JP2001330715A - Reflection transmission combination type plate and liquid crystal display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain brighter display when a reflection and transmission combination type liquid crystal display device is used as a reflection type. SOLUTION: The reflection and transmission combination plate 11 has a base plate 21 made of a transparent resin film. Many minute recesses 22 each in a concave mirror form are formed on the surface of the base plate 21. A reflection film 23 such as aluminum is formed on the inner face of each recess 22. An adhesive layer 24 is applied on the surface of the base plate 21. The reflection and transmission combination plate 11 is stuck to the back face of a liquid crystal display panel 1 through the adhesive layer 24. A back light 5 is disposed on the back face of the reflection and transmission combination plate 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection / transmission plate and a liquid crystal display using the same.

[0002]

2. Description of the Related Art There is a liquid crystal display device that uses both a reflection and transmission plate to perform display using reflected light and also performs reflection and transmission display using transmitted light. FIG. 4 is a sectional view of an example of such a conventional liquid crystal display device. This liquid crystal display device has a liquid crystal display panel 1
It has. The liquid crystal display panel 1 includes a front glass substrate 2
And the back glass substrate 3 are bonded to each other via a substantially frame-shaped sealing material 4, and a liquid crystal 5 is sealed between the two glass substrates 2, 3 inside the sealing material 4.
The front side polarizing plate 6 is stuck on the surface of the substrate, and the back side polarizing plate 7 is stuck on the back surface of the back side glass substrate 2.

[0003] A reflection / transmission plate 11 is arranged on the back surface of the back glass substrate 3. The transflective plate 11 has a semi-transmissive reflective layer 13 provided on the surface of a base plate 12 made of a transparent resin film, and an adhesive layer 14 provided on the surface of the semi-transmissive reflective layer 13. The reflection / transmission plate 11 is attached to the back surface of the rear polarizing plate 7 of the liquid crystal display panel 1 via the adhesive layer 14.
A backlight 15 is arranged on the back surface of the reflection / transmission plate 11.

When the surrounding environment is bright and this liquid crystal display device is used as a reflection type, the backlight 15 is not turned on and external light incident from the front side of the front-side polarizing plate 6 is used. 6 for transmitting and reflecting and transmitting / receiving plate 1
Then, the reflected light is emitted to the front side of the front-side polarizing plate 6 to perform display. On the other hand, when the surrounding environment is dark and this liquid crystal display device is used as a transmissive type, the backlight 15 is turned on, and the light from the backlight 15 is transmitted through the reflection / transmission plate 11 and the like, and the front side polarizing plate 6 is turned on. Is emitted to the front surface side of the device, thereby performing display.

[0005]

The reflection / transmission plate 11 used in the above-mentioned conventional liquid crystal display device is
It has substantially constant transmittance and reflectance over the entire visible light range, and the relational expression of reflectance + transmittance ≦ 100% holds. Therefore, if one of the reflection performance and the transmission performance is improved, the other performance is reduced, and it is not possible to achieve both performances. In particular, there is a problem that the reflection performance is poor. Therefore, there is a liquid crystal display device in which the reflectivity of the reflection / transmission plate 11 is increased and the light intensity of the backlight 15 is increased to compensate for the transmission performance. Can't be enough. An object of the present invention is to improve the reflection performance of a reflection / transmission plate.

[0006]

According to a first aspect of the present invention, there is provided a reflective / transmissive plate in which a reflective film is provided on inner surfaces of a plurality of concave portions provided on one surface of a transparent base plate. .
According to a second aspect of the present invention, in the reflection / transmission plate, the arrangement of the concave portions is random. According to a third aspect of the present invention, in the reflective / transmissive plate according to the first or second aspect, the size of the concave portion is different. A reflection / transmission plate according to a fourth aspect of the present invention is the reflection / transmission plate according to any one of the first to third aspects, wherein an adhesive layer is provided on one surface side of the base plate. A reflection / transmission plate according to a fifth aspect of the present invention is the reflection / transmission plate according to any one of the first to fourth aspects, wherein an adhesive layer is provided on the other surface of the base plate. The liquid crystal display device according to the invention according to claim 6 is a liquid crystal display device for reflection and transmission including a liquid crystal display panel, a backlight, and a reflection and transmission plate interposed therebetween, wherein: In this case, a transparent base plate is used in which a reflective film is provided on the inner surface of a number of concave portions provided on the surface facing the liquid crystal display panel. According to a seventh aspect of the present invention, in the liquid crystal display device according to the sixth aspect, the arrangement of the concave portions of the reflection / transmission plate is random. Claim 8
The liquid crystal display device according to the invention described in claim 6 is a liquid crystal display device according to claim 6 or 7.
In the invention described in (1), the size of the concave portion of the reflection / transmission plate is made different. A liquid crystal display device according to a ninth aspect of the present invention is the liquid crystal display device according to any one of the sixth to eighth aspects, wherein the reflective / transmissive plate is attached to the back surface of the liquid crystal display panel. A liquid crystal display device according to a tenth aspect of the present invention is the liquid crystal display device according to any one of the sixth to ninth aspects, wherein the reflective / transmissive plate is attached to a surface of the backlight. According to the reflective / transmissive plate according to the first aspect of the present invention, light from one surface side of the base plate and around the reflective film is reflected by the reflective film provided on the inner surface of the concave portion. The light is reflected and condensed in a direction close to the normal direction of one surface of the base plate, whereby the reflection performance can be improved. As a result, claim 6
In the case where the present invention is applied to a liquid crystal display device that is used for both reflection and transmission as in the invention described in (1), a brighter display can be obtained when used as a reflection type.

[0007]

FIG. 1 is a sectional view of a liquid crystal display device according to an embodiment of the present invention. This liquid crystal display device is structurally the same as the conventional case shown in FIG. Therefore, in FIG. 1, the same reference numerals are given to the same names as those in FIG. 4, and the description thereof will be omitted as appropriate. In this liquid crystal display device, the point different from the conventional case shown in FIG.

The reflection / transmission plate 11 is made of PET (polyethylene terephthalate), PC (polycarbonate), T
A base plate 21 made of a transparent resin film such as AC (triallyl cyanurate) is provided. On the surface of the base plate 21, a number of minute concave mirror-shaped concave portions 22 are provided. A reflective film 23 made of aluminum or the like is provided on the inner surface of the concave portion 22. An adhesive layer 24 is provided on the surface of the base plate 21 so as to be embedded in the recess 22. The reflection / transmission plate 11 is attached to the back surface of the rear polarizing plate 7 of the liquid crystal display panel 1 via the adhesive layer 24.

Here, it is desirable that the opening area on the surface side of the concave portion 22 is smaller than the size of the pixel of the liquid crystal display panel 1. The arrangement of the concave portions 22 may be regular, but it is preferable that the concave portions 22 be random to some extent in order to prevent the occurrence of the moire phenomenon, and the concave portions 22 may have different sizes. Further, the total opening area on the surface side of the concave portion 22 is desirably about 30 to 90% of the entire area of the reflection / transmission plate 11.

When the surrounding environment is bright and this liquid crystal display device is used as a reflection type, the backlight 15 is not turned on and the external light incident from the upper surface of the front side polarizing plate 6 is removed. 6 for transmitting and reflecting and transmitting / receiving plate 1
Then, the reflected light is emitted to the upper surface side of the front-side polarizing plate 6 to perform display.

In this case, as shown by a solid line arrow in FIG. 2, for example, the reflection film 23 provided on the inner surface of the concave mirror-shaped concave portion 22 is provided from the surface side of the base plate 21 and around the reflective film 23. Is reflected and collected in a direction close to the normal direction of the surface of the base plate 21. As described above, since the external light from around the reflection film 23 is collected in a direction close to the normal direction of the surface of the base plate 21, the reflection film 2
External light from the surroundings of 3 can be effectively used, and the reflection performance can be improved. For this reason, when this liquid crystal display device is used as a reflection type, when the reflection film 23 is used.
A sufficiently bright display can be obtained without increasing the density of the concave portions 22 having the above.

On the other hand, when the surrounding environment is dark and this liquid crystal display device is used as a transmission type, the backlight 15
Is turned on, and the light from the backlight 15 is transmitted through the reflection-transmission / combination plate 11 and the like and is emitted to the upper surface side of the front-side polarizing plate 6, thereby performing display. In this case, for example, as shown by a dotted arrow in FIG. 2, the backlight light incident on the reflection / transmission plate 11 in a portion not corresponding to the reflection film 23 passes through the reflection / transmission plate 11 as it is. Here, as described above, since the reflection / transmission plate 11 of the present invention has a high reflection performance, it is not necessary to increase the density of the concave portion 22 having the reflection film 23 so much. The intensity of the transmitted backlight light is increased, and a bright display can be obtained even when used as a transmission type.

Next, an example of a method of manufacturing the reflection / transmission plate 11 will be described with reference to FIG. First, FIG.
As shown in FIG. 1A, a photoresist film 31 is formed on the surface of the base plate 21. In this case, the photoresist film 3
A plurality of types of circular openings 31a having different diameters are formed in 1. Next, as shown in FIG. 3B, the surface side of the base plate 21 is wet-etched using the photoresist film 31 as a mask. Then, on the surface of the base plate 21, a large-diameter deep concave mirror-shaped concave portion 22 is formed at a portion corresponding to the large-diameter opening 31 a of the photoresist film 31, and is formed in the small-diameter opening 31 a of the photoresist film 31. A small-diameter shallow concave mirror-shaped concave portion 22 is formed in the corresponding portion.

Next, as shown in FIG. 3C, a reflective film 23 made of aluminum is formed on the surface of the photoresist film 31 and the inner surface of the concave portion 22 by an evaporation method or the like. Next, when the photoresist film 31 is peeled off together with the reflection film 23 formed on the surface thereof, as shown in FIG. 3D, the film having the reflection film 23 formed only on the inner surface of the concave portion 22 of the base plate 21 is obtained. can get. Next, as shown in FIG.
An adhesive layer 24 is applied to the surface of the base plate 21. Thus, the reflection / transmission plate 11 shown in FIG. 1 is obtained.

In the above embodiment, the case where the pressure-sensitive adhesive layer 24 is provided on the front side of the reflection / transmission plate 11 is described. However, the present invention is not limited to this. The pressure-sensitive adhesive layer may be provided on the front side and the back side of the reflection / transmission plate 11. Then, the backlight 15 may be attached to the pressure-sensitive adhesive layer on the back side of the reflection / transmission plate 11. In the above embodiment, the case where a transparent resin film is used as the base plate 21 of the reflection / transmission combined plate 11 has been described. However, the present invention is not limited to this, and a transparent resin plate, a glass plate, or the like may be used. .

[0016]

As described above, according to the reflective / transmissive plate according to the first aspect of the present invention, the reflection film provided on the inner surface of the recess allows the base plate to be viewed from one surface side. Light from the periphery of the reflective film is reflected and collected in a direction close to the normal direction of one surface of the base plate, whereby the reflection performance can be improved. As a result, when the present invention is applied to a liquid crystal display device that is also used for reflection and transmission, a brighter display can be obtained when used as a reflection type.

[Brief description of the drawings]

FIG. 1 is a sectional view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining the reflection / transmission characteristics of the reflection / transmission plate shown in FIG. 1;

FIGS. 3A to 3E are cross-sectional views illustrating an example of a method for manufacturing the reflective / transmissive plate shown in FIG.

FIG. 4 is a cross-sectional view of an example of a conventional liquid crystal display device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 liquid crystal display panel 11 reflection / transmission plate 15 backlight 21 base plate 22 concave portion 23 reflective film 24 adhesive layer

Claims (10)

[Claims] 1. A reflection / transmission plate, wherein a reflection film is provided on inner surfaces of a plurality of concave portions provided on one surface of a transparent base plate. 2. The reflection / transmission plate according to claim 1, wherein the arrangement of the concave portions is random. 3. The reflection / transmission plate according to claim 1, wherein the size of the recess is different. 4. The reflection / transmission plate according to claim 1, wherein a pressure-sensitive adhesive layer is provided on one surface of the base plate. 5. The reflection / transmission plate according to claim 1, wherein an adhesive layer is provided on the other surface of the base plate. 6. A reflection / transmission liquid crystal display device comprising a liquid crystal display panel, a backlight and a reflection / transmission plate interposed therebetween, wherein said reflection / transmission plate is a transparent base plate. A liquid crystal display device comprising a reflective film provided on the inner surface of a number of concave portions provided on a surface facing the liquid crystal display. 7. The liquid crystal display device according to claim 6, wherein the arrangement of the concave portions of the reflection / transmission plate is random. 8. The liquid crystal display device according to claim 6, wherein the size of the concave portion of the reflection / transmission plate is different. 9. The liquid crystal display device according to claim 6, wherein the reflective / transmissive plate is attached to a back surface of the liquid crystal display panel. 10. The liquid crystal display device according to claim 6, wherein the reflection / transmission plate is attached to a surface of the backlight.