Information
-
Patent Grant
-
6621551
-
Patent Number
6,621,551
-
Date Filed
Wednesday, June 27, 200123 years ago
-
Date Issued
Tuesday, September 16, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 349 187
- 349 123
- 349 124
- 349 117
- 349 121
-
International Classifications
-
Abstract
A liquid crystal display panel is placed on a fixed base and an anisotropic film is set in a position relative to the orientation layer of the display panel. Linearly polarized light is directed to the panel and the anisotropic film and light passing through them are detected. According to the intensity of the detected light, the angle of orientation of the anisotropic film is adjusted relative to the orientation layer. Angular misalignment, which may exist between the anisotropic film and the orientation layer, is minimized.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to liquid crystal display and more specifically to a method and a system for fabricating LCD panels by with a reduced angular misalignment between the anisotropic axes of laminated layers.
2. Description of the Related Art
Liquid crystal displays, such as twisted nematic type, usually comprise a liquid crystal layer and a pair of orientation (alignment) layers, one on each side of the liquid crystal layer, to cause their molecules to twist along its thickness and orient in mutually orthogonal directions on its opposite surface when no voltage is applied. On the outer side of each orientation layer is a polarization film so arranged that its polarization (anisotropic) is aligned with that of the orientation layer. When one of the polarization films is illuminated with natural light, only that portion of the incident light linearly aligned with the polarizaton axis of the film is allowed to enter the liquid crystal layer. Under zero electrical field, the linearly polarized light is subjected to a full 90-degree twist as it traverses the liquid crystal layer and allowed to pass through other polarization film, producing a maximum level of brightness (white luminance representation). When a full voltage is applied across the liquid crystal layer, the molecules are transposed in the direction of thickness, causing the polarized light aligned with one polarization film to be twisted out of alignment with the other polarization film, producing a maximum level of darkness (black luminance representation). In the IPS (in plane switching) type of liquid crystal displays, the axes of the orientation layers are equally aligned so that ON/OFF switching modes are in reverse to those of the twisted nematic types.
One of the important characteristics used to evaluate the quality of an LCD panel is the black-to-white contrast ratio, i.e., the ratio of the white luminance to the black luminance. Angular misalignment between the polarization film and the orientation layer, which may occur when they are pasted together, represents a potential cause of low contrast ratios. Experiments indicate that the angular misalignment of as small as 4 degrees causes the contrast ratio of LCD panels to decrease from the maximum value of 400 to as low as 150.
Mechanical methods are currently employed to align polarization films with the orientation layers of liquid crystal panels. However, due to manufacturing tolerances, precision alignment cannot consistently be obtained. As a result, variability exists in contrast ratio, which ranges significantly between 400 and 200 for misalignments of plus/minus 2 to 3 degrees.
To overcome this problem, Japanese Patent Publication 11-271778 discloses a method in which a polarization film is initially pasted on one surface of a liquid crystal layer where a light sensitive layer is applied and ultraviolet light of 350 nanometers is then used to illuminate the liquid crystal layer through the polarization film. The molecules in the illuminated light sensitive layer are excited and their axis is oriented in the same direction as the polarization film.
However, suitable materials for use with such orientation layers are not available at present.
In addition, optical compensation films are currently used in LCD panels. The films of this type is a birefringence characteristic that compensates for the loss of light transmissivity of the panel when viewed at a skewed angle. Since this optical compensation film has an anisotropic axis, it must be aligned with the axis of a polarization film when they are pasted together.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method and system for fabricating a liquid crystal display that eliminates angular misalignment between optically anisotropic films and orientation layers.
According to a first aspect, the present invention provides a method of fabricating a liquid crystal display, comprising the steps of setting a liquid crystal display panel on a fixed base, the panel including a liquid crystal layer and an orientation layer on one surface of the liquid crystal layer, setting an anisotropic film relative to the orientation layer, directing linearly polarized light to the panel and the anisotropic film and detecting light therefrom, and adjusting angle of orientation of the anisotropic film relative to the orientation layer according to intensity of the detected light.
According to a second aspect, the present invention provides a method of fabricating a liquid crystal display, comprising the steps of setting a liquid crystal display panel on a fixed base, the panel including a liquid crystal layer and an orientation layer on one surface of the liquid crystal layer, setting an optical compensation film and a polarizer relative to the orientation layer, directing linearly polarized light to the panel, the optical compensation film and the polarizer at a skewed angle and detecting light therefrom, the linearly polarized light having a polarization axis aligned with polarization axis of the polarizer, and adjusting angle of orientation of the optical compensation film relative to the orientation layer according to intensity of the detected light.
According to a third aspect, the present invention provides a system for fabricating a liquid crystal display, comprising base means for setting a liquid crystal display panel, the panel including a liquid crystal layer and an orientation layer on one surface of the liquid crystal layer, carrier means for setting an anisotropic film relative to the orientation layer, a light source for directing linearly polarized light to the panel and the anisotropic film, and an optical sensor for detecting the directed light from the anisotropic film. The carrier means is rotatable so that angle of orientation of the anisotropic film can be adjusted relative to the orientation layer according to intensity of the detected light.
According to a fourth aspect, the present invention provides a system for fabricating a liquid crystal display, comprising base means for setting a liquid crystal display panel, the panel including a liquid crystal layer and an orientation layer on one surface of the liquid crystal layer, carrier means for setting an optical compensation film and a polarizer relative to the orientation layer, a light source for directing linearly polarized light to the panel, the optical compensation film and the polarizer at a skewed angle, and an optical sensor for detecting the directed light from the polarizer. The linearly polarized light has a polarization axis aligned with polarization axis of the polarizer. The carrier means is rotatable so that angle of orientation of the optical compensation film can be adjusted relative to the orientation layer according to intensity of the detected light.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in detail further with reference to the following drawings, in which:
FIG. 1
is a schematic diagram of a manufacturing system of the present invention for fabricating liquid crystal displays;
FIG. 2
is a side view of an optical system of a first embodiment of the present invention shown mounted on a suction plate with respect to a suction base on which an LCD panel is secured in place;
FIG. 3A
is an enlarged perspective view of a portion of an LCD panel and the polarizer of the first embodiment through which polarized light is directed for detecting misalignment between a first polarization film and the first orientation layer of the LCD panel;
FIG. 3B
is an enlarged perspective view of a portion of an LCD panel and the polarizer of the first embodiment through which polarized light is directed for detecting misalignment between a second polarization film and the second orientation layer of the LCD panel;
FIG. 4
is a side view of a suction plate when pasting a polarization film on an LCD panel;
FIG. 5
is a side view of a suction plate on which an optical system of a second embodiment is mounted for sensing polarized light directed through an LCD panel and a polarization film;
FIG. 6A
is an enlarged perspective view of a portion of an LCD panel and a first polarization film of the second embodiment through which polarized light is directed;
FIG. 6B
is an enlarged perspective view of a portion of the LCD panel and a second polarization film of the second embodiment through which polarized light is directed;
FIG. 7
is a side view of a suction plate on which an optical system of a third embodiment of the present invention is mounted for sensing polarized light directed through an LCD panel and a polarization film;
FIG. 8
is a side view of a suction plate on which an optical system of a fourth embodiment of the present invention is mounted for sensing polarized light directed at a skewed angle through an LCD panel and an optical compensation film;
FIG. 9A
is an enlarged perspective view of a portion of an LCD panel and a first optical compensation film of the fourth embodiment;
FIG. 9B
is an enlarged perspective view of a portion of the LCD panel and a first polarization film of the fourth embodiment;
FIG. 9C
is an enlarged perspective view of a portion of the LCD panel and a second optical compensation film of the fourth embodiment; and
FIG. 9D
is an enlarged perspective view of a portion of the LCD panel and a second polarization film of the fourth embodiment.
DETAILED DESCRIPTION
In
FIG. 1
, there is shown a system for pasting a polarization film on each surface of an LCD (liquid crystal display) panel according to the present invention. The system is comprised of first, second, third and fourth work stations
61
to
64
.
At the first work station
61
, a holder (suction) base
21
is provided for setting a polarization film
4
in a predetermined fixed position using three vertically movable edge guides
70
and holding it in position with a flow of sucking air that is drawn to the outside through a plurality of holes provided on the surface of the base
21
. Guides
70
are lowered below the surface of the base
21
when the film
4
is properly held in position. Polarization film
4
is coated with a layer of transparent adhesive
41
covered with a separable sheet
42
. When the polarization film
4
is held on the surface of the base
21
, the separable sheet
42
is facing downwards.
Further, at the first work station, a film carrier
65
is provided above the suction base
21
. Carrier
65
includes a suction plate
22
which is supported by a movable arm
80
connected to a drive system, not shown, so that the plate
22
is vertically movable between high and low positions and horizontally slidable between the first and second stations
61
and
62
.
When the carrier
65
is in the lower position, the suction air that is holding the film
4
on the base
21
is stopped and the suction plate
22
starts sucking air upwards so that the film
4
is removed from the base
21
and attached to the bottom of the plate
22
. Carrier
65
is then raised to the higher position and is started moving towards the second work station
62
. Before reaching the second station, the carrier
65
encounters a sheet remover
66
where the separable sheet
42
of the polarization film is brought into contact with a roll
24
of adhesive tape which is rotating about its horizontal axis. While rotating about its axis, the roll
24
slides from one edge of the polarization film
4
to the other in a direction normal to the direction of its rotation. As a result, an adhesive layer is applied to the lower side of separable sheet
42
. At the end of the travel, the roll
24
stops and then moves backwards while rotating about its axis so that the separable sheet
42
is peeled off the polarization film
4
, exposing the sticking layer
41
to the outside.
Then, the carrier
65
moves to the second work station
62
. At the second work station, an LCD panel
10
is set on a suction base
25
using three vertically movable edge guides
71
and held under negative pressured caused by air downwardly sucked through a plurality of holes provided on the surface of the base
25
. Guides
71
are lowered below the surface of the base
25
when the LCD panel
10
is held in position.
As illustrated, the LCD panel
10
is comprised of a pair of glass substrates
11
and
12
, a color filter
13
below the substrate
11
, a common electrode
14
and a pixel electrode
15
. A liquid crystal layer
1
, which is sandwiched between orientation (or alignment) layers
2
and
3
, is disposed between the electrodes
14
and
15
. Each of these orientation layers has a polarization axis orthogonal to the polarization axis of the other.
In order to provide precision alignment of polarization axes between the polarization film
4
and the orientation layer
2
which is positioned on the upper side of the liquid crystal layer
1
, polarized light is directed from a polarized light source
26
mounted on the suction base
25
through the LCD panel
10
to an optical system
23
on the suction plate
22
.
Referring briefly to
FIGS. 2
to
4
, the optical system
23
according to a first embodiment of the present invention is illustrated.
In
FIG. 2
, the optical system
23
is shown comprising a polarizer
90
secured to one side of the suction plate
22
and an optical sensor
91
located above the polarizer
90
. Suction plate
22
horizontally and vertically moves with respect to the suction base
25
when the arm
80
is driven by the drive mechanism, not shown, so that the polarizer
90
is positioned above the LCD panel
10
. Polarization film
4
, whose polarization axis must be aligned with that of orientation layer
2
, is attached to the bottom of the suction plate
22
so that its axis is orthogonal to that of polarizer
90
. To allow adjustment for axial alignment, the suction plate is made to swivel on the vertical axis
81
of the arm
80
when the polarizer
90
is positioned above the LCD panel
10
. Polarized light source
26
includes a natural light source
84
and a polarizer
85
for forming the natural light into linearly polarized light whose polarization axis is aligned with the polarization axis of one of the orientation layers which is positioned on the lower side of the LCD panel
10
. Details of the optical alignment system of the first embodiment are shown in FIG.
3
A.
When the polarization film
4
is in the process of axial alignment, the orientation layer
3
is on the lower side of liquid crystal layer
1
and is irradiated from below with the linearly polarized light. With the electrodes
14
and
15
being turned off, the liquid crystal layer
1
is free of electrostatic charges. Under the influence of orientation layers
2
and
3
, liquid crystal molecules LC in the layer
1
are twisted and align at the opposite surfaces of the layer
1
with the orthogonal axes (
3
) and (
2
) of the orientation layers
3
and
2
. The polarized light from source
26
, having the same polarization axis (
3
) of the orientation layer
3
, is incident on the liquid crystal layer
1
. The incident light undergoes a 90-degree rotation of its axis as it travels across the liquid crystal layer
1
and emanates from the orientation layer
2
with an axis oriented in the same axis (
2
) of orientation layer
2
. The light from the LCD panel
10
is passed trough the polarizer
90
and impinges on the optical sensor
91
. The amount of light incident on the optical sensor
91
is monitored and adjusted by turning the plate
22
on the vertical axis
81
. Since the polarizer
90
has its axis oriented in a direction orthogonal to that of polarization film
4
, a minimum amount of rays will be incident on the optical sensor
91
when the axis of polarization film
4
is aligned with the axis of orientation layer
2
. The orthogonal orientation permits observers to perform black luminance measurement, rather than white luminance measurement. Since axial alignment occurs when the observed light is at a minimum level, the black luminance measurement allows a higher degree of precision than the white luminance measurement. If white luminance measurement is preferred for some reasons, the polarization film
4
has its axis aligned with that of the polarizer
90
.
When the optical alignment process is complete, a pasting process is provided for pasting the polarization film
4
to the LCD panel
10
. For this purpose, a roller
83
is attached to the opposite side of the plate
22
and the latter is mounted on a horizontal axle
82
of the arm
80
so that the surface of polarization film
4
can be tilted with respect to the surface of the LCD panel
10
and one edge of the former is in contact with a corresponding edge of the latter, as shown in FIG.
4
. In this position, the roller
83
is brought into pressure contact with the polarization film
4
. Suction plate
22
is then moved to slide over the suction base
25
. As the suction plate
22
is moved, the polarization film
4
is slidably moved downwards against the air-sucking holes (not shown) provided on the bottom of plate
22
and pressed into contact with to the LCD panel
10
. Since the lower surface of polarization film
4
is applied with an adhesive layer, the contact portion of the film
4
is cemented to the LCD panel
10
.
Returning to
FIG. 1
, the LCD panel
10
with the polarization film
4
being cemented is mounted on a reversing suction plate
27
which is hinged at one end on a horizontal pivot axle. The pivot axle of the reversing suction plate
27
is driven by a motor, not shown, whereby the LCD panel is turned upside down and set on a suction base
32
of the fourth work station
64
. Polarization film
4
is now positioned on the lower side of LCD panel
10
. LCD panel
10
is held in position using three vertically movable edge guides
73
and the air suction system, not shown.
In a manner similar to that described above, a polarization film
5
is positioned on a suction base
2
at the third work station
63
using movable upright guides
72
which are then lowered below the surface of the suction base
28
when the film
5
is properly held in position. Polarization film
5
is coated with a transparent adhesive layer
51
covered with a separable sheet
52
. When the polarization film
5
is held on the surface of the base
28
, the separable sheet
52
is facing downwards.
At the third work station
63
, a film carrier
68
is provided above the suction base
28
. Carrier
68
includes a suction plate
29
which is supported by a movable arm
86
connected to a drive system, not shown, so that the suction plate
29
is vertically movable between high and low positions and horizontally slidable between the third and fourth stations
63
and
64
. When the carrier
68
is in the lower position, the suction air that is holding the film
5
on the base
28
is stopped and the suction plate
29
starts sucking air upwards so that the film
5
is removed from the base
28
and attached to the bottom of the plate
29
. Polarization film
5
, whose polarization axis must be aligned with that of orientation layer
3
, is secured to the suction plate
29
with its axis oriented in a direction orthogonal to that of the polarizer
90
of optical system
30
.
Carrier
68
is then raised to the higher position and is started moving towards the fourth station
64
. Before reaching the fourth station, the carrier
68
encounters a sheet remover
69
where the separable sheet
52
of the polarization film is brought into contact with a pressure roller
31
of adhesive tape which is rotating about its horizontal axis. While rotating about its axis, the pressure roller
31
slides from one edge of the polarization film
5
to the other in a direction normal to the direction of its rotation. As a result, an adhesive layer is applied to the lower side of separable sheet
52
. At the end of the travel, the pressure roller
31
stops and then moves backwards while rotating about its axis so that the separable sheet
52
is peeled off the polarization film
5
, exposing the sticking layer
51
to the outside.
Then the carrier
68
moves to a position above the suction base
32
of the fourth station
64
. An optical system
30
, identical to the optical system
23
, is mounted on the suction plate
29
to begin an optical alignment process to align the axis of polarization film
5
with that of orientation layer
3
which is now positioned on the upper side of liquid crystal layer
1
. A light source
33
is mounted on the suction base
32
to direct natural light to the polarization film
4
which is now positioned on the lower side of liquid crystal layer
1
. As shown in detail in
FIG. 3B
, the natural light is converted to polarized light as it passes through the polarization film
4
. This polarized light is aligned with the polarization axis (
4
) of the film
4
as it impinges on the orientation layer
2
.
When the polarization film
5
is subjected to the optical alignment process, the orientation layer
2
is on the lower side of liquid crystal layer
1
and is irradiated from below with the light polarized by polarization film
4
cemented to the lower side of LCD panel
10
. The polarized light from the polarization film
4
, having the same polarization axis (
2
) of the orientation layer
2
, is incident on the liquid crystal layer
1
and undergoes a 90-degree rotation of its axis as it travels across the liquid crystal layer
1
and emanates from the orientation layer
3
with an axis aligned with the same axis (
3
) of orientation layer
3
.
The light from the orientation layer
3
is passed through the polarizer
90
of the optical system
30
and impinges on the optical sensor
91
. The amount of light incident on the optical sensor
91
is monitored and adjusted by turning the suction plate
29
on the vertical axis
81
in the same manner as described in connection with the polarization film
4
. Since the polarizer 90 of the optical system
30
is orthogonal to the polarization film
5
, a minimum amount of rays is incident on the optical sensor
91
when the axis of polarization film
5
is aligned with the axis of orientation layer
3
.
Optical system
30
may also include the optional polarizer
92
located above the first polarizer
90
to provide black luminance measurement, rather than white luminance measurement. A pasting process follows to paste the polarization film
5
to the LCD panel
10
in a manner identical to that described with reference to FIG.
4
.
In the first embodiment, the polarization films
4
and
5
are orthogonal to the polarizer
90
of the optical systems
23
and
30
. Since polarizer
90
is mounted on a machine and hence its polarization axis is fixed and precisely determined, misalignment between the polarization film
4
(or
5
) and the polarizer
90
is smaller than misalignment which usually occurs between polarization films and orientation layers. However, the misalignment between the polarization film
4
(or
5
) and the polarizer
90
can be eliminated by passing polarized light through the polarization films
4
and
5
.
As illustrated in
FIG. 5
, the optical system
23
(
30
) includes an optical sensor
93
which is mounted on the suction plate
22
(
29
) above the polarization film
4
(
5
) and the light from source
26
(
33
) is passed through the film
4
to th optical sensor
93
. Misalignment between the polarization film
4
(or
5
) and the orientation layer
2
(or
3
) is eliminated when a maximum light level is obtained at the optical sensor
93
by swiveling the suction plate
22
(or
29
) as seen from
FIG. 6A
(FIG.
6
B). Preferably, a polarizer
94
, whose axis is orthogonal to that of the polarization films
4
and
5
, may be provided below the optical sensor
93
to provide black luminance measurement.
The amount of variation that occurs in the output voltage of optical sensor
93
as the suction plate is turned on its vertical axis can be increased to advantage for precision measurement. This is achieved by a modification of the arrangement of
FIG. 5
as shown in FIG.
7
. In this modification, the optical sensor
93
is arranged to receive polarized light whose optical path traverses the LCD panel
10
and the polarization film
4
or
5
at a skewed angle relative to their surfaces.
In order too enlarge the viewing angle of an LCD panel, a film known as optical compensation film is sandwiched between a polarization film and a orientation layer on each side of a liquid crystal layer. The optical compensation film is an anisotropic liquid crystal layer of predetermined thickness in which molecules are arranged in a hybrid orientation. The use of optical compensation films prevents leakage of light from excited (turned-on) pixels which is seen at a skewed viewing angle. In contrast with twisted nematic LCD panels whose anisotropy is positive (i.e., molecules are elongated in z-axis direction), the optical compensation film has a negative anisotropic characteristics (i.e., molecules are elongated on the x-y plane). Combined use of a twisted nematic LCD panel and an optical compensation film results in a display having an isotropic refractive characteristic, enabling it to be seen at equal optical levels in a wide range of viewing angles.
However, angular misalignment can occur between the polarization film and the optical compensation film. While the angular misalignment between the polarization film and the orientation layer can be eliminated as described above, the misalignment between the anisotropic axis of the optical compensation film and the axis of the orientation layer cannot be minimized by the use of the previous embodiments.
The embodiment shown in
FIG. 8
overcomes this shortcoming. The optical system
23
of this embodiment is basically similar in configuration to that shown in FIG.
7
. However, the optical system
23
of this embodiment has a polarizer
101
whose axis is aligned with that of the polarizer
85
of light source
26
. Optical compensation films are pasted to the LCD panel using the system of
FIG. 1
prior to the pasting of polarization films. In
FIG. 8
, an optical compensation film
6
is shown as a pasting step prior to the pasting of a polarization film
4
.
FIG. 8
shows that the optical compensation film
6
was secured to the bottom of the suction plate
22
at the first work station
61
and then carried to the second work station
62
, where an LCD panel
10
has been held in place. At the second work station, the optical compensation film
6
is irradiated at a skewed angle with polarized light that has been subjected to a 90-degree rotation as it traversed through the LCD panel
10
.
Details of the optical arrangement for axial alignment of optical compensation film
6
at the second work station are shown in FIG.
9
A. The light incident on the optical compensation film
6
is one that is linearly polarized as it exits the orientation layer
2
. As the light traverses the optical compensation film
6
at a skewed angle, it undergoes a change from linear polarization to elliptical polarization. Since the elliptically polarized light contains a linear component in the direction of axis (
3
) of orientation layer
3
. This linear component, which would otherwise be seen as leakage light when viewed at an angle, is selected by the polarizer
101
and detected by an optical sensor
100
. Misalignment, which may exist between the anisotropic axis (
6
) of optical compensation film
6
and the polarization axis (
2
) of orientation layer
2
, is minimized by turning the suction plate
22
when the black luminance measurement of optical sensor
100
produces a minimum value. When this occurs, the viewing angle of the LCD panel
10
expands in the direction of polarization axis (
3
).
Optical compensation film
6
is then pasted on the LCD panel
10
in the same way as the polarization film
4
was pasted by using the arrangement of FIG.
4
.
With the optical compensation film
6
being pasted on the LCD panel
10
as shown in
FIG. 9B
, the axis (
3
) of polarizer
101
is orthogonal to the axis (
4
) of polarization film
4
. Therefore, a minimum value is obtained for black luminance measurement at the output of optical sensor
100
when the polarization film
4
is aligned with the orientation layer
2
. Polarization film
4
is then pasted on the optical compensation film
6
and then turned upside down by the reversing suction plate
27
and placed on the suction base
32
at the fourth work station
64
.
Processes similar to those described with reference to
FIGS. 9A and 9B
are repeated on an optical compensation film
7
and a polarization film
5
.
FIG. 9C
shows that the optical compensation film
7
is first placed on the suction base of third station
63
and carried by the carrier
68
to the fourth station
64
. Polarizer
101
of the optical system
40
is aligned with the axis (
2
) of the orientation layer
2
. Misalignment, which may exist between the anisotropic axis (
7
) of optical compensation film
7
and the polarization axis (
3
) of orientation layer
3
, is minimized by turning the suction plate
29
of the carrier
68
when the black luminance measurement of optical sensor
100
produces a minimum value. When this occurs, the viewing angle of the LCD panel
10
expands in the direction of polarization axis (
2
). Optical compensation film
7
is then pasted on the LCD panel
10
.
With the optical compensation film
7
being pasted on the LCD panel
10
as shown in
FIG. 9D
, the axis (
3
) of polarizer
101
is orthogonal to the axis (
5
) of polarization film
5
. A minimum value is thus obtained for black luminance measurement at the output of optical sensor
100
when the polarization film
5
is aligned with the orientation layer
3
. Polarization film
5
is then pasted on the optical compensation film
7
.
Note that in
FIGS. 9B and 9D
, the polarizer
101
may be dispensed with if white luminance measurement is used for detecting misalignment.
Claims
- 1. A method of fabricating a liquid crystal display, comprising the steps of:a) setting a liquid crystal display panel on a fixed base, said panel including a liquid crystal layer and an orientation layer on one surface of said liquid crystal layer; b) setting a first anisotropic film relative to said orientation layer; c) directing linearly polarized light to said panel and said anisotropic film and detecting light therefrom; and d) adjusting angle of orientation of said anisotropic film relative to said orientation layer according to intensity of the detected light.
- 2. The method of claim 1, wherein the step (b) further comprises setting a second anisotropic film and the first anisotropic film relative to said orientation layer, and wherein said second anisotropic film has a polarization axis aligned with polarization axis of the first anisotropic film.
- 3. The method of claim 2, wherein the polarization axis of said first anisotropic film is orthogonal to polarization axis of said orientation layer.
- 4. The method of claim 1, wherein the step (b) further comprises setting a second anisotropic film parallel to the first anisotropic film, whereby said linearly polarized light passes through the first and second anisotropic films, said second anisotropic film having a polarization axis orthogonal to polarization axis of the first anisotropic film.
- 5. The method of claim 1, further comprising pasting said first anisotropic film on said orientation layer after the step (c) is performed.
- 6. The method of claim 1, wherein the step (c) comprises directing said linearly polarized light in a direction perpendicular to said panel.
- 7. The method of claim 1, wherein the step (c) comprises directing said linearly polarized light at a skewed angle to said panel.
- 8. A method of fabricating a liquid crystal display, comprising the steps of:setting a liquid crystal display panel on a fixed base, said panel including a liquid crystal layer and an orientation layer on one surface of said liquid crystal layer; setting an optical compensation film and a polarizer relative to said orientation layer; directing linearly polarized light to said panel, said optical compensation film and said polarizer at a skewed angle and detecting light therefrom, said linearly polarized light having a polarization axis aligned with polarization axis of said polarizer; and adjusting angle of orientation of said optical compensation film relative to said orientation layer according to intensity of the detected light.
- 9. The method of claim 8, further comprising pasting said optical compensation film on said orientation layer after the adjusting step is performed.
- 10. The method of claim 9, further comprising the steps of:setting a polarization film relative to said orientation layer; directing linearly polarized light to said panel, said optical compensation film, and said polarization film at said skewed angle and detecting light therefrom; and adjusting angle of orientation of said polarization film relative to said orientation layer according to intensity of the detected light.
- 11. The method of claim 10, further comprising pasting said polarization film on said optical compensation film after the adjusting step is performed.
- 12. The method of claim 9, further comprising the steps of:setting a polarization film and said polarizer relative to said orientation layer; directing linearly polarized not to said panel, said optical compensation film, said polarization film and said polarizer at said skewed angle and detecting light therefrom, said linearly polarized light having a polarization axis aligned with polarization axis of said polarizer; and adjusting angle of orientation of said polarization film relative to said orientation layer according to intensity of the detected light.
- 13. The method of claim 12, further comprising pasting said polarization film on said optical compensation film after the adjusting step is performed.
- 14. A system for fabricating a liquid crystal display, comprising:base means for setting a liquid crystal display panel, said panel including a liquid crystal layer and an orientation layer on one surface of said liquid crystal layer; carrier means for setting a first anisotropic film relative to said orientation layer; a light source for directing linearly polarized light to said panel and said anisotropic film; and an optical sensor for detecting the directed light from said anisotropic film, said carrier means being rotatable so that angle of orientation of said anisotropic film can be adjusted relative to said orientation layer according to intensity of the detected light.
- 15. The system of claim 14, wherein said carrier means includes means for setting a second anisotropic film and the first anisotropic film relative to said orientation layer, and wherein said second anisotropic film has a polarization axis aligned with polarization axis of the first anisotropic film.
- 16. The system of claim 15, wherein the polarization axis of said first anisotropic film is orthogonal to polarization axis of said orientation layer.
- 17. The system of claim 14, wherein the carrier means further comprises means for setting a second anisotropic film parallel to the first anisotropic film, whereby said linearly polarized light passes through the first and second anisotropic films, said second anisotropic film having a polarization axis orthogonal to polarization axis of the first anisotropic film.
- 18. The system of claim 14, wherein said carrier means includes means for pasting said anisotropic film on said orientation layer.
- 19. The system of claim 14, wherein the light source is arranged to direct said linearly polarized light in a direction perpendicular to said liquid crystal display panel.
- 20. The system of claim 14, wherein the light source is arranged to direct said linearly polarized light at a skewed angle to said liquid crystal display panel.
- 21. A system for fabricating a liquid crystal display, comprising:base means for setting a liquid crystal display panel, said panel including a liquid crystal layer and an orientation layer on one surface of said liquid crystal layer; carrier means for setting an optical compensation film and a polarizer relative to said orientation layer; a light source for directing linearly polarized light to said panel, said optical compensation film and said polarizer at a skewed angle; an optical sensor for detecting the directed light from said polarizer, said linearly polarized light having a polarization axis aligned with polarization axis of said polarizer; and said carrier means being rotatable so that angle of orientation of said optical compensation film can be adjusted relative to said orientation layer according to intensity of the detected light.
- 22. The system of claim 21, wherein said carrier means includes means for pasting said optical compensation film on said orientation layer.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-199562 |
Jun 2000 |
JP |
|
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Number |
Name |
Date |
Kind |
4239349 |
Scheffer |
Dec 1980 |
A |
5311284 |
Nishino |
May 1994 |
A |
5734472 |
Ito et al. |
Mar 1998 |
A |