JPH11167112A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize transmitted light quantity all over the display area by changing the shading film width of each pixel corresponding to the light quantity distribution of a backlight unit and changing the aperture, area of each pixel. SOLUTION: The horizontal shading film 5a and the vertical shading film 5b constituting each pixel of a liquid crystal panel part are constituted so that the transmitted light quantity of each pixel may be equal by changing the aperture area corresponding to the transmitted light quantity distribution of light transmitted through a light diffuse transmission plate. In the case of a liquid crystal display device having no light diffuse transmission plate which diffuses and transmits the light from the backlight unit; the films 5a and 5b constituting each pixel of the liquid crystal panel part are constituted so that the transmitted light quantity of each pixel may be equal by changing the shading film width of each pixel corresponding to the light quantity distribution of the backlight unit and changing the aperture area of each pixel.

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 having a backlight unit for transmitting light to a liquid crystal panel, and more particularly to a liquid crystal display device having a light shielding film width of a light shielding film.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view of a liquid crystal display device, and FIG. 8 is a plan view of a filter substrate.

A conventional liquid crystal display device includes a light source 101, a reflection plate 103, a light diffusion transmission plate 105, and a liquid crystal panel unit 10.
7 and a filter substrate 111 constituting a black matrix 109. Light emitted from the light source 101 reaches the light diffusion transmission plate 105 directly and via the reflection plate 103. Transmission plate 105
The light is diffused, transmitted, and guided to the liquid crystal panel unit 107.

Then, by providing a filter substrate 111 in which the line width of the black matrix 109 is continuously changed on the display surface side of the liquid crystal panel unit 107, it has been attempted to achieve a uniform transmitted light amount on the display surface.

[0005]

However, in a liquid crystal display device having a two-dimensional transmitted light quantity distribution, the transmitted light quantity distribution is made uniform by using a filter substrate in which the line width of the black matrix is continuously changed. There is a problem that can not be.

FIG. 9 shows a plane transmitted light amount distribution in a liquid crystal display device provided with a sidelight type backlight unit. FIG. Display area 1 perpendicular to side 115
17 shows the transmitted light quantity distribution on the horizontal straight line AA ′, and FIG. 10 (b) shows the transmitted light quantity distribution on an arbitrary horizontal straight line BB ′ parallel to the straight line AA ′, and explains the conventional problems. I do.

In the case of a sidelight type backlight unit, the light emitted from the fluorescent tube 113 of the line light source at the side portion 115 passes through the light guide plate directly or as reflected light, and is diffused by the light diffusion transmission plate to be displayed on the display surface. At this time, the transmitted light amount distribution of the sidelight type backlight unit is shown in FIG.
As shown in FIGS. 10A and 10B, the closer to the fluorescent tube 113, the higher the transmitted light amount, and the farther away, the lower the transmitted light amount, and the distribution of the transmitted light amount in the horizontal direction of the display area is non-uniform. If the transmitted light quantity distribution on the horizontal straight line AA ′ in FIG. 10A is different from the transmitted light quantity distribution on the horizontal straight line BB ′ parallel to the straight line AA ′ in FIG. The transmitted light quantity distribution in the vertical direction is also non-uniform, and the transmitted light quantity distribution of the entire display area 117 has two-dimensional non-uniformity. At this time, if a filter substrate in which the line width of the black matrix is continuously changed is used, even if the transmitted light amount distribution in one of the vertical and horizontal directions can be made uniform, the transmitted light amount distribution of the entire display area is uniform. There is a problem that can not be.

Even if the backlight unit is not of the sidelight type but of the U-shaped fluorescent tube type or the W-shaped fluorescent tube type, the transmitted light amount distribution has a two-dimensional non-uniformity. In the method using a filter substrate in which the line width is continuously changed, it is difficult to obtain uniformity of the amount of transmitted light over the entire display area.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display device having a backlight unit and a light diffusing and transmitting plate, in which the amount of transmitted light in the entire display area is not uneven.

[0010]

According to a first aspect of the present invention, there is provided a liquid crystal display device comprising: a display electrode; and a light-shielding film formed on the display electrode. A pair of glass substrates having an alignment film formed in a display region, and a liquid crystal sandwiched between the pair of glass substrates,
A liquid crystal panel section having a pair of polarizing plates provided outside the glass substrate, and a matrix-shaped pixel is formed by arranging respective alignment films to face each other, and a backlight unit that transmits light to the liquid crystal panel section. In the liquid crystal display device to be formed, by changing the width of the light-shielding film of each pixel according to the light amount distribution of the backlight unit, the aperture area of each pixel is changed so that the amount of transmitted light of each pixel becomes equal. It is characterized by.

According to a second aspect of the present invention, there is provided a liquid crystal display comprising a backlight unit for transmitting light to a liquid crystal panel and a light diffusion transmission plate, wherein the transmission of light transmitted through the light diffusion transmission plate is performed. The width of the light-shielding film of each pixel is changed in accordance with the light quantity distribution, so that the aperture area of each pixel is changed so that the transmitted light quantity of each pixel is equalized.

According to a third aspect of the present invention, there is provided a liquid crystal display device comprising: a pair of electrodes having a display electrode, a light-shielding film formed on the display electrode, and an alignment film formed on the display region by oblique deposition of SiO. It has a glass substrate, a ferroelectric liquid crystal or an antiferroelectric liquid crystal sandwiched between a pair of glass substrates, and a pair of polarizing plates provided outside the glass substrate. In the liquid crystal display device, which is composed of a liquid crystal panel part in which the pixels are formed, a backlight unit that transmits light to the liquid crystal panel part, and a light diffusion transmission plate, it corresponds to a transmitted light amount distribution of light transmitted through the liquid crystal panel part. The opening area of each pixel is changed by changing the light-shielding film width of each pixel, so that the amount of transmitted light of each pixel is equalized.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal display device according to the present invention will be described with reference to the sectional view shown in FIG. 1 and the plan view shown in FIG.

The liquid crystal panel 1 of the liquid crystal display device includes display electrodes 3a and 3b formed of ITO, a horizontal light shielding film 5a and a vertical light shielding film 5a formed of metallic chromium, and alignment films 7a and 7b.
b are formed on the alignment films 7a, 7b.
b are opposed to each other, and a spacer and a liquid crystal 11 for keeping a constant interval are provided inside the sealants 13a and 13b.
The polarizing plates 15a and 15b are fixed on the outer surfaces of the glass substrates 9a and 9b by bonding or the like.

Backlight unit 27 of liquid crystal display device
Is composed of a fluorescent tube light source 17, a light condensing unit 19 for condensing the light of the fluorescent tube light source 17, a light guide unit 23 and a reflector 21, and a backlight unit 27 and a liquid crystal panel unit 1.
There is a light diffusion transmission plate 25 that diffuses and transmits the light from the backlight unit 27.

The horizontal light-shielding film 5a and the vertical light-shielding film 5b constituting each pixel of the liquid crystal panel section 1 correspond to each pixel corresponding to the transmitted light amount distribution of the light transmitted through the light diffusion transmission plate as shown in FIG. By changing the width of the light-shielding film, the aperture area of each pixel is changed so that the amount of transmitted light of each pixel becomes equal.

In the case of a liquid crystal display device without a light diffusion transmission plate 25 for diffusing and transmitting light from the backlight unit 27, the horizontal light shielding film 5 constituting each pixel of the liquid crystal panel unit 1 is used.
a, the vertical light-shielding film 5b is configured such that the aperture area of each pixel is changed by changing the light-shielding film width of each pixel in accordance with the light amount distribution of the backlight unit, so that the transmitted light amount of each pixel becomes equal. .

The alignment films 7a and 7b of the liquid crystal panel unit 1
Is formed by a SiO oblique evaporation method, and the liquid crystal 11 is a ferroelectric liquid crystal or an antiferroelectric liquid crystal, in the display region of the liquid crystal panel portion, in a direction connecting the evaporation source and each pixel of the display region. Since the determined alignment axis has an angle difference, the ferroelectric liquid crystal molecules that are aligned in the alignment axis direction have an angle difference depending on the location of the display area, and therefore, the direction of the molecular long axis of the ferroelectric liquid crystal molecule and the polarization plate deflection. Since the angle with the axis differs depending on the location of the display area, a difference occurs in the amount of transmitted light. Therefore, the horizontal light-shielding film 5a and the vertical light-shielding film 5b constituting each pixel of the liquid crystal panel section 1 are formed by changing the light-shielding film width of each pixel in accordance with the transmitted light amount distribution of the light transmitted through the liquid crystal panel section 1. The aperture area of the pixel is changed so that the amount of transmitted light of each pixel becomes equal.

Here, a method for setting the light-shielding film width of an arbitrary pixel will be described with reference to FIGS. 2, 4, and 5. FIG. First, as a method of measuring the amount of transmitted light, the display area 29 of the liquid crystal panel unit 1 is used.
Is captured by a personal computer using a CCD camera, and the captured image is subjected to image processing to display the amount of transmitted light.
The transmitted light amount distribution of the display area 29 thus obtained can be obtained as shown in the transmitted light amount distribution data of FIG. 9, and the transmitted light amount at the position corresponding to each pixel is obtained as a numerical value. Here, the pixel at which the minimum value of the transmitted light amount is obtained is the reference pixel 35, and the transmitted light amount IR of the reference pixel 35 is sufficient for the liquid crystal display device. Then, in order to eliminate unevenness in the amount of transmitted light in the display area 29, the amount of transmitted light of each pixel needs to be equal to the amount of transmitted light IR of the reference pixel 35. Accordingly, when the transmitted light amount of the reference pixel 35 is IR, the opening area is SR, and the transmitted light amount of the arbitrary pixel 33 at the opening area SR is IM, the opening area of the arbitrary pixel 33 is changed to A relational expression for equalizing the transmitted light amount IR and the transmitted light amount of the arbitrary pixel 33 is given by an expression of SM = SR × IR / IM, where SM is the opening area of the changed arbitrary pixel 33.

In this manner, the aperture area is determined so that the amount of transmitted light of each pixel is equal to the amount of transmitted light of the pixel 35 having the minimum amount of transmitted light, and the width of the light-shielding film is set in accordance with these opening areas. However, the width of the light-shielding film is made larger than the light-shielding film of the pixel having the minimum transmitted light amount in FIG. 6A by increasing only the width of the vertical light-shielding film 5b as shown in FIG. May be obtained, or may be obtained by increasing only the width of the horizontal light shielding film 5a as shown in FIG. Also, as shown in FIG. 6D, both the vertical light shielding film 5b and the horizontal light shielding film 5a may be thickened.

FIG. 3 shows transmission light amount distribution data of the liquid crystal panel of the liquid crystal display device according to the present invention. FIG. 3A is a transmission light amount distribution along a horizontal straight line AA ′ of the display area 29 shown in FIG. 2, and FIG. 3B is a display area 29 shown in FIG.
Shows a transmitted light amount distribution on a horizontal straight line BB ′. The straight line AA ′ passes through the middle point of the side 31 of the display area 29 in FIG. 2, and the straight line BB ′ passes through the reference pixel 35. 3 shows that the distribution of the transmitted light amount in the horizontal direction of the display area 29 is uniform, and the comparison between FIG. 3A and FIG.
9 also shows that the transmitted light amount distribution in the vertical direction is uniform.

In this way, the opening area of each pixel is obtained,
By increasing the width of the vertical light-shielding film, the horizontal light-shielding film, or both the vertical and horizontal light-shielding films, even if the transmitted light amount distribution of the display area of the liquid crystal panel has a two-dimensional non-uniformity, the transmission of the entire display area is possible The light quantity distribution can be made uniform.

[0023]

As described above, according to the first aspect of the present invention,
According to the liquid crystal display device, the aperture area of each pixel is changed by changing the light-shielding film width of each pixel according to the light amount distribution of the backlight unit, and the variation in the transmitted light amount due to the uneven light amount of the backlight unit Thus, the amount of transmitted light in the display area can be made uniform.
Further, according to the liquid crystal display device of the present invention, the aperture area of each pixel is changed by changing the width of the light-shielding film of each pixel in accordance with the transmitted light amount distribution of the light diffusion transmission plate, and the transmission of the light diffusion transmission plate is changed. Variations in the amount of transmitted light due to unevenness in the amount of light can be eliminated, and the amount of transmitted light in the display area can be made uniform. Furthermore, according to the liquid crystal display device of the third aspect, Si
An orientation film is formed by O oblique deposition, and the aperture of each pixel is changed by changing the width of the light-shielding film of each pixel in accordance with the transmitted light amount distribution of the liquid crystal panel using ferroelectric liquid crystal or antiferroelectric liquid crystal. By changing the area, it is possible to eliminate the variation in the amount of transmitted light caused by the unevenness in the amount of transmitted light in the liquid crystal panel portion, and to make the amount of transmitted light in the display area uniform.

[Brief description of the drawings]

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

FIG. 2 is a plan view of the liquid crystal display device according to the present invention.

FIG. 3 is a diagram showing a transmitted light amount distribution on a straight line AA ′ and a straight line BB ′ of the liquid crystal display device according to the present invention.

FIG. 4 is a plan view showing a reference pixel and an arbitrary pixel.

FIG. 5 is a diagram showing a transmitted light amount IR of a reference pixel and a transmitted light amount IM of an arbitrary pixel.

FIG. 6 is a view showing a light shielding film in the present invention.

FIG. 7 is a sectional view of a conventional liquid crystal display device.

FIG. 8 is a diagram showing a conventional black matrix.

FIG. 9 is a plan view illustrating a transmitted light amount distribution of a liquid crystal panel in a liquid crystal display device including a sidelight type backlight unit.

FIG. 10 is a diagram illustrating a transmitted light amount distribution on a straight line AA ′ and a straight line BB ′ of a liquid crystal panel unit in a liquid crystal display device including a sidelight type backlight unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal panel part 3a, 3b Display electrode 5a Horizontal light shielding film 5b Vertical light shielding film 7a, 7b Alignment film 9a, 9b Glass substrate 11 Liquid crystal 13a, 13b Sealant 15a, 15b Polarizer 17 Fluorescent tube light source 19 Condenser 21 Reflection Plate 23 Light guide part 25 Light diffusion transmission plate 27 Backlight unit 29 Display area 31 Side part 33 Arbitrary pixel 35 Reference pixel

Claims (3)

[Claims] A pair of glass substrates having a display electrode, a light-shielding film formed on the display electrode, and an alignment film formed in a display region; a liquid crystal sandwiched between the pair of glass substrates;
A liquid crystal panel section having a pair of polarizing plates provided outside the glass substrate, and a matrix-shaped pixel is formed by arranging respective alignment films to face each other, and a backlight unit that transmits light to the liquid crystal panel section. In the liquid crystal display device to be formed, by changing the width of the light-shielding film of each pixel according to the light amount distribution of the backlight unit, the aperture area of each pixel is changed so that the amount of transmitted light of each pixel becomes equal. A liquid crystal display device characterized by the above-mentioned. A pair of glass substrates having a display electrode, a light-shielding film formed on the display electrode, and an alignment film formed in a display region; a liquid crystal interposed between the pair of glass substrates;
A liquid crystal panel portion having a pair of polarizing plates provided outside a glass substrate, and a matrix-shaped pixel formed by arranging respective alignment films to face each other; a backlight unit for transmitting light to the liquid crystal panel portion; In a liquid crystal display device formed by a diffusion transmission plate, the aperture area of each pixel is changed by changing the width of the light-shielding film of each pixel in accordance with the transmitted light amount distribution of light transmitted through the light diffusion transmission plate. A liquid crystal display device characterized in that the transmitted light amounts are equal. 3. A pair of glass substrates having a display electrode, a light-shielding film formed on the display electrode, and an alignment film formed by oblique deposition of SiO in a display region, and sandwiched between a pair of glass substrates. Ferroelectric liquid crystal or antiferroelectric liquid crystal,
A liquid crystal panel portion having a pair of polarizing plates provided outside a glass substrate, and a matrix-shaped pixel formed by arranging respective alignment films to face each other; a backlight unit for transmitting light to the liquid crystal panel portion; In a liquid crystal display device formed by a diffusion transmission plate, the aperture area of each pixel is changed by changing the width of the light-shielding film of each pixel in accordance with the transmitted light amount distribution of the light transmitted through the liquid crystal panel. A liquid crystal display device characterized in that transmitted light amounts are equalized.