JPH09281491A - Liquid crystal display - Google Patents

Abstract

(57) An object of the present invention is to provide a liquid crystal display device capable of supporting a wide viewing angle by eliminating the brightness difference in the in-plane direction of the substrate. In a liquid crystal display device, a glass substrate (1)
The amount of light incident on the liquid crystal 30 sealed between 0 and 20 is
In the in-plane direction of the substrate, it is small on the clear side 101 (for example, the 12 o'clock side of the clock) and large on the reverse clear side 102 (for example, the 6 o'clock side of the clock). Therefore, the difference in brightness between the clear vision side 101 and the reverse vision side 102 is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type liquid crystal display device. More specifically, it relates to a technique for eliminating a brightness difference in the in-plane direction of a liquid crystal display device.

[0002]

2. Description of the Related Art In a liquid crystal display device, as shown in FIG.
Two glass substrates 10 and 20 are fixed so as to face each other with a gap (cell gap) of several μm therebetween, and a liquid crystal 30 is sealed in the gap. Among them, in the diode type liquid crystal display device, a large number of scanning lines 11 are formed in parallel on the lower glass substrate 10, and the MIM diodes 12 (active elements) are formed at a constant pitch with respect to these scanning lines 11 and the diodes. Pixel electrodes 13 connected to 12 are arranged in a matrix. Transparent signal lines (data lines) are formed as strip-shaped counter electrodes 22 on the glass substrate 20 on the side where the color filters 21 are formed. Therefore, the scanning line 11 and the counter electrode 22 (signal line) intersect, and the portion sandwiched between the pixel electrode 13 and the counter electrode 22 corresponding to this intersection portion is the liquid crystal cell of each pixel 110. It is 31. Since the pixels 110 thus configured have the same structure, the pixels 110 have the same aperture ratio.

Polarizing plates 19 and 29 are formed outside the glass substrates 10 and 20, respectively, and a backlight unit 70 is arranged on the back side of the polarizing plates 19. If the backlight unit 70 is an edge light type,
It is composed of a fluorescent lamp 71 arranged at a position corresponding to the side of the glass substrate 10, a light guide plate 72 for guiding the light from the fluorescent lamp 71 toward the glass substrate 10, and a diffusion plate 73 for the light guide plate 72. As shown in FIG. 12, the glass substrate 10 is irradiated with a uniform amount of white light.

The liquid crystal 30 is a liquid crystal for TM type display which is aligned with a predetermined twist angle and pretilt angle by an alignment film or rubbing treatment, and the liquid crystal molecules 32 depend on whether or not an electric field is applied to the liquid crystal cell 22. Switches to the twisted orientation and the untwisted state,
The transmission state of the light incident from the backlight unit 70 is switched, and a predetermined display can be performed.

[0005]

However, in the conventional liquid crystal display device, there is a problem that the viewing angle is narrow because the brightness difference occurs in the in-plane direction of the substrate when viewed from an oblique direction. Such a problem is that oblique light causes birefringence due to the liquid crystal 30, and the polarization state changes.

As shown in FIG. 13 (A), such a phenomenon is caused by the liquid crystal molecules 23 being obliquely aligned when white is displayed in the normally white mode, as shown in FIG. 13 (B). It is assumed that the liquid crystal molecules 23 are standing when displaying black in the normally white mode. As conceptually taken in this way, as shown in FIG. 14 (A), the lower glass substrate 10 is subjected to rubbing treatment from a diagonally lower left to a diagonally upper right as shown by an arrow A, and the color is Regarding the glass substrate 20 on the filter side, as shown by an arrow B, an intermediate color (gray) in a liquid crystal display device that has been subjected to a rubbing process from diagonally left upper to diagonally right lower.
Is displayed, the vertical direction of the board (12:00
At 6 o'clock), the liquid crystal molecules 32 are in the state shown in FIG. In this state, when the glass substrates 10 and 20 are viewed from a position corresponding to a substantially central position of the glass substrates 10 and 20, the liquid crystal molecules have the same orientation in the left-right direction with respect to the line of sight, but the vertical direction of the glass substrates 10 and 20. At (12 o'clock / 6 o'clock direction on the clock), liquid crystal molecules 32 with respect to the line of sight
The orientation is different. That is, the angle between the liquid crystal molecule 32 and the line of sight L1 on the normal to the glass substrates 10 and 20 is θ.
1 above the glass substrates 10 and 20 (direction 12 o'clock)
The angle formed by the line of sight L2 and the liquid crystal molecule 32 when viewing
And the angle between the line of sight L3 and the liquid crystal molecule 32 when viewing the lower side of the glass substrates 10 and 20 (direction at 6 o'clock) is θ3.
Then, θ3 <θ1 <θ2, and the angle difference is significantly large. Therefore, when the normally white mode is adopted and the drive voltage for the liquid crystal cell 31 is set in line with the line of sight L1 on the normal line to the glass substrates 10 and 20, even if an attempt is made to display gray, the glass substrate 10 and On the upper side of 20 (direction at 12 o'clock), the light transmission amount is large, so that the brightness is high, and on the lower side (6
In the direction of time), the amount of light transmitted is small, so the brightness becomes low. Thus, the side with high brightness is the so-called clear side 1
01, and the side with lower brightness is the so-called reverse vision side 10
Called 2.

Moreover, such a phenomenon is caused by the glass substrate 1
As the size of 0 and 20 increases, the parallax expands,
Since it becomes remarkable, it becomes a serious problem when trying to increase the screen size.

[0008] In view of the above problems, an object of the present invention is to provide:
An object of the present invention is to provide a liquid crystal display device that can cope with a wide viewing angle by eliminating the brightness difference in the in-plane direction.

[0009]

In order to solve the above problems, according to the present invention, a predetermined insulating substrate is provided between a first insulating substrate in which pixel electrodes and active elements are arranged in a matrix. A second counter electrode that is arranged to face the pixel electrode and that faces the pixel electrode.
A liquid crystal cell sealed between the second insulating substrate and the first insulating substrate and addressed by the active element between the pixel electrode and the counter electrode for each pixel. In a liquid crystal display device having a liquid crystal layer constituting the liquid crystal layer, the amount of light incident on the liquid crystal layer is configured to be higher on the reverse clear vision side than on the clear vision side in the in-plane direction of the substrate. And

In the present invention, the clear vision side means the side with high brightness, and the reverse clear vision side means the side with low brightness.

According to the present invention, even if the liquid crystal undergoes birefringence with respect to oblique light and the polarization state changes, the amount of light incident on the liquid crystal cell is set in advance so that it is higher on the reverse vision side. , The brightness difference between the clear vision side and the reverse vision side is eliminated. Therefore, a wide viewing angle of the liquid crystal display device can be achieved.

In the present invention, in order to increase the amount of light incident on the liquid crystal layer on the side opposite to the clear vision side, the amount of light emitted from the backlight toward the first insulating substrate is set to the substrate. It is possible to use a light amount adjusting plate that is different in the in-plane direction. According to this structure, it is possible to eliminate the difference in brightness between the clear vision side and the reverse clear vision side simply by adding the light amount adjusting plate to the backlight unit provided in the conventional liquid crystal display device.

In the present invention, in order to make the amount of light incident on the liquid crystal layer higher on the reverse vision side than on the clear vision side, the aperture ratio of each pixel should be higher on the reverse vision side than on the clear vision side. May be. According to this structure, the brightness difference between the clear-vision side and the reverse clear-vision side can be eliminated only by adjusting the aperture ratio of each pixel, and it is not necessary to add a new member.

[0014]

Embodiments of the present invention will be described with reference to the drawings. Here, before describing each mode, a configuration common to all modes as long as it is a diode type liquid crystal display device will be described with reference to FIGS. 1 to 4. In the following description, the same parts as those in the related art will be designated by the same reference numerals and will be described with reference to the same drawings.

FIG. 1 is a schematic configuration diagram of a MIM diode type liquid crystal display device as an example of a liquid crystal display device to which the present invention is applied, and FIG. 2 is an MIM diode used as an active element in the liquid crystal display device shown in FIG. Illustration of
3 and 4 are explanatory views for explaining a step of forming the MIM diode on the insulating substrate.

In FIG. 1, in a liquid crystal display device 1, two glass substrates 10 and 20 (insulating substrates) are fixed so as to face each other with a gap of several μm therebetween, and a liquid crystal 30 (T
It has a structure in which a clockwise liquid crystal for M type display is enclosed. A large number of scanning lines 11 are formed in parallel on the lower glass substrate 10 (first insulating substrate), and the MIM diodes 12 (diode elements) and the diodes 12 are formed at a constant pitch with respect to these scanning lines 11. Pixel electrode 1 connected to
3 and 3 are arranged in a matrix. On the glass substrate 20 on the side where the color filter 21 is formed, transparent signal lines (data lines) are formed as strip-shaped counter electrodes 22. Regarding the positional relationship between the color filter 21 and the counter electrode 22, either may be the upper layer or the lower layer. The signal line (data line) may be formed on the lower glass substrate 10 and the scanning line 11 may be formed on the glass substrate 20 on which the color filter 21 is formed.

In the liquid crystal display device 1 thus constructed,
The scanning line 11 and the counter electrode 22 (signal line) substantially intersect each other, and each pixel 1 corresponding to these intersections.
A liquid crystal cell 31 is formed between the pixel electrode 13 and the counter electrode 22 for each unit 10.

A polarizing plate 1 is provided outside the glass substrates 10 and 20.
9, 29 are optically arranged orthogonally, and the polarizing plate 2
9 functions as an analyzer. A direct type backlight unit or an edge light type backlight unit is disposed below the polarizing plate 19, and as shown in the figure, the edge light type backlight unit 70 is disposed at a position corresponding to the side of the glass substrate 10. Fluorescent lamp 71 and a light guide plate 72 for guiding the light from the fluorescent lamp 71 toward the glass substrate 10.
And a diffusion plate 73 for the light guide plate 72. In the backlight unit 70 of the edge light type, the fluorescent lamps 71 may be arranged at respective positions corresponding to the two opposite sides of the glass substrate 10.

As shown in FIG. 2A, in the MIM diode 12, the tantalum electrode 121 (lower layer side electrode) is formed on the surface of the transparent glass substrate 10 on which a base protective film (not shown) such as a tantalum oxide film is formed. ) Is formed, and a tantalum oxide film 122 (anodic oxide film / insulating film) is formed on the surface by anodic oxidation. A pixel electrode 13 made of an ITO electrode is also formed on the surface of the glass substrate 10. A chromium electrode 12 is formed on the surface of the tantalum oxide film 122.
3 (upper layer side electrode) is formed, and the chromium electrode 123 and the tantalum electrode 121 are opposed to each other with the tantalum oxide film 122 interposed therebetween to form the MIM diode 12. The chrome electrode 123 is electrically connected to the pixel electrode 13,
The MIM diode 12 can address the liquid crystal cell 31 corresponding to the pixel electrode 13 and write information in the liquid crystal cell 31. The tantalum electrode 121 is shown in FIG.
As shown in (B), it is formed as a part of the scanning line 11. The counter electrode 22 formed on the glass substrate 20 faces the pixel electrode 13, and light passes through these portions. However, since the chromium electrode 123, the tantalum electrode 121, and the like have a light-shielding property, light does not pass through this portion. Therefore, when the ratio of the area occupied by the light permeable portion in the pixel 110 is referred to as the aperture ratio,
It can be said that the higher the aperture ratio, the brighter the display can be.

As shown in FIG. 2C, the MIM diode 12 is a non-linear element, and the voltage (driving voltage) applied between the chrome electrode 123 and the tantalum electrode 121 corresponds to the threshold value. When the voltage is exceeded, the on-current changes greatly. MIM using the current-voltage characteristics
The diode 12 is turned on and off, and the predetermined liquid crystal cell 31
Address and store the charge there.

In order to form the MIM diodes 12 having such a structure in a matrix on the glass substrate 10, a large transparent glass substrate 100 is used as shown in FIG. FIG.
9 shows that nine glass substrates 10 are taken from the large glass substrate 100. That is, after the MIM diode 12 or the like is formed on the large glass substrate 100, another large glass substrate on which a counter electrode or the like is formed is attached to the large glass substrate 100, and then along the alternate long and short dash line. When the two large glass substrates are cut, the liquid crystal display device 1 can be formed using each of the cut glass substrates 10.

In order to manufacture the liquid crystal display device 1 by such a method, first, the thickness of the large substrate 100 is reduced to 1
After forming a tantalum thin film having a thickness of about 500 Å, the tantalum thin film is patterned by a photolithography technique, and the tantalum electrode 121 and the scanning line 11 are left. The tantalum thin film also remains as the power feeding section 120 along the upper side of the large glass substrate 100, and the power feeding section 120 is in a state of being electrically connected to each scanning line 11.

Next, the large glass substrate 100 is connected to the power feeding portion 12
It is immersed in an anodic oxidation bath containing phosphoric acid etc., leaving 0, and anodization is performed in this oxidation bath. As a result, tantalum electrode 1
A tantalum oxide film 122 having a thickness of about 500 Å is formed on the surface of 21. A tantalum oxide film is also formed on the scanning line 11.

Subsequently, the tantalum oxide film 122 is set to 3
Annealing is performed under a temperature condition of 00 ° C to 400 ° C.

Next, the IT on the surface of the large glass substrate 100.
After forming the O film, as shown in FIG. 4, patterning is performed by the photolithography technique to leave the pixel electrodes 13 made of the ITO film in a matrix.

Next, after forming a chromium film having a thickness of about 800 angstroms on the surface of the large glass substrate 100, patterning is performed by photolithography technique to form a chromium electrode 123.

Next, another large glass substrate on which a color filter or the like has already been formed is bonded to the large glass substrate 100, the liquid crystal 30 is sealed therein, and then the substrates are divided into each. In the meantime, well-known processes such as spraying a gap agent and rubbing treatment are also performed.

As a result, the panel for the liquid crystal display device shown in FIG. 5 is formed. That is, the two glass substrates 10,
A gap agent 41 made of beads made of plastics is interposed between the two 20, and the gap agent 41 is crushed by the two glass substrates 10 and 20 and is between the two glass substrates 10 and 20. The cell gap T10 is defined so as to be uniform in the in-plane direction. Such a state is held by the cured sealing material 50.

Between the glass substrates 10 and 20 thus bonded together, the liquid crystal 30 is aligned with a predetermined twist angle and pretilt angle by an alignment film or rubbing treatment, as shown in FIG. 6A. Liquid crystal of a liquid crystal type, and in the normally white-white mode, the liquid crystal molecules 32 are formed in a state where no electric field is applied to the liquid crystal cell 22.
Is twisted and oriented, so white is displayed. On the other hand, as shown in FIG. 6B, when an electric field is applied to the liquid crystal cell 22, the twisted alignment of the liquid crystal molecules 32 is released, so that black display is performed. Regarding such a phenomenon, FIG.
As described with reference to (A) and (B), when the liquid crystal molecules 23 are obliquely aligned when white is displayed in the normally white mode and black is displayed in the normally white mode. It can be considered that the liquid crystal molecules 23 are standing. However, the oblique light may undergo birefringence due to the liquid crystal 30 to change the polarization state, which may cause a brightness difference in the in-plane direction as described with reference to FIG.

For example, in the rubbing process of the manufacturing process of the liquid crystal display device 1, as shown in FIG. 7A, the lower glass substrate 10 is, as shown by the arrow A,
When the rubbing process is performed from the lower left to the upper right, and the glass substrate 20 on the color filter side is subjected to the rubbing from the upper left to the lower right as shown by an arrow B, FIG. As shown in B), all liquid crystal molecules are aligned in the same state. Therefore, the glass substrates 10, 2
From the position corresponding to the approximate center position of 0, the glass substrates 10, 2,
When you see 0, when grayed out, the glass substrate 1
The orientation of the liquid crystal with respect to the line of sight is different in the vertical direction of 0 and 20 (directions at 12:00 and 6:00 in the timepiece). That is,
The angle between the line of sight L1 on the normal line to the glass substrates 10 and 20 and the liquid crystal molecules 32 is θ1, and the glass substrates 10 and 20 are
The angle formed by the line of sight L2 and the liquid crystal molecule 32 when viewed from above (12 o'clock direction) is θ2, and the line of sight L3 and the liquid crystal molecule 3 when viewed from below the glass substrates 10 and 20 (6 o'clock direction).
When the angle formed with 2 is θ3, θ3 <θ1 <θ2
Becomes Therefore, in the normally white mode, the upper side (the 12 o'clock side) in the in-plane direction of the glass substrates 10 and 20.
Is bright and the lower side (6 o'clock side) tends to be dark. In this state, the upper side (12 o'clock side) is referred to as the clear vision side 101, and the lower side (6 o'clock side) is referred to as the reverse clear vision side 102, and a luminance difference is likely to occur between them.

Therefore, in the present invention, the balance of the amount of light incident on the liquid crystal 30 is adjusted so as to eliminate the luminance on the clear-vision side 101 and the reverse-vision side 102. That is, according to the present invention, the amount of light incident on the liquid crystal 30 can be adjusted as shown in FIGS.
As indicated by the size of arrow H, the amount of light incident on the liquid crystal 30 is configured to be larger on the reverse photopic side 102 than on the photopic side 101, and the light amount is clearly visible from the reverse photopic side 102. It becomes smaller toward the side 101 continuously. Therefore,
On the bright-sight side 101, which tends to be bright, the brightness is suppressed to a low level by the amount of light incident on the liquid crystal 30, and on the reverse-sight side 102, which tends to be dark, the brightness is increased by the amount of light incident on the liquid crystal 30. Has been corrected to. Therefore,
In the liquid crystal display device 1 of the present example, when a driving voltage is set only in accordance with the line of sight L1 on the normal line and an intermediate color (gray) is displayed, the liquid crystal 30 causes birefringence with respect to oblique light and the polarization state Even if the change occurs, on the clear side 101 (upper side / the 12 o'clock side of the clock) of the glass substrates 10 and 20, an intermediate color (gray) having substantially the same brightness as the central portion is displayed, and the reverse of the glass substrates 10 and 20. Also on the clear side 102 (lower side / clock side at 6 o'clock), an intermediate color (gray) having substantially the same brightness as the central portion is displayed. In this way, since the brightness difference in the in-plane direction is compressed, it is possible to widen the viewing angle of the liquid crystal display device 1.

The present invention is applicable not only to the transmissive liquid crystal display device but also to a reflective liquid crystal display device. In addition, the problem that the brightness difference is likely to occur in the in-plane direction occurs in the normally black mode, but in either method, the clear-view side 101 and the reverse clear-view side 102 are in the direction of eliminating the brightness difference. Adjust the light balance.

[Embodiment 1] FIG. 8A is a sectional view schematically showing the structure of a liquid crystal display device according to Embodiment 1 of the present invention.
FIG. 8B is a plan view schematically showing a light-transmitting pattern of the light amount adjusting plate added to the backlight unit of this liquid crystal display device.

As shown in FIG. 8A, in the liquid crystal display device 1 of this example, the two glass substrates 10 and 20 are held in a predetermined cell gap T10 by the gap agent 41 made of plastic beads. Moreover, this state is fixed by the cured sealing material 50. A liquid crystal 30 is provided between the glass substrates 10 and 20 thus arranged.
Are enclosed, and a liquid crystal cell 31 is formed for each pixel 110.

An edge light type backlight unit 70 is formed below the glass substrate 10. In this backlight unit 70, a fluorescent lamp 71 is provided at a position corresponding to the lower side of the glass substrate 10 (the 6 o'clock side of the clock).
And a light guide plate 72 for guiding the light from the fluorescent lamp 71 toward the glass substrate 10,
A diffusion plate 73 for the light guide plate 72 is configured. Further, on the inner surface of the diffusion plate 73, a light amount adjusting plate 75 having a light shielding portion 751 and a light transmitting portion 752 configured in a predetermined pattern is attached.

As the light quantity adjusting plate 75, there can be used, for example, a transparent substrate on which a chrome layer in which a transparent portion 752 is opened in a predetermined pattern is formed and which material is used. Also, in this example, as shown in FIG. 8B, in the up-down direction of the light amount adjustment plate 75, the reverse vision side 102
On the lower side of the substrate (at the 6 o'clock side of the clock), the translucent portion 752 is formed at a higher density than at the upper side of the substrate at the clear viewing side 101 (at the 12 o'clock side of the clock). Therefore, the amount of light emitted from the backlight unit 70 to the glass substrate 10 is large on the lower side of the substrate which is the reverse vision side 102, and is small on the upper side of the substrate which is the clear vision side 101. Changes continuously. Therefore, the amount of light incident on the liquid crystal 30 continuously changes such that the amount of light is large on the lower side of the substrate which is the reverse vision side 102 and is small on the upper side of the substrate that is the clear vision side 101.

In the liquid crystal display device 1 thus constructed,
The oblique light may be birefringent by the liquid crystal 30 to change the polarization state, which may cause a brightness difference in the in-plane direction as described with reference to FIG. That is,
In the rubbing step, as shown in FIG. 9A, the lower glass substrate 10 is subjected to a rubbing process from a diagonally lower left to a diagonally upper right as shown by an arrow A, and the glass substrate on the color filter side is subjected. With respect to 20, when the rubbing process is performed from the diagonally upper left to the diagonally lower right as indicated by the arrow B, all the liquid crystal molecules are aligned in the same state as shown in FIG. 9B. Therefore, the glass substrates 10, 2
From the position corresponding to the approximate center position of 0, the glass substrates 10, 2,
When viewing 0, the angle formed by the line of sight L1 on the normal to the glass substrates 10 and 20 and the liquid crystal molecules 32 is θ1, and the line of sight L2 and liquid crystal molecules 32 when looking at the upper side of the glass substrates 10 and 20 (direction at 12 o'clock). The angle of view is L2 and the line of sight L when the lower side of the glass substrates 10 and 20 (6 o'clock direction) is viewed
When the angle between 3 and the liquid crystal molecule 32 is θ3,
3 <θ1 <θ2. Therefore, in the normally white mode, the upper side (12 o'clock side / clear vision side 101) of the in-plane directions of the glass substrates 10 and 20 is bright, and the lower side (6 o'clock side / reverse vision side 102) is dark. Trying to become.

Even so, in this example, the light emitted from the backlight unit 70 to the glass substrate 10 is reversed as shown by the size of the arrow H in FIGS. 8 (A) and 9 (B). Since the light amount is large on the lower side of the substrate to be the clear viewing side 102 and is small on the upper side of the substrate to be the clear viewing side 101, on the clear viewing side 101 which tends to be bright, the light amount incident on the liquid crystal 30 is small. The brightness is suppressed to a low level, and on the reverse bright-vision side 102, which tends to be dark, the brightness is corrected to increase as the amount of light incident on the liquid crystal 30 increases. Therefore, in the liquid crystal display device 1 of this example, even if the liquid crystal 30 undergoes birefringence with respect to oblique light when the intermediate color (gray) is displayed, and the polarization state changes, the glass substrates 10, 2
On the clear-view side 101 of 0, an intermediate color (gray) having substantially the same brightness as the central part is displayed, and on the reverse clear-view side 102 of the glass substrates 10 and 20, the intermediate color (gray) having substantially the same brightness as the central part is displayed. . In this way, since the brightness difference in the in-plane direction is compressed, it is possible to widen the viewing angle of the liquid crystal display device 1.

Further, in this example, since the light quantity adjusting plate 75 adjusts the light quantity balance between the clear-view side 101 and the reverse clear-view side 102, the backlight unit provided in the conventional liquid crystal display device can be used. There is an advantage that it is possible to easily eliminate the brightness difference between the clear vision side 101 and the reverse clear vision side 102 by only adding the light amount adjusting plate 75.

The light quantity adjusting plate 75 is arranged at any position on the optical path from the fluorescent lamp 71 (light source) to the liquid crystal 30 as long as the difference in brightness between the clear viewing side 101 and the reverse clear viewing side 102 can be eliminated. You may.

[Embodiment 2] FIG. 10A is a sectional view schematically showing the structure of the liquid crystal display device according to Embodiment 1 of the present invention, and FIG. 10B shows each pixel of this liquid crystal display device. 3 is a plan view showing the structure of FIG.

As shown in FIG. 10A, even in the liquid crystal display device 1 of this example, in the liquid crystal display device 1 of this example, the two glass substrates 10 and 20 are formed by the gap agent 41 made of plastic beads. Is held in a predetermined cell gap T10, and this state is fixed by a cured sealing material 50. The liquid crystal 30 is sealed between the glass substrates 10 and 20 arranged in this manner, and each pixel 11
A liquid crystal cell 31 is formed for each 0.

An edge-light type backlight unit 70 is formed for the glass substrate 10. In the present example, the backlight unit 70 is used for the glass substrate 10.
Is illuminated with a uniform amount of white light.

In this example, as shown in FIG. 10B, the pixels 110 formed in a matrix on the glass substrate 10 are arranged.
In, the area of the chrome electrode 123 corresponding to the upper layer side electrode of the MIM diode 12 is set so as to continuously change along the scanning line 11, and the aperture ratio of each pixel 110 depends on its size. The lower side that is the side 102 (the 6 o'clock side of the clock) is higher than the upper side that is the clear viewing side 101 (the 12 o'clock side of the clock). Therefore, even if the light emitted from the backlight unit 70 to the glass substrate 10 is uniform in the in-plane direction of the substrate, the amount of light that passes through the glass substrate 10 and enters the liquid crystal 30 is as shown in FIG. ), As indicated by the size of the arrow H, the light amount is large on the lower side of the substrate which is the reverse vision side 102 and is small continuously on the upper side of the substrate which is the clear vision side 101. There is.

Even in the liquid crystal display device 1 having the above structure,
The oblique light may be birefringent by the liquid crystal 30 to change the polarization state, which may cause a brightness difference in the in-plane direction as described with reference to FIG. That is,
In the rubbing step, as shown in FIG. 11 (A), the lower glass substrate 10 is
When the rubbing process is performed from the lower left to the upper right, and the glass substrate 20 on the color filter side is subjected to the rubbing from the upper left to the lower right as shown by an arrow B, FIG. As shown in B), all liquid crystal molecules are aligned in the same state. Therefore, the glass substrate 1
From the position corresponding to the approximate center position of 0 and 20, the glass substrate 1
When viewing 0 and 20, the angle between the line of sight L1 on the normal to the glass substrate 10 and 20 and the liquid crystal molecule 32 is θ1,
The angle formed by the line of sight L2 and the liquid crystal molecule 32 when viewing the upper side (12 o'clock direction) of the glass substrates 10 and 20 is θ2, and the line of sight L3 when viewing the lower side (6 o'clock direction) of the glass substrates 10 and 20. When the angle between the liquid crystal molecule 32 and the liquid crystal molecule 32 is θ3, θ3 <θ1 <θ2. Therefore, in the normally white mode, of the in-plane directions of the glass substrates 10 and 20, the upper side (12 o'clock side / clear vision side 101) is bright and the lower side (6 o'clock side / reverse vision side 102) is. Trying to get dark.

Nevertheless, in this example, the light that has passed through the glass substrate 10 and is incident on the liquid crystal 30 is counter-illuminated as shown by the size of the arrow H in FIGS. 10 (A) and 11 (B). The light amount is large below the substrate which is the viewing side 102,
Since the amount of light is small on the upper side of the substrate that is 1, the brightness is suppressed to be low on the bright-vision side 101 that tends to be bright, and the brightness is corrected to be high on the reverse-vision side 102 that tends to be dark. Therefore, in the liquid crystal display device 1 of the present example, when the intermediate color (gray) is displayed, the liquid crystal 3 does not respond to the oblique light.
Even if 0 causes birefringence and the polarization state is changed, an intermediate color (gray) having substantially the same lightness as the central portion is displayed on the visible side 101 of the glass substrates 10 and 20.
On the reverse clear vision side 102 of 0, an intermediate color (gray) having substantially the same brightness as the central portion is displayed. In this way, since the brightness difference in the in-plane direction is compressed, it is possible to widen the viewing angle of the liquid crystal display device 1.

Further, in this example, it is only necessary to adjust the aperture ratio of each pixel 110 on the glass substrate 10 so that the clear side 101
It is possible to eliminate the difference in luminance between the reverse-clear vision side 102 and the advantage that there is no need to add a new member.

In adjusting the aperture ratio of each pixel 110, the scanning line 11 is not limited to the area of the chrome electrode 123, and the scanning line 11 may be thin on the reverse clear vision side 102 and thick on the clear vision side 101. The design dimensions of the part may be changed.

[Other Embodiments] The behavior of the liquid crystal 30 is shown to be different from that shown in the specification of the present application depending on various conditions, such as the case where a counterclockwise liquid crystal is used as the liquid crystal 30 and the like. However, in any case, the present invention adjusts the light quantity balance in the in-plane direction of the substrate so as to eliminate the brightness difference between the clear-vision side 101 and the reverse-vision side 102. is there.

Of course, the present invention can be applied to the case where another diode element of the MIM diode 12 is used as an active element. Further, when a TFT is used as an active element, both the scanning line 11 and the signal line (data line) are formed on the glass substrate 10. However, even though the clear-view side 101 and the reverse clear-view side 10
The present invention can be applied in which the balance of the amount of light in the in-plane direction of the substrate is adjusted so as to eliminate the difference in luminance from the value of 2.

[0051]

As described above, in the liquid crystal display device according to the present invention, the amount of light incident on the liquid crystal layer is optimized in the in-plane direction of the substrate so as to eliminate the brightness difference in the in-plane direction. It has a feature in becoming. Therefore, according to the present invention, even if the liquid crystal undergoes birefringence with respect to oblique light and the polarization state is changed, the amount of light incident on the liquid crystal cell is set to be large on the reverse clear vision side. Therefore, the brightness difference between the clear vision side and the reverse vision side is eliminated. Therefore, a wide viewing angle of the liquid crystal display device can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a diode type liquid crystal display device.

2 is an explanatory diagram of an MIM diode used as an active element in the liquid crystal display device shown in FIG.

FIG. 3 is an explanatory diagram showing a step of forming an MIM diode on an insulating substrate.

FIG. 4 is an explanatory diagram showing a step that follows the step shown in FIG.

FIG. 5 is a cross-sectional view that schematically shows a state in which the glass substrates are stacked in the liquid crystal display device to which the present invention is applied.

6A and 6B are explanatory diagrams schematically showing the behavior of liquid crystals enclosed between the substrates in the liquid crystal display device shown in FIG.

7A is an explanatory view showing a direction of a rubbing process performed in a manufacturing process of the liquid crystal display device shown in FIG. 1, FIG.
FIG. 3 is an explanatory diagram schematically showing the relationship between the line of sight and liquid crystal molecules when displaying an intermediate color and the balance of the amount of light incident on the liquid crystal in the liquid crystal display device to which the present invention is applied.

FIG. 8A is an explanatory view schematically showing the balance of the amount of light incident on the liquid crystal in the liquid crystal display device according to the first embodiment of the present invention, and FIG. 8B is provided in the backlight unit thereof. It is a top view which shows the translucent pattern of a light quantity adjustment plate typically.

9A is an explanatory view showing the direction of a rubbing process performed in the manufacturing process of the liquid crystal display device shown in FIG.
FIG. 4 is an explanatory diagram schematically showing the relationship between the line of sight and liquid crystal molecules when displaying an intermediate color and the balance of the amount of light incident on the liquid crystal in this liquid crystal display device.

FIG. 10A is an explanatory diagram schematically showing a balance of the amount of light incident on the liquid crystal in the liquid crystal display device according to the second embodiment of the present invention, and FIG. 10B is an aperture ratio for each pixel. It is a top view which shows the difference of typically.

11A is an explanatory diagram showing the direction of a rubbing process performed in the manufacturing process of the liquid crystal display device shown in FIG.
FIG. 3B is an explanatory diagram schematically showing the relationship between the line of sight and liquid crystal molecules when displaying an intermediate color and the balance of the amount of light incident on the liquid crystal in this liquid crystal display device.

FIG. 12 is an explanatory view conceptually showing a state of incident light in a conventional liquid crystal display device.

FIG. 13 is an explanatory diagram conceptually showing the behavior of liquid crystal molecules in a liquid crystal display device.

FIG. 14A is an explanatory view showing the direction of a rubbing process performed in the manufacturing process of the conventional liquid crystal display device, and FIG.
FIG. 4 is an explanatory view schematically showing the relationship between the line of sight and liquid crystal molecules when displaying an intermediate color in a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device 10 ... Glass substrate (first insulating substrate) 11 ... Scan line 12 ... MIM diode (diode element) 13 ... Pixel electrode 20 ... Glass substrate (first Insulating substrate 2) 22 ... Counter electrode 30 ... Liquid crystal 31 ... Liquid crystal cell 32 ... Liquid crystal molecule 70 ... Backlight unit 71 ... Fluorescent lamp 72 ... Light guide plate 73 ... -Diffusion plate 75 ... Light amount adjusting plate 101 ... Clear vision side 102 ... Reverse clear vision side 110 ... Pixel 751 ... Light transmitting part of light amount adjusting plate 752 ... Light amount adjusting plate's light shielding Department

Claims (3)

[Claims] 1. A first insulating substrate in which pixel electrodes and active elements are formed in a matrix, and a first insulating substrate are arranged to face each other so as to form a predetermined cell gap between the first insulating substrate and the first insulating substrate. A second counter electrode is formed.
A liquid crystal cell of each pixel, which is enclosed between the second insulating substrate and the first insulating substrate and is addressed by the active element between the pixel electrode and the counter electrode. In the liquid crystal display device having a liquid crystal layer, the amount of light incident on the liquid crystal layer is set so as to be larger on the reverse clear vision side than on the clear vision side in the in-plane direction of the substrate. Liquid crystal display device. 2. The light amount adjusting plate according to claim 1, further comprising: a light amount adjusting plate for varying the amount of light emitted from a backlight toward the first insulating substrate in an in-plane direction of the substrate, and the light amount adjusting plate allows A liquid crystal display device, characterized in that the amount of light incident on the liquid crystal layer is larger on the side of reverse vision than on the side of clear vision. 3. The light amount incident on the liquid crystal layer according to claim 1, wherein the aperture ratio of each pixel is higher on the reverse clear vision side than on the clear vision side. A liquid crystal display device characterized in that it is larger on the reverse photopic side.