JP2002236209A - Color filter and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter and a liquid crystal display device having high for light transmittance and excellent display characteristics. SOLUTION: A flattening layer formed to cover red, green and blue filter layers is also used as a wavelength converting layer. The light in the near ultraviolet region being a portion of the incident light is converted into the light in the wavelength region of blue color, so that the light transmittance of the blue filter layer is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter used for a liquid crystal display device capable of color display and a color liquid crystal display device using the same, and more particularly, to light transmitted through a color filter from a liquid crystal backlight. The present invention relates to a color liquid crystal display device in which the brightness of the image is improved and the display quality is improved.

[0002]

2. Description of the Related Art Many display devices, such as liquid crystal display devices, for displaying character information and image information, which support color display, have been developed. As one of means for realizing this color display, a color filter is widely used.

A conventional color filter is formed by forming a colored pattern (red (R), green (G), blue (B)) for color display, which is colored with a pigment, a dye, or the like on a glass substrate. I have. Since such a color filter selectively transmits only light in a specific wavelength range and absorbs and does not transmit light outside the specific wavelength range, there is a problem that the transmittance of light transmitted through the color filter is low. .

For example, in an RGB color filter, a filter portion for blue absorbs light in a wavelength range corresponding to red and green among incident white light and transmits blue light. / 3 loss or more.

To solve the above problem, Japanese Patent Laid-Open No. 11-2
According to the technique described in Japanese Patent Application Publication No. 02118, as shown in FIG. 1 which faithfully shows the outline, the red surface laminated on the other surface of the glass substrate 4, that is, the light emission side 11 of the glass substrate,
Wavelength conversion layers 3R, 3G and 3B for green and blue, and a filter layer 2R laminated on the light emission side 11 of the color conversion layer;
2 and 2B, and further provided with a color filter provided with a planarizing layer 1 for planarizing two stacked layers.

Here, the wavelength conversion layer includes a color conversion layer 3R for red for converting light in a wavelength range from near ultraviolet to near green to light in a wavelength range near to red, and light in a wavelength range from near ultraviolet to near blue. Color conversion layer 3G for converting green light into light in a wavelength range near green
And a blue color conversion layer 3B for converting light in the near ultraviolet region into light in the wavelength region near blue.

[0007]

The liquid crystal display device having the above-mentioned wavelength conversion color filter has the following problems. That is, in addition to the red, green, and blue filter layers, it is indispensable to form a wavelength conversion layer having a function of converting the wavelength of incident light corresponding to each of the filter layers. Therefore, the number of manufacturing steps for the color filter increases, and the productivity of the color filter decreases accordingly. Further, it is necessary to form each filter layer through a plurality of steps after forming the wavelength conversion layer,
Severe heat history in the process is applied to the lower wavelength conversion layer, so that the function of the wavelength conversion layer itself is likely to deteriorate.

An object of the present invention is to solve the above-mentioned problems and to provide a color filter capable of realizing a high light transmittance for incident light and a color liquid crystal display device realizing a high luminance display.

[0009]

In order to achieve the above object, the present invention comprises a light transmitting substrate, a color filter layer and a wavelength conversion layer, and the wavelength conversion layer is formed so as to cover the color filter layer. Have been. Further, a wavelength conversion layer, a color filter layer, and a flattening layer are sequentially laminated above the light transmitting substrate. As a result, of the light incident on the wavelength conversion layer, light having a wavelength
The light was converted to light of 0 nm or more.

Further, a light-transmitting substrate, a wavelength conversion layer, a black matrix layer, a color filter layer, and a flattening film layer are provided, and the wavelength conversion layer and the color filter layer are laminated above the light-transmitting substrate. And a black matrix layer is arranged in a gap between adjacent color filter layers,
A flattening film layer is provided so as to cover the black matrix layer and the color filter layer.

Further, the present invention comprises a first light transmitting substrate, a thin film transistor element, a liquid crystal layer, and a color filter,
In this color filter, a color filter layer and a wavelength conversion layer were sequentially laminated above a second light transmitting substrate, and a liquid crystal layer was disposed between the wavelength conversion layer and the thin film transistor element. Alternatively, for the color filter, a wavelength conversion layer and a color filter layer are sequentially laminated above the second light-transmitting substrate, and a liquid crystal layer is disposed between the color filter layer and the thin film transistor element.

Further, the present invention comprises a light-transmitting substrate, a thin film transistor element, a wavelength conversion layer, a color filter layer, and a liquid crystal layer, and the color filter layer formed above the wavelength conversion layer comprises a thin film transistor element and a liquid crystal layer. And a wavelength of 420 n out of the light incident on the wavelength conversion layer.
m or less is converted into light having a wavelength of 420 nm or more. The light from the backlight is incident on the color filter layer via the wavelength conversion layer.

The above-described color filter has a wavelength converting means for converting a part of the incident light into light of a specific wavelength range, and the wavelength converting layer has a function of flattening a resist layer forming each filter layer. And a filter function for transmitting only light in a specific wavelength range of the incident light.

This eliminates the necessity of separately forming a new wavelength conversion layer in the same pattern as the filter layers in addition to the red, green, and blue filter layers described in the prior art. Since the functions of flattening and wavelength conversion of each filter layer can be shared, there is no need to increase the number of manufacturing steps. And the incident wavelength 42
Since light having a wavelength of 0 nm or less can be converted to light having a wavelength of 420 nm or more, a color liquid crystal display device having high light transmittance can be realized.

At this time, as the phosphor material used for the wavelength conversion layer, for example, 7-dimethylamino-4-methylcoumarin, 7-hydroxy-4-methylcoumarin, perylene,
1,4-bis (4-methyl-5-phenyloxazol-2-yl) benzene, 7-dimethylamino-4-methyl-2-hydroxyquinoline and the like can be used, but are not limited thereto. No wavelength 420 incident on the wavelength conversion layer
Any fluorescent material that can convert light of nm or less into light of 420 nm or more can be used without any problem.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a cross-sectional view of a color filter for explaining an embodiment of the present invention. 0.7
A resist in which a red pigment was dispersed was applied to the upper side of the glass substrate 4 having a thickness of 1 mm using a well-known method, and then baked. Exposure, development, and post-baking were performed using a well-known photolithography technique to form a red filter layer 2R having a thickness of about 1.5 mm and patterned at a desired position. By repeating the same process, the green filter layer 2G and the blue filter layer 2B
Was formed.

Next, as a flattening film 3 for flattening the surface of each of the color filter layers 2R, 2G and 2B, a photothermosetting resin material (manufactured by Nippon Steel Chemical Co., Ltd., product name: V25)
9PA) was used. As an example of a phosphor material for converting light having a wavelength of 420 nm or less to light having a wavelength of 420 nm or more, the phosphor 7-hydroxy-4-methylcoumarin is used as an example of the phosphor material incident on the flattening film 3. Was.

This was dissolved in the photothermosetting resin material in an amount of 5% by weight, applied so as to cover each of the color filter layers 2R, 2G and 2B, and heated by a well-known hot plate method. Thereafter, after the entire surface was exposed, it was further heated and cured by using an oven furnace to form a flattening film 3 having a thickness of 1.5 mm. Through the above steps, a color filter in which the flattening layer also functions as the wavelength conversion layer and is capable of converting the wavelength of incident light is completed.

Further, for the purpose of comparison with this embodiment, a flattening film was formed using a photothermosetting resin material (product name: V259PA, manufactured by Nippon Steel Chemical Co., Ltd.) not containing the above-mentioned phosphor material. Formed. The method of forming each of the color filter layers 2R, 2G and 2B is the same as that of the embodiment.

FIG. 3 shows an example of measuring the spectral characteristics of the color filter manufactured as described above. However, only the blue filter layer 2B was formed as a color filter layer. In the measurement, light (for example, using a backlight often used for a liquid crystal display) is incident from the flattening film 3 side of the color filter, and light emitted through the blue filter layer 2B to the glass substrate 4 side. Was measured using a multi-channel analyzer manufactured by Hamamatsu Photonics and an imaging spectrum graph C5094.

In FIG. 3, the horizontal axis indicates the wavelength, and the vertical axis indicates the intensity of the output light. The solid line in FIG. 3 indicates the case where the incident light passes through the wavelength conversion layer which also serves as the flattening film. The dotted line indicates the case where the light passes through a mere flattening layer having no function of the wavelength conversion layer.

As is apparent from the results, the planarizing layer
That is, when the light is transmitted through the wavelength conversion layer and the blue color filter layer, light having a shorter wavelength side, particularly light having a wavelength of 420 nm or less, of the backlight light is absorbed by the wavelength conversion layer, and the wavelength 4
It emits fluorescence of 20 nm or more, and as a result, it is observed as a remarkable increase in emission light intensity in the wavelength range of 420 nm or more, particularly in the wavelength range of 440 nm to 480 nm.

As a color filter layer, a green filter 2G (center wavelength: 550 nm) and a red filter 2R
When (center wavelength 620 nm) is used, the light in the wavelength region where the above-described remarkable increase in the emitted light is
G and 2R are hardly transmitted, so that the function of the wavelength conversion layer is not exhibited as compared with the case of the blue filter 2B.

As described above, when the backlight is transmitted in the order of the wavelength conversion layer (also serving as a flattening layer) and the color filter layer from the light incident side, a part of the incident light 5 from the backlight is obtained. Light having a wavelength of 420 nm or less
m and is emitted to the outside as outgoing light 11 together with the incident light 5. Thereby, while realizing a brighter color filter with improved brightness compared to a color filter without a wavelength conversion layer, the above-mentioned wavelength conversion layer for blue covers the surface of each of the RGB filters,
By exerting the function of flattening the surface of the filter, an increase in the number of manufacturing steps can be suppressed.

FIG. 4 is a sectional view of a color filter for explaining another embodiment. A photothermosetting resin material (product name: V259PA, manufactured by Nippon Steel Chemical Co., Ltd.) is applied on a glass substrate 4 having a thickness of 0.7 mm. The light having a wavelength of 420 nm or less is incident on this photothermosetting resin material.
and a phosphor material for converting the light into light of not less than nm.
-5% by weight of methyl coumarin is dissolved. And
After heating using a well-known hot plate method and exposing the entire surface, the film was again heated and cured using an oven furnace to form a wavelength conversion layer 3 (thickness of 1.5 mm).

Next, a resist in which a red pigment is dispersed is applied on the wavelength conversion layer 3 and baking is performed. Thereafter, through the respective steps of exposure, development, and post-baking using a well-known photolithography technique, a red filter layer 2R (1.5 mm
Thickness). Similarly, the green filter layer 2
G and blue filter layers 2B were formed. The order of forming the filter layers does not depend on the above method.

Next, a flattening layer 1 is formed by a usual method so as to cover the above-mentioned filter layers 2R, 2G and 2B, and a color filter having a wavelength conversion function for incident light 5 is completed.

When the backlight of the liquid crystal is irradiated from the glass substrate 4 side of the above-mentioned color filter, for example, it is a part of the backlight 5 incident on the wavelength conversion layer 3 through the glass substrate 4. Light having a wavelength of 420 nm or less is absorbed by the fluorescent material, emits fluorescence having a wavelength of 420 nm or more, passes through the blue filter layer 2B together with the backlight, and is emitted to the outside as emission light 11.

Therefore, as illustrated in FIG.
m or less is converted into light having a wavelength of 420 nm or more, and an effect can be exerted as if the transmittance of the blue filter layer 2B was improved. As a result, it has become possible to realize a bright color filter with improved luminance as compared with a conventional color filter having no wavelength conversion layer 3.

FIG. 5 is a sectional view of a color filter for explaining another embodiment. The difference between this embodiment and the embodiment described in FIG. 4 is that a process for forming a black matrix layer 9 is added between the processes for forming the wavelength conversion layer 3 and the filter layers 2R, 2G and 2B. The method for forming the wavelength conversion layer 3 and the filter layers 2R, 2G, and 2B is the same as the method described with reference to FIG.

The black matrix layer 9 is formed as follows. That is, after the wavelength conversion layer 3 is formed on the glass substrate 4, a photosensitive resin black matrix material is applied and baking is performed. Thereafter, exposure, development, and post-baking processes were performed by using a known photolithography technique to form a patterned black matrix layer 9 (1.5 mm thick) at a desired position.

The red filter layer 2R, the green filter layer 2G, and the blue filter layer 2B are formed in the openings of the black matrix layer 9 described above, and the red filter layer 2R, the green filter layer 2G, and the blue Filter layer 2B
The flattening layer 1 is formed so as to cover the black matrix layer 9. Through the above steps, a color filter having a wavelength conversion layer is completed.

When, for example, a backlight for a liquid crystal display is irradiated from the glass substrate 4 side of the color filter produced by the above method, the wavelength of the incident light 5 from the backlight transmitted through the glass substrate 4 The light having a wavelength of 420 nm or less is absorbed by the fluorescent material existing in the wavelength conversion layer 3 to emit fluorescence, and is converted into light having a wavelength of 420 nm or more, passes through each of the filter layers 2R, 2G, 2B and the flattening layer 1 and is externally emitted. Is extracted as the outgoing light 11.

At this time, since the incident light 5 from the backlight and a part of the light converted by the wavelength conversion layer 3 are shielded by the black matrix layer 9, each of the filter layers 2R, 2R,
It is possible to prevent mixing of red, green, and blue light emitted through G and 2B. That is, compared with the conventional color filter, the contrast can be improved by providing the black matrix layer in the gap between the adjacent filter layers, and the luminance can be improved by providing the wavelength conversion layer. Color filter was realized.

FIG. 6 is a sectional view of a color filter for explaining still another embodiment. The difference between this embodiment and the embodiment described with reference to FIG. 2 is that a black matrix layer 9 is first formed at a predetermined position on the glass substrate 4, and then each filter layer 2 </ b> R, 2 </ b> R
G and 2B were formed. In other words, the black matrix layer 9 is provided in the gap between the adjacent filter layers 2R, 2G, 2B. The method of forming the black matrix layer 9 is the same as the method described in the embodiment of FIG. 5, and the method of forming the filter layers 2R, 2G, 2B and the flattening layer 3 serving also as the wavelength conversion layer is shown in FIG. This is the same as in the embodiment.

The above-mentioned color filter is irradiated with light from, for example, a backlight for liquid crystal display from the opposite side of the glass substrate, that is, from the side of the flattening layer 3 also serving as a wavelength conversion layer, so that the incident light 5 Part of the light having a wavelength of 420 nm or less is converted by the wavelength conversion layer 3 into light having a wavelength of 420 nm or more, passes through the filter layers 2R, 2G, and 2B and is extracted to the outside as emission light 11.

In this embodiment, as in the embodiment shown in FIG. 2, a brighter color filter whose luminance is improved as compared with the conventional color filter is provided by the wavelength conversion function provided in the wavelength conversion layer. Can be realized. Further, the black matrix layer 9 blocks the incident light 5 from the backlight and the light converted by the wavelength conversion layer 3, so that the filter layers 2R, 2G,
The contrast of light emitted outside through 2B can be improved. In addition, by using the wavelength conversion layer and the flattening layer together, it is possible to improve the luminance without increasing the number of manufacturing steps.

FIG. 7 is a sectional view of a color filter for explaining still another embodiment. The difference between this embodiment and the embodiment described with reference to FIG.
That is, each wavelength conversion layer 3R, 3G was formed above 2G. The method of forming the black matrix layer 9 is the same as the method described in the embodiment of FIG.
The method of forming R, 2G, and 2B is the same as that of the embodiment of FIG.

In order to form the wavelength conversion layer 3R, a photo-thermosetting resin material (manufactured by Nippon Steel Chemical Co., Ltd., product name: V259)
PA) was used. Phosphor 4-dicyanomethylene-2 is an example of a phosphor material for converting light having a wavelength of 550 nm or less to light having a wavelength of 550 nm or more from incident light.
-Methyl-6- (4-dimethylaminostyryl) -4H
-Pyran was used.

This was dissolved in the above-mentioned photothermosetting resin material in an amount of 5% by weight, applied to the entire surface of the color filter layer, and heated by a well-known hot plate method. Then, after performing exposure using the mask used at the time of 2R formation, development and post-baking are performed using a well-known photolithography technique,
A 3R having a thickness of about 1.5 mm was formed.

In the same manner, phosphor coumarin 3 is used as an example of a phosphor material for converting light having a wavelength of 480 nm or less to light having a wavelength of 480 nm or more from incident light.
Using 0, the wavelength conversion layer 3G was formed.

Further, light having a wavelength of 420 nm or less
A flattening film layer 3 for converting light into light of nm or more was formed so as to cover the color filter layer and the wavelength conversion layer. The method of forming the planarizing layer 3 is the same as that of the embodiment of FIG.

When, for example, a backlight for a liquid crystal display is irradiated from the side of the flattening film layer 3 of the color filter manufactured by the above method, the incident light 5 from the backlight transmitted through the flattening film layer 3 Of the light, the light having a wavelength of 420 nm or less is absorbed by the fluorescent material contained in the wavelength conversion layer 3 to emit fluorescence, and is converted to light having a wavelength of 420 nm or more, passes through the filter layer 2B, and is extracted to the outside as emission light 11. It is. In addition, the light converted into the light having a wavelength of 420 nm or more by the incident light 5 and the wavelength changing layer 3 is incident on the 3R and 3G wavelength conversion layers, and is absorbed by the intrinsic fluorescent material to emit fluorescent light. Is converted to light having a wavelength of 480 nm or more, passes through the filter layers 2R and 2G, and is extracted as outgoing light 11 to the outside.

In this embodiment, a brighter color filter whose luminance is improved as compared with the conventional color filter is realized by the wavelength conversion function provided in the wavelength conversion layer, as compared with the embodiment shown in FIG. You can do it.
In addition, by using the wavelength conversion layer and the flattening layer together, the number of manufacturing steps is small and the luminance can be improved.

FIG. 8 is a sectional view of a color filter for explaining still another embodiment. The difference between this embodiment and the embodiment described with reference to FIG.
That is, each wavelength conversion layer 3R, 3G was formed below 2G. The method of forming the black matrix layer 9 is the same as the method described in the embodiment of FIG.
G is formed in the same manner as in FIG.
The method of forming R, 2G, 2B and the wavelength conversion layer 3 is the same as in the embodiment of FIG.

When, for example, a backlight for a liquid crystal display is irradiated from the glass substrate 4 side of the color filter manufactured by the above method, the wavelength of the incident light 5 from the backlight transmitted through the glass substrate 4 Light having a wavelength of 420 nm or less is absorbed by a fluorescent material contained in the wavelength conversion layer 3 to emit fluorescence, and is converted into light having a wavelength of 420 nm or more, passes through the filter layer 2B, and is extracted to the outside as emission light 11. In addition, the light converted into the light having a wavelength of 420 nm or more by the incident light 5 and the wavelength changing layer 3 by the incident light 5 and the wavelength changing layer 3 enters the 3R and 3G wavelength conversion layers, and is absorbed by the intrinsic fluorescent material to emit fluorescence. Is converted to light having a wavelength of 480 nm or more, passes through the filter layers 2R and 2G, and is extracted as outgoing light 11 to the outside.

In this embodiment, a brighter color filter whose luminance is improved as compared with the conventional color filter is realized by the wavelength conversion function provided in the wavelength conversion layer, as compared with the embodiment shown in FIG. You can do it.

FIG. 9 shows an example of measuring the spectral characteristics of the color filter manufactured as described above. In the measurement, light (for example, using a backlight often used for a liquid crystal display) is incident from the flattening film 3 side of the color filter, and light emitted through the blue filter layer 2B to the glass substrate 4 side. Was measured in the same manner as in FIG.

In FIG. 9, the horizontal axis indicates the wavelength and the vertical axis indicates the intensity of the output light, and the dotted lines 2R, 2G,
2B shows a case where the light passes through a mere planarization layer having no function of a wavelength conversion layer and each of R, G, B, and a filter layer. Also,
Two-dot chain line 2R + 3 (R), 2G + 3 (G), 2B + 3
(B) is a case where a wavelength conversion layer is formed on each filter layer. And the solid line 2R + 3 (R) +3 (B),
2G + 3 (G) +3 (B) is a case where the B wavelength conversion layer also serving as a flattening film and R and G are transmitted through the respective wavelength conversion layers.

As is apparent from the result, the planarizing layer,
That is, when transmitted through the wavelength conversion layer and the blue color filter layer, light having a shorter wavelength side, particularly light having a wavelength of 420 nm or less, of the backlight light is absorbed by the wavelength conversion layer, and emits fluorescence having a wavelength of 420 nm or more. And consequently it is observed as a remarkable increase in emission light intensity at a wavelength of 420 nm or more. As a result, even in the wavelength conversion layer formed on the R and G filter layers, the light in the wavelength region where the above-mentioned remarkable increase of the emitted light is recognized is also applied to each of the filters 2G and 2R.
And the function of the wavelength conversion layer, that is, an increase in the intensity of emitted light as compared with the case where the wavelength conversion layer is formed only in the blue filter 2B, is exhibited.

As described above, when the backlight is transmitted in the order of the wavelength conversion layer (also serving as a flattening layer) and the color filter layer from the light incident side, a part of the incident light 5 from the backlight is obtained. Light having a wavelength of 420 nm or less
m and is emitted to the outside as outgoing light 11 together with the incident light 5.

As a result, a brighter color filter having a higher luminance than that of a color filter having no wavelength conversion layer and a color filter having a wavelength conversion layer formed on each of the filter layers can be realized. A wavelength conversion layer covers the surface of each of the RGB filters,
By exerting the function of flattening the surface of the filter, an increase in the number of manufacturing steps can be suppressed.

Next, an example in which the above-described color filter is applied to a liquid crystal display device will be described. FIG. 10 is a sectional view of a liquid crystal display device provided with the color filter shown in FIG. The filter layers 2R, 2
G, 2B, a black matrix layer 9 disposed in a gap between the adjacent filter layers 2R, 2G, 2B, and the black matrix layer 9 provided so as to cover the filter layers 2R, 2G, 2B and the black matrix layer 9; The method of forming the flattening layer 3 also serving as the wavelength conversion layer is the same as that of the embodiment described with reference to FIG. Thereafter, a polyimide alignment film 8 for aligning the liquid crystal 6 is formed on the flattening layer 3 described above.

On the other hand, a TFT is placed on the first glass substrate 14.
Polyimide alignment film 1 for aligning element 7 and liquid crystal
8 is formed using a well-known method. Note that the pixel region (not shown) of the TFT element 7 is provided in the above-described filter layer 2.
They are provided at positions corresponding to R, 2G, and 2B.

Next, the above two glass substrates 4 and 1
4 are arranged with the polyimide alignment films 8 and 18 facing each other, and the glass substrates 4 and 14 are sandwiched between the liquid crystal 6.
Is sealed by using a sealing agent provided in the peripheral portion of. Thus, a liquid crystal display device is completed.

Although no backlight is shown in FIG. 10, the backlight is arranged on the side of the first glass substrate 14 on which the TFT elements 7 are provided. The TFT element 7 is driven using a normal method, and a predetermined electric field is applied so as to sandwich the liquid crystal 6. At this time, the light from the backlight is incident on the first glass substrate 14 as incident light 5, passes through the alignment film 18, the liquid crystal 6, and the alignment film 8, and is incident on the wavelength conversion layer 3 also serving as a flattening layer. You.

In the wavelength conversion layer 3, the fluorescent material is excited by light having a wavelength of 420 nm or less among the incident light,
It emits light having a wavelength of 420 nm or more (see FIG. 3). Then, the wavelength-converted light passes through the filter layers 2R, 2G, and 2B together with the light from the backlight and is extracted to the outside.

Therefore, by allowing the light of the backlight to pass through the wavelength conversion layer containing the fluorescent material before being incident on the filter layer, compared with the conventional color filter having no wavelength conversion layer, In particular, in the wavelength region of 440 nm to 480 nm, the output light intensity can be significantly increased. In addition, a liquid crystal display device that improves luminance, which is one of the most important characteristics as a display device for displaying character information and image information, is realized.

FIG. 11 is a sectional view of a liquid crystal display device for explaining another embodiment. The difference from the embodiment shown in FIG. 10 is that the color filter shown in FIG. 5 is used as the color filter. That is, the wavelength conversion layer 3 is provided between the second glass substrate 4 and the filter layers 2R, 2G, and 2B. Further, a backlight (not shown) was arranged on the second glass substrate 4 side.

By using the above configuration, the light from the backlight is incident on the second glass substrate 4 as incident light 5 and the wavelength conversion layer 3, the filter layers 2R, 2G,
B, flattening layer 1, alignment film 8, liquid crystal 6, alignment film 18, TF
The T element 7 passes through the first glass substrate 14 and is extracted to the outside.

Therefore, similarly to the case of the embodiment shown in FIG. 7, compared with the case where a color filter having no wavelength conversion layer 3 is used, the light whose wavelength has been converted by the wavelength conversion layer is added and externally applied. Can be taken out. In other words, by allowing the light of the backlight to pass through the wavelength conversion layer containing the fluorescent material before being incident on the filter layer, it is particularly possible to reduce
In the wavelength region from 40 nm to 480 nm, the output light intensity can be significantly increased. In addition, it is possible to realize a liquid crystal display device that improves luminance, which is one of the most important characteristics as a display device for displaying character information and image information.

FIG. 12 is a sectional view of a liquid crystal display for explaining another embodiment. The difference from the embodiment shown in FIG. 10 or 11 is that the wavelength conversion layer 3, the filter layers 2R,
G, 2B, a black matrix layer 9, and a color filter including the flattening layer 1 are provided on the TFT element 7. That is, the TFT element 7 was formed on the first glass substrate 14 using the method described in the embodiment of FIG. 10 or FIG.

Thereafter, the wavelength conversion layer 3, the filter layer 2R,
A color filter including 2G, 2B, the black matrix layer 9, and the flattening layer 1 was formed in the same manner as in the embodiment of FIG. Note that a pixel region (not shown) of the TFT element 7 is provided so as to correspond to the filter layers 2R, 2G, and 2B. Then, an alignment film 18 was formed on the flattening layer 1 described above.

On the other hand, the alignment film 8 is formed on the second glass substrate 4.
Was formed. Then, the two glass substrates 4 and 14 described above are arranged so that the alignment films 8 and 18 face each other, and the liquid crystal 6 is sandwiched therebetween, thereby completing a liquid crystal display device.

A backlight (not shown) is first installed on the side of the glass substrate 14, and light from the backlight is used as incident light 5 as the first glass substrate 14, the TFT element 7, and the wavelength conversion layer 3. , The filter layers 2R, 2G, 2B, the planarizing layer 1, the alignment film 18, the liquid crystal 6, the alignment film 8, and the second glass substrate 4, and are extracted as outgoing light 11 to the outside.

By using the above structure, the light of the incident light 5 whose wavelength has been converted by the wavelength conversion layer 3 can be added and extracted. In particular, 440 nm to 480 n
To achieve a liquid crystal display device which enables a remarkable increase in the intensity of emitted light in the wavelength region of m, and improves luminance, which is one of the most important characteristics as a display device for displaying character information and image information. Becomes possible.

Further, since the color filter including the wavelength conversion layer 3 and the like is formed directly on the TFT element 7, FIG.
0 or the filter layer 2 compared to the embodiment shown in FIG.
It is possible to easily align the R, 2G, and 2B with the pixel region of the TFT element 7 and to suppress a decrease in light transmittance and a color shift due to a positional shift between the two. The conditions described for achieving some of the above-described embodiments are not limited to these embodiments.

[0068]

As described above, by converting part of the incident light into light of a specific wavelength range, it is possible to improve the luminance without lowering the color purity.

[Brief description of the drawings]

FIG. 1 is a sectional view of a color filter for explaining a conventional color filter.

FIG. 2 is a sectional view of a color filter for explaining an embodiment of the present invention.

FIG. 3 is a diagram illustrating a spectrum of a color filter and illustrating a function of a wavelength conversion layer.

FIG. 4 is a sectional view of a color filter for explaining another embodiment of the present invention.

FIG. 5 is a sectional view of a color filter for explaining another embodiment of the present invention.

FIG. 6 is a cross-sectional view of a color filter for explaining still another embodiment of the present invention.

FIG. 7 is a cross-sectional view of a color filter for explaining still another embodiment of the present invention.

FIG. 8 is a sectional view of a color filter for explaining still another embodiment of the present invention.

FIG. 9 is a diagram illustrating a spectral spectrum of a color filter and illustrating a function of a wavelength conversion layer.

FIG. 10 is a sectional view of a liquid crystal display device for explaining an example of the present invention.

FIG. 11 is a sectional view of a liquid crystal display device for explaining another embodiment of the present invention.

FIG. 12 is a sectional view of a liquid crystal display device for explaining another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Flattening layer, 2 ... Filter layer, 3 ... Wavelength conversion layer, 4,
14: glass substrate, 5: incident light, 6: liquid crystal layer, 7: TF
T element, 8, 18: alignment film, 9: black matrix layer, 11: outgoing light

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H042 AA09 AA15 AA26 2H048 BA45 BA48 BB02 BB03 BB07 BB28 BB44 BB47 2H091 FA02Y FA35Y FA41Z GA01 GA13 LA18

Claims (11)

[Claims] A light-transmitting substrate, a color filter layer, and a wavelength conversion layer, wherein the wavelength conversion layer is formed so as to cover the color filter layer, and wherein the wavelength conversion layer is A color filter characterized by converting light having a wavelength of 420 nm or less from light incident on a layer to light having a wavelength of 420 nm or more. 2. A wavelength conversion layer, a color filter layer, and a flattening layer are sequentially laminated above a light-transmitting substrate, and the wavelength conversion layer has a wavelength of light incident on the wavelength conversion layer. A color filter obtained by converting light having a wavelength of 420 nm or less into light having a wavelength of 420 nm or more. 3. A light-transmitting substrate, a wavelength conversion layer, a black matrix layer, a color filter layer, and a planarizing film layer, wherein the wavelength conversion layer and the color filter are provided above the light-transmitting substrate. And the black matrix layer is disposed in a gap between the adjacent color filter layers, and the flattening film layer is provided so as to cover the black matrix layer and the color filter layer. A color filter, comprising: 4. The color filter according to claim 1, wherein a surface of said color filter layer is flattened by said wavelength conversion layer. 5. A semiconductor device comprising a first light-transmitting substrate, a thin-film transistor element, a liquid crystal layer, and a color filter, wherein the color filter is provided above the second light-transmitting substrate with a color filter layer, a wavelength conversion layer, Are sequentially laminated, and the liquid crystal layer is disposed between the thin film transistor element and the wavelength conversion layer. 6. A first light-transmitting substrate, a thin-film transistor element, a liquid crystal layer, and a color filter, wherein the color filter has a wavelength conversion layer, a color filter layer, and a color filter layer above the second light-transmitting substrate. , And the liquid crystal layer is disposed between the thin film transistor element and the color filter layer. 7. A light-transmitting substrate, a thin-film transistor element, a wavelength conversion layer, a color filter layer, and a liquid crystal layer, wherein the color filter layer formed above the wavelength conversion layer is a thin-film transistor element. And a liquid crystal layer disposed between the liquid crystal layer and the liquid crystal layer. 8. A light-transmitting substrate comprising a first light-transmitting substrate, a thin film transistor element, a color filter layer, a wavelength conversion layer, a planarizing film layer, and a liquid crystal layer, wherein the color filter has a second light-transmitting property. A color filter layer is formed above the substrate.
A wavelength conversion layer obtained by converting light having a wavelength of 60 nm or less into light having a wavelength of 460 nm or more;
And a wavelength conversion layer characterized in that the following light is converted into light having a wavelength of 550 nm or more. The wavelength conversion layer is flattened by a wavelength conversion layer characterized by converting light having a wavelength of 420 nm or less into light having a wavelength of 420 nm or more so as to cover the filter layer and the wavelength conversion layer. A liquid crystal display device, which is arranged between an element and the color filter layer. 9. A color filter comprising a first light-transmitting substrate, a thin film transistor element, a color filter layer, a wavelength conversion layer, a planarizing film layer, and a liquid crystal layer, wherein the color filter has a second light-transmitting property. Light having a wavelength of 420 nm or less is emitted above the substrate at a wavelength of 420 nm.
a wavelength conversion layer formed by converting light having a wavelength of at least 460 nm into light having a wavelength of 460 nm or more; Light having a wavelength of 550 nm or less
and a wavelength conversion layer characterized by being converted into light having a wavelength of at least nm. The color conversion pattern of the color filter is laminated below green (G) and red (R), respectively, and the liquid crystal layer is A liquid crystal display device, which is disposed between a thin film transistor element and the color filter layer. 10. The wavelength conversion layer converts light having a wavelength of 420 nm or less out of light incident on the wavelength conversion layer to a wavelength of 420 nm.
The liquid crystal display device according to any one of claims 5 to 9, wherein the liquid crystal display device is converted into light of nm or more. 11. The liquid crystal display device according to claim 5, wherein light from a backlight is made incident on said color filter layer via said wavelength conversion layer.