WO2012002183A1

WO2012002183A1 - Liquid crystal display device and multilayer optical member

Info

Publication number: WO2012002183A1
Application number: PCT/JP2011/063970
Authority: WO
Inventors: 関口　泰広; 昭佳金光; 浩子中島
Original assignee: 住友化学株式会社
Priority date: 2010-07-01
Filing date: 2011-06-17
Publication date: 2012-01-05
Also published as: TW201227075A; JP2012032751A

Abstract

Disclosed is a liquid crystal display device (1) which comprises: a light-diffusing optical member (3); a light source device (50) that is arranged on the back surface side of the light-diffusing optical member (3); a VA liquid crystal panel (30) that is arranged on the front surface side of the light-diffusing optical member (3); and a reflective polarization splitting film (40) that is arranged between the light-diffusing optical member (3) and the VA liquid crystal panel (30). The light-diffusing optical member (3) comprises a transparent material and light diffusion particles that are dispersed in the transparent material. If the absolute value of the difference between the refractive index of the transparent material and the refractive index of the light diffusion particles is represented by ∆n and the cumulative 50% particle diameter of the light diffusion particles is represented by D₅₀ (μm), the relation 0.01 ≤ ∆n × D₅₀ ≤ 0.25 is satisfied.

Description

Liquid crystal display device and laminated optical member

The present invention relates to a VA liquid crystal display device capable of realizing natural color display without being reddish when viewed from an oblique direction as well as a front direction, and a laminated optical member used therefor.

As a liquid crystal display device, vertical alignment in which liquid crystal molecules sealed between a pair of transparent electrodes are aligned in a substantially vertical direction in a state where no voltage is applied, and is aligned in a substantially horizontal direction in a state where a voltage is applied (Vertical Alignment). A configuration using a liquid crystal cell is known (see Patent Document 1). A liquid crystal display device using this vertical alignment liquid crystal cell (VA type liquid crystal cell) has the advantages of high contrast and high response speed.

JP 2002-365636 A

The conventional VA-type liquid crystal display device has a problem that, when viewed from the front, a natural color display is obtained, but when viewed from an oblique direction, a reddish color is displayed. That is, there is a problem that the image display viewed from an oblique direction is reddish and a high-quality image cannot be obtained.

In general, in a configuration using a light emitting diode as a light source, redness when viewed from an oblique direction tends to be more prominent than when using other types of light sources. Even when a diode is used, it has been demanded that redness when viewed from an oblique direction can be sufficiently suppressed.

The present invention has been made in view of such a technical background, and can realize a natural and high-quality color display without being reddish when viewed from an oblique direction as well as a front direction, and has a high luminance. It is an object to provide a liquid crystal display device to be obtained and a laminated optical member used therefor.

In order to achieve the above object, the present invention provides the following means.

[1] A first light diffusing optical member, a light source device arranged on the back side of the first light diffusing optical member, a liquid crystal panel arranged on the front side of the first light diffusing optical member, A reflective polarization separation film disposed between the first light diffusing optical member and the liquid crystal panel,
The liquid crystal panel has a liquid crystal cell having a pair of transparent electrodes disposed apart from each other and a liquid crystal sealed between the pair of transparent electrodes,
The liquid crystal molecules are aligned in a direction substantially perpendicular to the transparent electrode in a state where no voltage is applied between the pair of transparent electrodes.
The first light diffusing optical member has a transparent material, and light diffusing particles dispersed in the transparent material, and
When the absolute value of the difference between the refractive index of the transparent material and the refractive index of the light diffusing particles is Δn, and the cumulative 50% particle diameter of the light diffusing particles is D ₅₀ (μm), 0.01 ≦ Δn × A liquid crystal display device satisfying D ₅₀ ≦ 0.25.

[2] The liquid crystal display device according to item 1, further comprising a condensing optical member disposed between the first light diffusing optical member and the light source device.

[3] A first light diffusing optical member, a light source device disposed on the back side of the first light diffusing optical member, a liquid crystal panel disposed on the front side of the first light diffusing optical member, A reflective polarization separation film disposed between the first light diffusing optical member and the light source device,
The liquid crystal panel has a liquid crystal cell having a pair of transparent electrodes disposed apart from each other and a liquid crystal sealed between the pair of transparent electrodes,
The liquid crystal molecules are aligned in a direction substantially perpendicular to the transparent electrode in a state where no voltage is applied between the pair of transparent electrodes.
The first light diffusing optical member has a transparent material and light diffusing particles dispersed in the transparent material, and an absolute value of a difference between a refractive index of the transparent material and a refractive index of the light diffusing particles. Is a liquid crystal display device that satisfies 0.01 ≦ Δn × D ₅₀ ≦ 0.25, where Δn is Δn and the cumulative 50% particle diameter of the light diffusing particles is D ₅₀ (μm).

[4] The liquid crystal display device according to item 3, further comprising a condensing optical member disposed between the reflective polarization separation film and the light source device.

[5] Front-side first light diffusing optical member, back-side first light-diffusing optical member, a light source device disposed on the back side of the back-side first light-diffusing optical member, and front-side first light A liquid crystal panel disposed on the front side of the diffusive optical member, a reflective polarization separation film disposed between the front side first light diffusing optical member and the back side first light diffusing optical member, With
The liquid crystal panel has a liquid crystal cell having a pair of transparent electrodes disposed apart from each other and a liquid crystal sealed between the pair of transparent electrodes,
The liquid crystal molecules are aligned in a direction substantially perpendicular to the transparent electrode in a state where no voltage is applied between the pair of transparent electrodes.
Each of the front-side first light-diffusing optical member and the back-side first light-diffusing optical member has a transparent material and light-diffusing particles dispersed in the transparent material, and the refractive index of the transparent material When the absolute value of the difference between the refractive index and the refractive index of the light diffusing particle is Δn, and the cumulative 50% particle diameter of the light diffusing particle is D ₅₀ (μm), 0.01 ≦ Δn × D ₅₀ ≦ 0.25 A liquid crystal display device that satisfies the requirements.

[6] The liquid crystal display device according to item 5, further comprising a condensing optical member disposed between the back side first light diffusing optical member and the light source device.

[7] The liquid crystal display device according to

item

2, 4 or 6, further comprising a second light diffusing optical member disposed between the light condensing optical member and the light source device.

[8] The light collecting optical member emits light emitted from the light collecting optical member when incident light having a half-value half width of 60 ° or more in the incident angle-luminance curve is incident on the light collecting optical member. 8. The liquid crystal display device according to

item

2, 4, 6 or 7, wherein the liquid crystal display device has a light collecting performance in which a half value half width in an emission angle-luminance curve of incident light is 10 ° or more smaller than a half value half width of the incident light.

[9] The light collecting optical member is a prism sheet,
The prism sheet has a half-value half-width in the emission angle-luminance curve of the emitted light emitted from the prism sheet when incident light having a half-width of 60 ° or more in the incident angle-luminance curve is incident on the prism sheet. 8. The liquid crystal display device according to

item

2, 4, 6, or 7, which has a light collecting performance that is 10 ° or more smaller than a half width at half maximum of the incident light.

[10] The light collecting optical member is a light diffusion sheet,
The light diffusing sheet has a half value in the emission angle-luminance curve of the emitted light emitted from the light diffusing sheet when incident light having a half-width of 60 ° or more in the incident angle-luminance curve is incident on the light diffusing sheet. 8. The liquid crystal display device according to the

above item

2, 4, 6 or 7, which has a light collecting performance whose half width is 10 ° or more smaller than the half width of the incident light.

[11] The light-collecting optical member is a light-diffusing optical member having an uneven shape on the surface,
The light diffusing optical member emits outgoing light emitted from the light diffusing optical member when incident light having a half-value half-width of 60 ° or more in the incident angle-luminance curve is incident on the light diffusing optical member. 8. The liquid crystal display device according to the

above item

2, 4, 6, or 7, wherein the liquid crystal display device has a light collecting performance in which a half-value half-width in an angle-luminance curve is 10 ° or more smaller than a half-value half width of the incident light.

[12] The light source device includes the light guide plate disposed on the back side of the first light diffusing optical member, and the light source disposed on the side of at least one side surface of the light guide plate. The liquid crystal display device according to any one of the above.

[13] The liquid crystal display device according to any one of items 1 to 11, wherein the light source device includes a plurality of light sources disposed on a back side of the first light diffusing optical member.

[14] The liquid crystal display device according to

item

12 or 13, wherein the light source is a light emitting diode.

[15] A first light diffusing optical member, and a reflective polarization separation film laminated and integrated on the first light diffusing optical member,
The first light diffusing optical member has a transparent material, and light diffusing particles dispersed in the transparent material,
When the absolute value of the difference between the refractive index of the transparent material and the refractive index of the light diffusing particles is Δn, and the cumulative 50% particle diameter of the light diffusing particles is D ₅₀ (μm), 0.01 ≦ Δn × A laminated optical member satisfying D ₅₀ ≦ 0.25.

In the invention of [1], when the first light diffusing optical member satisfies 0.01 ≦ Δn × D ₅₀ ≦ 0.25, the diffused light transmitted through the first light diffusing optical member in an oblique direction is bluish. As a result, the hue (blue / red) is canceled (compensated) with each other by the phenomenon and the phenomenon that the light is transmitted through the VA type liquid crystal panel in an oblique direction so that the light is reddish. Natural and high-quality color display is realized without being reddish when viewed from an oblique direction as well as the front direction. Furthermore, since the reflective polarization separation film is disposed between the first light diffusing optical member and the liquid crystal panel, the brightness of the screen of the liquid crystal display device can be improved.

In the invention [2], since the condensing optical member is disposed between the first light diffusing optical member and the light source device, the effect of suppressing redness when viewed from an oblique direction can be further enhanced.

In the invention [3], the diffused light transmitted through the first light diffusing optical member in an oblique direction is bluish by satisfying 0.01 ≦ Δn × D ₅₀ ≦ 0.25 in the first light diffusing optical member. As a result, the hue (blue / red) is canceled (compensated) with each other by the phenomenon and the phenomenon that the light is transmitted through the VA type liquid crystal panel in an oblique direction so that the light is reddish. Natural and high-quality color display is realized without being reddish when viewed from an oblique direction as well as the front direction. Furthermore, since the reflective polarization separation film is disposed between the first light diffusing optical member and the light source device, the brightness of the screen of the liquid crystal display device can be improved.

[4] In the invention of [4], since the condensing optical member is disposed between the reflective polarization separation film and the light source device, the effect of suppressing redness when viewed from an oblique direction can be further enhanced.

In the invention of [5], when the first light diffusing optical member satisfies 0.01 ≦ Δn × D ₅₀ ≦ 0.25, the diffused light transmitted through the first light diffusing optical member in an oblique direction is bluish. As a result, the hue (blue / red) is canceled (compensated) with each other by the phenomenon and the phenomenon that the light is transmitted through the VA type liquid crystal panel in an oblique direction so that the light is reddish. Natural and high-quality color display is realized without being reddish when viewed from an oblique direction as well as the front direction. Furthermore, since the reflective polarization separation film is disposed between the pair of front and rear first light diffusing optical members, the brightness of the screen of the liquid crystal display device can be improved.

In the invention of [6], the condensing optical member is disposed between the first light diffusing optical member on the back side of the pair of first light diffusing optical members and the light source device. The effect of suppressing redness when viewed from the direction can be further enhanced.

In the invention of [7], since the second light diffusing optical member is further arranged between the light condensing optical member and the light source device, an image having a more uniform brightness within the surface of the liquid crystal panel can be obtained. Can do.

In the inventions [8] to [11], the condensing optical member is configured such that when the incident light having a half width at half maximum of 60 ° or more in the incident angle-luminance curve is incident on the condensing optical member, Since the half-value half width in the emission angle-luminance curve of the emitted light emitted from the transmissive optical member has a condensing performance that is 10 ° or more smaller than the half-value half width of the incident light, the redness suppressing effect when viewed from an oblique direction Can be further enhanced.

In the inventions [10] and [11], since the condensing optical member has a light diffusing performance as well as a condensing function, the redness suppressing effect when viewed from an oblique direction can be further enhanced. Light can be diffused more.

The invention [12] provides a high-luminance edge-light type liquid crystal display device capable of realizing a natural and high-quality color display without being reddish when viewed from an oblique direction as well as the front direction.

The invention [13] provides a high-brightness direct-type liquid crystal display device capable of realizing a natural and high-quality color display without being reddish when viewed from an oblique direction as well as the front direction.

In the invention of [14], although a light emitting diode is used as a light source, a natural and high-quality color display is realized without being reddish when viewed from an oblique direction as well as a front direction.

In the invention [15] (laminated optical member), the first light diffusing optical member satisfies 0.01 ≦ Δn × D ₅₀ ≦ 0.25 so that the first light diffusing optical member is transmitted in an oblique direction. The hue (blue and red) cancel each other out (compensation) due to the phenomenon in which the light is bluish and the phenomenon in which the light passes through the VA type liquid crystal panel in an oblique direction and the light is reddish. As a result, it is possible to realize a natural and high-quality color display without being reddish when viewed from an oblique direction as well as the front direction. Further, since the reflective polarization separation film is laminated and integrated on the first light diffusing optical member, the liquid crystal display device configured using the laminated optical member has a high luminance screen.

1 is a schematic side view showing an embodiment of a liquid crystal display device according to the present invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a typical side view which shows other embodiment of the liquid crystal display device which concerns on this invention. It is a figure which shows an example of the incident angle-luminance curve and the emission angle-luminance curve about the condensing optical member used by this invention. In FIG. 13, “M” indicates the half width of the incident light, and “N” indicates the half width of the emitted light. The incident angle-luminance curve and the emission angle-luminance curve are shown only on the left and right sides, but both curves are substantially line-symmetric with respect to a vertical line with an angle of 0 °. .

FIG. 1 shows an embodiment of a liquid crystal display device (1) according to the present invention. The liquid crystal display device (1) includes a surface light source device (9) and a liquid crystal panel (30) disposed on the front side of the surface light source device (9). The surface light source device (9) includes a first light diffusing optical member (3) and a light source device (50) disposed on the back side of the first light diffusing optical member (3).

The liquid crystal panel (30) includes a liquid crystal cell (20) in which a liquid crystal (11) is sealed between a pair of upper and lower transparent electrodes (12) and (13) arranged in parallel and spaced apart from each other; And polarizing plates (14) and (15) disposed on both upper and lower sides of the liquid crystal cell (20). These constituent members (11), (12), (13), (14), and (15) constitute an image display unit. An alignment film (not shown) is laminated on the inner surfaces (surfaces on the liquid crystal side) of the transparent electrodes (12) and (13).

The molecules of the liquid crystal (11) are substantially perpendicular to the transparent electrodes (12) and (13) in a state where no voltage is applied between the pair of transparent electrodes (12) and (13). On the other hand, in a state in which a voltage is applied between the pair of transparent electrodes (12) and (13), it is substantially parallel (including parallel) to the transparent electrodes (12) and (13). Align (align in a substantially horizontal direction). That is, as the liquid crystal cell (20), a vertical alignment liquid crystal cell is used.

The surface light source device (9) is disposed on the lower surface side (rear surface side) of the lower polarizing plate (15). The surface light source device (9) is a thin box-shaped lamp box (5) whose top surface (front side) is open in a rectangular shape when viewed in plan, and is spaced apart from each other in the lamp box (5). A plurality of light sources (2) arranged in this manner, a first light diffusing optical member (3) arranged on the upper side (front side) of the plurality of light sources (2), and the first light diffusing optics. A reflective polarization separating film (40) disposed between the member (3) and the liquid crystal panel (30), and disposed between the first light diffusing optical member (3) and the light source (2). And a light collecting optical member (4). The first light diffusing optical member (3) and the light converging optical member (4) are placed and fixed so as to close the open surface of the lamp box (5). The reflective polarized light separating film (40) is laminated on the front surface of the first light diffusing optical member (3) through an adhesive layer (41), whereby the first light diffusing optical member (3) and The laminated optical member 100 is configured together with the first light diffusing optical member (3). A light reflecting layer (not shown) is provided on the inner surface of the lamp box (5). In the embodiment of FIG. 1, the light source device (50) includes a plurality of light sources (2) arranged on the back side of the first light diffusing optical member (3), and a lamp box (5). ing.

In the said embodiment, although the arrangement | positioning aspect (refer FIG. 1) where the said 1st light diffusable optical member (3) and the said condensing optical member (4) were piled up in the contact state is employ | adopted, especially this It is not limited to such an arrangement mode, for example, both members (3) through a slight air layer between the first light diffusing optical member (3) and the light collecting optical member (4). (4) You may employ | adopt the structure arrange | positioned in parallel with a mutually non-contact state.

The first light diffusing optical member (3) is a plate such as a sheet or film of a composition in which light diffusing particles are dispersed in a transparent material.

The first light diffusing optical member (3) is configured so that the following relational expression is established. That is, when the absolute value of the difference between the refractive index of the transparent material and the refractive index of the light diffusing particles is Δn, and the cumulative 50% particle diameter of the light diffusing particles is D ₅₀ (μm), 0.01 ≦ Δn The relational expression of × D ₅₀ ≦ 0.25 holds. That is, the first light diffusing optical member (3) is composed of a transparent material and light diffusing particles that satisfy such a relational expression.

In the VA liquid crystal display device (1) according to the above configuration, the first light diffusing optical member (3) is configured so that the relational expression of 0.01 ≦ Δn × D ₅₀ ≦ 0.25 holds. A phenomenon in which diffused light transmitted through the light diffusing optical member (3) in an oblique direction is bluish, and a phenomenon in which the light is transmitted through the liquid crystal panel (30) in an oblique direction to thereby add redness to the light. As a result, the hues (blue and red) are canceled (compensated) with each other. As a result, when the liquid crystal panel (30) is viewed from an oblique direction, a natural and high-quality color display is realized without redness. In addition, since the condensing optical member (4) is disposed between the first light diffusing optical member (3) and the light source (2), the effect of suppressing redness when viewed from an oblique direction is further enhanced. be able to. Moreover, since the diffused light which permeate | transmits the 1st light diffusable optical member (3) of the said structure in a front direction is white, when a liquid crystal panel (30) is seen from a front direction, a natural and high quality color display is possible. Realized. Further, since the reflective polarization separation film (40) is disposed between the first light diffusing optical member (3) and the liquid crystal panel (30), the brightness of the screen of the liquid crystal display device (1) is improved. be able to.

When the relational expression Δn × D ₅₀ <0.01 or 0.25 <Δn × D ₅₀ is satisfied in the first light diffusing optical member, redness is observed when the VA liquid crystal display device is viewed from an oblique direction. The color display is tinged.

Next, FIG. 3 shows another embodiment of the liquid crystal display device (1) according to the present invention. In this embodiment, the surface light source device (9) having the following configuration is employed in the liquid crystal display device of FIG. Other configurations are the same as those of the embodiment of FIG.

That is, in the embodiment of FIG. 3, the surface light source device (9) includes a thin box-shaped lamp box (5) having a rectangular shape and an open top surface (front surface) when viewed from above, and an incident from a side surface. A light guide plate (7) for emitting light to be emitted from the front surface (7b), a light source (2) disposed opposite to the side surface at one side of the side surface of the light guide plate (7), and the light guide A first light diffusing optical member (3) disposed on the upper side (front side) of the light plate (7), and disposed between the first light diffusing optical member (3) and the liquid crystal panel (30). A reflection-type polarized light separating film (40), and a condensing optical member (4) disposed between the first light diffusing optical member (3) and the light guide plate (7). . The first light diffusing optical member (3) and the light converging optical member (4) are placed and fixed so as to close the open surface of the lamp box (5). The reflective polarization separation film (40) is laminated on the front surface of the first light diffusing optical member (3) via an adhesive layer (41) and integrated with the first light diffusing optical member (3). Thus, the laminated optical member 100 is constituted together with the first light diffusing optical member (3). The light guide plate (7) and the light source (2) are accommodated in the lamp box (5). The lamp box (5) is made of a white resin plate or a white resin film. In the embodiment of FIG. 3, the light source device (50) includes a light guide plate (7) disposed on the back side of the first light diffusing optical member (3), and one of the light guide plates (7). The light source (2) arranged at the side position of the side surface and the lamp box (5) are configured.

The light guide plate (7) is an optical member that guides light so that light incident from the side surface of the light guide plate (7) (light from the light source) can be uniformly emitted from the front surface (7b) of the light guide plate. The said light-guide plate (7) is formed from the plate-shaped body of transparent resin or a transparent resin composition. In this embodiment, a dot printing portion (dot pattern) made of white ink is formed on the back surface (7a) of the light guide plate (7), and one of them is formed from the light source (2) into the light guide plate (7). The light incident from the side surface is reflected by the dot printing unit, so that the light can be uniformly emitted from the front surface of the light guide plate, that is, the light emitting surface (7b). On the back surface (7a) of the light guide plate (7), a dot pattern other than the dot printing portion with white ink may be formed. For example, the uneven | corrugated pattern by a laser beam may be formed in the back surface (7a) of the said light-guide plate (7). The light guide plate (7) may have fine particles dispersed in the transparent resin.

The light emitted from the front surface (7b) of the light guide plate (7) is the light collecting optical member (4), the first light diffusing optical member (3), the adhesive layer (41), and the reflection. The liquid crystal panel (30) is illuminated uniformly by passing through the mold polarization separation film (40) in this order.

In addition, in the said embodiment, although the arrangement | positioning aspect (refer FIG. 3) with which the said 1st light diffusable optical member (3) and the said condensing optical member (4) were piled up in the contact state is employ | adopted, It is not particularly limited to such an arrangement mode, and for example, both members (with a slight air layer between the first light diffusing optical member (3) and the light collecting optical member (4)) ( 3) You may employ | adopt the structure by which (4) is arrange | positioned in parallel with a non-contact state.

In the VA liquid crystal display device (1) of FIG. 3, the first light diffusing optical member (3) has a configuration in which the relational expression of 0.01 ≦ Δn × D ₅₀ ≦ 0.25 holds, so that the first light A phenomenon in which diffused light transmitted through the diffusing optical member (3) in an oblique direction is bluish, and a phenomenon in which the light is transmitted through the liquid crystal panel (30) in an oblique direction so that the light is reddish. Thus, the hues (blue and red) are canceled (compensated) with each other. As a result, when the liquid crystal panel (30) is viewed from an oblique direction, a natural and high-quality color display is realized without being reddish. In addition, since the condensing optical member (4) is disposed between the first light diffusing optical member (3) and the light guide plate (7), the effect of suppressing redness when viewed from an oblique direction is further increased. Can be increased. Moreover, since the diffused light which permeate | transmits the 1st light diffusable optical member (3) of the said structure in a front direction is white, when a liquid crystal panel (30) is seen from a front direction, a natural and high quality color display is possible. Realized. Further, since the reflective polarization separation film (40) is disposed between the first light diffusing optical member (3) and the liquid crystal panel (30), the brightness of the screen of the liquid crystal display device (1) is improved. be able to.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, a configuration in which a second light diffusing optical member (6) is further disposed between the light converging optical member (4) and the light source (2) in the liquid crystal display device of FIG. 1 is employed. ing. Other configurations are the same as those of the embodiment of FIG.

In the liquid crystal display device (1) of FIG. 2, in addition to the above-described effect (a natural and high-quality color display is realized without being reddish when viewed from an oblique direction), the light collecting optical Since the second light diffusing optical member (6) is disposed between the member (4) and the light source (2), it is possible to obtain an image with more uniform brightness in the plane of the liquid crystal panel (30). it can.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, a configuration in which a second light diffusing optical member (6) is further disposed between the light converging optical member (4) and the light guide plate (7) in the liquid crystal display device of FIG. Has been. Other configurations are the same as those of the embodiment of FIG.

In addition to the above-described effect (a natural and high-quality color display is realized without being reddish when viewed from an oblique direction), the liquid crystal display device (1) of FIG. Since the second light diffusing optical member (6) is disposed between the member (4) and the light guide plate (7), an image having a more uniform brightness in the plane of the liquid crystal panel (30) can be obtained. Can do.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, the liquid crystal display device of FIG. 1 employs a configuration in which the first light diffusing optical member (3) and the reflective polarization separation film (40) are interchanged in position. That is, the reflective polarization separation film (40) is disposed on the front side of the light collecting optical member (4), and the first light is disposed on the front surface of the reflective polarization separation film (40) via the adhesive layer (41). The diffusible optical member (3) is laminated and integrated with the reflective polarization separation film (40). Other configurations are the same as those of the embodiment of FIG. The liquid crystal display device (1) having the configuration shown in FIG. 5 has the same effects as the liquid crystal display device (1) having the configuration shown in FIG.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, in the liquid crystal display device of FIG. 1, the first light diffusing optical member (3) is laminated and integrated on the front surface of the reflective polarization separating film (40) via an adhesive layer (42). Is adopted. That is, the back side first light diffusing optical member (3) is disposed on the front side of the light collecting optical member (4), and an adhesive layer (on the front side of the back side first light diffusing optical member (3)). 41), a reflection type polarization separation film (40) is laminated, integrated with the back side first light diffusing optical member (3), and an adhesive layer (40) is formed on the front surface of the reflection type polarization separation film (40). 42), the front side first light diffusing optical member (3) is laminated and integrated with the reflective polarization separation film (40). Other configurations are the same as those of the embodiment of FIG. The liquid crystal display device (1) configured as shown in FIG. 6 has the same effect as the liquid crystal display device (1) configured as shown in FIG.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, the liquid crystal display device of FIG. 2 employs a configuration in which the positions of the first light diffusing optical member (3) and the reflective polarization separation film (40) are interchanged. That is, the second light diffusing optical member (6) is disposed on the back side of the condensing optical member (4), and the reflective polarized light separating film (40) is disposed on the front side of the condensing optical member (4). The first light diffusing optical member (3) is laminated on the front surface of the reflective polarization separation film (40) via an adhesive layer (41), and is integrated with the reflective polarization separation film (40). ing. Other configurations are the same as those of the embodiment of FIG. The liquid crystal display device (1) having the configuration shown in FIG. 7 has the same effect as the liquid crystal display device (1) having the configuration shown in FIG.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, the first light diffusing optical member (3) is further laminated on the front surface of the reflective polarization separation film (40) via the adhesive layer (42) in the liquid crystal display device of FIG. A structure integrated with the separation film (40) is employed. That is, the second light diffusing optical member (6) is disposed on the back side of the condensing optical member (4), and the back side first light diffusing optical member is disposed on the front side of the condensing optical member (4). (3) is disposed, a reflective polarization separation film (40) is laminated on the front surface of the back side first light diffusing optical member (3) via an adhesive layer (41), and the back side first light diffusion The first light diffusing optical member (3) on the front surface side is laminated on the front surface of the reflective polarized light separating film (40) via the adhesive layer (42), and is integrated with the reflective optical member (3). It is integrated with the polarized light separating film (40). Other configurations are the same as those of the embodiment of FIG. The liquid crystal display device (1) having the configuration shown in FIG. 8 has the same effect as the liquid crystal display device (1) having the configuration shown in FIG.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, the liquid crystal display device of FIG. 3 employs a configuration in which the first light diffusing optical member (3) and the reflective polarization separation film (40) are interchanged in position. That is, the reflective polarization separation film (40) is disposed on the front side of the light collecting optical member (4), and the first light is disposed on the front surface of the reflective polarization separation film (40) via the adhesive layer (41). The diffusible optical member (3) is laminated and integrated with the reflective polarization separation film (40). Other configurations are the same as those of the embodiment of FIG. The liquid crystal display device (1) having the configuration shown in FIG. 9 has the same effect as the liquid crystal display device (1) having the configuration shown in FIG.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, the first light diffusing optical member (3) is further laminated on the front surface of the reflective polarization separation film (40) via the adhesive layer (42) in the liquid crystal display device of FIG. A structure integrated with the separation film (40) is employed. That is, the back side first light diffusing optical member (3) is disposed on the front side of the light collecting optical member (4), and an adhesive layer (on the front side of the back side first light diffusing optical member (3)). 41), a reflection type polarization separation film (40) is laminated, integrated with the back side first light diffusing optical member (3), and an adhesive layer (40) is formed on the front surface of the reflection type polarization separation film (40). 42), the front side first light diffusing optical member (3) is laminated and integrated with the reflective polarization separation film (40). Other configurations are the same as those of the embodiment of FIG. The liquid crystal display device (1) configured as shown in FIG. 10 has the same effect as the liquid crystal display device (1) configured as shown in FIG.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, the liquid crystal display device of FIG. 4 employs a configuration in which the first light diffusing optical member (3) and the reflective polarization separation film (40) are interchanged with each other. That is, the second light diffusing optical member (6) is disposed on the back side of the condensing optical member (4), and the reflective polarized light separating film (40) is disposed on the front side of the condensing optical member (4). The first light diffusing optical member (3) is laminated on the front surface of the reflective polarization separation film (40) via an adhesive layer (41), and is integrated with the reflective polarization separation film (40). ing. Other configurations are the same as those of the embodiment of FIG. The liquid crystal display device (1) having the configuration shown in FIG. 11 has the same effects as the liquid crystal display device (1) having the configuration shown in FIG.

Next, still another embodiment of the liquid crystal display device (1) according to the present invention is shown in FIG. In this embodiment, in the liquid crystal display device of FIG. 4, the first light diffusing optical member (3) is further laminated on the front surface of the reflective polarization separation film (40) via the adhesive layer (42), and the reflective polarization A structure integrated with the separation film (40) is employed. That is, the second light diffusing optical member (6) is disposed on the back side of the condensing optical member (4), and the back side first light diffusing optical member is disposed on the front side of the condensing optical member (4). (3) is disposed, a reflective polarization separation film (40) is laminated on the front surface of the back side first light diffusing optical member (3) via an adhesive layer (41), and the back side first light diffusion The first light diffusing optical member (3) on the front surface side is laminated on the front surface of the reflective polarized light separating film (40) via the adhesive layer (42), and is integrated with the reflective optical member (3). It is integrated with the polarized light separating film (40). Other configurations are the same as those of the embodiment of FIG. The liquid crystal display device (1) configured as shown in FIG. 12 has the same effect as the liquid crystal display device (1) configured as shown in FIG.

2, 4, 7, 8, 11, and 12, an arrangement mode in which the light collecting optical member (4) and the second light diffusing optical member (6) are overlapped in a contact state is employed. However, it is not particularly limited to such an arrangement mode. For example, a slight air layer is interposed between the light collecting optical member (4) and the second light diffusing optical member (6). The members (4) and (6) may be arranged in parallel with each other in a non-contact state.

In the present invention, a rectangular light guide plate is preferably used as the light guide plate (7) when viewed in plan with a thickness of 1 mm to 30 mm. In particular, the thickness of the light guide plate (7) is particularly preferably 1 mm to 10 mm. The side surface of the light guide plate (7) is preferably formed on a smooth surface by polishing treatment or the like. Further, as the light guide plate (7), a light guide plate having a refractive index of 1.4 to 1.7 is usually used. The material of the light guide plate having such a refractive index is not particularly limited, and examples thereof include colorless and transparent resins such as acrylic resin, polystyrene, and polycarbonate. For example, the refractive index of PMMA (polymethyl methacrylate) which is an example of an acrylic resin is 1.49.

The first light diffusing optical member (3) is not particularly limited as long as it is a plate such as a sheet or film of a composition in which light diffusing particles are dispersed in a transparent material, and any material can be used. The thickness of the first light diffusing optical member (3) is not particularly limited, but is usually 0.05 mm to 15 mm, preferably 0.05 mm to 3 mm, more preferably 0.05 mm to 1 mm. is there. In particular, it is preferably set to 0.2 mm or less.

The transparent material constituting the first light diffusing optical member (3) is not particularly limited, and examples thereof include glass and transparent resin. Examples of the transparent resin include polycarbonate resin, ABS resin (acrylonitrile-styrene-butadiene copolymer resin), methacryl resin, MS resin (methyl methacrylate-styrene copolymer resin), polystyrene resin, AS resin (acrylonitrile-styrene). Copolymer resin), polyolefin resin (polyethylene, polypropylene, cyclic polyolefin resin, etc.).

The light diffusing particles (light diffusing agent) constituting the first light diffusing optical member (3) are particles having a refractive index different from that of the transparent material constituting the first light diffusing optical member (3). Anything can be used without particular limitation as long as it can diffuse transmitted light. For example, inorganic particles such as glass beads, silica particles, aluminum hydroxide particles, calcium carbonate particles, barium sulfate particles, titanium oxide particles, talc, styrene polymer particles, acrylic polymer particles, siloxane polymer particles, etc. Resin particles and the like.

The addition amount of the light diffusing particles is set in a range of 0.01 to 20 parts by mass, further 0.03 to 10 parts by mass, and particularly 5 parts by mass or less with respect to 100 parts by mass of the transparent material. It is preferred that A sufficient light diffusion function can be ensured by setting it to 0.01 parts by mass or more, and the degree of blueness of diffused light transmitted through the first light diffusing optical member in an oblique direction is insufficient due to being 20 parts by mass or less. Can be prevented.

The cumulative 50% particle diameter (D ₅₀ ) of the light diffusing particles is usually 10 μm or less, preferably 0.3 μm to 8 μm.

The absolute value Δn of the difference between the refractive index of the transparent material and the refractive index of the light diffusing particles is usually set to 0.01 to 0.20, but a preferable range is 0.02 to 0.18.

The first light diffusing optical member (3) contains various additives such as an ultraviolet absorber, a heat stabilizer, an antioxidant, a weathering agent, a light stabilizer, a fluorescent brightening agent, and a processing stabilizer. You may squeeze it. In addition, other light diffusing particles other than the light diffusing particles satisfying the specific relational expression can be added as long as the effects of the present invention are not impaired.

In addition, a coating layer may be formed on the surface of the first light diffusing optical member (3) as long as the effect of the present invention is not impaired. The thickness of the coating layer is preferably set to 20% or less of the thickness of the first light diffusing optical member (3), and particularly preferably the thickness of the first light diffusing optical member (3). It is 10% or less of the thickness.

As a method for producing the first light diffusing optical member (3), a known molding method can be used as a method for molding a resin plate, and is not particularly limited. For example, a hot press method, a melt extrusion method, an injection molding method can be used. Etc.

The reflective polarization separation film (40) has a property of transmitting a certain kind of polarized light and reflecting polarized light having the opposite property. Specifically, it reflects linearly polarized light in a specific vibration direction and reflects linearly polarized light in a direction orthogonal to it, or reflects linearly polarized light in a certain rotational direction, and reverses the direction. There is a reflective circularly polarized light separating film that reflects circularly polarized light that rotates. Examples of commercially available reflective linearly polarized light separating films include “DBEF (Dual Brightness Enhancement Film)” manufactured by 3M, “NIPOX” manufactured by Nitto Denko Corporation, and the like.

The thickness of the reflective polarization separation film (40) is usually 0.02 mm to 5 mm, preferably 0.02 mm to 2 mm.

The reflective polarization separation film (40) is laminated on the front surface or the back surface of the first light diffusing optical member (3) via an adhesive layer (41) (42), and the first light diffusing optical member ( 3) is preferably integrated (see FIGS. 1 to 12). When such a configuration is adopted, it is possible to prevent the first light diffusing optical member (3) and the reflective polarization separation film (40) from being scratched (scratched due to mutual rubbing or the like). Note that the reflective polarization separation film (40) and the first light diffusing optical member (3) may be laminated by heat or the like without using an adhesive, and these may be integrated.

The material for forming the adhesive layers (41) and (42) is not particularly limited. For example, an adhesive such as an acrylic adhesive, a urethane adhesive, a polyether adhesive, a silicone adhesive, and the like. In addition to the agent, other adhesives other than the above-mentioned pressure-sensitive adhesive can be used. Among these, it is preferable to use a colorless and transparent pressure-sensitive adhesive in that a higher-quality display image can be formed. Moreover, as the adhesive, a pressure-sensitive adhesive is preferably used.

The thickness of the adhesive layer (41) (42) is preferably set in the range of 1 μm to 30 μm. Sufficient bonding strength can be ensured by being 1 μm or more. It is preferable that the adhesive layers (41) and (42) are laminated on the substantially entire rear surface of the reflective polarization separating film (40) or on the almost entire front surface with no gap.

When the direct-type liquid crystal display device (FIGS. 1, 2, 5 to 8) is configured as the condensing optical member (4), the condensing optical member (4) collects incident light from the light source (2) in the front direction. Any member can be used as long as it is a member having a function. When the edge light type liquid crystal display device (FIGS. 3, 4, 9 to 12) is constituted, the light guide plate (7) Any member can be used as long as it is a member having a condensing function for collecting incident light from the front surface (7b) in the front direction. For example, a prism sheet (including a film) having a condensing function for collecting incident light in the front direction, a light diffusion sheet (including a film) having a condensing function for collecting incident light in the front direction, and the incident light in the front direction And a light diffusing optical member having a concave and convex shape on the surface.

Among these, as the light collecting optical member (4), it is preferable to use one having the following light collecting performance. That is, when incident light having a half-value half width (M) of 60 ° or more in the incident angle-luminance curve of incident light is incident on the converging optical member, the outgoing angle of the outgoing light emitted from the converging optical member A condensing optical member having a condensing performance (hereinafter sometimes referred to as “specific condensing performance”) in which the half-width (N) in the luminance curve is 10 ° or more smaller than the half-width of the incident light. Is preferably used (see FIG. 13). Here, the incident light incident angle-luminance curve is a curve showing the luminance at each incident angle of the incident light on the condensing optical member (4), the horizontal axis is the incident angle, and the vertical axis is the luminance. . The emission angle-luminance curve of the emitted light is a curve indicating the luminance for each emission angle of the emitted light from the condensing optical member (4), where the horizontal axis is the emission angle and the vertical axis is the luminance. The half width at half maximum (M) is half of the angle range between two points corresponding to half the maximum value of luminance.
For example, the prism sheet (including the film) having the specific light collecting performance, the light diffusion sheet (including the film) having the specific light collecting performance, and the surface having the specific light collecting performance. Examples thereof include a light diffusing optical member having a shape.

Further, the condensing optical member (4) is configured such that when incident light having a half-width (M) of 60 ° or more in the incident angle-luminance curve of incident light is incident on the condensing optical member, The half-width (N) in the emission angle-luminance curve of the emitted light emitted from the optical optical member has a light collecting performance that is 15 ° or less smaller than the half-width (M) of the incident light. Particularly preferred.

In the incident angle-luminance curve, the direction of incident light where the incident angle = 0 ° is a direction perpendicular to the surface (back surface) of the light collecting optical member (4). Further, in the emission angle-luminance curve, the direction of outgoing light where the outgoing angle = 0 ° is a direction perpendicular to the surface (front surface) of the condensing optical member (4) (see FIG. 13).

The prism sheet (including a film) (4) is usually formed from a transparent resin material and is not particularly limited. For example, a fine prism lens, a fine convex lens, a lenticular lens, and the like. The sheet | seat (a film is included) etc. in which this fine condensing lens was provided over the whole surface of one side can be illustrated.

Examples of the prism sheet (including film) (4) include polycarbonate resin, ABS (acrylonitrile-butadiene-styrene copolymer) resin, methacrylic resin, methyl methacrylate-styrene copolymer resin, polystyrene resin, acrylonitrile-styrene. A material based on a thermoplastic resin such as a copolymer resin (AS), a polyolefin resin such as a polyethylene resin, or a polypropylene resin is used. Although it does not specifically limit as a commercial item of the said prism film (4), For example, Sumitomo 3M "BEF (Brightness Enhancement Film)" (brand name) (thickness 30 micrometers on the 125-micrometer-thick polyester film) A V-groove having a depth of 25 μm and a groove bottom opening angle of 90 degrees formed at a pitch interval of 50 μm on the surface of the acrylic resin layer), manufactured by Sekisui Film Co., Ltd. “Estina” (trade name), “Illuminx ADF film” (trade name) manufactured by GE Plastics, and the like.

The light diffusing sheet (including film) (4) is not particularly limited. For example, the light diffusing sheet (including film) in which light diffusing particles are dispersed in a transparent material is formed from a transparent material. Examples thereof include a light diffusion sheet (including a film) in which light diffusion particles are coated on a surface of a base material sheet together with a binder.

The transparent material constituting the light diffusion sheet (including film) (4) is not particularly limited, and examples thereof include inorganic glass and transparent resin. As the transparent resin, a transparent thermoplastic resin is preferable in terms of easy molding. The transparent thermoplastic resin is not particularly limited. For example, polycarbonate resin, ABS (acrylonitrile-butadiene-styrene copolymer) resin, methacrylic resin, methyl methacrylate-styrene copolymer resin, polystyrene resin. And polyolefin resins such as acrylonitrile-styrene copolymer (AS) resin, polyethylene resin, polypropylene resin, and cyclic polyolefin resin.

The light diffusing particles constituting the light diffusing sheet (including film) (4) are incompatible with the transparent material and exhibit a refractive index different from that of the transparent material, and the light diffusing sheet (4) The particles are not particularly limited as long as the particles have a function of diffusing transmitted light that passes through (including powder). For example, the particles may be inorganic particles made of an inorganic material, or organic particles made of an organic material. There may be. The inorganic material constituting the inorganic particles is not particularly limited. For example, silica, calcium carbonate, barium sulfate, titanium oxide, aluminum hydroxide, inorganic glass, mica, talc, white carbon, magnesium oxide, oxidized Zinc etc. are mentioned. The organic material constituting the organic particles is not particularly limited, and examples thereof include methacrylic crosslinked resins, methacrylic high molecular weight resins, styrene crosslinked resins, styrene high molecular weight resins, and siloxane polymers. It is done. The particle diameter of the inorganic particles and organic particles used as the light diffusing agent is usually 0.1 μm to 50 μm. The amount of the light diffusing particles used varies depending on the desired degree of diffusion of transmitted light, but is usually 0.01 to 20 parts by weight, preferably 0.1 parts by weight with respect to 100 parts by weight of the transparent resin. ~ 10 parts by mass.

The light diffusing optical member (4) having a concavo-convex shape on the surface is not particularly limited, but, for example, a semicircular convex portion having a semicircular cross-sectional shape on the surface of a resin sheet (including a film) Alternatively, the surface of a resin sheet (including a film) is formed with a plurality of triangular ridges having a triangular cross-section in parallel with each other. The one provided along the direction (one-dimensional type), the surface of the resin sheet (including the film) is provided along two directions (for example, two directions orthogonal to each other) with different triangular protrusions having a triangular cross-sectional shape. Thing (two-dimensional type) etc. are mentioned.

The thickness of the light collecting optical member (4) is usually 0.02 mm to 5 mm, preferably 0.02 mm to 2 mm, more preferably 0.05 mm to 1 mm.

The second light diffusing optical member (6) is not particularly limited, and examples thereof include a light diffusing sheet (including a film) in which light diffusing particles are dispersed in a transparent material.

The transparent material constituting the light diffusion sheet (including film) (6) is not particularly limited, and examples thereof include inorganic glass and transparent resin. As the transparent resin, a transparent thermoplastic resin is preferable in terms of easy molding. The transparent thermoplastic resin is not particularly limited. For example, polycarbonate resin, ABS (acrylonitrile-butadiene-styrene copolymer) resin, methacrylic resin, methyl methacrylate-styrene copolymer resin, polystyrene resin. And polyolefin resins such as acrylonitrile-styrene copolymer (AS) resin, polyethylene resin, polypropylene resin, and cyclic polyolefin.

The light diffusing particles constituting the light diffusing sheet (including film) (6) are incompatible with the transparent material and exhibit a refractive index different from that of the transparent material. The light diffusing sheet (6) ) Is not particularly limited as long as it is a particle (including powder) having a function of diffusing transmitted light that passes through, for example, an inorganic particle composed of an inorganic material, or an organic particle composed of an organic material It may be. The inorganic material constituting the inorganic particles is not particularly limited. For example, silica, calcium carbonate, barium sulfate, titanium oxide, aluminum hydroxide, inorganic glass, mica, talc, white carbon, magnesium oxide, oxidized Zinc etc. are mentioned. The organic material constituting the organic particles is not particularly limited, and examples thereof include methacrylic crosslinked resins, methacrylic high molecular weight resins, styrene crosslinked resins, styrene high molecular weight resins, and siloxane polymers. It is done. The particle diameter of the inorganic particles and organic particles used as the light diffusing agent is usually 0.1 μm to 50 μm. The amount of the light diffusing particles used varies depending on the desired degree of diffusion of transmitted light, but is usually 0.01 to 20 parts by weight, preferably 0.1 parts by weight with respect to 100 parts by weight of the transparent resin. ~ 10 parts by mass.

Although it does not specifically limit as said light source (2), For example, the light source containing red light (R), green light (G), and blue light (B) is mentioned, Specifically, a fluorescent tube, a halogen lamp, for example are mentioned. , A tungsten lamp, an RGB type light emitting diode that emits red light, green light, and blue light.

In the direct liquid crystal display device (FIGS. 1, 2, 5 to 8), the distance (L) between the adjacent light sources (2) and (2) may be set to 10 mm or more from the viewpoint of power saving. Preferably, the distance (D) between the light collecting optical member (4) and the light source (2) is preferably set to 50 mm or less from the viewpoint of thinning. Further, D: L is preferably 1: 5 to 5: 1. In particular, the distance (L) between the adjacent light sources (2) and (2) is more preferably set to 10 mm to 100 mm. The distance (D) between the light converging optical member (4) and the light source (2) is particularly preferably set to 10 mm to 50 mm (see FIGS. 1, 2, 5 to 8).

In the edge light type liquid crystal display device (FIGS. 3, 4, 9 to 12), when the light source (2) is a straight tube type, it is arranged in parallel along the side surface of the light guide plate (7). Is done. The distance (d) between the light source (2) and the side surface of the light guide plate (7) is usually set to 1 mm to 15 mm, preferably 10 mm or less, more preferably 5 mm or less (FIGS. 3, 4, 9). To 12).

When a straight tube light source is used as the light source (2) in the edge light type liquid crystal display device (FIGS. 3, 4, 9 to 12), the outer diameter (t) of the straight tube light source is a surface light source device. From the viewpoint of reducing the size of (9), it is preferably 8 mm or less, more preferably 4 mm or less (see FIGS. 3, 4, 9 to 12). In addition, the outer diameter (t) of the straight tube light source is preferably 1 mm or more from the viewpoint of securing mechanical strength and extending the life (see FIGS. 3, 4, and 9 to 12).

In the edge-light type liquid crystal display device (FIGS. 3, 4, 9 to 12), when a point light source such as a light emitting diode, a halogen lamp, or a tungsten lamp is used as the light source (2), a plurality of light sources are used side by side. At this time, the interval between the adjacent light sources (2) and (2) is usually set to 1 mm to 25 mm, and preferably set to 10 mm or less from the viewpoint of power saving.

The transparent electrodes (12) and (13) are not particularly limited, and examples thereof include ITO (indium tin oxide).

In the edge light type liquid crystal display device (1) according to the above-described embodiment (FIGS. 3, 4, 9 to 12), the light source (2) is provided only on one side of the four side surfaces of the light guide plate (7). Although the arrangement | positioning structure was employ | adopted, it is not limited to such a structure in particular, For example, the structure by which the light source (2) is each arrange | positioned on a pair of mutually opposing side surface in a light-guide plate (7). You may employ | adopt and may employ | adopt the structure by which the light source (2) is each arrange | positioned at all the four side surfaces in a light-guide plate (7).

The liquid crystal display device (1) according to the present invention is not particularly limited to that of the above-described embodiment, and any design change can be allowed as long as it does not depart from the spirit of the invention as long as it is within the scope of the claims. Is.

Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples. In addition, the numerical value of the cumulative 50% particle diameter of the light diffusion particles used below is a value obtained by the following measurement method.

<Measurement method of 50% cumulative particle size of light diffusion particles>
The cumulative 50% particle size (D ₅₀ ) of the light diffusing particles was measured by a Fraunhofer diffraction method of laser light forward scattered light using a Nikkiso Co., Ltd. Microtrac particle size analyzer (model 9220FRA). In measurement, about 0.1 g of light diffusing particles is dispersed in methanol to obtain a dispersion, and after irradiating the dispersion with ultrasonic waves for 5 minutes, the dispersion is put into a sample of the Microtrac particle size analyzer. The measurement was performed by putting it in the mouth. The cumulative 50% particle diameter (D ₅₀ ) is determined by measuring the particle diameter and volume of all particles, and accumulating the volume in order from the smallest particle diameter, and the accumulated volume is 50% of the total volume of all particles. The particle diameter of the particles to be

<Example 1>
After mixing 100 parts by weight of polystyrene resin and 2.4 parts by weight of silicone resin particles (“XC99-A8808” manufactured by Shin-Etsu Chemical Co., Ltd.) (light diffusing particles) with a Henschel mixer, the mixture is melt-kneaded with an extruder and extruded. Thereby, the 1st light diffusable optical member (3) formed from the sheet | seat of thickness 0.1mm is manufactured. The refractive index of the polystyrene resin is 1.59, the refractive index of the silicone resin particles is 1.43, and the absolute value (Δn) of the refractive index difference between them is 0.16. The 50% cumulative particle diameter (D ₅₀ ) of the silicone resin particles is 0.6 (μm). Therefore, Δn × D ₅₀ = 0.096 μm.

Next, the VA liquid crystal display device (1) having the configuration shown in FIG. 1 is manufactured using the first light diffusing optical member (3). As the light source (2), a straight fluorescent tube that emits white light including R (red light), G (green light), and B (blue light) is used. Reflective polarized light separation film (40) made of “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) provided with an acrylic pressure-sensitive adhesive on both sides. It is laminated on the front surface of the member (3) and integrated with the first light diffusing optical member (3). Further, as the condensing optical member (4), a prism film A is used in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the overall thickness is 230 μm. This prism film A has the above-mentioned specific light collecting performance (that is, when incident light having a half-value half-width of 67 ° in the incident angle-luminance curve of incident light is incident on the prism film, it is emitted from the prism film. The half value half width in the emission angle-luminance curve of the emitted light is 48 °).

In the VA liquid crystal display device of Example 1, when the liquid crystal panel is displayed in a white display state with the light source turned on, a natural high brightness without redness when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 2>
Using the same first light diffusing optical member (3) as in Example 1, the VA liquid crystal display device (1) having the configuration shown in FIG. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. Reflective polarization separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) to which an acrylic pressure-sensitive adhesive is applied on both sides. It is laminated on the front surface of the optical member (3) and integrated with the first light diffusing optical member (3). Further, as the light condensing optical member (4), a prism film A in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the total thickness is 230 μm is used. "Sumipex E RM802S" (trade name) manufactured by Sumitomo Chemical Co., Ltd. is used as the photosensitive optical member (6).

In the VA liquid crystal display device according to the second embodiment, when the liquid crystal panel is displayed in a white display state with the light source turned on, a natural high brightness without being reddish when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 3>
Using the same first light diffusing optical member (3) as in Example 1, the VA type liquid crystal display device (1) having the structure shown in FIG. 3 is manufactured. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. A light guide plate made of a transparent thermoplastic resin is used as the light guide plate (7). Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. It laminates | stacks on the front surface of a diffractive optical member (3), and is integrated with a 1st light diffusable optical member (3). Further, as the condensing optical member (4), a prism film A is used in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the overall thickness is 230 μm.

In the VA liquid crystal display device of Example 3, when the liquid crystal panel is in a white display state with the light source turned on, a natural high brightness without being reddish when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 4>
Using the same first light diffusing optical member (3) as in Example 1, the VA type liquid crystal display device (1) having the structure shown in FIG. 4 is manufactured. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. A light guide plate made of a transparent thermoplastic resin is used as the light guide plate (7). Reflective polarized light separation film (40) formed by 3M “DBEF-M” (thickness: 242 μm) is passed through a pressure-sensitive adhesive sheet (41) provided with an acrylic pressure-sensitive adhesive on both sides. It is laminated on the front surface of the member (3) and integrated with the first light diffusing optical member (3). Further, as the light condensing optical member (4), a prism film A in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the total thickness is 230 μm is used. "Sumipex E RM802S" (trade name) manufactured by Sumitomo Chemical Co., Ltd. is used as the photosensitive optical member (6).

In the VA type liquid crystal display device of Example 4, when the liquid crystal panel is in a white display state with the light source turned on, a natural high brightness without being reddish when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 5>
It was formed from a sheet having a thickness of 0.1 mm by mixing 100 parts by weight of polycarbonate resin and 2.5 parts by weight of acrylic resin particles (light diffusing particles) with a Henschel mixer, and then melt-kneading and extruding with an extruder. A first light diffusing optical member (3) is manufactured. The polycarbonate resin has a refractive index of 1.59, the acrylic resin particles have a refractive index of 1.49, and the absolute value (Δn) of the refractive index difference between them is 0.10. The 50% cumulative particle diameter (D ₅₀ ) of the acrylic resin particles is 0.9 (μm). Therefore, Δn × D ₅₀ = 0.090 μm.

Next, the VA liquid crystal display device (1) having the structure shown in FIG. 2 is manufactured using the first light diffusing optical member (3). The light source (2), the reflective polarization separating film (40), the adhesive sheet (41), the condensing optical member (4) and the second light diffusing optical member (6) are the same as those in Example 2. Use.

In the VA type liquid crystal display device of Example 5, when the liquid crystal panel is in a white display state with the light source turned on, natural high brightness without redness when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 6>
It was formed from a sheet having a thickness of 0.1 mm by mixing 100 parts by weight of polycarbonate resin and 5.0 parts by weight of acrylic resin particles (light diffusing particles) with a Henschel mixer, then melt-kneading with an extruder and extruding. A first light diffusing optical member (3) is manufactured. The polycarbonate resin has a refractive index of 1.59, the acrylic resin particles have a refractive index of 1.49, and the absolute value (Δn) of the refractive index difference between them is 0.10. The 50% cumulative particle diameter (D ₅₀ ) of the acrylic resin particles is 0.9 (μm). Therefore, Δn × D ₅₀ = 0.090 μm.

Next, the VA liquid crystal display device (1) having the configuration shown in FIG. 4 is manufactured using the first light diffusing optical member (3). The light source (2), the reflective polarization separating film (40), the adhesive sheet (41), the condensing optical member (4), the second light diffusing optical member (6), and the light guide plate (7) are implemented. The same as in Example 4 is used.

In the VA liquid crystal display device of Example 6, when the liquid crystal panel is in a white display state with the pattern generator in a state where the light source is turned on, natural high brightness without being reddish when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 7>
It was formed from a sheet having a thickness of 0.1 mm by mixing 100 parts by mass of polycarbonate resin and 5.6 parts by mass of acrylic resin particles (light diffusion particles) with a Henschel mixer, and then melt-kneading and extruding with an extruder. A first light diffusing optical member (3) was produced. The polycarbonate resin has a refractive index of 1.59, the acrylic resin particles have a refractive index of 1.49, and the absolute value (Δn) of the refractive index difference between them is 0.10. The 50% cumulative particle diameter (D ₅₀ ) of the acrylic resin particles is 0.9 (μm). Therefore, Δn × D ₅₀ = 0.090 μm.

In the VA type liquid crystal display device of Example 7, when the liquid crystal panel is in a white display state with the light source turned on, a natural high brightness without being reddish when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 8>
100 parts by weight of polycarbonate resin and 0.5 parts by weight of acrylic resin particles (“Techpolymer MBX-2” (light diffusing particles) manufactured by Sekisui Plastics Co., Ltd.) are mixed with a Henschel mixer, then melt-kneaded with an extruder and pressed. Thus, a first light diffusing optical member (3) formed from a sheet having a thickness of 0.1 mm was manufactured, the refractive index of the polycarbonate resin was 1.59, and the refractive index of the acrylic resin particles was The absolute value (Δn) of the refractive index difference between the two is 0.10, and the cumulative 50% particle diameter (D ₅₀ ) of the acrylic resin particles is 2.4 (μm). Therefore, Δn × D ₅₀ = 0.24 μm.

In the VA liquid crystal display device of Example 8, when the liquid crystal panel is in a white display state with the light source turned on, a natural high brightness without being reddish when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 9>
After mixing 100 parts by weight of polycarbonate resin and 5.0 parts by weight of MS resin particles (methyl methacrylate-styrene copolymer particles) (light diffusion particles) with a Henschel mixer, the mixture is melt-kneaded with an extruder and extruded. A first light diffusing optical member (3) formed from a sheet having a thickness of 0.1 mm was manufactured. The refractive index of the polycarbonate resin was 1.59, the refractive index of the MS resin particles was 1.54, and the absolute value (Δn) of the refractive index difference between them was 0.05. Further, the 50% cumulative particle diameter (D ₅₀ ) of the MS resin particles was 1.6 (μm). Therefore, Δn × D ₅₀ = 0.08 μm.

In the VA liquid crystal display device of Example 9, when the liquid crystal panel is in a white display state with the light source turned on, a natural high brightness without being reddish when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 10>
After mixing 100 parts by weight of polycarbonate resin and 12.0 parts by weight of MS resin particles (methyl methacrylate-styrene copolymer particles) (light diffusion particles) with a Henschel mixer, the mixture is melt-kneaded with an extruder and extruded. A first light diffusing optical member (3) formed from a sheet having a thickness of 0.1 mm is manufactured. The refractive index of the polycarbonate resin is 1.59, the refractive index of the MS resin particles is 1.54, and the absolute value (Δn) of the refractive index difference between the two is 0.05. The MS resin particles have a cumulative 50% particle diameter (D ₅₀ ) of 1.6 (μm). Therefore, Δn × D ₅₀ = 0.08 μm.

In the VA liquid crystal display device of Example 10, when the liquid crystal panel is in a white display state with the pattern generator in a state where the light source is turned on, natural high brightness without being reddish when viewed from an oblique direction as well as the front direction. A white screen display can be seen.

<Example 11>
A VA liquid crystal display device is manufactured in the same manner as in the first embodiment except that the condensing optical member (4) is not disposed (deleted) in the VA liquid crystal display device of the first embodiment.

In the VA liquid crystal display device of Example 11, when the liquid crystal panel is put in a white display state with the pattern generator in a state where the light source is turned on, a natural high-brightness white screen display can be seen without being reddish in the front direction. When viewed from the direction, a natural high brightness white screen display with less redness is obtained.

<Example 12>
A VA liquid crystal display device is manufactured in the same manner as in Example 3 except that the condensing optical member (4) is not disposed (deleted) in the VA liquid crystal display device of the third embodiment.

In the VA liquid crystal display device of Example 12, when the liquid crystal panel is put in a white display state with the pattern generator in a state where the light source is turned on, a natural high-brightness white screen display can be seen without redness in the front direction. When viewed from the direction, a natural high brightness white screen display with less redness is obtained.

<Comparative Example 1>
By mixing 100 parts by weight of polystyrene resin and 6.0 parts by weight of silicone resin particles (“Tospearl 120” manufactured by Toshiba Silicone Co., Ltd.) (light diffusion particles) with a Henschel mixer, the mixture is melt-kneaded with an extruder and extruded. A first light diffusing optical member (3) formed from a sheet having a thickness of 0.1 mm is manufactured. The refractive index of the polystyrene resin is 1.59, the refractive index of the silicone resin particles is 1.43, and the absolute value (Δn) of the refractive index difference between them is 0.16. The 50% cumulative particle diameter (D ₅₀ ) of the silicone resin particles is 1.7 (μm). Therefore, Δn × D ₅₀ = 0.272 μm.

Next, the VA liquid crystal display device (1) having the configuration shown in FIG. 1 is manufactured using the first light diffusing optical member (3). As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. Reflective polarized light separation film (40) formed by 3M “DBEF-M” (thickness: 242 μm) is passed through a pressure-sensitive adhesive sheet (41) provided with an acrylic pressure-sensitive adhesive on both sides. It is laminated on the front surface of the member (3) and integrated with the first light diffusing optical member (3). Further, as the condensing optical member (4), a prism film A is used in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the overall thickness is 230 μm.

In the VA liquid crystal display device of Comparative Example 1, when the liquid crystal panel is in a white display state with a light source turned on, a natural white screen display can be seen without redness in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 2>
Using the same first light diffusing optical member (3) as in Comparative Example 1, the VA liquid crystal display device (1) having the configuration shown in FIG. 2 is manufactured. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the light condensing optical member (4), a prism film A in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the total thickness is 230 μm is used. "Sumipex E RM802S" (trade name) manufactured by Sumitomo Chemical Co., Ltd. is used as the photosensitive optical member (6).

In the VA liquid crystal display device of Comparative Example 2, when the liquid crystal panel is in a white display state with a light source turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 3>
Using the same first light diffusing optical member (3) as in Comparative Example 1, the VA liquid crystal display device (1) having the configuration shown in FIG. 3 is manufactured. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. A light guide plate made of a transparent thermoplastic resin is used as the light guide plate (7). Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the condensing optical member (4), a prism film A is used in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the overall thickness is 230 μm.

In the VA liquid crystal display device of Comparative Example 3, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative example 4>
Using the same first light diffusing optical member (3) as in Comparative Example 1, the VA liquid crystal display device (1) having the configuration shown in FIG. 4 is manufactured. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. A light guide plate made of a transparent thermoplastic resin is used as the light guide plate (7). Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the light condensing optical member (4), a prism film A in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the total thickness is 230 μm is used. "Sumipex E RM802S" (trade name) manufactured by Sumitomo Chemical Co., Ltd. is used as the photosensitive optical member (6).

In the VA type liquid crystal display device of Comparative Example 4, when the liquid crystal panel is in a white display state with a light source turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 5>
After mixing 100 parts by weight of polystyrene resin and 40 parts by weight of acrylic resin particles (“Techpolymer MBX-8” manufactured by Sekisui Plastics Co., Ltd.) (light diffusion particles) with a Henschel mixer, the mixture is melt-kneaded with an extruder and pressed. The first light diffusing optical member (3) formed from a sheet having a thickness of 0.1 mm was manufactured. The refractive index of the polystyrene resin is 1.59, the refractive index of the acrylic resin particles is 1.49, and the absolute value (Δn) of the refractive index difference between them is 0.10. The 50% cumulative particle diameter (D ₅₀ ) of the acrylic resin particles is 6.0 (μm). Therefore, Δn × D ₅₀ = 0.6 μm.

Next, the VA liquid crystal display device (1) having the configuration shown in FIG. 1 is manufactured using the first light diffusing optical member (3). As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the condensing optical member (4), a prism film A is used in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the overall thickness is 230 μm.

In the VA liquid crystal display device of Comparative Example 5, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 6>
Using the same first light diffusing optical member (3) as in Comparative Example 5, the VA liquid crystal display device (1) having the configuration shown in FIG. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the light condensing optical member (4), a prism film A in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the total thickness is 230 μm is used. "Sumipex E RM802S" (trade name) manufactured by Sumitomo Chemical Co., Ltd. is used as the photosensitive optical member (6).

In the VA liquid crystal display device of Comparative Example 6, when the liquid crystal panel is in a white display state with the pattern generator in a state where the light source is turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 7>
Using the same first light diffusing optical member (3) as in Comparative Example 5, the VA liquid crystal display device (1) having the configuration shown in FIG. 3 is manufactured. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. A light guide plate made of a transparent thermoplastic resin is used as the light guide plate (7). Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the condensing optical member (4), a prism film A is used in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the overall thickness is 230 μm.

In the VA type liquid crystal display device of Comparative Example 7, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without redness in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 8>
Using the same first light diffusing optical member (3) as that of Comparative Example 5, the VA liquid crystal display device (1) having the configuration shown in FIG. 4 is manufactured. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. A light guide plate made of a transparent thermoplastic resin is used as the light guide plate (7). Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the light condensing optical member (4), a prism film A in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the total thickness is 230 μm is used. "Sumipex E RM802S" (trade name) manufactured by Sumitomo Chemical Co., Ltd. is used as the photosensitive optical member (6).

In the VA liquid crystal display device of Comparative Example 8, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 9>
After mixing 100 parts by mass of polystyrene resin and 10 parts by mass of silicone resin particles (“Tospearl 145” manufactured by Toshiba Silicone Co., Ltd.) (light diffusing particles) with a Henschel mixer, the mixture is melt-kneaded with an extruder and extruded. A first light diffusing optical member (3) formed from a 0.1 mm thick sheet is manufactured. The refractive index of the polystyrene resin is 1.59, the refractive index of the silicone resin particles is 1.43, and the absolute value (Δn) of the refractive index difference between them is 0.16. The 50% cumulative particle diameter (D ₅₀ ) of the silicone resin particles is 3.9 (μm). Therefore, Δn × D ₅₀ = 0.624 μm.

In the VA liquid crystal display device of Comparative Example 9, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 10>
Using the same first light diffusing optical member (3) as in Comparative Example 9, the VA liquid crystal display device (1) having the configuration shown in FIG. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the light condensing optical member (4), a prism film A in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the total thickness is 230 μm is used. "Sumipex E RM802S" (trade name) manufactured by Sumitomo Chemical Co., Ltd. is used as the photosensitive optical member (6).

In the VA type liquid crystal display device of Comparative Example 10, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 11>
Using the same first light diffusing optical member (3) as in Comparative Example 9, the VA liquid crystal display device (1) having the configuration shown in FIG. 3 is manufactured. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. A light guide plate made of a transparent thermoplastic resin is used as the light guide plate (7). Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the condensing optical member (4), a prism film A is used in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the overall thickness is 230 μm.

In the VA liquid crystal display device of Comparative Example 11, when the liquid crystal panel is in a white display state by a pattern generator with the light source turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 12>
Using the same first light diffusing optical member (3) as in Comparative Example 9, the VA liquid crystal display device (1) having the configuration shown in FIG. 4 is manufactured. As the light source (2), a straight tube type fluorescent tube that emits white light including R, G, and B is used. A light guide plate made of a transparent thermoplastic resin is used as the light guide plate (7). Reflective polarized light separation film (40) formed from “DBEF-M” (thickness: 242 μm) manufactured by 3M Co., Ltd. is passed through a pressure-sensitive adhesive sheet (41) with an acrylic pressure-sensitive adhesive on both sides. Is laminated on the front surface of the diffractive optical member (3) and integrated with the first light diffusing optical member (3). Further, as the light condensing optical member (4), a prism film A in which the apex angle of the prism triangle is 90 °, the pitch interval between the apexes of adjacent prisms is 48 μm, and the total thickness is 230 μm is used. "Sumipex E RM802S" (trade name) manufactured by Sumitomo Chemical Co., Ltd. is used as the photosensitive optical member (6).

In the VA type liquid crystal display device of Comparative Example 12, when the liquid crystal panel is brought into a white display state with the light source turned on, a natural white screen display can be seen without being reddish in the front direction, but in an oblique direction When viewed from the top, it becomes a high brightness white screen display with reddishness.

<Comparative Example 13>
The VA liquid crystal display device is the same as that of the first embodiment except that the reflective polarization separation film (40) and the adhesive layer (41) are not disposed (deleted) in the VA liquid crystal display device of the first embodiment. Is produced.

In the VA type liquid crystal display device of Comparative Example 13, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without being reddish when viewed from the front or oblique direction. However, the luminance is insufficient as compared with Example 1.

<Comparative example 14>
The VA liquid crystal display device of the second embodiment is the same as the second embodiment except that the reflective polarization separating film (40) and the adhesive layer (41) are not disposed (deleted). Is produced.

In the VA type liquid crystal display device of Comparative Example 14, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without being reddish when viewed from the front or oblique direction. However, the luminance is insufficient as compared with Example 2.

<Comparative Example 15>
The VA liquid crystal display device of the third embodiment is the same as the third embodiment except that the reflective polarized light separating film (40) and the adhesive layer (41) are not disposed (deleted). Is produced.

In the VA type liquid crystal display device of Comparative Example 15, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without being reddish when viewed from the front or oblique direction. However, the luminance is insufficient as compared with Example 3.

<Comparative Example 16>
The VA liquid crystal display device of the fourth embodiment is the same as the fourth embodiment except that the reflective polarized light separating film (40) and the adhesive layer (41) are not disposed (deleted). Is produced.

In the VA liquid crystal display device of Comparative Example 16, when the liquid crystal panel is in a white display state with the light source turned on, a natural white screen display can be seen without being reddish when viewed from the front or oblique direction. However, the luminance is insufficient as compared with Example 4.

The liquid crystal display devices according to the first to tenth embodiments of the present invention can realize a natural, high-quality, high-luminance color display without being reddish when viewed from an oblique direction as well as a front direction.

In addition, the liquid crystal display devices according to the eleventh and twelfth embodiments of the present invention can realize a natural, high-quality, high-luminance color display without redness in the front direction, and a natural, high-luminance color display with little redness in the oblique direction. Can be realized.

On the other hand, in the liquid crystal display devices of Comparative Examples 1 to 12 that deviate from the specified range of the present invention, a reddish color display is obtained when viewed from an oblique direction. In addition, in the liquid crystal display devices of Comparative Examples 13 to 16 that do not include the reflective polarization separation film, natural color display is achieved without redness when viewed from the front direction or the oblique direction. In comparison, the brightness is insufficient.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device 2 ... Light source 3 ... 1st light diffusable optical member 4 ... Light condensing optical member 6 ... 2nd light diffusable optical member 7 ... Light guide plate 11 ... Liquid crystal 12 ... Transparent electrode 13 ... Transparent electrode 20 ... Liquid crystal cell 30 ... Liquid crystal panel 40 ... Reflective polarized light separation film 50 ... Light source device 100 ... Laminated optical member

Claims

A first light diffusing optical member;
A light source device disposed on the back side of the first light diffusing optical member;
A liquid crystal panel disposed on the front side of the first light diffusing optical member;
A reflective polarization separation film disposed between the first light diffusing optical member and the liquid crystal panel,
The liquid crystal panel has a liquid crystal cell having a pair of transparent electrodes disposed apart from each other and a liquid crystal sealed between the pair of transparent electrodes,
The liquid crystal molecules are aligned in a direction substantially perpendicular to the transparent electrode in a state where no voltage is applied between the pair of transparent electrodes.
The first light diffusing optical member has a transparent material, and light diffusing particles dispersed in the transparent material, and
When the absolute value of the difference between the refractive index of the transparent material and the refractive index of the light diffusing particles is Δn, and the cumulative 50% particle diameter of the light diffusing particles is D 50 (μm), 0.01 ≦ Δn × A liquid crystal display device satisfying D 50 ≦ 0.25.
The liquid crystal display device according to claim 1, further comprising a condensing optical member disposed between the first light diffusing optical member and the light source device.
A first light diffusing optical member;
A light source device disposed on the back side of the first light diffusing optical member;
A liquid crystal panel disposed on the front side of the first light diffusing optical member;
A reflective polarization separation film disposed between the first light diffusing optical member and the light source device,
The liquid crystal panel has a liquid crystal cell having a pair of transparent electrodes disposed apart from each other and a liquid crystal sealed between the pair of transparent electrodes,
The liquid crystal molecules are aligned in a direction substantially perpendicular to the transparent electrode in a state where no voltage is applied between the pair of transparent electrodes.
The first light diffusing optical member has a transparent material and light diffusing particles dispersed in the transparent material, and an absolute value of a difference between a refractive index of the transparent material and a refractive index of the light diffusing particles. Is a liquid crystal display device that satisfies 0.01 ≦ Δn × D 50 ≦ 0.25, where Δn is Δn and the cumulative 50% particle diameter of the light diffusing particles is D 50 (μm).
The liquid crystal display device according to claim 3, further comprising a condensing optical member disposed between the reflective polarization separation film and the light source device.
A front side first light diffusing optical member;
A back side first light diffusing optical member;
A light source device disposed on the back side of the back side first light diffusing optical member;
A liquid crystal panel disposed on the front side of the front side first light diffusing optical member;
A reflective polarization separation film disposed between the front-side first light-diffusing optical member and the back-side first light-diffusing optical member,
The liquid crystal panel has a liquid crystal cell having a pair of transparent electrodes disposed apart from each other and a liquid crystal sealed between the pair of transparent electrodes,
The liquid crystal molecules are aligned in a direction substantially perpendicular to the transparent electrode in a state where no voltage is applied between the pair of transparent electrodes.
Each of the front side first light diffusing optical member and the back side first light diffusing optical member has a transparent material and light diffusing particles dispersed in the transparent material, and refraction of the transparent material When the absolute value of the difference between the refractive index and the refractive index of the light diffusing particles is Δn, and the cumulative 50% particle diameter of the light diffusing particles is D 50 (μm), 0.01 ≦ Δn × D 50 ≦ 0. A liquid crystal display device satisfying 25.
The liquid crystal display device according to claim 5, further comprising a condensing optical member disposed between the back side first light diffusing optical member and the light source device.
The liquid crystal display device according to claim 2, 4 or 6, further comprising a second light diffusing optical member disposed between the light condensing optical member and the light source device.
The condensing optical member emits outgoing light emitted from the condensing optical member when incident light having a half-value half-width in an incident angle-luminance curve of 60 ° or more enters the condensing optical member. The liquid crystal display device according to claim 2, 4, 6, or 7, wherein the liquid crystal display device has a light collecting performance in which a half-value half width in an angle-luminance curve is 10 ° or more smaller than a half value half-width of the incident light.
The light collecting optical member is a prism sheet,
The prism sheet has a half-value half-width in the emission angle-luminance curve of the emitted light emitted from the prism sheet when incident light having a half-width of 60 ° or more in the incident angle-luminance curve is incident on the prism sheet. The liquid crystal display device according to claim 2, 4, 6, or 7, comprising a light collecting performance that is 10 ° or more smaller than a half width at half maximum of the incident light.
The light collecting optical member is a light diffusion sheet,
The light diffusing sheet has a half value in the emission angle-luminance curve of the emitted light emitted from the light diffusing sheet when incident light having a half-width of 60 ° or more in the incident angle-luminance curve is incident on the light diffusing sheet. 8. The liquid crystal display device according to claim 2, 4, 6, or 7, comprising a light collecting performance whose half width is 10 ° or more smaller than the half width of the incident light.
The light collecting optical member is a light diffusing optical member having a concavo-convex shape on the surface,
The light diffusing optical member emits outgoing light emitted from the light diffusing optical member when incident light having a half-value half-width of 60 ° or more in the incident angle-luminance curve is incident on the light diffusing optical member. The liquid crystal display device according to claim 2, 4, 6, or 7, wherein the liquid crystal display device has a condensing performance in which a half-value half-width in an angle-luminance curve is 10 ° or more smaller than a half-value half width of the incident light.
The light source device includes: a light guide plate disposed on a back side of the first light diffusing optical member; and a light source disposed on a side of at least one side surface of the light guide plate. 2. A liquid crystal display device according to item 1.
12. The liquid crystal display device according to claim 1, wherein the light source device includes a plurality of light sources arranged on a back side of the first light diffusing optical member.
The liquid crystal display device according to claim 12 or 13, wherein the light source is a light emitting diode.
A first light diffusing optical member;
A reflective polarization separation film laminated and integrated on the first light diffusing optical member,
The first light diffusing optical member has a transparent material, and light diffusing particles dispersed in the transparent material,
When the absolute value of the difference between the refractive index of the transparent material and the refractive index of the light diffusing particles is Δn, and the cumulative 50% particle diameter of the light diffusing particles is D 50 (μm), 0.01 ≦ Δn × A laminated optical member satisfying D 50 ≦ 0.25.