the alignment film 13 toward the counter-side alignment film 7 described above. Each alignment treatment direction of the alignment films 7 and 13 is set. That is, the liquid crystal display panel LP of the present embodiment is an STN (Super Twisted Nematic) type liquid crystal display panel LP.

  A rear polarizing plate 14 is attached to the outer surface (front surface) of the rear glass substrate 5 with its transmission axis positioned in a predetermined direction.

  In the liquid crystal display panel LP of the present embodiment, which is configured as described above, as shown in FIG. 2, one partition region where the display electrode 6 and the scanning electrode 12 intersect and face each other is one for display. This is the pixel. For each pixel, an opening 9a is formed in the light reflection film 9 described above, and an area in which the opening 9a is formed becomes a transmissive display area for performing transmissive display, and an opening 9a in one pixel is provided. The area that is not provided becomes a reflective display area for performing reflective display.

  Thus, in the region where the light reflecting film 9 is formed in one pixel of the green element 10g, the red element 10r 'and the blue element 10b' are arranged in an island shape. In this case, holes for installing the island-like red elements 10r 'and the island-like blue elements 10b' are provided in the green element 10g, and the island-like red elements 10r 'and the island-like blue elements 10b' are provided in these holes. It is installed. These red and blue island-like color elements 10r ′ and 10b ′ are provided in order to prevent green coloring in white light.

  That is, in the case of a conventional color filter layer in which the areas of the red, green, and blue color elements 10r, 10g, and 10b are the same, the color filter layers are transmitted due to the difference in spectral characteristics of the color elements 10r, 10g, and 10b. White light obtained by additively mixing red, green, and blue colored lights is colored to a slight extent in green. This degree of green coloration is relatively prominent in the reflective display in which the light is transmitted through the color element twice before and after the reflection than in the transmissive display.

Therefore, in the present embodiment, as described above, the red and blue island-like color elements 10r ′ and 10b ′ are arranged in one pixel of the green element 10g, thereby preventing white light from being colored green. Here, as described above, green coloring of white light appears in both reflective display and transmissive display, but in the present embodiment, green coloring of white light in reflective display with a more pronounced degree of expression is prevented. Therefore, the red and blue island-like color elements 10r ′ and 10b ′ are arranged in the reflective display area in which the light reflecting film 6 is arranged in one pixel of the green element. In this case, the ratio of the area Ag of the green element 10g ′ to the area Ar of the red element 10r ′ and the area Ab of the blue element 10b ′ in the reflective display area is:
Ar: Ag: Ab = 0.01 to 0.50: 0.50 to 0.99: 0.01 to 0.50
Preferably set to
Among them,
Ar: Ag: Ab = 0.03 to 0.08: 0.80 to 0.90: 0.07 to 0.12
More preferably,
In this embodiment,
Ar: Ag: Ab = 0.05: 0.86: 0.09
Is set to

  As described above, in the present embodiment, the island-shaped red element 10r ′ and the island-shaped blue element 10b ′ are arranged in the reflective display area in the reflective display area for each green pixel. By preventing white light from being colored green, it is possible to stably obtain a high-quality reflection color display with high purity white display with good color reproducibility.

  In addition, the white color of green light can be obtained by providing a blank portion in which no green element material is arranged in one pixel of the green element and appropriately setting the area ratio of the red, green, and blue color elements in the entire display area. In this case, the blank portion of the green element becomes a recess, and the layer thickness (gap) of the liquid crystal layer L in this portion locally increases. As a result, display defects such as display unevenness due to poor alignment of liquid crystal molecules and a decrease in contrast due to drive voltage deviation are caused. On the other hand, in the present embodiment, as shown in FIG. 4, a red element and a blue element having a predetermined area are arranged in one pixel of the green element without arranging the green element, thereby providing red In addition, the area ratio of each of the green and blue color elements can be set to a desired ratio, and a substantially uniform layer thickness can be secured over the entire liquid crystal layer without generating a recess in the color filter layer. As a result, green coloration of white light is prevented, liquid crystal molecule alignment failure and drive voltage deviation are avoided, and high-quality reflective color display with high purity white display is stably obtained with good color reproducibility. be able to.

  In addition, the shape of the island-shaped red element 10r ′ and the island-shaped blue element 10b ′ is not limited to a circle and can be formed in an arbitrary shape as long as the desired area ratio can be secured.

Next, an embodiment of the first modification of the above embodiment will be described based on a partially enlarged plan view of FIG. 5 and a sectional view taken along the line VI-VI. In addition, the same code | symbol is attached | subjected about the component same as the said embodiment, and the description is abbreviate | omitted.

  In this example, as shown in FIG. 5, in one pixel region of the green element 15g, notches c1 and c2 are formed on both side edges, and the notches c1 and c2 are respectively adjacent to the red color. Convex portions b1 and b2 provided on corresponding side edges of the element 15r and the blue element 15b are fitted with no gap.

The ratio of the area Ag of the green element on the light reflecting film 9 to the area Ar of the red element (convex part b1) and the area Ab of the blue element (convex part b2) in one pixel region of the green element 15g is as described above. The same ratio as the area ratio in the embodiment,
Ar: Ag: Ab = 0.05: 0.86: 0.09
Is set to

  Even with the transflective liquid crystal display device of this modification configured as described above, high-quality color reflective display with high-purity white display is prevented by preventing green coloring of white light in reflective display. It can be obtained well and stably.

  Further, according to the present modification, the desired area ratio between the color elements in the reflective display area in one pixel region of the green element 15g is determined by cutting out both side edges of the green element 15g and the red element adjacent thereto. Since each side edge of the 15r and the blue element 15b is projected to secure it, when forming each color element by photolithography, the resolution limit of the exposure machine and the expansion during firing of the color element material It is possible to secure a desired area ratio between the color elements more accurately by minimizing the deviation of the outline of the color elements due to the above.

Next, a second modification of the above embodiment will be described based on the partially enlarged plan view of FIG.
In this modification, a desired area ratio is obtained by setting the widths of the red, green, and blue stripe-shaped color elements 16r, 16g, and 16b to a predetermined size ratio.

That is, as shown in FIG. 7, the width wg of the green element 16g is smaller than the width W of one pixel by w1 on the red element 16r side and by w2 on the blue element 16b side. The adjacent red element 16r extends to the reduced area of width w1, and the adjacent blue element 16b extends to the reduced area of width w2. As a result, the red, green, and blue color element area ratios Ar: Ag: Ab on the reflective display area in one pixel region having a width W corresponding to the green element 16g
Ar: Ag: Ab = 0.05: 0.86: 0.09
And

  The transflective liquid crystal display device of the present modification configured as described above also prevents green coloration of white light in the reflective display, as in the above-described embodiment and the first modification thereof, and improves the purity. High-quality color reflection display with high white display can be obtained stably with good color reproducibility.

  In addition, according to the present modification, a desired area ratio between the color elements in the reflective display area in one pixel region of the green element 16g is simply a structure in which the width of each color element is simply set to a predetermined size ratio. Therefore, when forming each color element by photolithography, the deviation of the outline of each color element due to the limit of the resolution of the exposure machine and the expansion at the time of firing of the color element material is substantially eliminated, and the desired color element is desired. The area ratio can be ensured extremely accurately and easily.

  Note that the present invention is not limited to the above-described embodiments and modifications. For example, the present invention can be effectively applied when the color filter layer is formed on the front substrate instead of the rear substrate.

The present invention is not limited to the liquid crystal display device, and can be applied to other various display devices using color filters. Further, the present invention is not limited to the simple matrix transflective liquid crystal display device among the liquid crystal display devices. Of course, the present invention can be widely applied to other various liquid crystal display devices such as a liquid crystal display device that performs only reflective display or only transmissive display, a segment type other than a simple matrix type, and an active matrix type.

1 is a configuration explanatory diagram illustrating an overall configuration of a transflective liquid crystal display device as an embodiment of the present invention. It is a partial enlarged plan view which shows the detailed structure of the said transflective liquid crystal display device. It is the III-III sectional view taken on the line of FIG. 2 which shows the detailed structure of the said transflective liquid crystal display device. FIG. 4 is a sectional view taken along line IV-IV in FIG. 2 showing a detailed structure of the transflective liquid crystal display device. It is the elements on larger scale which show the transflective liquid crystal display device as a 1st modification of the said embodiment. FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5 showing the transflective liquid crystal display device of the first modified example. It is a partial enlarged plan view which shows the transflective liquid crystal display device as a 2nd modification of the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light guide plate 2 Cold cathode tube 4 Front side glass substrate 5 Rear side glass substrate 6 Display electrode 7, 13 Orientation film 9 Light reflection film 9a Opening 10r, 15r, 16r Red element 10g, 15g, 16g Green element 10b, 15b, 16b Red Element 12 Scan electrode

Claims (5)

A color display device having a color filter composed of a plurality of color elements having different spectral characteristics and performing color display by additively mixing each colored light transmitted through each color element,
An area ratio between the color elements is set so that white light obtained by additively mixing colored light transmitted through the color elements is not colored.   In the color display device, a plurality of pixels having the same area are arranged in parallel in a predetermined arrangement to form a display region, and the color filter is composed of red, green, and blue color elements, and each of these color elements is a pixel of each pixel. The color display device according to claim 1, wherein the color display device is installed so as to correspond to the arrangement.   3. The light reflecting film according to claim 2, further comprising: a light reflecting film that reflects and emits light incident from the front side, which is a viewing side of the display, and the color filter is disposed on the front side of the light reflecting film. The color display device described. The red element and the blue element are arranged in one pixel in which the green element is arranged, and the areas of the red, green, and blue color elements on the light reflecting film in the one green element pixel The ratio is
0.01 to 0.50: 0.50 to 0.99: 0.01 to 0.50
The color display device according to claim 3, wherein: The color display device is a liquid crystal display device in which a liquid crystal is sealed between a pair of substrates arranged opposite to each other, and a region where the electrodes respectively disposed on the opposed surfaces of the pair of substrates form pixels forms a pixel. 2. The reflective display area in which the light reflecting film is disposed and the transmissive display area in which the light reflecting film is not disposed are formed in one of the pixels. The color display device according to claim 4.

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