JPH0850283A - Liquid crystal display panel - Google Patents

Abstract

PURPOSE:To make the transmissivity of light high, to improve apparent numerical aperture and to realize brighter screen display by providing an optical path changing means for increasing a projected light quantity to an aperture part by changing the optical path direction of the light made incident on a non-transmissive area. CONSTITUTION:A liquid crystal cell part 3 is provided between a TFT substrate 1 and a counter electrode substrate 2. A black matrix part 4 is provided in the liquid crystal cell part 3. A concave lens 5 functioning as the optical path changing means is provided above the black matrix part 4. The lens 5 is formed in a line state along the black matrix part 4. The light made incident on the aperture part between the black matrix parts 4 is projected as it is through the counter electrode substrate 2, the liquid crystal cell part 3 and the TFT substrate 1. The optical path of the light made incident on the lens 5 is changed by the lens 5, and a part of the light does not reach the black matrix part 4 but is projected to the aperture part between the black matrix parts 4. Therefore, the light quantity projected to the aperture part is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more particularly to a liquid crystal display panel having a non-transmissive region such as a black matrix which is relatively hard to transmit light.

[0002]

PRIOR ART AND PROBLEM TO BE SOLVED BY THE INVENTION TFT
In an active matrix type liquid crystal display panel or the like, there is a region such as a black matrix part or a bus line part where it is difficult to transmit light. Further, also in a simple matrix type liquid crystal display panel, similarly, an opaque region exists between stripes of transparent electrodes. Due to the presence of such an opaque region, there is a problem that the amount of light that can be transmitted through the liquid crystal display panel is reduced and the display screen becomes dark.

An object of the present invention is to solve the above-mentioned conventional problems, increase the light transmittance, and improve the apparent aperture ratio, thereby making it possible to display a brighter screen liquid crystal display panel. To provide.

[0004]

A liquid crystal display panel of the present invention is a liquid crystal display panel having a non-transmissive region through which light is relatively hard to pass, and the optical path direction of light incident on the non-transmissive region is changed to open the aperture. It is characterized in that an optical path changing means for increasing the amount of light emitted to the section is provided.

In the present invention, it is preferable that the optical path changing means is provided in a region overlapping the non-transmissive region on the light incident side of the non-transmissive region. Further, in the present invention, the optical path changing means may be formed on the light incident side substrate or inside the light incident side substrate.

The optical path changing means in the present invention is not particularly limited as long as it can change the optical path.
For example, light refraction means for refracting light to change the optical path,
A light reflection means for changing the optical path by reflecting light is used.

In the present invention, the method for forming the optical path changing means is not particularly limited, but for example, the optical path changing means can be formed by the back exposure method using the opaque region as a mask.

[0008]

The liquid crystal display panel according to the present invention is provided with the optical path changing means for changing the optical path direction of the light incident on the non-transmissive region and increasing the amount of light emitted to the opening. Therefore, the light that was conventionally blocked by the non-transmissive region is emitted to the opening, and the amount of emission to the opening can be increased. Further, by providing the optical path changing means in a region overlapping the non-transmissive region on the light incident side of the non-transmissive region, there is no flicker even when the liquid crystal display panel is directly viewed.

In the present invention, the optical path changing means may be smaller in area than the opaque region. According to the present invention, it is possible to change the optical path of the light incident on the opaque region and increase the amount of light emitted to the opening, so that the apparent aperture ratio can be improved and a brighter screen display can be obtained. It will be possible.

[0010]

1 is a sectional view showing an embodiment according to the present invention. With reference to FIG. 1, a liquid crystal cell section 3 is provided between a TFT substrate 1 and a counter electrode substrate 2. A black matrix portion 4 is formed in the liquid crystal cell portion 3. In this embodiment, a concave lens 5 as an optical path changing means is provided above the black matrix portion 4. The concave lens 5 is formed in a line along the black matrix portion 4. The concave lens 5 is formed of a material similar to that of the substrate or a high-refractive material, for example, SiO ₂ , T doped with P, K, or Ti.
It is formed of a material such as iO ₂ or SiO ₂ / TiO ₂ .

As shown in FIG. 1, the light incident on the opening between the black matrix portions 4 is directly emitted through the counter electrode substrate 2, the liquid crystal cell portion 3 and the TFT substrate 1. As shown in FIG. 1, the optical path of the light incident on the concave lens 5 is changed by the concave lens 5, and a part of the light does not reach the black matrix portion 4 and is emitted to the opening between the black matrix portions 4. It Therefore, the amount of light emitted to the opening increases.

FIG. 10 is a sectional view for explaining the embodiment shown in FIG. 1 in more detail. Referring to FIG. 10, the counter electrode substrate 2 made of a glass substrate has a thickness d of 1 mm, a black matrix portion 4 has a width of 20 μm, and a pixel pitch b is 1.
Assuming that the concave lens 5 has a refractive index of 100 μm and the refractive index of the concave lens 5 is substantially equal to that of the glass substrate 2, the width W of the concave lens 5 is preferably substantially equal to the width of the black matrix portion 4, and in this case, it is preferably about 15 to 30 μm.

Assuming that the focal length of the concave lens 5 is A, FIG.
At 0, the light is refracted as shown by the optical path A, and the optical path is changed in the range of C ₂ . If the focal length is shortened to B, the optical path is changed in a wider range C ₁ , as shown by the optical path B in FIG.

Under the above conditions of size and shape, the focal length is preferably in the range of -250 to -125 μm. When the focal length is -250 μm, the radius of curvature of the concave lens 5 is about 8
It becomes 0 μm. If the focal length is -125 μm,
The radius of curvature of the concave lens 5 is about 41 μm.

Under the above conditions of size and shape, the focal length is set to -125.
The amount of light emitted from the opening in the case of μm increased by 28% as compared with the case where the concave lens 5 is not provided. In the above embodiment, the material of the concave lens is glass (refractive index 1.5).
However, when the concave lens 5 is formed of a material having a refractive index of 1.8, for example, the focal length is −250 μm and the radius of curvature of the concave lens can be increased to 110 μm.
As a material having a refractive index of 1.8, for example, Ti content is 30
Examples include atomic% SiO ₂ TiO ₂ glass and the like.

FIG. 2 is a sectional view showing another embodiment according to the present invention. In this embodiment, a triangular prism-shaped light reflecting member 6 as an optical path changing unit is provided on the counter electrode substrate 2. The light reflecting member 6 can be made of SiO ₂ or a glass material similar to the counter substrate 2, or a material having a high refractive index used for the concave lens 5 of the embodiment shown in FIG. Further, a reflective film such as a metal film may be formed on the surface. The light reflecting member 6 is also formed in a line shape along the black matrix portion 4.

As shown in FIG. 2, the light that has hit the inclined surface of the light reflecting member 6 has its optical path changed, and does not reach the black matrix portion 4 and is emitted to the opening between the black matrix portions 4. To do. Therefore, the amount of light emitted to the opening can be increased.

FIG. 11 is an enlarged sectional view for explaining the embodiment shown in FIG. 2 in more detail. With reference to FIG. 11, the counter substrate 2 has a thickness d of 0.3 mm, the black matrix portion 4 has a width a of 20 μm, and a pixel pitch b of 100 μ.
When the height is m, for example, the height h of the light reflecting member 6 is 6
A substrate having a width of 0 μm and a width W of 20 μm is formed of the same glass material as the substrate 2. In this case, the rate of increase in the amount of light is about 1
It is about 0%.

FIG. 3 is a sectional view showing still another embodiment according to the present invention. In this embodiment, a concave lens 7 as an optical path changing means is formed in the counter electrode substrate 2. In this embodiment, for example, the concave lens having the same size and shape as the embodiment of the concave lens shown in FIGS. 1 and 10 can be formed. When the refractive index of the substrate is 1.5 and the refractive index of the concave lens 7 is 1.8 and the radius of curvature of the concave lens 7 is about 50 μm, the focal length is about 250 μm.

FIG. 4 is a sectional view showing still another embodiment according to the present invention. In this embodiment, the light reflection member 8 is embedded in the counter electrode substrate 2. As shown in FIGS. 3 and 4, the optical path changing means of the present invention may be formed in the substrate on the light incident side.

FIG. 12 is an enlarged sectional view for explaining the embodiment shown in FIG. 4 in more detail. With reference to FIG. 12, the size and shape of the light reflecting member 8 embedded in the counter substrate 2 have a height h of 60 μm and a width W of 12 μm. Further, the thickness d of the substrate 2 is 0.3 mm, the width a of the black matrix portion 4 is 20 μm, and the pixel pitch b is
Is 100 μm. The light reflecting member 8 is made of MgF ₂ (refractive index 1.382), and the material of the substrate 2 is glass (refractive index 1.5). Under this condition, the reflection on the wall surface of the light reflecting member 8 can be total reflection. Under the above conditions, the increase rate of the amount of light emitted to the opening is about 13.4%.

In the light reflection member 8 embedded in the counter electrode substrate 2 as shown in FIG. 12, the concave lens 8 is first formed on the glass substrate having the surface as shown by the dotted line in FIG. _The concave lens 8 can be embedded by applying ₂ to form an embedded structure as shown in FIG.

Further, the light reflecting member 8 is formed of SiO ₂ ,
By using TiO _{2 as the} coating material for embedding this, the reflection on the wall surface of the light reflecting member 8 can also be totally reflected.

FIG. 5 is a sectional view showing an example of a step of forming a concave lens formed inside the substrate shown in FIG. Figure 5
, The resist films 10 and 1 are formed on the counter substrate 2.
1 is formed. The resist film 10 is formed so that the central portion is thick and the peripheral portion is thin. The concave lens 7 is formed in the substrate 2 by implanting ions such as Ti and Sb from above the resist film 10 and forming a region having a high refractive index in the substrate 2.

FIG. 9 is formed inside the substrate shown in FIG.
It is sectional drawing which shows the other example of the process of forming a concave lens.
Referring to FIG. 9A, the counter electrode substrate 2 made of glass or the like
On top of SiO₂Forming a layer 40, this SiO₂Layer 40
A resist film 41 is formed on top. Next, photolithography
By using the Pee method, a lens other than the part above the concave lens is formed.
The dysto film is removed, and the resist is removed as shown in FIG.
Leave the film 41a. Next, by isotropic etching, Si
O₂Etch layer 40. Due to the side edge effect
The convex SiO 2 as shown in FIG.₂The membrane 40a
It is left on the counter substrate 2. Next, referring to FIG.
By performing ion implantation in the same manner as in FIG.
A concave lens 7 is formed in the substrate 2 as shown in FIG.
It In this embodiment, the convex Si is formed by the side edge effect.
O₂The film 40a is formed, but SiO ₂In layer 40
By doping Rakajime P, SiO₂Layer 4
After etching 0, reflow (900)
The convex SiO₂Form the film 40a
Alternatively, ion implantation may be performed.

FIG. 6 is a sectional view showing an example of a manufacturing process for forming a concave lens as an optical path changing means as shown in FIG. 1 on a substrate. With reference to FIG. 6A, a high refractive material layer 20 made of a high refractive material is formed on the counter electrode substrate 2. A resist film 21 is formed on the high-refractive material layer 20, and the resist film in the portion forming the concave lens is removed by photolithography. After patterning the resist film 21 in this manner, the exposed portion of the high refractive material layer 20 is etched to form a concave surface 20a as shown in FIG. 6 (a).
To form.

Next, referring to FIG. 6B, the resist film is removed to form the high refractive material layer 20 having the concave surface 20a. Since the concave surface 20a is formed above the black matrix portion 4 in the high-refractive material layer 20, FIG.
The optical path changing means can be used even in the state shown in (b).

Referring to FIG. 6 (c), in this embodiment, the high refractive material layer 20 other than the portion where the concave surface 20a is formed is removed by photolithography to form the concave lens 5. There is. Here, in order to prevent side etching, anisotropic etching is adopted to remove the portion other than the concave lens 5.

FIG. 7 is a sectional view showing an example of a manufacturing process for forming the light reflecting member shown in FIG. FIG. 7 (a)
6, the counter electrode substrate 2 is manufactured similarly to the manufacturing process shown in FIG.
A high-refractive material layer 20 is formed on the top surface. The thickness of the high refractive material layer 20 is, for example, the width t of the black matrix portion 4.
It is formed to have a thickness of several times to about half of that. A resist film 21 is formed on the high refractive material layer 20. Next, the resist film 21 is exposed by backside exposure using the black matrix portion 4 as a mask. As a result, as shown in FIG. 7B, only the upper portion of the black matrix portion 4 remains as the resist film 21. Note that the resist film 2 is formed by another mask or the like without using the backside exposure method.
1 may be patterned.

Next, as shown in FIG. 7C, the high refractive material layer 20 is etched using the resist film 21 as a mask. At this time, by adopting isotropic etching,
The vicinity of the resist film 21 is over-etched. Therefore, it is formed in a shape having a triangular prism-shaped inclined surface as shown in FIG. Thereby, the light reflecting member 6 is formed.

FIG. 8 is a sectional view showing an example of a manufacturing process of a further embodiment according to the present invention. Referring to FIG. 8A, a resist film is formed on counter electrode substrate 2, the portion above black matrix portion 4 is removed, and resist film 31 is formed so as to remain only above the opening portion.

Next, using the resist film 31 as a mask, etching is performed to form a groove 2a having a triangular cross section above the black matrix portion 4 of the counter electrode substrate 2 as shown in FIG. 8 (b). The groove 2a is formed in a line along the black matrix portion 4. This groove 2a
Or by embedding a material 32 having a low refractive index in the groove 2a, an optical path changing means is formed.

FIG. 13 is a sectional view for explaining the embodiment shown in FIG. 8B in more detail. Referring to FIG. 13, width W of groove 2a having a triangular cross section, that is, V-shape
Is 20 μm, the inclination angle θ ₁ is 45 °, and the groove depth h is 10 μm. The width a of the black matrix portion 4 is set to 20 μm, and the pixel pitch b is set to 100 μm.
μm. When the counter electrode substrate 2 is formed of glass (refractive index 1.5) in such a dimension and shape that air (refractive index 1.0) exists without embedding other material in the groove 2a, the counter electrode The thickness d of the substrate 2 is preferably 570 μm or less. This is because when θ ₂ becomes 28 ° and the thickness d of the substrate 2 becomes thicker than this, the optical path is blocked by the adjacent black matrix portion 4.

As mentioned above, a material having a low refractive index may be embedded in the groove 2a. Examples of such a material include MgF ₂ (refractive index 1.382) and LiF (refractive index 1.35). Groove by MgF _{2 2}
When a is embedded, θ ₂ becomes 38.8 °, and the thickness d of the glass substrate 2 can be increased to 736 μm.

FIG. 14 is a plan view showing a pixel portion of the liquid crystal display panel of the present invention. In FIG. 14, pixel 1
The pixel electrode 60 is formed in the display area of the pixel. Gate bus line 5 on the board
6 and the drain bus line 59 orthogonal to this are arranged in a matrix. A TFT 61 for driving the pixel is formed near each pixel, and is electrically connected to the drain bus line 59 by a drain electrode 62. The source electrode 63 is electrically connected to the pixel electrode 60.

15 and 16 show XX shown in FIG.
It is sectional drawing which follows the line 'and the YY' line. Referring to FIG. 15, liquid crystal 55 is held between substrate 51 and substrate 52, and black matrix portion 53 is formed inside substrate 52 as a counter electrode substrate. On the outer surface of the substrate 52 above the black matrix portion 53, a V-shaped groove 52a as an optical path changing unit in the present invention is formed as a stripe-shaped groove along the black matrix portion 53. A counter electrode 54 is provided inside the substrate 52 so as to cover the substrate 52 and the black matrix portion 53.

A gate insulating film 55, a gate bus line 56, and an interlayer insulating film 57 are sequentially laminated on the substrate 51. Referring to FIG. 16, FIG. 16 is a cross section in a direction orthogonal to the cross section shown in FIG. 15, and the black matrix portion 53 is also formed in this cross section. Further, above the black matrix portion 53, V-shaped grooves 52a are similarly formed on the surface of the substrate 52 in stripes along the black matrix portion 53. Therefore, the V-shaped grooves 52a are formed on the glass substrate 52 in directions orthogonal to each other, and as a result, a large number of grooves are formed on the substrate 52 in a grid pattern.

An active layer made of polysilicon or the like having a drain region 58a, a channel region 58b, and a source region 58c is formed on the substrate 51, and a gate insulating film 55 and a gate electrode 56 are formed thereon. ,
Furthermore, an interlayer insulating film 57 and a drain bus line 59 are formed thereon. The drain bus line 59 and the drain region 58a are electrically connected at the drain electrode 62.

In the TFT active matrix type liquid crystal display panel constructed as described above, the light which has been conventionally blocked by the black matrix portion 53 changes its optical path due to the existence of the groove 52a as an optical path changing means. Since the light is emitted from the opening, the amount of emitted light can be increased as compared with the conventional case.

In the above embodiment, the TFT active matrix type liquid crystal display panel has been described as an example, but the present invention can be applied to other liquid crystal display panels. Further, it can also be applied to an opaque area other than the black matrix portion.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment according to the present invention.

FIG. 2 is a sectional view showing another embodiment according to the present invention.

FIG. 3 is a sectional view showing still another embodiment according to the present invention.

FIG. 4 is a sectional view showing still another embodiment according to the present invention.

FIG. 5 is a cross-sectional view showing an example of a process for manufacturing the embodiment shown in FIG.

FIG. 6 is a sectional view showing an example of a process for manufacturing the embodiment shown in FIG.

FIG. 7 is a cross-sectional view showing an example of a process for manufacturing the embodiment shown in FIG.

FIG. 8 is a sectional view showing still another embodiment according to the present invention.

9 is a sectional view showing another example of the process of manufacturing the embodiment shown in FIG.

FIG. 10 is an enlarged sectional view for explaining the embodiment shown in FIG. 1 in more detail.

FIG. 11 is an enlarged cross-sectional view for explaining the embodiment shown in FIG. 2 in more detail.

FIG. 12 is an enlarged sectional view for explaining the embodiment shown in FIG. 4 in more detail.

FIG. 13 is an enlarged sectional view for explaining the embodiment shown in FIG. 8B in more detail.

FIG. 14 is an enlarged plan view showing a pixel portion of the liquid crystal display panel according to the present invention.

FIG. 15 is a sectional view taken along line XX ′ shown in FIG.

16 is a cross-sectional view taken along line YY 'shown in FIG.

[Explanation of symbols]

 1 ... TFT substrate 2 ... Counter electrode substrate 3 ... Liquid crystal cell part 4 ... Black matrix part 5 ... Concave lens 6 ... Reflecting member 7 ... Concave lens 8 ... Reflecting member

Claims (9)

[Claims] 1. A liquid crystal display panel having a non-transmissive region in which light is relatively hard to pass, wherein an optical path is changed to change the optical path direction of light incident on the non-transmissive region to increase the amount of light emitted to the opening. A liquid crystal display panel, characterized in that means are provided. 2. The liquid crystal display panel according to claim 1, wherein the optical path changing unit is provided in a region overlapping with the non-transmissive region on the light incident side of the non-transmissive region. 3. The liquid crystal display panel according to claim 1, wherein the optical path changing means is provided on a light incident side substrate. 4. The liquid crystal display panel according to claim 1, wherein the optical path changing means is formed inside the substrate on the light incident side. 5. The liquid crystal display panel according to claim 1, wherein the optical path changing unit is a light refracting unit. 6. The liquid crystal display panel according to claim 1, wherein the optical path changing unit is a light reflecting unit. 7. The liquid crystal display panel according to claim 1, wherein the liquid crystal display panel is a TFT active matrix type liquid crystal display panel, and the non-transmissive region is a black matrix portion or a bus line. 8. The liquid crystal display according to claim 1, wherein the liquid crystal display panel is a simple matrix type liquid crystal display panel, and the non-transmissive region is formed between stripes of transparent electrodes. panel. 9. The liquid crystal display panel according to claim 1, wherein the optical path changing unit is formed by backside exposure using the non-transmissive region as a mask.