JP2003139937A - Color filter for liquid crystal display device and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a black matrix of a color filter for a liquid crystal display device using a cholesteric liquid crystal filter which returns reflected light to the illumination light source side and which is easily manufactured. SOLUTION: In the color filter for the liquid crystal display device constructed by aligning and laminating a first cholesteric liquid crystal color filter 51 and a second cholesteric liquid crystal color filter 52 on a transparent substrate 1, a light reflecting and scattering layer 51 or a multilayer coating to reflect and scatter light made incident through the transparent substrate 1 is patterned and disposed on a position between the filter regions of the first and second cholesteric liquid crystal color filters 51 and 52 on the transparent substrate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter for a liquid crystal display device and a liquid crystal display device using the same, and more particularly to a color filter for a liquid crystal display device using a cholesteric liquid crystal filter as a color filter and a liquid crystal using the same. The present invention relates to a display device.

[0002]

2. Description of the Related Art Hitherto, the use of a cholesteric film in which a cholesteric liquid crystal is dispersed as a color filter has been disclosed in, for example, JP-A-9-318807. This color filter has superior performance in brightness and color purity as compared with a color filter using a conventional pigment or dye. In particular, the wavelength of the selectively reflected light changes depending on the temperature and the ratio of the chiral agent, and further, by using an ultraviolet curable cholesteric liquid crystal that can be cured while maintaining the state of the liquid crystal by ultraviolet irradiation, it can be easily manufactured compared with the conventional method. There is an advantage that you can.

Cholesteric liquid crystal as described above, and
The chiral nematic liquid crystal has a characteristic that, in addition to the long-range orientational order of the liquid crystal molecular axes, the director is spirally spatially changing. That is, in the plane parallel to the liquid crystal molecular axis, the liquid crystal has the same alignment order as in the nematic phase, but when it moves to the adjacent plane, this local alignment direction is slightly rotated, so this continues sequentially. It has a spiral structure.

On the other hand, natural light can be divided into right-handed circularly polarized light and left-handed circularly polarized light. In a cholesteric liquid crystal or a chiral nematic liquid crystal, both right-handed and left-handed light components are incident parallel to the helical axis of the liquid crystal. In this case, there is a characteristic that only the circularly polarized light component in the same rotation direction as the twist direction of the liquid crystal is reflected and the other circularly polarized light component is transmitted.

At this time, since the phase of the reflected light with respect to the incident light does not change, the polarization direction before and after the incident of the reflected light is unchanged, and the wavelength of the reflected light is the twist of the cholesteric liquid crystal or the chiral nematic liquid crystal. It changes according to the pitch. This pitch changes depending on the addition amount of a chiral agent that generates a twisting force in the liquid crystal and an appropriate external field (for example, temperature, electric field, magnetic field, etc.).

Therefore, the above parameters are
By controlling in the visible range, it is possible to form red, green, and blue transmitted light, and the light other than the transmitted light is reflected to the light source side and reused, and the brightness is changed to the conventional color filter. It can be set higher than.

In the present invention, the reflection filter using the liquid crystal having such a spiral structure is hereinafter referred to as a cholesteric liquid crystal filter. The cholesteric liquid crystal filter reflects a specific circularly polarized light in a specific wavelength range and It has the property of transmitting wavelength bands and other circularly polarized light.

Conventionally, as a transmissive color liquid crystal display device using such a cholesteric liquid crystal filter as a color filter, there are disclosed in JP-A-8-320480, JP-A-8-234196, and JP-A-2000-347179.
In cholesteric, the R (red), G (green), and B (blue) pixels transmit light in the R, G, and B wavelength ranges from the backlight side and reflect light in other wavelength ranges, respectively. R, G, B respectively on the liquid crystal filter and its observation side
An absorption type color filter that transmits only light in the wavelength range of and absorbs light in the wavelength range of other colors is arranged to improve backlight utilization efficiency and prevent the influence of external light. There is. It is also possible to configure each of the R, G, and B pixels with a two-layer cholesteric liquid crystal filter that reflects light in different wavelength regions.
No. 0 and JP-A-8-234196.

A black matrix provided between pixels of a color filter for a liquid crystal display device using such a cholesteric liquid crystal filter is also composed of three layers of cholesteric liquid crystal filters, and light reflected by the black matrix is used as an illumination light source. Japanese Patent Application Laid-Open No. 2000-275629 proposes that the efficiency of use of the backlight is improved by returning the light to the side and using it again as illumination light to enable bright display.

[0010]

However, the one in which this black matrix is composed of three layers of cholesteric liquid crystal filter has a complicated layer structure, and therefore there is a problem that it is not easy to manufacture.

The present invention has been made in view of the above problems of the prior art, and its object is to use the reflected light as an illumination light source as a black matrix of a color filter for a liquid crystal display device using a cholesteric liquid crystal filter. It is to provide a configuration that can be returned to the side and is easy to manufacture.

[0012]

A color filter for a liquid crystal display device according to the present invention that achieves the above object has a color of a pixel corresponding to a pixel arrangement of R, G and B of the liquid crystal display device on a transparent substrate. The first filter region is arranged in an array that reflects light of a specific circularly polarized light of one color of the colors other than, and transmits other circular wavelengths and other circularly polarized light. In a color filter for a liquid crystal display device, in which a cholesteric liquid crystal color filter is laminated, a light scattering layer and a patterned reflective layer are arranged on the transparent substrate between the filter regions of the first cholesteric liquid crystal color filter. It is characterized by that.

In this case, the light scattering layer and the reflecting layer may be formed of the same layer, or the light scattering layer may be arranged between the transparent substrate and the reflecting layer. In the latter case, The light scattering layer may be patterned.

Another color filter for a liquid crystal display device of the present invention is a liquid crystal display device comprising R, G, and R on a transparent substrate.
According to the pixel arrangement of B, the light in the wavelength range of one of the colors other than the color of the corresponding pixel reflects a specific circularly polarized light,
A color filter for a liquid crystal display device, comprising: a first cholesteric liquid crystal color filter, the first cholesteric liquid crystal color filter being composed of filter regions arranged in an array that transmits another wavelength region and another circularly polarized light; Is characterized in that a multilayer coating that reflects incident light is patterned and arranged at a position between filter regions of the cholesteric liquid crystal color filter.

In the above, on the first cholesteric liquid crystal color filter, the wavelength range of the other color of the colors other than the colors of the pixels corresponding to the R, G, B pixel arrangement of the liquid crystal display device is displayed. A second cholesteric liquid crystal color filter composed of filter regions arranged in an array which is light and reflects a specific circularly polarized light and transmits another wavelength region and other circularly polarized light is aligned and laminated. Is desirable.

The wavelength of the color of the corresponding pixel in the light transmitted through the transparent substrate and each filter region of the first or second cholesteric liquid crystal color filter is further provided on the first or second cholesteric liquid crystal color filter. It is desirable that absorptive color filters composed of filter regions arranged in an array that transmits only the light in the region and absorbs the light in the wavelength regions of other colors are aligned and laminated.

In the latter case, it is desirable that the light reflection preventing layer or the light absorbing layer is patterned and arranged on the position between the filter regions of the absorption type color filter.

According to the present invention, a liquid crystal layer for modulating the phase of incident light according to an applied voltage is sandwiched between two transparent substrates, and an electrode and a drive circuit for independently applying a voltage to each liquid crystal layer for each pixel are provided. A liquid crystal display element provided, an illumination light source provided on the opposite side of the observation side, a circularly polarizing plate disposed between the illumination light source and the liquid crystal display element, and an observation side of the liquid crystal display element A liquid crystal display device provided with the circularly polarizing plate includes a liquid crystal display device in which the color filter for a liquid crystal display device according to any one of claims 1 to 8 is arranged as a transparent substrate on an observation side.

Further, according to the present invention, a liquid crystal layer for modulating the phase of incident light according to an applied voltage is sandwiched between two transparent substrates, and an electrode and a drive for independently applying a voltage to each liquid crystal layer for each pixel. A liquid crystal display element provided with a circuit, an illumination light source provided on the side opposite to the observation side, a circularly polarizing plate arranged between the illumination light source and the liquid crystal display element, and an observation side of the liquid crystal display element In the liquid crystal display device including the circularly polarizing plate provided in the above, a color other than the color of the pixel corresponding to the R, G, and B pixel arrangement of the liquid crystal display device on the transparent substrate is used as the transparent substrate on the observation side. First cholesteric liquid crystal color consisting of filter regions arranged in an array that reflects light of one of the wavelengths of one of the colors and reflects a specific circularly polarized light, and transmits other wavelengths and other circularly polarized light The transparent substrate on which the filters are laminated A patterned reflective layer is disposed between the filter regions of the first cholesteric liquid crystal color filter, and between the transparent substrate and the circularly polarizing plate disposed on the side of the illumination light source. It also includes a liquid crystal display device in which a light scattering layer is arranged at a position including the circularly polarizing plate.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a color filter for a liquid crystal display device of the present invention and a liquid crystal display device using the same will be described with reference to Examples.

FIG. 1 is a schematic sectional view showing the constitution of one embodiment of a color liquid crystal display device incorporating a color filter 10 for liquid crystal display device according to the present invention.

In FIG. 1, in this color liquid crystal display device, a liquid crystal layer 3 is sandwiched between glass substrates 1 and 2,
On the inner surface of the substrate 1 on the backlight side, light in the R (red), G (green), and B (blue) wavelength ranges depending on the pixel arrangement, for example, right circularly polarized light is reflected, and Filters that transmit light in the color wavelength range and left circularly polarized light in all wavelength ranges (represented by R _r , G _r , and B _r , respectively, and the subscript “r” means reflection). A first cholesteric liquid crystal color filter 51 arranged in an array, and R having a color characteristic different from that of the pixels of the first cholesteric liquid crystal color filter 51 aligned in the pixel arrangement.
Filters that reflect light in the G and B wavelength ranges, for example, right circularly polarized light, and transmit light in other wavelengths and left circularly polarized light in all wavelength ranges are arrayed. The arrayed second cholesteric liquid crystal color filter 52 is laminated to form a first cholesteric liquid crystal color filter 51.
And the second cholesteric liquid crystal color filter 52 constitute the cholesteric liquid crystal color filter 5. A region (left side region in FIG. 1) where the filters G _r and B _r of the cholesteric liquid crystal color filter 5 are aligned and overlap with each other transmits light in the R wavelength range, and is in a complementary color relationship with the G and B wavelength ranges. Configure an R filter that reflects light,
A region where the filters R _r and B _r are aligned and overlapped (see FIG. 1).
(The central region of G) transmits a light in the G wavelength range and constitutes a G filter that reflects light in the R and B wavelength ranges which are in a complementary color relationship with the G filter, and the filters R _r and G _r are aligned and superposed. The region (right side region in FIG. 1) constitutes a B filter that transmits light in the B wavelength region and reflects light in the R and G wavelength regions that are in a complementary color relationship with it.

In order that the absorption type R, G, B filters are aligned with the R, G, B filters of the cholesteric liquid crystal color filter 5, only the light in the R, G, B wavelength range is transmitted and other colors are transmitted. filter that absorbs light in a wavelength range (respectively R _t, G _t, shown in B _t, the subscript "t" is intended to mean the permeation.) absorption type color filter 6 arranged in an array Are stacked on the second cholesteric liquid crystal color filter 52.

A black matrix 4 is provided on the glass substrate 1 between the pixels of the cholesteric liquid crystal color filter 5 and the absorption type color filter 6 before the color filters 5 and 6 are laminated. In this embodiment, the black matrix 4 is composed of, for example, a reflection / scattering layer 41 made of a metal such as Cr having a reflection-scattering property on the glass substrate 1 side, and an absorption layer 42 such as CrO provided thereon. In order to make the glass substrate 1 side of the black matrix 4 reflective and scattering, the reflective scattering layer 41 may be composed of a transmission type light scattering layer and a metal reflective layer in order from the glass substrate 1 side.

The above glass substrate 1, the black matrix 4, the first cholesteric liquid crystal color filter 51 and the second cholesteric liquid crystal color filter 52.
Cholesteric liquid crystal color filter 5 consisting of
The absorption type color filter 6 constitutes a color filter 10 for a liquid crystal display device.

On the incident side of the glass substrate 1 on the backlight side, a circular polarizing plate 7 comprising a linear polarizing plate 9 and a quarter-wave plate 8 is provided on the observation side of the glass substrate 2 on the observation side. ,
Circular polarizing plate 1 including a quarter-wave plate 8 and a linear polarizing plate 9
1 is arranged, and an illumination light source 12 and a reflection plate 13 therefor are arranged on the incident side of the circularly polarizing plate 7. In addition, on the inner surfaces of the glass substrates 1 and 2, a pixel electrode which is aligned with the pixels of the filters 5 and 6 to form a pixel and its counter electrode, and a voltage applied between the pixel electrode and the counter electrode is controlled.
Although FT (TFD) and the like are provided, illustration is omitted (hereinafter,
the same. ).

Incidentally, instead of the circularly polarizing plate 7, it is disclosed in
As disclosed in 0-347179, a circularly polarized light separating film in which three or more birefringent films are laminated and a quarter wavelength plate is further laminated may be used.

With the above arrangement, the naturally polarized illumination light emitted from the light source 12 is only the circularly polarized light component which matches the reflection characteristic of the cholesteric liquid crystal color filter 5 by the circularly polarizing plate 7, for example, the right circularly polarized light component. Pass and the opposite circularly polarized light component, for example the left circularly polarized light component, is absorbed. The light in the R, G, and B wavelength regions in the right circularly polarized white light transmitted through the circularly polarizing plate 7 is filtered by each filter R _t of the cholesteric liquid crystal color filter 5 (filter G of the first cholesteric liquid crystal color filter 51). _r and filter B _r and are superposed areas of the second cholesteric liquid crystal color filter 52), a filter R _r and filter B _r of the second cholesteric liquid crystal color filter 52 of the G _t (first cholesteric liquid crystal color filter 51 Overlapping region) and B _t (region where the filter R _{r of} the first cholesteric liquid crystal color filter 51 and the filter G _{r of} the second cholesteric liquid crystal color filter 52 overlap each other), and the wavelengths other than the corresponding wavelength regions are passed. The light is reflected, and the reflected light is transmitted through the circularly polarizing plate 7 in the opposite direction to the light source 12 side. That.

The right circularly polarized R, which has passed through the R _t , G _t , and B _t filters of the cholesteric liquid crystal color filter 5,
The light in the G and B wavelength ranges passes through the corresponding R _t , G _t , and B _t filters of the absorption type color filter 5,
The right circularly polarized light in the R, G, and B wavelength regions reaches the liquid crystal layer 3 and remains right circularly polarized light or is converted into left circularly polarized light according to the modulation state of the pixel, and reaches the circularly polarizing plate 11. However, when the right circularly polarized light remains as it is, it goes out to the observation side as linearly polarized light through the circularly polarizing plate 11 and displays the bright state. When the light is converted into left-handed circularly polarized light, the light is left-handed circularly polarized light which is the opposite of the left-handed circularly polarized light which is passed through the circularly polarizing plate 11, so that it is cut off here and a dark state is displayed.

In this structure, when the absorption color filter 6 is not arranged, the cholesteric liquid crystal color filter 5 reflects the circularly polarized light component having the characteristic of reflecting in the wavelength range of the complementary color of the corresponding external light. Therefore, the color reproducibility becomes poor and accurate display becomes difficult. Therefore, the absorption type color filter 6 is arranged on the observation side of the cholesteric liquid crystal color filter 5.

Since the light returning to the light source 12 side is reflected and scattered by the reflecting plate 13 and the like and used again as illumination light, the utilization efficiency of the backlight is improved and bright display is possible.

Then, the right circularly polarized white light emitted from the light source 12 and passing through the circularly polarizing plate 7 has the color filters 5 and 6 therein.
The light that is directly incident on the black matrix 4 between the pixels is reflected and scattered by the reflection / scattering layer 41 of the black matrix 4. Due to the reflection and scattering, the right circularly polarized white light that is incident is naturally polarized white light and is circularly polarized. Since it returns to the plate 7 side, half of the right circularly polarized light component passes through the circularly polarizing plate 7, returns to the light source 12 side, is reflected and scattered by the reflecting plate 13 and the like and is used again for illumination light. The utilization efficiency of the backlight is improved as compared with the case where it is absorbed, and a brighter display is possible. In addition, external light that enters between pixels from the viewing side is not absorbed by the absorption layer 42 of the black matrix 4 and is not scattered and reflected, so that color bleeding between pixels can be prevented and color reproducibility is improved.

Instead of the reflective / scattering layer 41 of the black matrix 4, the layer 41 may be formed of a multilayer coating that reflects light in the entire visible wavelength range. In that case, the white light reflected by the multilayer coating layer 41 remains right-handed circularly polarized light, and the total amount of light passes through the circularly polarizing plate 7 and returns to the light source 12 side, so that the utilization efficiency of the backlight is further improved. improves. In that case, the absorption layer 42 is configured as a black layer such as a black resin layer.

By the way, the embodiment shown in FIG.
Telic liquid crystal color filter 51 and second cholesterol
Filter element of lick liquid crystal color filter 52
R_r, G _r, B_rSurrounded by black matrix 4
When a liquid crystal layer that can be patterned into a shape
But the filter element R_r, G_r, B_rFrom
Cholesteric liquid crystal color filter
Of cholesteric liquid crystal layer of the layer, the amount of ultraviolet light to irradiate
Etc. for each pixel so that the continuous single layer
Filter element R_r, G_r, B_rConfiguring an array of
Is performed (Japanese Patent Laid-Open No. 8-320480 and 2001).
-242315, International Publication WO00 / 34808). This
Using a cholesteric liquid crystal color filter like
The configuration of the color filter 10 'for the liquid crystal display device is shown in FIG.
Show. The color filter 1 for this liquid crystal display device
0'is a substitute for the color filter 10 for the liquid crystal display device of FIG.
Used instead.

In FIG. 2, a part of the black matrix is formed on the glass substrate 1, for example, the glass substrate 1
A reflection / scattering layer 41 made of a metal such as Cr whose side has reflection / scattering properties is formed and patterned. As in the case of FIG. 1, the reflective / scattering layer 41 may be composed of a transmissive light-scattering layer and a metal reflective layer in this order from the glass substrate 1 side, or instead, it reflects light in the entire visible wavelength range. The layer 41 may be composed of a multilayer coating.

Then, the first cholesteric liquid
Crystal layer is applied, for example R_rMost in the filter area
G ultraviolet rays_rA moderate amount of UV in the filter area
Line B_rIt has the least UV light in the filter area
By irradiating each, R _r, G_r, B_rFilter
The first cholesteric liquid crystal array in which the pixels are arranged in an array.
The color filter 51 as part of the black matrix.
It is produced by aligning it with the layer 41 to be formed.
Apply a resteric liquid crystal layer and apply R_r, G_r, B
_rSecond Cholesteres with filters arranged in an array
Lick liquid crystal color filter 52 to the first cholesteric
The color filter area together with the LCD color filter 51
Area R_t, G_t, B_tTo be arranged in an array
Then, it is used as a cholesteric liquid crystal color filter 5.

The R _t , G _t , and B _t filters of this cholesteric liquid crystal color filter 5 are absorption-type R _t and G _t filters.
Absorption-type color filter 6 in which filters that transmit only light in the R, G, and B wavelength ranges and absorb light in other wavelength ranges are arranged in an array so that the _t and B _t filters are aligned. The second cholesteric liquid crystal color filter 5
2 is stacked on top.

Then, a black layer 42 'such as a black resin layer, which constitutes the other part of the black matrix, is applied and patterned so as to be aligned between the pixels of the absorption type color filter 6 and on the reflection / scattering layer 41. As a result, the color filter 10 'for the liquid crystal display device is completed. If the black layer 42 ′ is not provided, outside light passes through the absorption color filter 6 and only the light in the wavelength regions of R, G, and B is transmitted, and the cholesteric liquid crystal filter 5 in the transmitted light is Since the circularly polarized light component having the characteristic of being reflected is reflected, a problem such as lowering the contrast of display occurs.

Next, an example of manufacturing the color filter 10 'for the liquid crystal display device of the embodiment of FIG. 2 will be described with reference to FIGS.

As shown in FIG. 3A, the glass substrate 1 forming a part of the black matrix on the glass substrate 1.
The glass substrate 1 (black matrix 20) on which the Cr whose side is made to reflect and scatter is patterned at a pitch of 100 μm
3 μm, glass 80 μm), a polyimide film was formed by spin coating as shown in FIG.
A polyimide film 21 of 000Å was obtained. Then, the polyimide film 21 thus formed was subjected to a rubbing treatment in a certain direction to prepare an oriented substrate.

Here, the black matrix is made of Cr (thickness 1000Å), and the Cr is applied from the glass substrate 1 side.
The scattering reflectance was measured to find that the wavelength was 400 to 700n.
It was about 70% in m.

Next, as shown in FIG. 3C, 85% by weight of the monomer represented by the chemical formula (A1) described below, 14% by weight of the monomer having an optically active group represented by the chemical formula (A2), and A 40 wt% toluene solution B in which 1 wt% of an initiator (Darocure 4265) was dissolved was spin-coated on the polyimide film 21 of FIG. 3 (b) so as to have a thickness of 4.0 μm.
Then, it was dried and oriented at 60 ° C. for about 30 seconds to obtain a blue reflector having a selective reflection center wavelength of 460 nm. Further, when the reflected color was observed through the left circularly polarizing plate, blue was seen, and when viewed through the right circularly polarizing plate, it was colorless, and thus it was confirmed that the obtained cholesteric liquid crystal 22 reflects left circularly polarized light.

Next, as shown in FIG. 3 (d), this substrate is provided with 100 regions of 100%, 50% and 0%.
Photomask 23 arranged in stripes at a pitch of μm
Through the ultraviolet ray 24 of wavelength 365 nm in the atmosphere.
After irradiation with 4 J / cm ² , alignment treatment was performed at 50 ° C. for 60 seconds.

Then, as shown in FIG. 3 (e), an ultraviolet ray 25 having a wavelength of 405 nm was irradiated at 1.5 J / c in a nitrogen atmosphere.
It was irradiated with m ² and cured by ultraviolet light.

When the substrate was observed under a microscope, the line width of each was 100 μm, and when the spectral characteristics of each were measured, the selective reflection center wavelengths were each 650.
nm (R _r ), 550 nm (G _r ), 460 nm
(B _r ), and the circularly polarized light reflectance peak value was 95%.

As a result, the patterned glass substrate 1 with the Cr pattern 41 for the black matrix is formed.
Then, a color filter was obtained in which the cholesteric liquid crystal color filter 51 reflecting blue, green and red was formed on the oriented polyimide 21.

Next, as shown in FIG. 4 (a), the toluene solution B was again spin-coated on the obtained color filter so as to have a thickness of 4.0 μm, and the coating was performed at 60 ° C. for about 30 seconds. It was dried and oriented.

Next, as shown in FIG. 4 (b), the position of the photomask 23 and the substrate was adjusted so that this substrate was laterally shifted by 100 μm using the photomask 23 and was shifted by exactly one pixel. Later, through this photomask,
Ultraviolet ray 24 with a wavelength of 365 nm is 0.4 J / cm in the atmosphere.
^{After two} irradiations, alignment treatment was performed at 50 ° C. for 60 seconds.

Then, as shown in FIG. 4 (c), 1.5 J / c of ultraviolet light 25 having a wavelength of 405 nm is applied in a nitrogen atmosphere.
It was irradiated with m ² and cured by ultraviolet light.

When the substrate was observed under a microscope, the line width of each was 100 μm, and the second cholesteric liquid crystal color filter 52 was formed on the cholesteric liquid crystal color filter 51.
It was green, and it was confirmed by reflection observation that it was cyan, magenta, and yellow.

Further, when the respective spectral characteristics were measured, a layer having a reflectance peak at 460 nm and 550 nm (right side region of FIG. 4C), 550 nm and 650 nm.
A layer having a reflectance peak at the center (center region of FIG. 4 (c))
And a layer having a reflectance peak at 650 nm and 460 nm (left side region of FIG. 4C) was formed, and the circularly polarized reflectance peak value of each layer was 95%.

As a result, the patterned glass substrate 1 with the Cr pattern 41 for the black matrix is provided.
, Blue + green, green + on the oriented polyimide 21
A color filter was obtained in which cholesteric liquid crystal color filters 51 and 52 that reflect red, blue and red were formed.

Next, as shown in FIG. 4 (d), as the pigment dispersion type color filter 6, a pigment which transmits red in the layer reflecting blue + green is provided on the cholesteric liquid crystal color filters 51 and 52. The dispersion type color filter layer (R _t ) is formed by photolithography so as to have a width of 100 μm and a thickness of 1.2 μm, and the layer that reflects green + red is a pigment dispersion type color filter layer that transmits blue (B).
_t ) has a width of 100 μm and a thickness of 1.2 μm and is formed by photolithography, and a red + blue reflecting layer transmits green as a pigment dispersion type color filter layer (G _t ).
Was formed by photolithography to have a width of 100 μm and a thickness of 1.2 μm.

As a result, the patterned glass substrate 1 with the Cr pattern 41 for the black matrix is formed.
, Blue + green, green + on the oriented polyimide 21
A transmissive cholesteric color filter was obtained in which cholesteric liquid crystal color filters 51 and 52 reflecting red, blue + red and an absorption color filter 6 were formed.

Next, as shown in FIG. 4 (e), a black resin layer 42 'is formed on the obtained transmissive cholesteric color filter (on the pigment dispersion type color filter 6) as Cr forming a black matrix. A width of 20 μm and a thickness of 1.0 μm were formed by photolithography so as to be aligned.

A left circularly polarizing plate was attached to both sides of the obtained transmissive cholesteric color filter 10 ', and the backlight of the constitution shown in FIG. The luminance was measured and found to be 255 cd / m ² .

Further, a transmissive cholesteric color filter 10 'using a black resin layer instead of the Cr pattern 41 was similarly prepared, and the same luminance measurement was carried out to find that it was 233 cd / m ² .

In addition, the transmissive cholesteric color filter 10 'is a cholesteric liquid crystal color filter 51.
When the luminance was measured for the one excluding (1) and (52) (pigment-dispersed color filter 6 only), it was 182 cd / m ² .

[0059]

[Chemical 1]

[0060]

[Chemical 2]

By the way, in the structure of the color liquid crystal display device of FIG. 1 or in the structure using the color filter 10 'for liquid crystal display device of FIG. 2 instead of the color filter 10 for liquid crystal display device of FIG. Even if the filter 6 is provided on the inner surface of the glass substrate 2 on the observation side instead of being provided on the inner surface of the substrate 1 on the backlight side, the effect of preventing the adverse effect of the external light is the same. 5, the absorption type color filter 6 of the color filter 10 'for liquid crystal display device of FIG. 2 is omitted, and the color filter 1 for liquid crystal display device is omitted.
The structure of the color liquid crystal display device in which the absorption type color filter 6 is arranged on the inner surface of the glass substrate 2 on the observation side and the liquid crystal layer 3 is sandwiched therebetween is schematically shown.

In the above, the light utilization efficiency is substantially two-thirds, but the cholesteric liquid crystal color filter may be a single layer.

As a modification in which the reflection / scattering layer 41 is composed of a transmission type light scattering layer and a metal reflection layer in this order from the glass substrate 1 side, the layer 41 is composed of a metal reflection layer, and the transmission type light scattering layer is 4 layers. Between the quarter-wave plate 8 and the glass substrate 1, for example, the quarter-wave plate 8 itself is made to have a light-scattering property.
Even if the transmissive light scattering layer is provided on the outer surface of the device, it is possible to obtain some effect of improving the backlight utilization efficiency.
In that case, it is not necessary to pattern the transmissive light scattering region or the transmissive light scattering layer.

Further, in the above embodiments, the circularly polarizing plate 7 on the incident side of the backlight absorbs and cuts one polarized light emitted from the illumination light source 11, but reflects the polarization component which cannot be transmitted. When the plate 7 is used, the backlight utilization efficiency is further improved. A circularly polarized light selection layer that reflects one of right circularly polarized light and left circularly polarized light and transmits the other, as disclosed in JP-A-10-232313, on the incident side of the linearly polarizing plate 9 of the circularly polarizing plate 7 and 4 By arranging a circularly polarized light separating film formed by laminating a half-wave plate, one circularly polarized light component emitted from the illumination light source 11 is used for illumination and the other circularly polarized light component that cannot be transmitted is reflected. Even so, the backlight utilization efficiency is further improved.

The liquid crystal display device of the present invention has been described above based on some embodiments, but the present invention is not limited to these embodiments and various modifications can be made.

[0066]

As is apparent from the above description, according to the color filter for a liquid crystal display device of the present invention and the liquid crystal display device using the same, a liquid crystal in which a backlight utilization efficiency is improved by using a cholesteric liquid crystal color filter. In a color filter for a display device and a liquid crystal display device using the same, since a light scattering layer and a patterned reflective layer or a multilayer coating that reflects incident light is disposed between filter regions of a cholesteric liquid crystal color filter. , The black matrix is easy to fabricate, and the light reflected by the light scattering layer and the patterned reflective layer or the multilayer coating constituting the black matrix is returned to the illumination light source side to be reused as illumination light. This will improve the efficiency of backlight usage. Are allowed, it is possible to allow a bright display.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a configuration of an embodiment of a color liquid crystal display device incorporating a color filter for a liquid crystal display device according to the present invention.

FIG. 2 is a schematic cross-sectional view of a color filter for a liquid crystal display device of another embodiment.

FIG. 3 is a diagram showing a first half of a manufacturing process of the color filter for a liquid crystal display device of FIG.

FIG. 4 is a diagram showing the latter half of the manufacturing process of the color filter for a liquid crystal display device of FIG.

5 is a schematic cross-sectional view showing a configuration of a modified example of the color liquid crystal display device of FIG.

[Explanation of symbols]

1, 2 ... Glass substrate 3 ... Liquid crystal layer 4 ... Black matrix 5 ... Cholesteric liquid crystal color filter 6 ... Absorption type color filter 7 ... Circular polarizing plate 8 ... Quarter wave plate 9 ... Linear polarizing plates 10, 10 ', 10 "... Color filter 11 for liquid crystal display device ... Circular polarization plate 12 ... Illumination light source 13 ... Reflector 21 ... Polyimide film 22 ... Cholesteric liquid crystal coating layer 23 ... Photomask 24 ... UV ray 25 ... UV ray 26 ... Cholesteric liquid crystal coating layer 41 ... Reflection Scattering layer (multi-layer coating) 42 ... Absorption layer (black layer) 42 '... Black layer 51 ... First cholesteric liquid crystal color filter 52 ... Second cholesteric liquid crystal color filter

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H048 AA06 BA02 BA04 BA64 BB01                       BB02 BB03 BB04 BB10 BB43                 2H091 FA02Y FA14Y FA16Y FA31Y                       FA35Y FB02 FD06 LA12                       LA15 LA17

Claims (10)

[Claims] 1. A liquid crystal display device comprising R, G, and R on a transparent substrate.
According to the pixel arrangement of B, the light in the wavelength range of one of the colors other than the color of the corresponding pixel reflects a specific circularly polarized light,
A color filter for a liquid crystal display device, comprising: a first cholesteric liquid crystal color filter, the first cholesteric liquid crystal color filter including filter regions arranged in an array that transmits another wavelength region and another circularly polarized light, A color filter for a liquid crystal display device, characterized in that a light scattering layer and a patterned reflection layer are arranged between the filter regions of the cholesteric liquid crystal color filter. 2. The color filter for a liquid crystal display device according to claim 1, wherein the light scattering layer and the reflection layer are formed of the same layer. 3. The color filter for a liquid crystal display device according to claim 1, wherein the light scattering layer is arranged between the transparent substrate and the reflective layer. 4. The color filter for a liquid crystal display device according to claim 3, wherein the light scattering layer is patterned. 5. A liquid crystal display device comprising R, G, and R on a transparent substrate.
According to the pixel arrangement of B, the light in the wavelength range of one of the colors other than the color of the corresponding pixel reflects a specific circularly polarized light,
A color filter for a liquid crystal display device, comprising: a first cholesteric liquid crystal color filter, the first cholesteric liquid crystal color filter including filter regions arranged in an array that transmits another wavelength region and another circularly polarized light, A color filter for a liquid crystal display device, wherein a multilayer coating that reflects incident light is patterned and arranged at a position between the filter regions of the cholesteric liquid crystal color filter. 6. On the first cholesteric liquid crystal color filter, a wavelength range of the other color among colors other than the colors of pixels corresponding to the R, G, B pixel arrangement of the liquid crystal display device is displayed. A second cholesteric liquid crystal color filter composed of filter regions arranged in an array which is light and reflects a specific circularly polarized light and transmits another wavelength region and other circularly polarized light is aligned and laminated. A color filter for a liquid crystal display device according to any one of claims 1 to 5. 7. Corresponding light in the light transmitted through each filter region of the transparent substrate and the first or the second cholesteric liquid crystal color filter, further on the first or the second cholesteric liquid crystal color filter. An absorption type color filter composed of filter regions arranged in an array which transmits only light in the wavelength range of the pixel and absorbs light in the wavelength range of other colors is aligned and laminated. A color filter for a liquid crystal display device according to claim 1. 8. The color for a liquid crystal display device according to claim 7, wherein a light reflection preventing layer or a light absorbing layer is patterned and arranged on a position between the filter regions of the absorption type color filter. filter. 9. A liquid crystal layer for modulating the phase of incident light according to an applied voltage is sandwiched between two transparent substrates, and an electrode and a drive circuit for independently applying a voltage to each pixel are provided in the liquid crystal layer. A liquid crystal display element, an illumination light source provided on the opposite side to the observation side, a circularly polarizing plate arranged between the illumination light source and the liquid crystal display element, and an observation side of the liquid crystal display element A liquid crystal display device comprising a circularly polarizing plate, wherein the color filter for liquid crystal display device according to any one of claims 1 to 8 is arranged as a transparent substrate on an observation side. 10. A liquid crystal layer for modulating the phase of incident light according to an applied voltage is sandwiched between two transparent substrates, and an electrode and a drive circuit for independently applying a voltage to each pixel are provided in the liquid crystal layer. A liquid crystal display element, an illumination light source provided on the opposite side to the observation side, a circularly polarizing plate arranged between the illumination light source and the liquid crystal display element, and an observation side of the liquid crystal display element In a liquid crystal display device provided with a circularly polarizing plate, as a transparent substrate on the observation side, one of colors other than the pixel color corresponding to the R, G, B pixel arrangement of the liquid crystal display device on the transparent substrate. The first cholesteric liquid crystal color filter, which is composed of filter regions arranged in an array that reflects a specific circularly polarized light having a wavelength region of the color and transmits another wavelength region and another circularly polarized light, is laminated. And the first on the transparent substrate A patterned reflective layer is arranged at a position between filter regions of a cholesteric liquid crystal color filter, and the circular polarizing plate is formed between the transparent substrate and the circular polarizing plate arranged on the illumination light source side. A liquid crystal display device, wherein a light scattering layer is disposed at a position including the light scattering layer.