JPH0713171A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To sufficiently decrease transmittance in the peripheral part of a liquid crystal display element without using special parts for light shielding, to prevent leak of light through the peripheral part, and to improve the display quality by coloring the frame-like sealing material in the peripheral part of a liquid crystal display element. CONSTITUTION:Two transparent glass substrates 11, 12 are laminated at a specified distance in such a manner that each surface facing to each other has a transparent electrode for display and an orienting film. These substrates 11, 12 are adhered with a frame-like sealing material 52 disposed between the substrates 11, 12 in the edge part. Also, a liquid crystal layer 50 is sealed in the inside of the sealing material 52 between the substrates 11, 12. Polarizing plates 15, 16 are disposed on and under the substrate 11, 12, respectively. The sealing material 52 of the liquid crystal display element 62 having the structure is colored in black.

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 device,
In particular, the present invention relates to a technique suitable for preventing light leakage from a peripheral portion of a liquid crystal display screen in a liquid crystal display device that includes a backlight and drives a liquid crystal display element in a transmissive negative mode.

[0002]

2. Description of the Related Art A conventional twisted nematic type of liquid crystal display device has a 90 ° twisted helix structure made of nematic liquid crystal having a positive dielectric anisotropy between two electrode substrates, and A pair of polarizing plates is arranged outside the electrode substrate such that the polarization axis (or absorption axis) thereof is orthogonal or parallel to the axis of liquid crystal molecules adjacent to the electrode substrate (Japanese Patent Publication No. 13666
Issue).

In such a liquid crystal display device having a twist angle of 90 °, there are problems in the steepness γ of the change in the transmittance of the liquid crystal layer with respect to the voltage applied to the liquid crystal layer and in the viewing angle characteristics. The practical limit was 64 for the number of electrodes). However, in order to cope with recent demands for improving image quality and increasing the amount of display information for liquid crystal display elements, the twist angle α of liquid crystal molecules sandwiched between a pair of polarizing plates is set to be larger than 180 °, and the voltage applied to this liquid crystal layer is increased. Applying physics by TJ Scheffer and J. Nailing to improve the time-division drive characteristics and increase the number of time-divisions by adopting a configuration that detects changes in the birefringence effect of the liquid crystal layer due to
Letter 45, No. 10, 1021, 1984 "Ann Hailey
Multiplexer "(Applied Physics Letter, T.J.
Scheffer, J. Nehring: “A new, highly multiplexabl
e liquid crystal display ”), and a super twisted birefringence effect (SBE) liquid crystal display device has been proposed.

In a liquid crystal display device, for example, two transparent glass substrates are superposed with a predetermined gap so that the surfaces on which the display electrodes made of a transparent conductive film and the alignment film are laminated face each other. A frame-shaped sealing material is provided at the edge between the substrates to bond the two substrates together, and liquid crystal is sealed inside the sealing material between the two substrates from the liquid crystal sealing port provided in a part of the sealing material. Further, a liquid crystal display element in which polarizing plates are installed or attached on the outer sides of both substrates and a liquid crystal driving circuit are formed so as to form substantially the same plane on the outer sides of the three sides of the liquid crystal display element. A plurality of tape carrier packages mounted with a printed circuit board and a semiconductor IC chip for driving a liquid crystal, electrically connecting the liquid crystal display element and the printed circuit board, and arranged under the liquid crystal display element, and the light is applied to the liquid crystal display element. Supply A backlight, and a frame-shaped body is a molded article which holds each of these members, accommodating each of these members, is configured to include a liquid crystal display window is opened metal frame or the like. In addition, as the sealing material, an organic adhesive such as an epoxy resin is applied in a frame shape to the edge portion of the opposite surface of one substrate, and the two substrates are stacked and adhered. In addition, a part of the sealing material has no sealing material, that is,
A liquid crystal filling port formed of an opening of the sealing material is provided.

When the liquid crystal display element is driven in the transmissive negative mode, the backlight light is transmitted through the peripheral portion of the liquid crystal display element, that is, the non-aligned area where the liquid crystal is not aligned including the seal portion provided with the seal material. There is a problem that the peripheral portion becomes bright and the display quality deteriorates. The light transmittance of the non-lighting portion in the alignment region where the liquid crystal is aligned is about 5%, and the transmittance of the peripheral portion is about 85%. In order to prevent this light leakage, conventionally, a light-shielding spacer is provided between the peripheral portion of the liquid crystal display element and the backlight to prevent the light from passing through the peripheral portion. As another method, the size of the lower polarizing plate of the liquid crystal display device is made larger than that of the upper polarizing plate, and the light of the backlight is passed through the lower polarizing plate to increase the transmittance from about 85% to about 50%. The reduction in display quality was reduced.

[0006]

However, in the conventional method of providing the light-shielding spacer, a special component for light-shielding is required, which causes a manufacturing cost increase. Further, the method of enlarging the lower polarizing plate of the liquid crystal display element can reduce the light transmission in the peripheral portion of the liquid crystal display element, but since the transmittance is about 50%, it is still detected as light leakage.

The object of the present invention is to eliminate the need for special parts for light shielding, to sufficiently reduce the transmittance of the peripheral portion of the liquid crystal display element (to 10% or less), and to prevent the light leakage of the peripheral portion. It is an object of the present invention to provide a liquid crystal display device that can prevent and improve display quality.

[0008]

In order to achieve the above-mentioned object, the present invention provides the above-mentioned two substrates, each having a transparent electrode for display and an alignment film provided on opposite surfaces of two transparent glass substrates. And a liquid crystal is sealed inside the sealing material between the both substrates by a sealing material provided in a frame shape at an edge portion between the both substrates, and the liquid crystal is sealed inside the sealing material. In a liquid crystal display device including a liquid crystal display element in which polarizing plates are respectively arranged above and below the both substrates, the sealing material is colored.

[0009]

In the present invention, since the frame-shaped sealing material provided in the peripheral portion of the liquid crystal display element is colored, the transmittance of the peripheral portion of the liquid crystal display element is 10 without using any special part for light shielding.
% Or less, light leakage from the peripheral portion can be prevented, and display quality can be improved.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 (a) is a plan view of a liquid crystal display element according to an embodiment of the present invention, and FIG. 1 (b) is a cross-sectional view of a main part of a liquid crystal display device including the liquid crystal display element of FIG. 1 (a). It is a figure.

Reference numerals 11 and 12 denote transparent glass substrates in which a transparent electrode for display and an alignment film are laminated (not shown here; see FIGS. 3 and 8), 11 is an upper electrode substrate, 12 is a lower electrode substrate, 52 is a sealing material provided by applying an epoxy resin in a frame shape to the edge portion between the substrates 11 and 12, 51 is a liquid crystal sealing port formed by the opening of the sealing material 51, and 65 is the liquid crystal sealing port 51. Liquid crystal encapsulant sealed with epoxy resin,
41 is a metal frame (shield case), 50 is a liquid crystal layer sealed inside a sealing material 52 between both substrates 11 and 12, 15 is an upper polarizing plate, 16 is a lower polarizing plate, and 62 is an upper electrode substrate 11. , Lower electrode substrate 12, sealing material 52, liquid crystal layer 50,
A liquid crystal display element composed of the upper polarization plate 15, the lower polarization plate 16 and the like, 37 is a light guide body made of an acrylic plate for uniformly irradiating the liquid crystal display element 62 with light from a light source, and 36 is a light guide body 37. A cold cathode fluorescent lamp, which is a light source disposed near one side surface of the cold cathode fluorescent lamp, and a light guide member 37 for guiding light from the cold cathode fluorescent lamp 36.
, 39 is a reflection sheet for reflecting the light toward the liquid crystal display element 62, and a diffuser plate 39 is disposed on the upper surface of the light guide body 37 to diffuse the light from the light guide body 37 toward the liquid crystal display element 62. A reflection plate for reflecting the light from 37 toward the liquid crystal display element 62, and 66 is a backlight composed of the light guide 37, the cold cathode fluorescent lamp 36, the reflection sheet 67, the diffusion plate 39, and the reflection plate 38. is there.

An organic adhesive such as an epoxy resin, which becomes the sealing material 52, is applied in a frame shape to one of the edges of the opposing surfaces of the substrates 11 and 12, and the two substrates 11 and 12 are overlapped and bonded. did. In this example, 3% by weight of carbon powder was added to the epoxy resin and colored black to form the sealing material 52.

When the liquid crystal display element is driven in the transmissive negative mode, the light transmittance of the non-lighted portion of the alignment region where the liquid crystal layer 50 of the liquid crystal display element 62 is aligned is 5%, and the periphery of the liquid crystal display element 62. The transmittance of the seal portion provided with the seal material 52 is about 8% because the seal material 52 is colored black. Therefore, the user does not see light leaking from the peripheral portion of the liquid crystal display element 62. Since the sealing material 52 in the peripheral portion of the liquid crystal display element 62 is colored black as described above, the transmittance in the peripheral portion of the liquid crystal display element can be sufficiently reduced, light leakage in the peripheral portion can be prevented, and display quality can be improved. Can be improved. In addition, since it is not necessary to use a special part for shading, the manufacturing cost is not increased.

FIG. 2 shows a liquid crystal display device 6 to which the present invention is applicable.
2 when viewed from above, the alignment direction of the liquid crystal molecules on the electrode substrate (for example, the rubbing direction), the twist direction of the liquid crystal molecules, the polarization axis (or absorption axis) direction of the polarizing plate, and the optics of the member that causes the birefringence effect. The axial direction is shown, and FIG. 3 is a perspective view of a main part of the liquid crystal display element 62.

Twisting direction 10 of liquid crystal molecules and twist angle θ
Is a rubbing direction 6 of the alignment film 21 on the upper electrode substrate 11, a rubbing direction 7 of the alignment film 22 on the lower electrode substrate 12, and a positive dielectric anisotropy sandwiched between the upper electrode substrate 11 and the lower electrode substrate 12. It is defined by the type and amount of the optical rotatory substance added to the nematic liquid crystal layer 50 having the property.

In FIG. 3, in order to align the liquid crystal molecules between the upper and lower electrode substrates 11 and 12 sandwiching the liquid crystal layer 50 so as to form a twisted spiral structure, a transparent upper layer made of, for example, glass is used. The rubbing method, which is a method of rubbing the surfaces of the alignment films 21 and 22 made of an organic polymer resin made of polyimide, for example, in contact with the liquid crystal on the lower electrode substrates 11 and 12 with a cloth in one direction, is used. ing. The rubbing direction at this time, that is, the rubbing direction, the rubbing direction 6 in the upper electrode substrate 11, and the rubbing direction 7 in the lower electrode substrate 12 are the alignment directions of the liquid crystal molecules. The two upper and lower electrode substrates 1 that have been oriented in this way
1 and 12 are made to face each other with a gap d ₁ so that the rubbing directions 6 and 7 intersect each other at approximately 180 to 360 degrees, and the two electrode substrates 11 and 12 are notched for injecting liquid crystal. That is, when a nematic liquid crystal having a positive dielectric anisotropy and having a predetermined amount of an optical rotatory substance is sealed, the liquid crystal molecules are bonded by a frame-shaped sealing material 52 having a liquid crystal sealing port 51. Has a helical molecular arrangement with a twist angle θ in the figure between the electrode substrates. Incidentally, 31 and 32 are, for example, indium oxide or ITO, respectively.
(Indium Tin Oxide) transparent upper and lower electrodes. A member that brings about a birefringence effect on the upper electrode substrate 11 of the liquid crystal cell 60 thus configured (hereinafter referred to as a birefringence member. Fujimura et al. "STN-LCD retardation film", magazine electronic material 1991 2 (Month issue, pages 37-41)
40 is provided, and upper and lower polarizing plates 15 and 16 are provided with the member 40 and the liquid crystal cell 60 sandwiched therebetween.

The twist angle θ of the liquid crystal molecules in the liquid crystal 50 can take a value in the range of 180 ° to 360 °, but is preferably 200 ° to 300 °, but lighting near the threshold value of the transmittance-applied voltage curve. From the practical viewpoint of avoiding the phenomenon that the state becomes an orientation that scatters light and maintaining excellent time division characteristics, the range of 230 to 270 degrees is more preferable. This condition basically makes the response of the liquid crystal molecules to the voltage more sensitive and acts to realize excellent time division characteristics. In order to obtain excellent display quality and the refractive index anisotropy [Delta] n ₁ of the liquid crystal layer 50 a product [Delta] n ₁ of the thickness d ₁
-D ₁ is preferably set in the range of 0.5 μm to 1.0 μm, more preferably 0.6 μm to 0.9 μm.

The birefringent member 40 acts so as to modulate the polarization state of light passing through the liquid crystal cell 60, and converts what could only be colored display by the liquid crystal cell 60 into black and white display. Thus the birefringent member 40 refractive index anisotropy [Delta] n ₂ and is extremely important product [Delta] n ₂ · d ₂ of a thickness d _2, preferably 0.8μm from 0.4 .mu.m, more preferably 0.5μm To 0.7 μm.

Further, since the liquid crystal display element 62 utilizes elliptically polarized light due to birefringence, the axes of the polarizing plates 15 and 16 and the optical axis of the uniaxial transparent birefringent plate when the birefringent member 40 is used. And the electrode substrate 11 of the liquid crystal cell 60,
The relationship between the liquid crystal alignment directions 12 and 6 is extremely important.

A liquid crystal display element 62 is used as the sealing material 52.
In order to prevent light leakage in the peripheral portion, the carbon powder is contained and colored black.

The operation and effect of the above relationship will be described with reference to FIG. FIG. 2 shows an axis of a polarizing plate, an optical axis of a uniaxial transparent birefringent member when the liquid crystal display device having the configuration of FIG. 3 is viewed from above,
3 shows the relationship between the alignment directions of liquid crystal molecule axes of an electrode substrate of a liquid crystal cell.

In FIG. 3, 5 is the optical axis of the uniaxial transparent birefringent member 40, 6 is the alignment direction of the liquid crystal molecules of the birefringent member 40 and the upper electrode substrate 11 adjacent thereto, and 7 is the lower electrode substrate 12. The liquid crystal alignment direction, 8 is the absorption axis or polarization axis of the upper polarization plate 15, 9 is the absorption axis or polarization axis of the lower polarization plate 16, and the angle α is uniaxial birefringence with the liquid crystal alignment direction 6 of the upper electrode substrate 11. The angle β formed by the optical axis 5 of the member 40 is the angle formed by the absorption axis or polarization axis 8 of the upper polarizing plate 15 and the optical axis 5 of the uniaxial transparent birefringent member 40, and the angle γ is the lower polarizing plate 16. Is the angle between the absorption axis or polarization axis 9 of the liquid crystal and the liquid crystal alignment direction 7 of the lower electrode substrate 12.

Here, how to measure the angles α, β, and γ in this specification will be defined. In FIG. 7, the intersection angle between the optical axis 5 of the birefringent member 40 and the liquid crystal alignment direction 6 of the upper electrode substrate will be described as an example. The intersection angle between the optical axis 5 and the liquid crystal alignment direction 6 is shown in FIG.
As shown in FIG. ₂ , it can be represented by φ ₁ and φ ₂ , but in the present specification, the smaller corner of φ ₁ and φ ₂ is adopted. That is, since φ ₁ <φ ₂ in FIG. 7A, φ ₁ is the intersection angle α between the optical axis 5 and the liquid crystal alignment direction 6,
Since φ ₁ > φ ₂ in FIG. 7B, φ ₂ is defined as an intersection angle α between the optical axis 5 and the liquid crystal alignment direction 6. Of course, either one may be adopted when φ ₁ = φ ₂ .

In the liquid crystal display device, the angles α, β and γ are extremely important.

The angle α is preferably 50 to 90 degrees, more preferably 70 to 90 degrees, the angle β is preferably 20 to 70 degrees, more preferably 30 to 60 degrees, and the angle γ is preferably. It is desirable to set each to 0 to 70 degrees, and more preferably to 0 to 50 degrees.

If the twist angle θ of the liquid crystal layer 50 of the liquid crystal cell 60 is in the range of 180 degrees to 360 degrees, the above angle is satisfied regardless of whether the twist direction 10 is clockwise or counterclockwise. α, β, and γ may be within the above range.

In FIG. 3, the birefringent member 40 is arranged between the upper polarizing plate 15 and the upper electrode substrate 11, but instead of this position, the lower electrode substrate 12 and the lower polarizing plate 16 are provided.
It may be disposed between and. This case corresponds to the case where the entire configuration of FIG. 3 is inverted.

FIG. 4 is a diagram showing a specific example of the twist angle θ and the like. As shown in the figure, the twist angle θ of the liquid crystal molecules is 240 degrees, and as the uniaxial transparent birefringent member 40, a liquid crystal cell having a parallel orientation (homogeneous orientation), that is, a twist angle of 0 degree was used. Here, the thickness d (μm) of the liquid crystal layer and the helical pitch p (μ of the liquid crystal material added with the optical rotatory substance)
The ratio d / p of m) was set to 0.67. Alignment films 21 and 22
Was used, which was formed of a polyimide resin film and rubbed. The tilt angle (pretilt angle) at which the alignment film subjected to the rubbing process causes the liquid crystal molecules in contact with the alignment film to be tilted with respect to the substrate surface is 4 degrees. The Δn ₂ · d ₂ of the uniaxial transparent birefringent member 40 is about 0.6 μm. On the other hand, Δn ₁ · of the liquid crystal layer 50 in which the liquid crystal molecules are twisted by 240 degrees
d ₁ is about 0.8 μm.

At this time, by setting the angle α to about 90 degrees, the angle β to about 30 degrees, and the angle γ to about 30 degrees, the voltage applied to the liquid crystal layer 50 via the upper and lower electrodes 31 and 32 is increased. When the voltage is below the threshold value, light non-transmission, that is, black display, and when the voltage exceeds a threshold value, light transmission, that is, white and black display, can be realized. In addition, the axis of the lower polarizing plate 16 is 50
When rotated 90 degrees from 90 degrees, white display was realized when the voltage applied to the liquid crystal layer 50 was below the threshold value, and black when the voltage was above the threshold value, which was the reverse of the above.

FIG. 5 shows changes in contrast during time-division driving at 1/200 duty when the angle α is changed in the configuration of FIG. Although the contrast was extremely high when the angle α was in the vicinity of 90 degrees, the contrast decreased as the angle deviated. Moreover, when the angle α is small, both the lighting part and the non-lighting part are bluish, and when the angle α is large, the non-lighting part is purple and the lighting part is yellow, and in any case black and white display is impossible. Similar results are obtained for the angle β and the angle γ, but in the case of the angle γ, as described above, when the image is rotated from 50 degrees to 90 degrees, the black and white display is reversed.

FIG. 6 is a diagram showing another specific example of the twist angle θ and the like. The basic structure is the same as the specific example shown in FIG.
However, the twist angle of the liquid crystal molecules of the liquid crystal layer 50 is 260 degrees,
The difference is that Δn ₁ · d ₁ is about 0.65 μm to 0.75 μm. The Δn ₂ · d ₂ of the parallel alignment liquid crystal layer used as the uniaxial transparent birefringent member 40 is about 0.5, which is the same as that in the above-mentioned specific example.
It is 8 μm. The thickness d ₁ (μm) of the liquid crystal layer and the helical pitch p (μm) of the nematic liquid crystal material added with the optically active substance.
And the ratio was set to d / p = 0.72.

At this time, by setting the angle α to about 100 degrees, the angle β to about 35 degrees, and the angle γ to about 15 degrees, the black and white display similar to that in the first specific example can be realized. Also, the reverse black-and-white display is possible by rotating the position of the axis of the lower polarizing plate by 50 to 90 degrees from the above value, which is similar to the first specific example. The tendency with respect to the deviations of the angles α, β, and γ is almost the same as in the first specific example.

In any of the above examples, a parallel alignment liquid crystal cell having no twist of liquid crystal molecules is used as the uniaxial transparent birefringent member 40, but rather a liquid crystal layer in which liquid crystal molecules are twisted by about 20 to 60 degrees is used. There is less color change depending on the angle. Like the above-mentioned liquid crystal layer 50, this twisted liquid crystal layer is formed by sandwiching liquid crystal between a pair of transparent substrates that have been subjected to the alignment treatment so that the alignment treatment directions intersect a predetermined twist angle. It In this case, the bisected angle of the two orientation treatment directions sandwiching the twisted structure of the liquid crystal molecules may be treated as the optical axis of the birefringent member. A transparent polymer film may be used as the birefringent member 40 (uniaxially stretched film is preferable at this time). In this case, PET (polyethylene terephthalate), acrylic resin film and polycarbonate are effective as the polymer film.

Further, although the single birefringent member is used in the above embodiment, in addition to the birefringent member 40 in FIG. 3, another birefringent member is provided between the lower electrode substrate 12 and the lower polarizing plate 16. It is also possible to insert a bending member. In this case, Δn ₂ · d ₂ of these birefringent members should be readjusted.

However, as shown in FIG. 8, the upper electrode substrate 11
Red, green, and blue color filters 33R, 33G, 33 on top
B. By providing the light shielding film 33D between the filters, multicolor display is possible. FIG. 6 shows the relationship among the alignment direction of the liquid crystal molecules, the twisting direction of the liquid crystal molecules, the axis direction of the polarizing plate, and the optical axis of the birefringent member in the above specific example.

In FIG. 8, each filter 33
On the R, 33G, 33B and the light shielding film 33D, a smoothing layer 23 made of an insulating material is formed in order to reduce the influence of these irregularities, and then an upper electrode 31 and an alignment film 21 are formed.

FIG. 9 is an exploded perspective view showing a liquid crystal display element 62, a drive circuit for driving the liquid crystal display element 62, and a liquid crystal display module 63 in which a light source is integrated compactly. IC 34 for driving the liquid crystal display element 62
Is mounted on a frame-shaped printed circuit board 35 having a window for fitting the liquid crystal display element 62 in the center. The printed circuit board 35 in which the liquid crystal display element 62 is fitted is fitted in the window portion of the frame-like body 42 formed by plastic molding,
The metal frame 41 is superposed on this, and the claw 43 is bent into the notch 44 formed in the frame-shaped body 42 to fix the frame 41 to the frame-shaped body 42.

A cold cathode fluorescent lamp 36 arranged at the upper and lower ends of the liquid crystal display element 62, a light guide 37 made of an acrylic plate for uniformly irradiating the liquid crystal display cell 60 with light from the cold cathode fluorescent lamp 36, A reflecting plate 38 formed by applying white paint to a metal plate and a milky white diffusing plate 39 for diffusing light from the light guide 37 are fitted into the window portion from the back side of the frame-shaped body 42 in the order of FIG. Be done. An inverter power supply circuit (not shown) for turning on the cold cathode fluorescent lamp 36 is provided with a recess (not shown) provided on the right side rear portion of the frame-shaped body 42. The recess 45 of the reflector 38 is provided.
It is in a position facing. ). Diffusion plate 39,
The light guide 37, the cold cathode fluorescent lamp 36, and the reflector 38 are fixed by bending a tongue piece 46 provided on the reflector 38 into an edge 47 provided on the frame-shaped body 42.

FIG. 10 is a block diagram of a laptop personal computer using the liquid crystal display module 63 in the display section, and FIG. 11 is a diagram showing a state in which the liquid crystal display module 63 is mounted on the laptop personal computer 64. In this laptop personal computer 64, the microprocessor 4
The result calculated in 9 is transferred to the liquid crystal display module 63 by the liquid crystal driving semiconductor IC 34 via the control LSI 48.
Is to drive.

As described above, according to the above-mentioned specific example, it is possible to realize a field effect liquid crystal display device having excellent time-division drive characteristics and capable of monochrome and multicolor display.

An active matrix type color liquid crystal display device to which the present invention is applicable will be described below.

FIG. 12 is an exploded perspective view showing each component of the active matrix type liquid crystal display module MDL.

SHD is a frame-shaped shield case (metal frame) made of a metal plate, LCW is its display window, PNL.
Is a liquid crystal display panel, SPB is a light diffusion plate, MFR is an intermediate frame, BL is a cold cathode fluorescent lamp as a light source of a backlight, BLS is a backlight support, and LCA is a lower case. In this arrangement, the respective members are stacked to assemble the module MDL.

The module MDL is a shield case SH.
The whole is fixed by the claw CL and the hook FK provided on D.

The intermediate frame MFR is formed in a frame shape so that an opening corresponding to the display window LCW is provided, and the frame portion has a diffusion plate SPB, a backlight support BLS, and various circuit components in accordance with the shapes and thicknesses thereof. There are irregularities and openings for heat dissipation.

The lower case LCA also serves as a reflector for backlight light, and a reflection mountain RM is formed corresponding to the fluorescent tube BL so as to reflect light efficiently.

In FIG. 13, the pixel portion of the matrix of the liquid crystal display panel PNL of the active matrix type color liquid crystal display device is in the center (b), and both sides are near the corner portion (a) of the panel PNL and the video signal terminal portion ( It is sectional drawing which shows c).

As shown in FIG. 13, the thin film transistor TFT1 and the transparent pixel electrode ITO1 are formed on the lower transparent glass substrate SUB1 side with the liquid crystal layer LC as a reference, and the color filter FI is formed on the upper transparent glass substrate SUB2 side.
L, a black matrix pattern BM for shading is formed. Silicon oxide films SI formed by dipping or the like on both surfaces of the transparent glass substrates SUB1 and SUB2
O is provided.

On the inner (liquid crystal LC side) surface of the upper transparent glass substrate SUB2, a light shielding film BM and a color filter FI are provided.
L, protective film PSV2, common transparent pixel electrode ITO2 (CO
M) and the upper alignment film ORI2 are sequentially stacked. The seal material SL contains carbon powder or the like and is colored black in order to prevent light leakage from the peripheral portion of the liquid crystal display panel PNL.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the scope of the invention. . For example, in the above-described embodiment shown in FIG. 1, carbon powder was used as the pigment for coloring the sealing material in black, but it is not limited to this. Further, black is the most preferable coloring color, but is not limited to black. Further, the size of the lower polarizing plate may be made larger than that of the upper polarizing plate to shield the peripheral portion of the liquid crystal display element from light. In addition, the present invention is most effective when it has a backlight and drives a liquid crystal display element in a transmissive negative mode, but the present invention is not limited to this. further,
The present invention is applicable to a simple matrix type liquid crystal display device and an active matrix type liquid crystal display device.

[0052]

As described above, according to the present invention,
It is possible to prevent light leakage from the peripheral portion of the liquid crystal display element without increasing the manufacturing cost, and it is possible to improve the display quality.

[Brief description of drawings]

FIG. 1A is a plan view of a liquid crystal display element of an embodiment of the present invention, and FIG. 1B is a cross-sectional view of a main part of a liquid crystal display device including the liquid crystal display element of FIG.

FIG. 2 shows an example of a relationship among an alignment direction of liquid crystal molecules, a twisting direction of liquid crystal molecules, a direction of a polarizing plate axis, and an optical axis of a birefringent member in a simple matrix type liquid crystal display device to which the present invention is applicable. FIG.

FIG. 3 is an exploded perspective view of a main part of an example of a liquid crystal display element.

FIG. 4 is an explanatory diagram showing a relationship among a twist direction of liquid crystal molecules, a direction of an axis of a polarizing plate, and an optical axis of a birefringent member in a liquid crystal display element of another example.

5 is a graph showing the contrast and transmitted light color-crossing angle α characteristics of the example of FIG. 2 of the liquid crystal display device.

FIG. 6 is an explanatory diagram showing a relationship among an arrangement direction of liquid crystal molecules, a twisting direction of liquid crystal molecules, a direction of an axis of a polarizing plate, and an optical axis of a birefringent member in a liquid crystal display element of still another example.

FIG. 7 is a diagram for explaining how to measure intersection angles α, β, and γ.

FIG. 8 is a partially cutaway perspective view of an example of an upper electrode substrate portion of a liquid crystal display element.

FIG. 9 is an exploded perspective view of an example of a liquid crystal display module.

FIG. 10 is a block diagram of an example of a laptop personal computer.

FIG. 11 is a perspective view of an example of a laptop computer.

FIG. 12 is an exploded perspective view of an active matrix type liquid crystal display module.

FIG. 13 is a cross-sectional view showing a pixel portion of a matrix of an active matrix type liquid crystal display panel in the center, and around both corners of the panel and around video signal terminal portions on both sides.

[Explanation of symbols]

11 ... Upper electrode substrate, 12 ... Lower electrode substrate, 15 ... Upper polarizing plate, 16 ... Lower polarizing plate, 36 ... Cold cathode fluorescent lamp, 37 ... Light guide, 38 ... Reflector, 39 ... Diffuser, 41 ... Metal Manufacturing frame, 50 ... Liquid crystal layer, 51 ... Liquid crystal sealing port, 52 ... Sealing material, 62 ... Liquid crystal display element, 65 ... Liquid crystal sealing material, 66 ... Backlight, 67 ... Reflective sheet.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toyokazu Otaka 3300 Hayano, Mobara-shi, Chiba Electronic Device Division, Hitachi, Ltd. (72) Inventor Katsu Suzuki 3300 Hayano, Mobara-shi, Chiba Hitachi, Ltd. Electronic Device Business Department

Claims (1)

[Claims] 1. A pair of transparent glass substrates, each of which has a transparent electrode for display and an alignment film provided on opposite surfaces of the two transparent glass substrates, are superposed on each other with a predetermined gap therebetween, and is provided at an edge portion between the two substrates. A liquid crystal in which both substrates are bonded together by a frame-shaped sealing material, liquid crystal is sealed inside the sealing material between the both substrates, and polarizing plates are respectively arranged above and below the both substrates. A liquid crystal display device comprising a display element, wherein the sealing material is colored.