WO2016035212A1 - Liquid crystal display device and method for manufacturing liquid crystal display device - Google Patents

Abstract

Provided are: a liquid crystal display device which is able to be produced at low cost and is able to be increased in size, while having good productivity; and a method for manufacturing this liquid crystal display device. A display panel 52 of a display module 51 of this liquid crystal display device is provided with: an active matrix substrate 1; a CF substrate 2; a liquid crystal layer 3 that is interposed between the substrates; and polarizers 4, 7. A 1/2λ retardation film 10 is arranged outside the active matrix substrate 1, and the polarizer 4 is arranged outside the 1/2λ retardation film 10, while being covered with protective films 5, 6. An optical compensation plate 8 is arranged outside the CF substrate 2, and the polarizer 7 is arranged outside the optical compensation plate 8, while being covered with a protective film 9. The absorption axes of the polarizers 4, 7 are generally parallel to each other. The slow axis of the 1/2λ retardation film 10 is at an angle of 45° ± 5° or 135° ± 5° to the absorption axes.

Description

Liquid crystal display device and method of manufacturing liquid crystal display device

The present invention relates to a liquid crystal display device provided in a television receiver, a personal computer, and the like, and a method for manufacturing the liquid crystal display device.

Among display devices, a liquid crystal display device is thin and has low power consumption.
FIG. 8 is a schematic cross-sectional view showing a display module 58 of a conventional liquid crystal display device.
The display panel 59 of the display module 58 includes an active matrix substrate (TFT substrate) 1, a CF (color filter) substrate 2, a liquid crystal layer 3, and two polarizers 15 and 17. The active matrix substrate 1 and the CF substrate 2 are bonded to each other with a sealing material interposed therebetween, and a liquid crystal layer 3 is formed by injecting a vertical alignment type liquid crystal material therebetween. The two polarizers 15 and 17 are disposed on the side of the active matrix substrate 1 and the CF substrate 2 opposite to the liquid crystal layer 3 side.

The polarizers 15 and 17 are made of, for example, a PVA (polyvinyl alcohol) film. Both surfaces of the polarizer 15 are covered with a protective film 5 made of, for example, a TAC (triacetyl cellulose) film, and a protective film made of, for example, a TAC film or the like or the optical compensator 6. A polarizing plate 18 is configured by the polarizer 15, the protective film 5, and the protective film or the optical compensation plate 6.

A protective film or an optical compensation plate 8 made of, for example, a TAC film or the like is interposed between the polarizer 17 and the CF substrate 2, and the opposite side of the surface of the polarizer 17 on which the protective film or the optical compensation plate 8 is disposed. The surface is covered with a protective film 9 made of, for example, a TAC film. The polarizer 17, the protective film or optical compensation plate 8, and the protective film 9 constitute a polarizing plate 19.
A backlight unit 53 is disposed on the back side of the display panel 59.

FIG. 9 is a schematic plan view showing the relationship between the absorption axis of the polarizer 17 and the absorption axis of the polarizer 15 when viewed from the polarizer 17 side.
The polarizer 17 is arranged such that the absorption axis forms an angle of 0 ° with respect to the horizontal direction, and the polarizer 15 is arranged so that the absorption axis forms an angle of 90 ° with respect to the horizontal direction. In other words, the front and back polarizers of the liquid crystal display device are arranged so that the absorption axes thereof are 90 °. With this configuration, it is possible to obtain effects such as less light leakage in black display and an increased contrast ratio.

As described above, the polarizer 15 made of PVA or the like and the polarizer 17 are covered with the protective film 5 made of TAC film or the like, the protective film or optical compensation plate 6, the protective film or optical compensation plate 8, or the protective film 9. However, a polarizer is usually bonded to a protective film by roll-to-roll to form a polarizing plate material, and the polarizing plate is cut out from the polarizing plate material and disposed on the active matrix substrate 1 or the CF substrate 2. There are many.
Here, as described above, in the liquid crystal display device in which the absorption axis angles of the polarizer 17 on the front side and the polarizer 15 on the back side are each 90 °, the longitudinal dimension of the polarizing plate 18 is determined by the roll width of the polarizing plate material. There is a problem that it cannot be made longer.

FIG. 10A and FIG. 10B are explanatory diagrams when a polarizing plate is cut out from the polarizing plate material.
As shown in FIG. 10A, the polarizing plate material is wound in a state where the longitudinal direction coincides with the axial direction of the absorption axis.
As shown in FIG. 10B, there is a restriction due to the roll width, and the polarizing plate 19 is cut out with the horizontal width direction aligned with the longitudinal direction of the polarizing plate material, so the vertical dimension of the polarizing plate 19 (the length in the direction perpendicular to the absorption axis). ) Cannot be greater than the roll width. And since the polarizing plate 18 cuts out the horizontal width direction so that it may correspond to the transversal direction of a polarizing plate material, it is possible to make the horizontal dimension (length in the direction perpendicular to the absorption axis) of the polarizing plate 18 greater than the roll width. Can not.

In a normal polarizing plate production line, the roll width is 1330 mm, 1490 mm, 1960 mm, 2250 mm.
Accordingly, in the case of a liquid crystal display device having an aspect ratio of 16: 9, when the roll width is 1960 mm, only 85 inch size (approximately 1900 mm × 1075 mm) can be taken, and when the roll width is 2250 mm, 98 inch size ( Only about 2190 mm x 1240 mm) can be taken. The width of the polarizing plate production line is 2300 mm with an ultra-wide line, and a polarizing plate with a width of 2300 mm or more cannot be produced. If the aspect ratio is 16: 9, a polarizing plate with a size of 100 inches or more is required. It cannot be produced.
Although it is conceivable that the polarizer is stretched in a direction perpendicular to the flow direction of the roll, it is not preferable in production because the productivity is low and the cost becomes high.

Incidentally, liquid crystal display devices used in mobile devices such as mobile phones and PDAs (personal digital assistants) are required to have high brightness, high definition, and low power consumption. A transflective display type liquid crystal display device has been developed that performs display by switching between or in combination with the reflective display mode. In a transflective liquid crystal display device using this transflective display system, a circularly polarizing plate is used. That is, in the liquid crystal display device, a circularly polarizing plate having a multigap structure in the liquid crystal layer and including at least one polarizer and a wave plate (retardation plate) is used. In Patent Document 1, a 1 / 4λ phase plate and a 1 / 2λ phase plate are bonded together, and a circularly polarizing plate having a birefringent body of Nz <0 between the bonded plate and the polarizer, An invention of a liquid crystal display device including the same is disclosed.

JP 2005-326818 A

Also in the above-described invention of Patent Document 1, the front-side polarizing plate and the back-side polarizing plate are arranged so that the respective absorption axis angles are 90 °, and the configuration of the liquid crystal display device of Patent Document 1 is large. Even when applied to a liquid crystal display device, a polarizing plate having a size of 100 inches or more cannot be cut out from the polarizing plate material. Further, when the absorption axis angles of the front-side polarizing plate and the rear-side polarizing plate are 45 ° and 135 ° with respect to the horizontal direction, a polarizing plate having a size of 90 inches or more cannot be cut out.

The present invention has been made in view of such circumstances, a liquid crystal display device that has good productivity, can be manufactured at low cost, and can be increased in size, and a method for manufacturing the liquid crystal display device. The purpose is to provide.

A liquid crystal display device according to the present invention includes a liquid crystal display including two substrates arranged opposite to each other, a liquid crystal layer interposed between the substrates, and two polarizers arranged on the outside of each substrate. In the apparatus, each absorption axis of each polarizer is substantially parallel, and a slow axis is 45 ° ± 5 ° or 135 ° ± 5 ° with respect to the absorption axis between one polarizer and one substrate. It has the 1 / 2lambda phase difference plate which makes the angle of.

In the present invention, linearly polarized light that has passed through one polarizer is rotated by 90 ° by a 1 / 2λ phase difference plate. Thereby, it is possible to obtain the same effect as when a pair of polarizers are arranged so that their respective absorption axes are substantially parallel, and a pair of polarizers are arranged so that their respective absorption axes intersect.
Since the axial directions of the absorption axes of the pair of polarizers are substantially the same direction, when the polarizer is cut out from the polarizer material, or the polarizer material is bonded to a protective film by a roll-to-roll to become a polarizing plate material, When the polarizing plate is cut out from the polarizing plate material, the dimension in the short direction (roll width) of the polarizer material (polarizing plate material) is applied as the maximum dimension in the short direction of the polarizer (polarizing plate). be able to. The dimension in the longitudinal direction of the polarizer (polarizing plate) can be taken in the longitudinal direction of the polarizer material (polarizing plate material) based on the aspect ratio. Therefore, the polarizer (polarizing plate) can be cut out in a state where the size is increased.

The liquid crystal display device according to the present invention is characterized in that an angle formed by each absorption axis of each polarizer is 0 ° or more and 4 ° or less.

In the present invention, there is less light leakage in black display, the contrast ratio can be increased, and the light transmission control accuracy becomes better.

The liquid crystal display device according to the present invention is characterized in that the 1 / 2λ retardation plate is formed by aligning a liquid crystal layer on a film containing triacetyl cellulose.

In the present invention, a phase difference of ½λ can be favorably given to visible light of each wavelength.

The liquid crystal display device according to the present invention is characterized in that the 1 / 2λ retardation plate is formed by stretching a film containing a cycloolefin polymer.

In the present invention, a phase difference of ½λ can be more favorably given to visible light of each wavelength.

The method for manufacturing a liquid crystal display device according to the present invention is a method in which two rectangular substrates are bonded together in a state where liquid crystal is interposed between the substrates, or the substrates are bonded together, and the liquid crystal is filled between the substrates. Then, in a method for manufacturing a liquid crystal display device in which a polarizing plate is arranged on the outside of each substrate, the polarizing plate is cut out so that the longitudinal direction of the polarizing plate material coincides with the longitudinal direction of the polarizing plate material. A 1 / 2λ retardation plate whose slow axis forms an angle of 45 ° ± 5 ° or 135 ° ± 5 ° with respect to the longitudinal direction of the substrate is disposed outside the 1 / 2λ retardation plate. The polarizing plate is arranged so that the longitudinal direction thereof coincides with the longitudinal direction of the substrate, and the other polarizing plate is disposed outside the other substrate so that the longitudinal direction thereof coincides with the longitudinal direction of the substrate. It is characterized by arranging.

In the present invention, linearly polarized light that has passed through one polarizing plate is rotated by 90 ° by a 1 / 2λ phase difference plate. Thereby, a pair of polarizing plates can be arranged so that the respective absorption axes are substantially parallel.
Since the axial direction of the absorption axis of the pair of polarizing plates is substantially the same direction, the dimension in the short direction of the polarizing plate material (roll width) can be applied as the maximum dimension in the short direction of the polarizing plate. . Accordingly, the polarizing plate can be cut out by taking the dimension in the longitudinal direction in the longitudinal direction of the polarizing plate material based on the aspect ratio, and the size of the polarizing plate can be increased.

According to the present invention, between the polarizer and one substrate, a 1 / 2λ phase difference plate whose slow axis forms an angle of 45 ° ± 5 ° or 135 ° ± 5 ° with respect to the absorption axis of the polarizer. Therefore, linearly polarized light that has passed through one polarizer is rotated by 90 ° by the 1 / 2λ phase difference plate. As a result, a pair of polarizers are arranged so that their respective absorption axes are substantially parallel to each other so that light leakage in black display can be reduced and the contrast ratio can be increased. The effect when the axes are crossed can be obtained.

Since the axial directions of the absorption axes of the pair of polarizers can be made substantially the same direction, when the polarizer is cut out from the polarizer material, or the polarizer material is bonded to the protective film by a roll-to-roll and the polarizing plate material When the polarizing plate is cut out from the polarizing plate material, the dimension in the short direction of the polarizer (polarizing plate) is the maximum dimension in the short direction of the polarizer material (polarizing plate material) (roll width). Can be applied. The dimension in the longitudinal direction of the polarizer (polarizing plate) can be taken in the longitudinal direction of the polarizer material (polarizing plate material) based on the aspect ratio. Therefore, the polarizer (polarizing plate) can be cut out in a state where the size is increased.

And as above-mentioned, productivity is favorable and can manufacture a liquid crystal display device cheaply compared with the case where the method of extending | stretching a polarizer in the direction perpendicular | vertical to the flow direction of a roll is employ | adopted. .

1 is an external perspective view of a liquid crystal display device according to Embodiment 1 of the present invention. It is typical sectional drawing which shows the display module of a liquid crystal display device. It is a typical top view which shows the relationship between each absorption axis of each polarizer at the time of seeing from the front side, and the slow axis of a 1/2 (lambda) phase difference plate. It is a typical top view which shows the relationship between the absorption axis of the back side polarizer at the time of seeing from the front side, and the slow axis of a 1/2 (lambda) phase difference plate. It is a typical top view which shows the relationship of the absorption axis of a pair of polarizer at the time of seeing from the front side. It is explanatory drawing in the case of cutting out a polarizing plate from polarizing plate material. It is explanatory drawing in the case of cutting out a polarizing plate from polarizing plate material. It is typical sectional drawing which shows the display module of the liquid crystal display device which concerns on Embodiment 2 of this invention. 6 is a graph showing the results of examining wavelength dispersion characteristics for a 1 / 2λ phase difference plate of a display panel of Example 1. 6 is a graph showing the results of examining wavelength dispersion characteristics for a ½λ phase difference plate of a display panel of Example 2. It is typical sectional drawing which shows the display module of the conventional liquid crystal display device. It is a typical top view which shows the relationship of each absorption axis of each polarizer at the time of seeing from the front side. It is explanatory drawing in the case of cutting out a polarizing plate from polarizing plate material. It is explanatory drawing in the case of cutting out a polarizing plate from polarizing plate material.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
Embodiment 1 FIG.
1 is an external perspective view of a liquid crystal display device 50 according to Embodiment 1 of the present invention, and FIG. 2 is a schematic cross-sectional view showing a display module 51 of the liquid crystal display device 50.
The liquid crystal display device 50 includes a display module 51 having a display panel 52 and a backlight unit 53, a synthetic resin front cabinet 54 and rear cabinet 57 that are accommodated so as to sandwich the display module 51, and a stand 60. The display module 51 has a horizontally long and substantially rectangular parallelepiped shape as a whole, and is housed in the front cabinet 54 and the rear cabinet 57 in a vertical posture.

The display panel 52 is a display panel in MVA mode (Multi-domain Vertical Alignment). A mode in which a vertical alignment type material is used as the liquid crystal material is called a VA (Vertical Alignment) mode. The VA mode in which the alignment is regulated by providing a slit 11a in a pixel electrode 11 to be described later and a plurality of liquid crystal domains are formed in one pixel is called an MVA mode.

The display panel 52 includes an active matrix substrate 1, a CF substrate 2, a liquid crystal layer 3, and two polarizers 4 and 7. The active matrix substrate 1 and the CF substrate 2 are bonded to each other with a sealing material interposed therebetween, and a liquid crystal layer 3 is formed by injecting a vertical alignment type liquid crystal material therebetween. As a method for forming the liquid crystal layer 3, a dropping bonding method is adopted in which a liquid crystal material is dropped into a frame of a seal pattern of one substrate before being overlapped, and then the other substrate is overlapped and bonded under reduced pressure. You may decide.

The active matrix substrate 1 includes, for example, a glass insulating substrate (hereinafter, not shown), a TFT (thin film transistor), a plurality of gate wirings (scanning wirings) that apply scanning signals to the TFTs, and a plurality of video signals that apply video signals to the TFTs. Source wiring (signal wiring), and a pixel electrode 11 made of, for example, ITO is formed on the surface. The pixel electrode 11 is provided with a slit 11a by patterning.

The CF substrate 2 is formed by arranging, for example, a black matrix (BM) and color filters such as R (red), G (green), and B (blue) on an insulating substrate made of glass (hereinafter, not shown). Thus, the common electrode 21 made of, for example, ITO or the like is formed on the surface.

The two polarizers 4 and 7 are arranged on the side opposite to the liquid crystal layer 3 side of each of the active matrix substrate 1 and the CF substrate 2.
The polarizers 4 and 7 are made of, for example, a PVA film. Both surfaces of the polarizer 4 are covered with a protective film 5 made of, for example, a TAC film and a protective film 6 made of, for example, an acrylic film having a low birefringence. A polarizing plate 12 is constituted by the polarizer 4 and the protective films 5 and 6.

Between the polarizer 7 and the CF substrate 2, an optical compensation plate 8 made of COP having an in-plane retardation of 63 nm and a thickness direction retardation of 225 nm is interposed, and the optical compensation plate 8 of the polarizer 7 is disposed. The surface opposite to the surface on which it is present is covered with a protective film 9 made of, for example, a TAC film. The polarizer 7, the optical compensation plate 8, and the protective film 9 constitute a polarizing plate 13.
The surface of the display panel 52 is subjected to an antiglare surface treatment having a haze value of about 1.

The backlight unit 53 is disposed on the back side of the display panel 52. The backlight unit 53 may be either an edge light method (side light method, light guide plate method) or a direct type. In the case of the edge light system, the backlight unit 53 includes a light source such as an optical sheet, a light guide plate, and an LED substrate in a chassis.

In the present embodiment, a ½λ phase difference plate 10 is interposed between the protective film 6 of the display panel 52 and the active matrix substrate 1.
The 1 / 2λ phase difference plate 10 is obtained by aligning a liquid crystal layer on a TAC film. The 1 / 2λ phase difference plate 10 is obtained, for example, by forming a liquid crystal alignment film on the surface of the TAC film and curing a polymerizable liquid crystal on the surface of the liquid crystal alignment film to form a liquid crystal layer.

The absorption axis of the polarizer 4 and the absorption axis of the polarizer 7 are substantially parallel. The angle formed by the absorption axis of the polarizer 4 and the absorption axis of the polarizer 7 is preferably 0 ° or more and 4 ° or less.
The slow axis of the ½λ phase difference plate 10 forms an angle of 45 ° ± 5 ° with respect to the absorption axis of the polarizer 4.

FIG. 3A is a schematic plan view showing the relationship between the absorption axes of the polarizers 4 and 7 and the slow axis of the ½λ phase difference plate 10 when viewed from the polarizer 7 side.
In the present embodiment, the absorption axis of the polarizer 4 forms an angle of 0 ° ± 2 ° with respect to the horizontal direction, and the absorption axis of the polarizer 7 forms an angle of 0 ° ± 2 ° with respect to the horizontal direction. . The slow axis of the 1 / 2λ phase difference plate 10 forms an angle of 45 ° ± 5 ° with respect to the horizontal direction.

The light emitted from the backlight unit 53 and transmitted through the polarizer 4 having the absorption axis shown in FIG. 3B becomes linearly polarized light polarized in a direction perpendicular to the absorption axis. The axis perpendicular to the absorption axis is the transmission axis or the polarization axis. The linearly polarized light has a slow axis that forms an angle of 45 ° ± 5 ° with the absorption axis of the polarizer 4, that is, the slow axis forms an angle of 45 ° ± 5 ° with the polarization axis. When it passes through the phase difference plate 10, it is rotated by 90 °. Therefore, the light transmitted through the ½λ phase difference plate 10 becomes linearly polarized light in the 0 ° direction with respect to the horizontal direction. The linearly polarized light in the horizontal direction corresponds to the polarized light when the absorption axis of the polarizer is in the vertical direction.

Therefore, as shown in FIG. 3C, the absorption axes of the two polarizers 4 and 7 are parallel, but when the axis direction of the absorption axis of the polarizer 4 is vertical, that is, the two polarizers are absorbed. The same effect can be obtained as when the axes are arranged so as to intersect.

Hereinafter, a method for manufacturing the display panel 52 of the liquid crystal display device 50 will be described.
The mother glass substrate of the active matrix substrate 1 and the mother glass substrate of the CF substrate 2 are bonded together with a sealing material interposed therebetween, and a liquid crystal material is injected between them to form a liquid crystal layer 3, which is cut out for each substrate. Alternatively, a liquid crystal material is dropped into the frame of the seal pattern of the mother glass substrate of one substrate, and then the mother glass of the other substrate is overlaid and attached under reduced pressure, and is cut out for each substrate.

The polarizing plate 13 is obtained by laminating the polarizer 7 with the protective film 9 by roll-to-roll to form a polarizing plate material, and cutting out from the polarizing plate material.
The polarizing plate 12 is obtained by bonding the polarizer 4 in a state of being sandwiched between the protective films 5 and 6 by roll-to-roll to form a polarizing plate material, and cutting out from the polarizing plate material. Alternatively, the acrylic film is bonded to a roll-to-roll on the polarizing plate material of the polarizing plate 13 to obtain the polarizing plate material of the polarizing plate 12.

4A and 4B are explanatory diagrams in the case of cutting out a polarizing plate from a polarizing plate material. In FIG. 4B, the polarizer 4 and the polarizer 7 are shown among the polarizing plates.
As shown in FIG. 4A, the polarizing plate material is wound in a state where the longitudinal direction coincides with the axial direction of the absorption axis.
As shown in FIG. 4B, the polarizing plates 13 and 12 including the polarizers 7 and 4 are cut out in a state where the horizontal width direction coincides with the longitudinal direction of the polarizing plate material.

As described above, since the polarizing plate material is produced by roll-to-roll, it is subject to restrictions based on the roll width. When the absorption axis angles of the polarizer 4 and the polarizer 7 are the same direction, the length of the polarizer in the short side direction (the length in the direction perpendicular to the absorption axis) is restricted by the roll width. In other words, the dimension in the short direction of the polarizing plate material (roll width) can be applied as the dimension in the short direction of the polarizer. The longitudinal dimension of the polarizer can be taken in the longitudinal direction of the polarizing plate material based on the aspect ratio of the display panel 52.

In a normal polarizing plate production line, the roll width is 1330 mm, 1490 mm, 1960 mm, 2250 mm.
When the aspect ratio of the display panel 52 is 16: 9, when the roll width is 1490 mm, the size is 114 inches (approximately 2545 mm × 1440 mm), and when the roll width is 1960 mm, the size is 150 inches (approximately 3340 mm × 1910 mm). ) Can be cut out. Therefore, it becomes possible to produce a very large size polarizing plate.

A 1 / 2λ phase difference plate 10 is disposed outside the active matrix substrate 1, and the polarizing plate 12 cut out as described above is disposed outside the 1 / 2λ phase difference plate 10.
An optical compensation plate 8 is disposed outside the CF substrate 2, and a polarizing plate 13 is disposed outside the optical compensation plate 8. Thereby, the display panel 52 is obtained.

In the present embodiment, as described above, the productivity is good and the liquid crystal display device is manufactured at a low cost compared with the case where the method of stretching the polarizer in the direction perpendicular to the flow direction of the roll is adopted. can do.

Note that the ½λ phase difference plate 10 may be disposed on either the lower side or the upper side of the liquid crystal layer 3.
3A and 3B show a case where the slow axis of the 1 / 2λ phase difference plate 10 forms an angle of 45 ° ± 5 ° with respect to the absorption axis of the polarizer 4, but 135 ° ± You may make it make an angle of 5 degrees.
An optical compensation plate may be interposed between the active matrix substrate 1 and the ½λ phase difference plate 10.

Embodiment 2. FIG.
In the display module 55 of the liquid crystal display device according to the second embodiment of the present invention, the material of the 1 / 2λ phase difference plate 14 provided in the display panel 56 is the 1 / 2λ phase difference of the display panel 52 according to the first embodiment. The display module 51 has the same configuration except that it is different from the material of the plate 10.

FIG. 5 is a schematic cross-sectional view showing the display module 55 of the liquid crystal display device according to the second embodiment. In the figure, the same parts as those in FIG.
The display panel 56 of the display module 55 includes an active matrix substrate 1, a CF substrate 2, a liquid crystal layer 3, and two polarizers 4 and 7. A liquid crystal layer 3 is interposed between the active matrix substrate 1 and the CF substrate 2.
A pixel electrode 11 is formed on the surface of the active matrix substrate 1, and a common electrode 21 is formed on the surface of the CF substrate 2.

The two polarizers 4 and 7 are arranged on the side opposite to the liquid crystal layer 3 side of each of the active matrix substrate 1 and the CF substrate 2.
The polarizers 4 and 7 are made of, for example, a PVA film. The polarizer 4 is covered with a protective film 5 made of, for example, a TAC film and a protective film 6 made of, for example, an acrylic film having a low birefringence.

Between the polarizer 7 and the CF substrate 2, an optical compensation plate 8 made of COP having an in-plane retardation of 63 nm and a thickness direction retardation of 225 nm is interposed, and the optical compensation plate 8 of the polarizer 7 is disposed. The surface opposite to the surface on which it is present is covered with a protective film 9 made of, for example, a TAC film.

In the present embodiment, a ½λ phase difference plate 14 is interposed between the protective film 6 and the active matrix substrate 1.
The 1 / 2λ phase difference plate 14 is formed by causing an optical anisotropy film made of cycloolefin polymer (COP) to have optical anisotropy by stretching.

The absorption axis of the polarizer 4 forms an angle of 0 ° ± 2 ° with respect to the horizontal direction, the absorption axis of the polarizer 7 forms an angle of 0 ° ± 2 ° with respect to the horizontal direction, and the 1 / 2λ phase difference plate 14 The slow axis forms an angle of 45 ° ± 5 ° with respect to the horizontal direction.

The light emitted from the backlight unit 53 and transmitted through the polarizer 4 becomes linearly polarized light polarized in a direction perpendicular to the absorption axis. When linearly polarized light passes through the ½λ phase difference plate 14, it is rotated by 90 °. Therefore, the light transmitted through the ½λ phase difference plate 14 becomes linearly polarized light in the 0 ° direction with respect to the horizontal direction.
Therefore, the same effect can be obtained as when the axis direction of the absorption axis of the polarizer 4 is the vertical direction, that is, when two polarizers are arranged so that the absorption axes cross each other.

In the present embodiment, since the axial directions of the absorption axes of the polarizers 4 and 7 are substantially the same direction, the dimension in the short direction of the polarizing plate material (roll) is the maximum dimension in the short direction of the polarizer. Width) can be applied. The longitudinal dimension can be taken in the longitudinal direction of the polarizing plate material based on the aspect ratio of the display panel 56, and the size of the polarizers 4 and 7 can be increased.

Hereinafter, examples of the present invention will be described in detail, but the present invention is not limited to these examples.

[Example 1]
A display panel 52 of Example 1 having the above-described 1 / 2λ retardation plate 10 was produced.

[Example 2]
A display panel 56 of Example 2 having the above-described 1 / 2λ retardation plate 14 was produced.

[Chromatic dispersion characteristics]
FIG. 6 shows the results of examining the wavelength dispersion characteristics of the 1 / 2λ phase difference plate 10 of the display panel 52 of Example 1, and the wavelength dispersion characteristics of the 1 / 2λ phase difference plate 14 of the display panel 56 of Example 2 were examined. The results are shown in FIG.
6 and 7, it can be seen that both the 1 / 2λ phase difference plates 10 and 14 can satisfactorily give a phase difference of approximately 1 / 2λ to visible light of each wavelength. In particular, in the case of the 1 / 2λ phase difference plate 14 in which optical anisotropy film made of COP causes optical anisotropy by stretching, a phase difference closer to 1 / 2λ is given for each wavelength. You can see that

By using a liquid crystal display device of the present invention that can give a phase difference of 1 / 2λ for each wavelength of visible light as described above, it transmits the polarizer 4, The linearly polarized light polarized in the direction perpendicular to the absorption axis is reliably rotated by 90 °, and the same effect as in the case where the two polarizers are arranged so that the absorption axes cross each other can be obtained with certainty.

In addition, this invention is not limited to the content of Embodiment 1 and 2 mentioned above, A various change is possible in the range shown to the claim. In other words, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.
For example, the liquid crystal display device is not limited to the VA mode, but may be an IPS (In-Plane Switching) mode, a TN (Twisted Nematic) mode, or the like.

DESCRIPTION OF SYMBOLS 1 Active matrix substrate 11 Pixel electrode 2 CF board | substrate 21 Common electrode 3 Liquid crystal layer 4, 7 Polarizer 5, 6, 9 Protective film 8 Optical compensator 10, 14, 1/2 (lambda) phase difference plate 12, 13 Polarizing plate 50 Liquid crystal display device 51, 55 Display module 52, 56 Display panel 53 Backlight unit

Claims (5)

In a liquid crystal display device comprising two substrates arranged opposite to each other, a liquid crystal layer interposed between the substrates, and two polarizers arranged on the outside of each substrate,
Each absorption axis of each polarizer is substantially parallel,
A 1 / 2λ phase difference plate having a slow axis of 45 ° ± 5 ° or 135 ° ± 5 ° with respect to the absorption axis is provided between one polarizer and one substrate. Liquid crystal display device. The liquid crystal display device according to claim 1, wherein an angle formed by each absorption axis of each polarizer is 0 ° or more and 4 ° or less. 3. The liquid crystal display device according to claim 1, wherein the ½λ phase difference plate is formed by aligning a liquid crystal layer on a film containing triacetyl cellulose. 3. The liquid crystal display device according to claim 1, wherein the 1 / 2λ retardation plate is formed by stretching a film containing a cycloolefin polymer. After bonding two rectangular substrates in a state where liquid crystal is interposed between the substrates, or after bonding the substrates and filling the liquid crystal between the substrates, a polarizing plate is placed on the outside of each substrate. In the manufacturing method of the liquid crystal display device to be arranged,
Cut out the polarizing plate so that the longitudinal direction of the polarizing plate material matches the longitudinal direction,
A 1 / 2λ phase difference plate whose slow axis forms an angle of 45 ° ± 5 ° or 135 ° ± 5 ° with respect to the longitudinal direction of the substrate is disposed outside one substrate,
On the outside of the 1 / 2λ retardation plate, the polarizing plate is arranged so that its longitudinal direction coincides with the longitudinal direction of the substrate,
A method of manufacturing a liquid crystal display device, comprising: arranging another polarizing plate on the outside of the other substrate so that the longitudinal direction thereof coincides with the longitudinal direction of the substrate.

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