JPH03137617A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To improve the utilization efficiency of illumination greatly and to obtain the bright display device by arranging a 2nd substrate where many fine projection parts for light convergence are formed outside a substrate on the side of an illuminating source. CONSTITUTION:The 2nd transparent substrate 8 is arranged in contact with the 1st substrate 1 on the side of the illuminating source 30 and many fine projection parts 9 for light convergence are formed thereupon in a spherical or lenticular shape. The lighting luminous flux is converged effectively on a light transmission window 5 through the transmitted light refracting effect of the projection parts 9. Consequently, the light for illumination which is cut off by the wiring pattern, TFTs, etc., of a liquid crystal panel can be transmitted through the transmission window 5, so the utilization efficiency of the illumination can be improved greatly and the bright display device can be realized.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid crystal panel optical system used in liquid crystal displays, liquid crystal shutter arrays, liquid crystal televisions, etc., and particularly relates to an optical system suitable for liquid crystal projectors. .

[Conventional technology]

The liquid crystal matrix array used in liquid crystal televisions and other devices is manufactured by sandwiching a liquid crystal layer of several micrometers of steel between two glass substrates, and then forming and patterning electrodes, signal lines, TPT, etc. Ru.

- The boat fishing configuration is as shown in FIG. In the figure, 1.2 is a glass substrate, 3 is a liquid crystal layer, 4 is a transparent electrode, and 5
is the liquid crystal window, 6 is the wiring pattern, non-transparent parts such as TPT,
7 is illumination light. TF for switching each pixel
T is often made of α-5i or Poly Si. Therefore, the glass substrate 1.2 is alkali-free, that is, for α-5i, for example, Corning glass #7059, Poly Si For this purpose, quartz glass or the like is often used.

[Problem that the invention seeks to solve]

However, the liquid crystal surface has electrodes, signal lines, TP
Since T is patterned, the area through which light actually passes (hereinafter referred to as "liquid crystal window") is small compared to the area of the LIII element. In particular, when increasing the number of pixels, the area of 1 pixel becomes smaller, and in such cases, the window aperture ratio (LCD window area/
One pixel area) is extremely low (often about 20 to 30%), which has the disadvantage that the display becomes dark as a result.

[Means for solving problems]

In order to solve the above-mentioned conventional problems, the present invention provides an illumination light source side of a pair of substrates constituting a liquid crystal display panel equipped with an array of light transmitting windows arranged in a large number in one dimension or two dimensions. A second transparent substrate is fixedly arranged in close contact with the outside of the substrate (first substrate), and a large number of approximately spherical or approximately lenticular surfaces are formed on the surface of the second substrate that is in contact with the first substrate. The above-mentioned micro-convex portions and each light-transmitting window are formed so that the illumination light beam incident on the liquid crystal panel is effectively focused on the light-transmitting window by the transmitted light refraction effect of these convex portions. were arranged facing each other.

[Effect]

According to the present invention, since a microlens is provided for each pixel, illumination light is effectively focused on a liquid crystal window with a small area, and the effective aperture ratio can be improved.

(Example〕 The present invention will be described below with reference to the embodiment shown in FIG.

In FIG. 1, the portion of the liquid crystal display panel indicated generally by the reference numeral 20 may be the same as the conventional structure of FIG.

In the present invention, the second glass substrate 8 is fixed closely to the outer surface of the substrate 1 (first substrate) located on the illumination light source 30 side among the pair of glass substrates 1.2 constituting the liquid crystal display panel 20. Deploy. On the surface of the second substrate 8 facing the first substrate 1, there are a large number of substantially spherical minute convex portions 9.
is formed. The second plate provided with such minute convex portions 9
The glass substrate 8 is heated through a low refractive index medium 10 so that the position of each minute convex portion 9 is opposite to the position of each liquid crystal window 5.
It is closely fixed to the first glass substrate 1. In the liquid crystal display device having the above structure, the illumination light 7 emitted from the light source 30 is refracted by each minute convex portion 9, condensed into each liquid crystal window 5 facing each convex portion, and transmitted. As a result, until now, LCD panel 2
Illumination light that has been blocked by the opaque portion 6 such as the wiring patterning and the TFT section can also be transmitted to the rear through the liquid crystal window 5, making it possible to realize a bright liquid crystal display device with high lighting utilization efficiency.

Here, each minute convex portion 9 has a spherical shape with a radius of curvature R, is made of a material with a refractive index n, and is made of a material with a low refractive index medium 1
Assume that the refractive index of 0 is nt.

Further, the thickness of the first glass substrate 1 is t, and the refractive index is n.

At this time, the radius of curvature R of the minute convex portion 9 is R= (n
t − nl ) t/ns If set to be narrow, the minute convex portion 9 acts as a convex lens whose focal plane is the surface where the liquid crystal window 5 is present, and the above-mentioned improvement in the transmission efficiency of illumination light can be realized. .

Note that the respective thicknesses of the low refractive index medium 10, the liquid crystal layer 4, and the liquid crystal layer 3 are extremely small and can be ignored.

For example, the first glass substrate 1 is made of Corning #7059 glass (refractive index 1.53) with a thickness of 1.1 fi, and the minute convex portions 9 are made of polycarbonate resin (refractive index 1.53).
59) with a refractive index of 1.4 as a low refractive index medium 1rlO.
When using the matching oil No. 5, the radius of curvature R of the minute convex portion 9 may be approximately R = 100 μ-. The minute convex portion 9 can be produced by press molding using a stamper such as rainbow kelp. .

When a liquid material is used as the low refractive index medium 10, it is only necessary to adhesively fix the outer periphery of the effective pixel area of the liquid crystal panel. Depending on the circumstances, it is possible to set the appropriate refractive index as the low refractive index medium 10 to about 1.5 (for example, n = 1.59, R = 64 μs, n! = = t
, s 3, when t -1,1m, n= -1,5),
In such a case, an ultraviolet curable resin material may be selected as the low refractive index medium 10, thereby bonding the first glass substrate 1 and the second glass substrate 8 provided with the minute convex portions 9. You can also do that.

Further, the minute convex portions 9 may be produced using the 2P method or the sol-gel method.

Furthermore, the second substrate 8 may be a plastic plate.
Further, even if the minute convex portions 9 have a lenticular surface shape, a sufficient effect may be obtained in some cases.

〔Effect of the invention〕

According to the present invention, wiring patterning of a conventional liquid crystal panel,
Since the illumination light that has been blocked by the TFT section or the like can pass through the liquid crystal window, the efficiency of use of illumination can be greatly improved and a bright liquid crystal display device can be realized.

In addition, since the light condensing minute protrusions are formed on the surface of a transparent substrate that is separate from the glass substrate that makes up the liquid crystal panel, the fabrication of the minute protrusions and the liquid crystal panel can be performed separately and independently. Since the manufacturing process of the liquid crystal panel can be performed in exactly the same manner as before, there are great advantages in the actual production process, such as the fact that the yield during the manufacturing of the convex portions does not affect the manufacturing yield of the liquid crystal panel itself. Furthermore, since the present invention can use the press method or 2P method using resin materials, which are currently widely used, it is relatively simple to produce the microscopic convex portions for condensing light.
Furthermore, since there are no restrictions on the selection of the second substrate, there is an advantage that the second substrate can be freely selected in consideration of the difference in expansion coefficient with the glass substrate on the liquid crystal panel side, cost, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional liquid crystal display panel. 1.2...LCD panel glass substrate

Claims (1)

[Claims] A liquid crystal display panel has an array of light transmission windows arranged one-dimensionally or two-dimensionally, and a substrate located on the illumination light source side (the first
a second transparent substrate closely fixed to the outside of the second substrate (substrate), and a large number of minute convex portions having a substantially spherical shape or a substantially lenticular shape are formed on the surface of the second substrate facing the first substrate. Each of the minute convex portions and each of the light transmission windows are arranged to face each other so that the illumination light beam incident on the liquid crystal panel is effectively focused on the light transmission window by the refraction effect of the minute convex portions. A liquid crystal display device characterized by: