JP2013120266A - Optical module and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical module capable of adjusting brightness distribution without using a light guide plate.SOLUTION: An optical module 20 includes a reflection sheet 21, a deflection optical sheet 50 arranged at a position facing the reflection sheet, and a light source illuminating a region between the deflection optical sheet and the reflection sheet. The reflection sheet reflects the light in accordance with reflection characteristics having directivity which depends on an incident direction of the light. The deflection optical sheet includes a sheet-like body part 55, and a plurality of unit optical elements 60 which are arranged on the body part and which protrude toward the reflection sheet.

Description

  The present invention relates to an optical module having a light source, a reflection sheet, and a deflecting optical sheet, and a display device having the optical module.

  Today, an optical module having a light source and a deflecting optical sheet is used by being incorporated in various optical devices. As a typical use example, the optical module is used in a display device, particularly a liquid crystal display device. As disclosed in, for example, Patent Document 1, the liquid crystal display device includes a liquid crystal display panel and a surface light source device that functions as a backlight that illuminates the liquid crystal display panel.

  As shown in FIG. 30, a conventional backlight includes a light source E including a light emitter F, a reflector D for directing light source light toward the liquid crystal display panel, and a liquid crystal display panel and the reflector D. And a large number of optical sheets arranged. Many optical sheets are designed so that the liquid crystal display panel can be illuminated with desired optical characteristics by changing the traveling direction of light from the light emitter. The backlight shown in FIG. 30 is configured as an edge light type, and a light guide plate A, a deflection sheet B, and a light diffusion sheet C are provided in this order from the reflection plate D side to the liquid crystal display panel side. . The light emitter F of the light source E is disposed on the side of the light guide plate A, and the light emitted from the light emitter F enters the light guide plate A from the side surface of the light guide plate A. The light that has entered the light guide plate is repeatedly reflected by the pair of main surfaces of the light guide plate A, and is guided toward the side surface opposite to the incident surface. The light traveling in the light guide plate is gradually emitted from one main surface (light exit surface) of the light guide plate as it proceeds in the light guide direction. As a result, the amount of light emitted from the light exit surface of the light guide plate is made uniform to some extent along the light guide direction. The light emitted from the light guide plate A enters the deflection sheet B, and then enters the light diffusion sheet C. The deflection sheet B has a function (deflection function) for narrowing the traveling direction of light to the front direction and improving the luminance in the front direction.

  On the other hand, as shown in FIG. 30, the liquid crystal display panel includes a liquid crystal cell 11 capable of controlling the orientation of the liquid crystal for each pixel, a lower polarizing plate 13 disposed on the light incident side of the liquid crystal cell, and a liquid crystal cell. 11 and an upper polarizing plate 12 disposed on the light output side. The pair of polarizing plates 12 and 13 is a polarizer that transmits light of a specific polarization component and absorbs light of components other than the specific polarization component, a protective film that is bonded to the polarizer and protects the polarizer, have.

JP 2007-227405 A

  That is, in the edge light type surface light source device shown in FIG. 30, the light source is arranged on the side of the optical sheet, and the light guide plate makes the light quantity distribution along the light guide direction uniform. Yes. As a result, in the edge light type surface light source device, since it is not necessary to arrange the light source at a position facing the optical sheet, the thickness of the surface light source device and the thickness of the display device incorporating the surface light source device can be reduced. It becomes possible.

  However, the thickness of the light guide plate that guides the light from the light source is larger than the width of the light emitting portion of the light source in order to effectively use the light from the light source, and as a result, compared with the thickness of other optical sheets. It becomes very thick. For this reason, the material cost of a light-guide plate is high, and it will also obstruct the thickness reduction and weight reduction of a surface light source device and a display apparatus. Furthermore, it may be necessary to provide a special support structure for supporting the light guide plate.

  The present invention has been made in consideration of such points, and provides an optical module capable of adjusting the brightness distribution without using a thick light guide plate, and a display device including the optical module. For the purpose.

The first optical module according to the present invention comprises:
A reflection sheet that reflects the light with a reflection characteristic having directivity depending on the incident direction of light;
A deflecting optical sheet disposed at a position facing the reflecting sheet, and a sheet-like main body portion, and a plurality of unit optical elements arranged on the main body portion and projecting toward the reflecting sheet. A deflection optical sheet having
A light source that projects light traveling from one side to the other side in a direction parallel to the arrangement direction of the unit optical elements onto a region between the deflection optical sheet and the reflection sheet.

  In the first optical module according to the present invention, the reflection sheet measured in accordance with JISZ8741 using incident light that travels in a plane parallel to the arrangement direction of the unit optical elements and is incident at an incident angle of 60 °. The specular gloss may be 24 or more.

  In the first optical module according to the present invention, the surface of the reflection sheet facing the deflection optical sheet may be a smooth surface.

  In the first optical module according to the present invention, the reflection sheet may contain a diffusing component therein.

  The first optical module according to the present invention may further include an auxiliary reflecting element disposed at a position facing the light source along a direction parallel to the arrangement direction of the unit optical elements.

  In the first optical module according to the present invention, the specular gloss of the auxiliary reflecting element measured in accordance with JISZ8741 proceeds in a plane parallel to the arrangement direction of the unit optical elements at an incident angle of 60 °. You may make it be more than the specular glossiness of the said reflective sheet measured based on JISZ8741 using the incident incident light.

  In the first optical module according to the present invention, the light source so that an optical axis of light emitted from the light source extends between the deflecting optical sheet and the reflective sheet and is directed to a position on the auxiliary reflective element. May be configured.

  In the first optical module according to the present invention, a surface of the auxiliary reflection element facing the light source is inclined with respect to a direction parallel to an arrangement direction of the unit optical elements, and the auxiliary reflection element is the unit. Light traveling in a direction parallel to the arrangement direction of the optical elements may be reflected to a position on the deflecting optical sheet.

  In the first optical module according to the present invention, light emitted from the light source along the optical axis travels between the deflection optical sheet and the reflection sheet and enters the auxiliary reflection element, and the auxiliary reflection element The light source and the auxiliary reflecting element are configured so that they can be reflected by the light and enter the deflecting optical sheet.

  The first optical module according to the present invention irradiates a region between the deflecting optical sheet and the reflective sheet with light traveling from the other side to one side in a direction parallel to the arrangement direction of the unit optical elements. May be further provided.

  The first optical module according to the present invention may further include a second auxiliary reflecting element disposed at a position facing the second light source along a direction parallel to the arrangement direction of the unit optical elements. .

  In the first optical module according to the present invention, the specular glossiness of the second auxiliary reflecting element measured in accordance with JISZ8741 proceeds in a plane parallel to the arrangement direction of the unit optical elements and is incident at 60 °. You may make it be more than the specular glossiness of the said reflective sheet measured based on JISZ8741 using the incident light which injects at an angle.

  In the first optical module according to the present invention, the optical axis of the light emitted from the second light source extends between the deflecting optical sheet and the reflecting sheet and is directed to a position on the second auxiliary reflecting element. In addition, the second light source and the auxiliary reflection element may be configured.

  In the first optical module according to the present invention, a surface of the second auxiliary reflecting element facing the second light source is inclined with respect to a direction parallel to an arrangement direction of the unit optical elements, and the second auxiliary reflecting element is inclined. The reflection element may reflect light traveling in a direction parallel to the arrangement direction of the unit optical elements to a position on the deflection optical sheet.

  The first optical module according to the present invention may further include a polarizer provided on the side of the deflecting optical sheet opposite to the side facing the reflecting sheet and bonded to the deflecting optical sheet. .

The second optical module according to the present invention comprises:
A reflective sheet;
A deflecting optical sheet disposed at a position facing the reflecting sheet, and a sheet-like main body portion, and a plurality of unit optical elements arranged on the main body portion and projecting toward the reflecting sheet. A deflection optical sheet having
A light source that projects light traveling from one side to the other side in a direction parallel to the arrangement direction of the unit optical elements onto a region between the deflection optical sheet and the reflection sheet;
An auxiliary reflection element disposed at a position facing the light source along a direction parallel to the arrangement direction of the unit optical elements,
The light source is configured such that the optical axis of light emitted from the light source extends between the deflecting optical sheet and the reflecting sheet and is directed to a position on the auxiliary reflecting element.

  In the second optical module according to the present invention, the specular gloss of the auxiliary reflecting element measured in accordance with JISZ8741 proceeds in a plane parallel to the arrangement direction of the unit optical elements at an incident angle of 60 °. It may be greater than or equal to the specular gloss of the reflective sheet measured in accordance with JISZ8741 using incident incident light.

  In the second optical module according to the present invention, light emitted from the light source along the optical axis travels between the deflection optical sheet and the reflection sheet and enters the auxiliary reflection element, and the auxiliary reflection element The light may be reflected by and incident on the deflecting optical sheet.

  In the second optical module according to the present invention, a surface of the auxiliary reflection element facing the light source is inclined with respect to a direction parallel to an arrangement direction of the unit optical elements, and the auxiliary reflection element is the unit. Light traveling in a direction parallel to the arrangement direction of the optical elements may be reflected to a position on the deflecting optical sheet.

  The second optical module according to the present invention irradiates a region between the deflecting optical sheet and the reflective sheet with light traveling from the other side to one side in a direction parallel to the arrangement direction of the unit optical elements. May be further provided.

  The second optical module according to the present invention may further include a second auxiliary reflecting element disposed at a position facing the second light source along a direction parallel to the arrangement direction of the unit optical elements. .

  In the second optical module according to the present invention, the specular glossiness of the second auxiliary reflecting element measured in accordance with JISZ8741 proceeds in a plane parallel to the arrangement direction of the unit optical elements and is incident at 60 °. It may be greater than or equal to the specular gloss of the reflection sheet measured in accordance with JISZ8741 using incident light incident at an angle.

  In the second optical module according to the present invention, the second light source has one or more light emitting portions, and an optical axis of light emitted from the second light source is between the deflection optical sheet and the reflection sheet. The second light source may be configured to extend to a position on the second auxiliary reflection element.

  In the second optical module according to the present invention, a surface of the second auxiliary reflecting element facing the second light source is inclined with respect to a direction parallel to the arrangement direction of the unit optical elements, The reflection element may reflect light traveling in a direction parallel to the arrangement direction of the unit optical elements to a position on the deflection optical sheet.

  The second optical module according to the present invention may further include a polarizer provided on a side opposite to the side facing the reflection sheet of the deflection optical sheet and bonded to the deflection optical sheet. .

  The display device according to the present invention includes any one of the first and second optical modules according to the present invention described above.

  In the display device according to the present invention, the deflection optical sheet may form a surface on the most incident light side of the liquid crystal display panel.

  According to the present invention, it is possible to adjust the brightness distribution without using a light guide plate.

FIG. 1 is a perspective view showing a schematic configuration of a display device and an optical module for explaining an embodiment according to the present invention. FIG. 2 is a side view showing the display device and the optical module. FIG. 3 is a plan view for explaining the positional relationship between the deflecting optical sheet and the light emitting part of the light source. FIG. 4 is a diagram for explaining the reflection characteristics of the reflection sheet. FIG. 5 is a perspective view showing a deflection optical sheet. FIG. 6 is a schematic view showing a liquid crystal display panel. FIG. 7 is a view showing the polarizing plate in the same cross section as FIG. 2, and is a view for explaining a modified example of the deflecting optical sheet. FIG. 8 is a view showing the polarizing plate in the same cross section as FIG. 2, and is a view for explaining another modified example of the deflecting optical sheet. FIG. 9 is a view showing the polarizing plate in the same cross section as FIG. 2 and is a view for explaining still another modified example of the deflecting optical sheet. 10 is an enlarged view of the unit optical element of the deflecting optical sheet shown in FIG. 9 in the same cross section as FIG. FIG. 11 is a view showing the deflection optical sheet in the same cross section as FIG. 2, and is a view for explaining still another modification of the deflection optical sheet. FIG. 12 is a diagram showing a unit optical element of the deflecting optical sheet in the same cross section as FIG. 11, and is a diagram for explaining a modification of the unit optical element. FIG. 13 is a diagram showing a unit optical element of the deflecting optical sheet in the same cross section as FIG. 11, and is a diagram for explaining another modification of the unit optical element. FIG. 14 is a view showing the deflection optical sheet in the same cross section as FIG. 2, and is a view for explaining still another modification of the deflection optical sheet. FIG. 15 is a view showing the deflection optical sheet in the same cross section as FIG. 2, and is a view for explaining still another modification of the deflection optical sheet. FIG. 16 is a view showing the deflection optical sheet in the same cross section as FIG. 2, and is a view for explaining still another modification of the deflection optical sheet. FIG. 17 is a view showing the deflecting optical sheet in the same cross section as FIG. 2, and is a view for explaining still another modified example of the deflecting optical sheet. FIG. 18 is a diagram corresponding to FIG. 3 and a plan view for explaining a modification of the optical module. FIG. 19 is a diagram corresponding to FIG. 3 and a plan view for explaining another modified example of the optical module. FIG. 20 is a perspective view showing a light diffusion layer of the deflecting optical sheet, and is a view for explaining a modification of the light diffusion layer. FIG. 21 is a view corresponding to FIG. 2 and a cross-sectional view for explaining still another modification of the optical module. FIG. 22 is a view corresponding to FIG. 2 and a cross-sectional view for explaining still another modification of the optical module. FIG. 23 is a view corresponding to FIG. 2 and a cross-sectional view for explaining still another modification of the optical module. FIG. 24 is a diagram showing a modification of the liquid crystal display panel from the side. FIG. 25 is a diagram for explaining a modification of the light source. FIG. 26 is a diagram illustrating a luminance distribution in the front direction at each position of the optical module according to the first embodiment. FIG. 27 is a diagram illustrating a luminance distribution in the front direction at each position of the optical module according to the second embodiment. FIG. 28 is a diagram illustrating a luminance distribution in the front direction at each position of the optical module according to the third embodiment. FIG. 29 is a diagram illustrating a luminance distribution in the front direction at each position of the optical module according to Comparative Example 1. FIG. 30 is a cross-sectional view showing a display device including a conventional surface light source device. FIG. 31 is a diagram corresponding to FIG. 2 for explaining another modification of the light source. FIG. 32 is a diagram corresponding to FIG. 2 and is a diagram for explaining another modified example of the light source. FIG. 33 is a diagram corresponding to FIG. 2 and illustrating another modified example of the light source.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual ones.

  FIGS. 1-6 is a figure for demonstrating one Embodiment by this invention. Among these, FIG. 1 and FIG. 2 are a perspective view and a side view showing schematic configurations of the display device and the optical module, respectively. FIG. 3 is a plan view showing the optical module, and shows the positional relationship between the deflection optical sheet of the optical module and the light emitting part (light emitter) of the light source. FIG. 4 is a side view for explaining the reflection characteristics of the reflection sheet, and FIG. 5 is a perspective view showing the deflection optical element.

  The display device 10 shown in FIG. 1 is a liquid crystal display device, and is disposed on the liquid crystal display panel 15 and on the back side of the liquid crystal display panel 15, in other words, on the side opposite to the observer side with respect to the liquid crystal display panel 15. The reflecting sheet (reflecting plate, reflecting element, reflecting member) 21 and a light source 25 for irradiating light from the side to the region between the deflecting optical sheet 50 and the reflecting sheet 21 are provided. The liquid crystal display panel 15 is a device that functions as a shutter that controls transmission or blocking of light for each pixel of the color filter to form an image.

  As will be described in detail later, the liquid crystal display panel 15 includes a pair of polarizing plates 12 and 40 and a liquid crystal cell 11 disposed between the pair of polarizing plates. Then, the optical module 20 is formed by the deflection optical sheet 50 of the one polarizing plate 40 positioned closest to the light incident side of the liquid crystal display panel 15, the light source 25, and the reflection sheet 21. In the present embodiment, the auxiliary reflecting element 31 extending between the deflecting optical sheet 50 and the reflecting sheet 21 is disposed to face the light source 25, and this auxiliary reflecting element 31 is also a part of the optical module 20. Is configured. In the following, in order to distinguish a pair of polarizing plates included in the liquid crystal display panel 15, the light incident side polarizing plate 40 is referred to as a lower polarizing plate regardless of the arrangement state of the display device 10, and the light emitting side polarized light. The plate 12 is called an upper polarizing plate.

  As shown in FIGS. 1, 2, 5, and 6, in the present embodiment, a liquid crystal display panel 15, a pair of polarizing plates 12 and 40 and a liquid crystal cell 11 as components constituting the liquid crystal display panel 15. Furthermore, the deflection optical sheet 50 that also functions as a protective film for the polarizer 41 in the lower polarizing plate 40 described later is configured to have a quadrangular shape in plan view. As a result, each member (each component) ) Has two pairs of edges, a pair of edges facing the first direction d1 and another pair of edges facing the second direction d2. Therefore, the deflecting optical sheet 50 has two pairs of edge portions, that is, a pair of edge portions 50c1 and 50c2 facing the first direction d1, and another pair of edge portions facing the second direction d2. In the present embodiment, the first direction d1 and the second direction d2 are orthogonal to each other.

  As will be described in detail later, the light emitted from the light emitting unit 26 of the light source 25 is reflected by the auxiliary reflecting element 31 and / or reflected by the reflecting sheet 21 or directly enters the liquid crystal display panel. The light enters the deflecting optical sheet 50 forming the light side surface. Hereinafter, the reflection sheet 21, the auxiliary reflection element 31, the light source 25, and the liquid crystal display panel 15 will be described in order.

  In the present specification, the “light exit side” refers to the downstream side of the optical path planned for the observer (the right side of the paper in FIGS. 1 and 2), that is, the observer side. The “light incident side” is the upstream side in the planned optical path. Further, the “back side” is the side opposite to the “light emission side” in the front direction.

  Further, in the present specification, the terms “sheet” and “film” are not distinguished from each other only based on the difference in names. Therefore, for example, “sheet” is a concept including a member that can also be called a film, and is not distinguished only by its name. As a specific example, the “deflection optical sheet” includes a member that can be called a “deflection optical film”. Similarly, the “reflective sheet” includes a member that can be called a “reflective plate”.

  Further, in this specification, the “front direction” means a normal line to a light incident side surface (surface facing the reflection sheet 21) 55 b of a main body portion 55 to be described later of the deflection optical sheet 50 constituting the optical module 20. It refers to the direction nd. The front direction in the present embodiment is the normal direction to the display surface 10a of the display device 10 formed by the surface of the liquid crystal display panel 15 closest to the observer (most light-emitting side), and the liquid crystal display panel 15 The normal direction to the panel surface, the normal direction to the plate surface of the lower polarizing plate 40, the normal direction to the sheet surface of the deflecting optical sheet 50, and the method of the deflecting optical sheet 50 to the sheet surface of the main body 55 described later. It matches the line direction. Further, in this specification, the “panel surface (sheet surface, film surface, plate surface)” is the plane of the target sheet-like member when the target sheet-like member is viewed overall and globally. A surface that matches the direction.

  Furthermore, the terms used in this specification for specifying shapes and geometric conditions, for example, terms such as “parallel” and “orthogonal” are not limited to strict meaning, and expect similar optical functions. Interpretation will be made including possible errors.

  First, the reflection sheet 21 will be described. The reflection sheet 21 is disposed at a position facing the deflecting optical sheet 50 forming the light incident side surface of the liquid crystal display panel 15 from the front direction. The reflective sheet 21 has a reflective surface 22 that reflects light as a surface facing the deflecting optical sheet 50. The reflection sheet 21 reflects the light incident on the reflection surface 22 toward the light incident side surface 50 b of the deflecting optical sheet 50, that is, the light incident side surface of the liquid crystal display panel 15.

  The reflection sheet 21 includes at least a reflection surface 22 made of a material having a high reflectance such as metal. In particular, the reflection sheet 21 described here reflects the light with a reflection characteristic having directivity depending on the incident direction of light. Here, “reflection characteristics having directivity depending on the incident direction of light” refers to characteristics in which the reflected light distribution of reflected light in each direction changes when the incident direction changes. That is, “a reflection characteristic having directivity depending on the incident direction of light” means a reflection characteristic that is not completely diffused so that the amount of reflected light in each direction is uniform without depending on the incident direction. In FIG. 4, the amount of reflected light in each direction when light incident from a specific direction is reflected is indicated by a solid line and a two-dot chain line. The solid line in FIG. 4 is an example of “a reflection characteristic having directivity depending on the incident direction of light”, and the two-dot chain line in FIG. 5 indicates the reflection characteristic in the case of complete diffusion. In particular, in the example shown by the solid line in FIG. 4, the mirror-reflected light is contained most in the reflected light. That is, in the example shown in FIG. 4, the direction in which the amount of reflected light is maximized changes depending on the incident direction.

  In the conventional optical module and surface light source device using the light guide plate A shown in FIG. 30, a reflection sheet D having a reflection characteristic that completely diffuses incident light has been widely used. White dots having a completely diffuse reflection function are printed on the back surface of the light guide plate A that is most widely used. In order to give the reflection sheet D the same reflection characteristics as the white dots, a complete diffuse reflection function is provided. There was a tendency to use a reflective sheet D having Further, for the purpose of preventing optical adhesion between the light guide plate A and the reflection sheet D, the reflection sheet D having a concavo-convex surface and strong diffusivity has been used.

  As a result of intensive studies, the inventors of the present invention have found the following as demonstrated in Examples described later. By incorporating a reflection sheet having a reflection characteristic having directivity depending on the incident direction of light into the optical module 20 having the configuration described here, instead of the reflection sheet exhibiting the perfect diffuse reflection characteristic which has been used conventionally. The brightness distribution along the first direction d1 can be effectively uniformed. Describing more quantitatively, the specular glossiness of the reflective sheet 21 measured in accordance with JISZ8741 using incident light that travels in a plane parallel to the first direction d1 and is incident at an incident angle of 60 °, When it is 24 or more, the brightness distribution along the first direction d1 can be more effectively uniformized. Furthermore, when the reflecting surface 22 facing the deflecting optical sheet 50 of the reflecting sheet 21 is a smooth surface, the brightness distribution along the first direction d1 can be more effectively uniformized.

  As used herein, “smoothing” means smoothing in an optical sense. Therefore, for example, if the 10-point average roughness Rz (JISB0601) of the reflecting surface 22 of the reflecting sheet 21 is equal to or shorter than the shortest visible light wavelength (0.38 μm), the surface is sufficiently smooth.

  However, the reflection sheet 21 may have a diffuse reflection function as long as the reflection sheet 21 has a directivity characteristic depending on the incident direction of light as in the reflection characteristic indicated by a solid line in FIG. When the reflection on the reflection sheet 21 is diffuse reflection, the reflection may be isotropic diffusion or anisotropic diffusion. For example, by forming irregularities on the reflection surface 22 of the reflection sheet 21 by embossing or the like, reflection on the reflection sheet 21 can be made isotropic diffusion. Further, for example, by applying a hairline process to the reflection surface 22 of the reflection sheet 21, the reflection on the reflection sheet 21 can be anisotropic diffusion. Furthermore, a transparent optical element such as a prism, a lens, and a microlens is provided on the flat reflecting surface 22 of the reflecting sheet 21. Due to these optical elements, the reflecting sheet 21 has an isotropic diffuse reflection function. Or you may make it express an anisotropic diffuse reflection function.

  As shown in FIGS. 1 and 2, the reflection sheet 21 is disposed at a position shifted from the deflection optical sheet 50 in the front direction. More specifically, the reflection sheet 21 is arranged at a position shifted from the light incident side surface 50 b of the deflecting optical sheet 50 toward the back side along the front direction. Thereby, the light reflected by the reflecting surface 22 of the reflecting sheet 21 can be directly incident on the light incident side surface 50b of the deflecting sheet 50, in other words, can be incident as it is without passing through another member. It has become. In particular, in the present embodiment, as shown in FIG. 2, the reflection sheet 21 is disposed so that at least a part thereof faces the deflecting optical sheet 50 and the front direction nd. That is, no other member is interposed between at least a part of the reflection sheet 21 and the deflecting optical sheet 50, and the light reflected by at least a part of the reflecting sheet 21 is directly applied to the deflecting optical sheet 50. Can be incident.

  As the reflection sheet 21 as described above, for example, a reflection sheet in which the reflection surface 22 is made of silver and has a specular reflection function can be used. Moreover, as the reflection sheet 21 having diffuse reflection properties that are not completely diffused, for example, the surface roughness of the reflection surface 22 is low or the reflection surface 22 is smooth, and contains a diffusion component 21a (see FIG. 4) inside. A reflective sheet can be used. The diffusion component 21a of the reflective sheet is not particularly limited, and may be, for example, a metal compound, a porous material containing a gas, or even a simple bubble. Good.

  Next, the light source will be described. As shown in FIGS. 1 to 3, the light source 25 is provided in the vicinity of the edge 50 c 1 corresponding to one edge 50 c 1 of the deflecting optical sheet 50 having a rectangular planar shape. And as shown in FIG. 3, the light emission part 26 radiates | emits light so that this edge part 50c1 may be crossed in planar view.

  As the light emitting unit 26 forming the light source 25, various known light emitting units, for example, a cold cathode tube, in particular, a cold cathode tube with a narrow light distribution direction can be used. However, in the illustrated example, the light source 25 is configured by a plurality of dot-like light emitting units 26, typically a plurality of light emitting diodes (LEDs) 26. A large number of point light emitting portions 26 constituting the light source 25 are arranged side by side along the longitudinal direction of the edge portion 50c1 of the corresponding deflecting optical sheet 50. In other words, in the present embodiment, a large number of point light emitting units 26 that form the light source 25 are arranged side by side in a second direction d2 orthogonal to the first direction d1.

  As well shown in FIGS. 3 and 2, in the display device 10, the light emitting unit 26 that forms the light source 25 follows the outer contour of the liquid crystal display panel 15, as in the edge light type liquid crystal display device. It is located outside the outer contour. More specifically, the light emitting unit 26 of the light source 25 is disposed at a position that is outside the edge portion 50c1 of the deflecting optical sheet 50 in the observation from the front direction. That is, as shown in FIG. 3, in the observation from the front direction, the light emitting unit 26 that constitutes the light source 25 has the liquid crystal display panel 15 (more precisely, the display surface 10 a that forms an image in the liquid crystal display panel 15. It is arranged at a position that does not overlap with the area to be made.

  Further, in the display device 10 according to the present embodiment, as shown in FIG. 2, the light emitting unit 26 that constitutes the light source 25 is arranged at a position shifted from the liquid crystal display panel 15 in the front direction. More specifically, the light emitting unit 26 that constitutes the light source 25 is a position shifted to the back side along the front direction from the light incident side surface 50 b of the deflecting optical sheet 50, and is in front of the reflecting surface 22 of the reflecting sheet 21. It is arranged at a position shifted to the viewer side along the direction. With such an arrangement, the light source 25 projects light onto a region between the reflective sheet 21 and the deflecting optical sheet 50, and the light is transmitted from the edge 50c1 side of the deflecting optical sheet 50 in the first direction d1. It proceeds to the other edge 50c2. Therefore, the reflecting surface 22 of the reflecting sheet 21 and the light incident side surface 50b of the deflecting optical sheet 50 can receive at least a part of the light emitted from the light source 25 directly, that is, without passing through another member.

  By the way, the light source 25 including the point light emitting unit 26 such as an LED does not emit light radially with a uniform luminous intensity but has directivity. That is, the light source 25 configured to include the point light emitting unit 26 such as an LED emits light at different luminosity (unit: candela) in each direction. In general, light emitted from a light source has a peak luminous intensity in a specific direction pd. As the inclination angle with respect to the specific direction pd increases, the value of the luminous intensity gradually decreases. Preferably, the arrangement of the light emitting units 26 constituting the light source 25 is determined in consideration of such directivity characteristics (light distribution characteristics, in other words, luminous intensity angle (direction) distribution). In the present specification, the above-described specific direction that provides the peak luminous intensity is referred to as an “optical axis”.

  As shown in FIG. 2, in the present embodiment, the optical axis pd of the light emitted from the light source 25 in the cross section parallel to both the front direction nd and the first direction d1 is the deflection optical sheet 50 and the reflection sheet 21. So that the deflecting optical sheet 50 and the reflecting sheet 21 do not come into contact with each other. That is, the light source 25 is configured such that the optical axis pd of the light emitted from the light source 25 extends between the deflection optical sheet 50 and the reflection sheet 21 and is directed to a position on the auxiliary reflection element 31. Furthermore, in the present embodiment, the light emitting unit 26 of the light source 25 is positioned so that the optical axis pd of the light emitted from the light source 25 is parallel to the first direction.

  According to such an arrangement, most of the light emitted from the light emitting unit 26 of the light source 25 can enter the auxiliary reflecting element 31 without entering the deflecting optical sheet 50 and the reflecting sheet 21. As a result of extensive research conducted by the inventors, when the arrangement of the optical axis pd of the light source 25 is applied to the optical module 20 described here, the brightness distribution along the first direction d1 is effective. Can be made uniform.

  Next, the auxiliary reflection element 31 will be described. The auxiliary reflection element 31 is disposed at a position facing the light emitting unit 26 of the light source 25 along the first direction d1 and extends between the deflection optical sheet 50 and the reflection sheet 21. More precisely, the auxiliary reflection element 31 deflects the deflection optical so as to close a gap between the other edge 50c2 of the deflection optical sheet 50 and the edge of the reflection sheet 21 on the side facing the edge 50c2. It extends between the sheet 50 and the reflection sheet 21.

  According to such an auxiliary reflecting element 31, most of the light from the light emitting section 26 travels from one side to the other side substantially along the first direction d1, and the liquid crystal display panel on the other side in the first direction d1. It is possible to prevent leakage from between 15 and the reflection sheet 21. Therefore, loss of light emitted from the light emitting unit 26 can be effectively prevented. That is, the utilization efficiency of light from the light source 25 can be effectively improved, and the energy efficiency of the optical module 20 and the display device 10 can be effectively improved.

  Further, in the present embodiment, the light source 25 is configured so that the optical axis pd extends between the deflecting optical sheet 50 and the reflecting sheet 21 toward the position on the auxiliary reflecting element 31 in the cross section of FIG. Has been. For this reason, most of the light projected from the light emitting unit 26 is incident on the auxiliary reflecting element 31, and the auxiliary reflecting element 31 reflects a large amount of light. Therefore, the auxiliary reflective element 31 can function like a light emitting unit disposed on the other side of the first direction d1. As a result, the optical module 20 is configured to have light emitting portions on both sides in the first direction d1, and the brightness distribution along the first direction d1 can be effectively uniformed.

  From the viewpoint of effectively exhibiting the function of the auxiliary reflecting element 31 and reducing the variation in brightness distribution, the specular gloss of the auxiliary reflecting element 31 measured in accordance with JISZ8741 is in the first direction d1. It is preferable that it is not less than the specular gloss of the reflection sheet 21 measured in accordance with JISZ8741 using incident light that travels in a parallel plane and is incident at an incident angle of 60 °. More preferably, the reflecting surface 32 of the auxiliary reflecting element 31 is smooth, and even more preferably, the auxiliary reflecting element 31 has a specular reflection function. According to such an auxiliary reflection element 31, it is possible to effectively uniformize the brightness distribution along the first direction d1 while effectively preventing a light amount loss due to reflection.

  Further, from the viewpoint of effectively exhibiting the function of the auxiliary reflecting element 31 and alleviating the variation in the brightness distribution, the reflecting surface 32 facing the light emitting portion 26 of the auxiliary reflecting element 31 is 90 with respect to the first direction d1. It is preferable that the auxiliary reflection element 31 is inclined at an angle other than degrees and reflects light traveling in a direction parallel to the first direction d1 toward a position on the deflecting optical sheet 50. According to this form, the light emitted from the light source 25 along the optical axis pd of the light emitted from the light source 25 travels between the deflecting optical sheet 50 and the reflective sheet 21 and directly to the auxiliary reflective element 31. After being incident and reflected by the auxiliary reflecting element 31, it can be directly incident on the deflecting optical sheet 50. Therefore, it is possible to effectively uniformize the brightness distribution along the first direction d1 while effectively preventing light loss due to reflection.

  Further, for the purpose of improving the utilization efficiency of light from the light source 25, as shown by a two-dot chain line in FIG. 2, the gap between the liquid crystal display panel 15 and the reflection sheet 21 on one side in the first direction d1. You may make it provide the reflecting material 23 which plugs up.

  Next, the liquid crystal display panel 15 will be described. As described above, the liquid crystal display panel 15 includes the pair of polarizing plates 12 and 40 and the liquid crystal cell 11 disposed between the pair of polarizing plates 12 and 40. Among these, the polarizing plates 12 and 40 have a function (absorption type polarization separation function) of decomposing incident light into orthogonal polarization components, transmitting one polarization component, and absorbing the other polarization component. Yes.

  The polarizing plates 12 and 40 have a function (absorptive polarization separation function) of decomposing incident light into orthogonal polarization components, transmitting one polarization component, and absorbing the other polarization component. On the other hand, the liquid crystal cell 11 has a pair of transparent substrates and a liquid crystal layer provided between the transparent substrates. An electric field can be applied to the liquid crystal layer for each region where one pixel is formed, and the alignment of the liquid crystal layer to which the electric field is applied changes. For example, the polarization component in a specific direction (direction parallel to the transmission axis) transmitted through the lower polarizing plate 40 disposed on the light incident side passes through a region of the liquid crystal layer to which an electric field is applied in the liquid crystal cell 11. At that time, the polarization direction is rotated by 90 °, and the polarization direction is maintained when passing through the liquid crystal layer to which no electric field is applied. For this reason, depending on whether or not an electric field is applied to each region of the liquid crystal layer, whether the polarization component in a specific direction transmitted through the lower polarizing plate 40 is further transmitted through the upper polarizing plate 12 disposed on the light output side of the lower polarizing plate 40. Alternatively, it is possible to control whether the light is absorbed and blocked by the upper polarizing plate 12.

  Here, the lower polarizing plate 40 will be described in further detail. The lower polarizing plate 40 includes a polarizer 41 that can exhibit an absorption polarization separation function, and a deflecting optical sheet 50 bonded to the polarizer 41. As shown in FIG. 2, the deflection optical sheet 50 is laminated on the polarizer 41 from the side not facing the liquid crystal cell 11, in other words, from the light incident side, and functions as a protective film that protects the polarizer 41 from the outside. It is like that.

  Further, an adhesive layer (not shown) is provided between the polarizer 41 and the deflection optical sheet 50 so as to be adjacent to the polarizer 41 and the deflection optical sheet 50 and adheres the polarizer 41 and the deflection optical sheet 50 to each other. May be provided. The adhesive layer for improving the adhesion between the polarizer 41 and the deflecting optical sheet 50 can be formed using various conventional adhesives. As one specific example, for example, an adhesive layer can be formed using an aqueous adhesive mainly composed of a polyvinyl alcohol-based resin. In addition, the adhesion in this specification is a concept including adhesion and gluing, and similarly, the adhesive in this specification is a concept including pressure-sensitive adhesive and glue.

  Various polarizers have been developed to date, and any of these polarizers can be used as the polarizer 41. As a specific example, a polarizer 41 having a polyvinyl alcohol film as a base material can be used. The polarizer 41 based on a polyvinyl alcohol film is anisotropic in absorbing light by adsorbing or dyeing a dichroic dye such as iodine or dye on the polyvinyl alcohol film, and then orienting it by uniaxial stretching. Can be imparted to the polyvinyl alcohol film.

  Next, the deflection optical sheet 50 will be described. The deflection optical sheet 50 described here has a light control function for changing the traveling direction of light. As a specific configuration, the light incident side surface 50b of the deflecting optical sheet 50 is formed by unit optical elements (unit prisms) 60 arranged side by side as well shown in FIGS. (Prism surface). By this optical element surface, the deflecting optical sheet 50 exhibits a condensing function (deflecting function). The deflection optical sheet 50 includes a diffusion component 59b dispersed in a binder resin, and the deflection optical sheet 50 exhibits a light diffusion function by the diffusion component 59b. As described above, the deflection optical sheet 50 is positioned on the most light incident side of the liquid crystal display panel 15, and the light incident side surface 50 b of the deflection optical sheet 50 forms the light incident side surface of the liquid crystal display panel 15. Yes. Hereinafter, the configuration of the deflection optical sheet 50 will be further described in detail.

  As well illustrated in FIG. 5, the deflection optical sheet 50 includes a sheet-like main body portion 55 and unit optical elements 60 arranged side by side on the light incident side surface 55 b of the main body portion 55. Each unit optical element 60 extends in a direction intersecting the arrangement direction and parallel to the sheet surface of the deflecting optical sheet 50. Further, the unit optical elements 60 included in the deflecting optical sheet 50 are configured identically. As shown in FIGS. 1 to 3, in the present embodiment, the arrangement direction of the unit optical elements 60 is parallel to the first direction d1, and each unit optical element 60 is a straight line along the second direction d2. It extends in a shape.

  The “unit optical element” in the present specification refers to an element having a function of changing the traveling direction of the light by exerting an optical action such as refraction or reflection on the light. ”,“ Unit prism ”, and“ unit lens ”are not distinguished based only on the difference in designation and elements. Similarly, “prism” and “lens” are not distinguished from each other based solely on the difference in designation.

  By the way, the liquid crystal display panel 15 defines a large number of pixels. The liquid crystal display panel 15 forms an image by controlling transmission and blocking of light for each pixel. Then, the arrangement direction d1 of the unit optical elements 60 intersects with the arrangement direction of the pixels of the liquid crystal cell 11 of the liquid crystal display panel 15 when observed from the front direction nd, that is, is inclined or orthogonal to the arrangement direction of the pixels. Preferably it is. Specifically, when observed from the front direction, the arrangement direction of the unit optical elements 60 and the arrangement direction of the pixels of the liquid crystal cell 11 are preferably inclined at an angle of 1 ° or more and less than 45 °. More preferably, it is inclined at an angle of not less than 30 ° and not more than 30 °. In this case, moire (interference fringes) caused by interference between the periodicity caused by the regular arrangement of the pixels and the periodicity caused by the regular arrangement of the unit optical elements 60 can be effectively made inconspicuous. it can. From the viewpoint of making the moire inconspicuous, it is preferable that the arrangement pitch of the unit optical elements 60 is 30 μm or less.

  The cross section shown in FIG. 2 is a cross section along both the arrangement direction of the unit optical elements 60 and the normal direction to the sheet-like main body 55 (hereinafter simply referred to as “the main cutting surface of the deflecting optical sheet”). It also corresponds to). As shown in FIG. 2, each unit optical element 60 has a triangular shape on the main cutting plane. In particular, in the illustrated example, the cross-sectional shape of the unit optical element 60 at the main cut surface is an isosceles triangle that is symmetrically disposed about the normal direction to the sheet surface of the deflecting optical sheet 50. The angle θ1 (see FIG. 2) of the isosceles triangle shape can be set to, for example, 15 ° or more and 100 ° or less in consideration of the light collecting function. Further, the width W1 (see FIG. 2) along the arrangement direction of the isosceles triangle can be, for example, 5 μm or more and 250 μm or less, and the height H1 along the front direction of the isosceles triangle (see FIG. 2). Can be, for example, 2.5 μm or more and 250 μm or less.

  Further, as described above, the deflection optical sheet 50 has the diffusion component 59b, and the deflection optical sheet 50 exhibits the light diffusion function by the diffusion component 59b. More precisely, the deflection optical sheet 50 includes a light diffusion layer 51a having a main part 59a made of resin and a diffusion component 59b dispersed in the main part 59a.

  The deflection optical sheet 50 in the present embodiment includes a light diffusion layer 51a and a resin layer 51b that does not contain the diffusion component 59b, as well shown in FIG. In the illustrated example, the resin layer 51b is disposed on the light incident side with respect to the light diffusion layer 51a. That is, the light diffusion layer 51a is disposed closer to the polarizer 41 than the resin layer 51b. The resin layer 51 b constitutes the unit optical element 60 described above and the light incident side portion of the main body portion 55. On the other hand, the light diffusion layer 51a constitutes a part on the light output side of the main body 55 adjacent to the resin layer 51b.

  For example, such a deflection optical sheet 50 can be manufactured by extruding two layers of the light diffusion layer 51a and the resin layer 51b by coextrusion molding, and further shaping the unit optical element 60 at the time of molding. In the deflection optical sheet 50 manufactured by such a manufacturing method, there is no optical interface between the main portion 59a of the light diffusion layer 51a and the resin layer 51b. That is, the light enters the deflecting optical sheet 50 from the resin layer 51b to the light diffusion layer 51a without being optically affected.

  As the resin material forming the resin layer 51b and the resin material forming the main portion 59a of the light diffusion layer 51a, various resin materials having excellent optical characteristics, for example, polycarbonate resins can be used. On the other hand, the diffusing component 59b dispersed in the light diffusing layer 51a can be composed of a granular material having a refractive index different from that of the main portion 59a, or a granular material having its own reflectivity. The particulate material forming the diffusion component 59b may be a metal compound, a porous material containing a gas, or may be a simple bubble. Further, the shape of the diffusion component 59b made of a granular material is not particularly limited. Therefore, the diffusion component 59b does not have to be spherical (particulate) as in the illustrated example, and can have various shapes such as a spheroid shape and a linear shape.

  However, the deflection optical sheet 50 can also be produced by molding using an ionizing radiation curable resin.

  The deflecting optical sheet 50 can exhibit a diffusing function for diffusing light due to the light diffusing layer 51a including the diffusing component 59b. The degree of the light diffusing function of the deflecting optical sheet 50 caused by the internally added diffusion component 59b is as follows. The resin material constituting the main portion 59a, the thickness of the main portion 59a, the configuration (shape, size ( By appropriately setting the particle size), the refractive index, etc.), the concentration of the diffusing component 59b, etc., it can be adjusted within a very wide range. Specifically, the haze value of the light diffusing layer 51a is set within a range that is not normally reached by simply matting (roughening) the surface layer, for example, within a range of 60% to 90%. It is also possible to set.

  By the way, the light incident side surface of the lower polarizing plate 40 and the light incident side surface 50 b of the deflection optical sheet 50 that forms the light incident side surface of the liquid crystal display panel 15 are formed as optical element surfaces composed of the unit optical elements 60. On the other hand, the light exit side surface 50a of the deflection optical sheet 50 is formed as a flat surface. Accordingly, it is possible to stably laminate and bond the deflecting optical sheet 50 and the polarizer 41 while preventing air and the like from being mixed.

  In this specification, “flat” used for the surface 50a of the deflecting optical sheet 50 facing the polarizer 41 ensures stable lamination and adhesion between the deflecting optical sheet 50 and the polarizer 41. It refers to the flatness you get. For example, when the surface roughness of the surface 50a facing the polarizer 41 of the deflecting optical sheet 50 is measured as a ten-point average roughness Rz in accordance with JIS B0601 (1982), it is 1.0 μm or less. If there is, it can be said that it is flat.

  In this way, the light exit side surface 50a of the deflecting optical sheet 50 is flat, although the deflecting optical sheet 50 has the diffusion component 59b internally added. The child 41 can be laminated and bonded. Specifically, the deflection optical sheet 50 and the polarizer 41 are overlapped with each other with an aqueous solution (or suspension) mixed with water or a suitable additive such as a surfactant interposed therebetween. I will match. Accordingly, the deflecting optical sheet 50 and the polarizer 41 can be stacked while preventing entry of foreign matters such as air. At this time, an adhesive (for example, glue) is mixed with water or an aqueous solution (or suspension), or an adhesive layer is provided in advance on at least one of the deflecting optical sheet 50 and the polarizer 41. The deflecting optical sheet 50 and the polarizer 41 may be positively bonded.

In addition, in order to promote the removal of moisture from the deflecting optical sheet 50 and the polarizer 41 after “water sticking”, the moisture permeability of the deflecting optical sheet 50 is 10 g under the condition of a temperature of 40 ° C. and a humidity of 90% RH. / m ² · 24 hr or more is preferable. However, if the moisture permeability is too high, warping or bending due to moisture absorption may occur. Therefore, the moisture permeability is preferably 400 g / m ² · 24 hr or less as measured at a temperature of 40 ° C. and a humidity of 90% RH. . In addition, the moisture permeability in this specification refers to the numerical value measured using the cup method based on JISZ0208.

  Next, operations of the display device 10 and the optical module 20 will be described mainly with reference to FIG.

  As described above, in the cross section shown in FIG. 2, the optical axis pd of the light emitted from the light source 25 extends toward the position on the reflecting surface 32 of the auxiliary reflecting element 31. In particular, in the present embodiment, the optical axis pd of the light emitted from the light source 25 extends in parallel with the first direction d1 toward the position on the reflecting surface 32 of the auxiliary reflecting element 31. For this reason, much light L21 projected from the light emission part 26 of the light source 25 injects into the reflective surface 32 of the auxiliary | assistant reflective element 31 directly, ie, without injecting into another member. This light L 21 is reflected by the reflecting surface 32 of the auxiliary reflecting element 31 and enters the liquid crystal display panel 15. However, the light from the light emitting unit 26 is also emitted in a direction inclined from the optical axis pd. Accordingly, a part of the light L23 emitted from the light emitting unit 26 of the light source 25 enters the liquid crystal display panel 15 directly, that is, without entering another member. Further, another part of the light L22 from the light emitting unit 26 enters the reflection sheet 21 directly, that is, without entering another member, and is reflected by the reflection sheet 21, and then directly or via the auxiliary reflection element 31. Then, the light enters the liquid crystal display panel 15.

  By the way, in this Embodiment, the light guide plate A (refer FIG. 30) for equalizing the light quantity distribution along the irradiation direction (light guide direction) of the light from the light-emitting body 25 is not provided. Therefore, it is expected that the brightness in a region away from the light emitting unit 26 of the light source 25 is significantly reduced.

  However, in the present embodiment, the optical axis pd of the light emitted from the light source 25 extends toward the position on the reflecting surface 32 of the auxiliary reflecting element 31. Most of the light projected from the light emitting unit 26 is reflected by the auxiliary reflecting element 31 and can then enter the liquid crystal display panel 15. Therefore, the amount of light incident on the liquid crystal display panel 15 can be ensured in a region away from the light emitting unit 26, and the distribution of the light amount incident on each position along the first direction d1 of the liquid crystal display panel 15 is uniform. It can be made. Such an effect is that the reflecting surface 32 of the auxiliary reflecting element 31 is inclined with respect to the first direction d1, and the light that the auxiliary reflecting element 31 travels in the first direction d1 forms the light incident side surface of the liquid crystal display panel 15. This is particularly effective when reflected at a position on the deflecting optical sheet 50. Further, when the specular gloss of the auxiliary reflecting element 31 measured in accordance with JISZ8741 is high, a light amount loss at the time of reflection by the auxiliary reflecting element 31 is prevented, and an area separated from the light emitting unit 26 in the first direction d1 The amount of light at can be more effectively ensured.

  In addition, in the present embodiment, the reflection sheet 21 has a reflection characteristic having directivity depending on the incident direction of light. That is, the reflection sheet 21 has a reflection characteristic different from that of a reflection sheet having a perfect diffusion reflection characteristic that has been conventionally used. In this regard, the inventors of the present invention conducted a simulation in addition to the experiment, and found the following. When the reflection on the reflection sheet is complete diffusion, as indicated by a two-dot chain line in FIG. 2, the light L22a incident on the reflection sheet is diffused on the reflection surface of the reflection sheet, and most of the reflection light L22a Stop traveling in one direction d1. Therefore, when the conventional reflection sheet 21 having the reflection characteristics of complete diffusion is used, the amount of light is excessive in the vicinity of the light emitting unit 26 of the light source 25 and can be visually recognized in the brightness distribution along the first direction d1. It is probable that this variation was occurring.

  On the other hand, in the present embodiment, since the reflection sheet 21 that is not completely diffused is used, a certain amount of light L22 out of the light reflected by the reflection sheet 21 continues to travel along the first direction d1. For this reason, it is possible to increase the density of light incident on the liquid crystal display panel 15 in a region away from the light emitting unit 26 that tends to reduce the amount of light, that is, the region on the other side in the first direction d1. Thereby, the distribution of the amount of light incident on each position along the first direction d1 of the liquid crystal display panel 15 can be made uniform. With regard to this point, the inventors of the present invention have made extensive studies, and as demonstrated in the examples described later, according to the configuration of the present embodiment, the liquid crystal display panel 15 ( The distribution of the amount of incident light on the deflecting optical sheet 50) along the first direction d1 can be adjusted as appropriate, and moreover, it is desired to be used in an actual display device, in particular, a large-sized television receiver. Thus far, the distribution of the amount of incident light on the liquid crystal display panel 15 (deflection optical sheet 50) along the first direction d1 can be sufficiently uniformed.

  On the most incident light side of the liquid crystal display panel 15, a lower polarizing plate 40 having a deflection optical sheet 50 and a polarizer 41 is provided. The deflecting optical sheet 50 of the lower polarizing plate 40 forms the most incident side surface of the liquid crystal display panel 15.

  As described above, the deflecting optical sheet 50 has a light collecting function (deflecting function) that changes the traveling direction of the light so that the angle formed by the traveling direction of the light with respect to the front direction nd is reduced as a whole. Has a light diffusion function of diffusing light. Among these, the light condensing function is expressed by the unit optical element 60 of the deflection optical sheet 50, and the light diffusion function is mainly expressed by the light diffusion layer 51 a of the deflection optical sheet 50. The unit optical element 60 forms the light incident side surface of the deflecting optical sheet 50, and the light diffusion layer 51 a is provided on the light exit side of the deflecting optical sheet 50. For this reason, the light incident on the deflecting optical sheet 50 is first given a condensing function and then given a light diffusing function.

  As shown well in FIG. 2, the basic principle of the light collecting function by the unit optical element 60 having a triangular cross section is that the light L22 incident from one surface (incident surface) 60b1 of the unit optical element 60 is changed to the other. In this case, the angle of the traveling direction of the light with respect to the front direction nd is reduced. That is, the light condensing function by the unit optical element 60 is mainly exerted on the light component parallel to the arrangement direction of the unit optical elements 60. Then, by appropriately designing the cross-sectional shape of the unit optical element 60, as shown in FIG. 2, the condensing function of the unit optical element 60 of the deflecting optical sheet 50 is effectively exhibited. Specifically, by appropriately setting the shape of the unit optical element 60, the refractive index of the unit optical element 60, and the like, the degree of the light collecting function in the deflecting optical sheet 50 can be adjusted within a very wide range.

  As described above, the unit optical element 60 of the deflecting optical sheet 50 is useful for improving the luminance in the front direction. In particular, in the present embodiment, since the diffusion component 59b is not dispersed in the unit optical element 60, the surface (prism surface) of the unit optical element 60 functioning as the incident surface 60b1 and the total reflection surface 60b2 is diffused component 59b. It can be formed with high accuracy as a smooth surface free of irregularities due to the above. Thereby, the unit optical element 60 of the deflection | deviation optical sheet 50 can exhibit the desired desired optical function.

  The light incident on the deflecting optical sheet 50 through the unit optical element 60 then travels in the main body 55 from the resin layer 51b to the light diffusion layer 51a having a light diffusion function. The light diffusion layer 51a has a main portion 59a and a diffusion component 59b dispersed in the main portion 59a, and expresses a light diffusion function due to the internally added diffusion component 59b. The light diffusing function in the light diffusing layer 51a due to the internally added diffusing component 59b is, for example, matting the surface by molding or providing a granular material on the surface layer to make the surface matte. Compared with the light diffusing function resulting from this, the degree (diffusion intensity) and quality (diffusion uniformity) are remarkably superior.

  Specifically, when the surface is merely matted, light that passes through (the traveling direction cannot be changed) inevitably occurs. On the other hand, according to the internally added diffusion component 59b, the diffusion component 59b is dispersed not only in the plane direction but also in the thickness direction. For this reason, the light incident on the light diffusion layer 51a collides with the diffusion component 59b at least once and changes its traveling direction with a high probability. Further, as described above, the resin material forming the main portion 59a, the thickness of the main portion 59a, the configuration (shape, size (particle size), refractive index, etc.) of the diffusing component 59b, the concentration of the diffusing component 59b, etc. are set as appropriate. By doing so, the degree of the light diffusion function of the light diffusion layer 51a can be adjusted within a very wide range.

  As described above, the light from the surface light source device 20 can be diffused to some extent by the light diffusion layer 51 a of the deflection optical sheet 50. Thereby, it is possible to smoothly change the angular distribution of luminance after the light is condensed by the unit optical element 60 of the deflection optical sheet 50.

  The light diffused by the light diffusion layer 51 a of the deflecting optical sheet 50 is then directed to the polarizer 41, the liquid crystal cell 11, and the upper polarizing plate 12 of the lower polarizing plate 40 disposed on the light output side of the deflecting optical sheet 50. Become. At this time, the liquid crystal cell 11 selectively transmits light for each pixel, so that an observer of the display device 10 can observe an image.

  As described above, according to the optical module 20 incorporated in the display device 10 according to the present embodiment, the light emitting unit 26 forming the light source 25 is shifted from the display region in the first direction d1 in the observation from the front direction nd. Even if the light source 25 is disposed only at one side in the first direction d1 without depending on the light guide plate A (see FIG. 30), the light quantity along the first direction d1 The distribution can be made sufficiently uniform. Thereby, a light guide plate can be excluded from the optical module 20 and the display apparatus 10, and the malfunction resulting from presence of a light guide plate can be eliminated. That is, it is possible to reduce the cost of the light guide plate, which is expensive due to the large thickness. In addition, a special support structure for supporting the light guide plate, which may be necessary due to the large thickness, can be eliminated from the optical module 20 and the display device 10. Furthermore, by eliminating the light guide plate, the optical module 20 and the display device 10 can be reduced in thickness and weight.

  In addition, in this embodiment, the deflecting optical sheet 50 joined to the polarizer 41 to form the polarizing plate (lower polarizing plate) 40 has an excellent light control function that can change the traveling direction of light. doing. Specifically, the deflecting optical sheet 50 has an excellent light diffusing function due to the diffusing component 59b dispersed in the resin material, and projects toward the light emitter 26 to form a light incident surface of the deflecting optical sheet 50. An excellent light collecting function due to the plurality of unit optical elements 60 can be exhibited. Due to the excellent light control function of the deflection optical sheet 50, not only the light guide plate but also the deflection sheet B and the light diffusion sheet C incorporated in the surface light source device of the conventional display device 1 shown in FIG. Optical sheets can also be deleted.

  Thereby, the number of members (optical sheets) incorporated in the display device can be greatly reduced, and the manufacturing cost of the display device can be greatly reduced directly. Further, it is possible to omit a complicated operation such as positioning of optical sheets necessary for assembling the display device or the surface light source device, and the manufacturing cost of the display device can also be reduced in this respect. Further, by omitting a member (optical sheet) incorporated in the display device, the display device can be thinned. Further, since only the reflection sheet 21 and the auxiliary reflection element 31 are disposed in the optical path of the light source light from the light emitting unit 26 constituting the light source 25 to the deflecting optical sheet 50 of the polarizing plate 40, the optical sheet is bent, bent, warped, and the like. The degree of deterioration of display image quality due to the deformation of can be greatly reduced.

  In addition, the optical sheets incorporated in the conventional display device are members for correcting the traveling direction of light, but on the other hand, part of the incident light is absorbed. In the conventional display device, a large amount of light is expected to be reflected by one of a large number of optical sheets before entering the liquid crystal display panel. As a result, most of the light emitted from the light emitter 26 serving as the light source 25 is absorbed by any one of the optical sheets and cannot be used for displaying an image. On the other hand, in the present embodiment, the light emitted from the light emitting unit 26 of the light source 25 is directly or after being reflected by the reflective sheet 21 and / or the auxiliary reflecting element 31 to the polarizing plate 40 of the liquid crystal display panel 15. Can be incident. For this reason, the utilization efficiency of the light emitted by the light emitting unit 26 can be significantly increased. As a result, for example, it is possible to significantly widen the viewing angle while maintaining the luminance in the front direction without increasing the output of the light source 25 as compared with the conventional display device.

  In the above-described example, the polarizing optical sheet 50 having a light control function (function of changing the traveling direction of light) is joined to the polarizer 41 to form the polarizing plate 40. According to such a form, compared with the form shown in FIG. 30, that is, the form in which the light collecting sheet B and the diffusion sheet C are provided separately from the polarizing plate 13, the air layer through which light should be transmitted. The number of decreases. For this reason, it is possible to effectively prevent the generation of light that is reflected at the interface with the air layer, in particular, totally reflected, and proceeds to the side opposite to the light exit side, and as a result, the light utilization efficiency can be improved. It becomes possible.

  In particular, in the above-described example, the deflecting optical sheet 50 having the unit optical element 60 that can exhibit the light collecting function is bonded to the polarizer 41 to form the polarizing plate 40. As a result of extensive studies by the present inventors, it has been found that according to such a configuration, it is possible to improve the utilization efficiency of light from the light source 25 more stably. The reason why such a phenomenon occurs is estimated as follows.

  As schematically shown in FIG. 6, when there is no air layer between the deflecting optical sheet 50 and the polarizer 41, the light L <b> 6 from the light emitter 26 of the light source 25 has a very high transmittance and the deflecting optical sheet 50. And the interface between the polarizer 41 and the polarizer 41 can be transmitted. However, when the traveling direction of the light L6 traveling from the deflecting optical sheet 50 to the polarizer 41 is greatly inclined from the front direction nd, the light L6a does not significantly change the traveling direction thereafter. In the example in which light travels through the liquid crystal display panel 15 at the interface with the air layer that reaches next, the light is totally reflected at the interface between the display surface 10a and the air layer. In theory, such light L6a can be reused by being reflected at any interface thereafter. However, in practice, most of the light traveling through the liquid crystal display panel is absorbed by these members when passing through the polarizer 41 of the lower polarizing plate 40, the liquid crystal display cell 11 including the color filter, and the upper polarizing plate. End up. As a result, the light that has reciprocated through the liquid crystal display panel 15 cannot be effectively reused. That is, when the traveling direction of the light L6 traveling in the deflecting optical sheet 50 is greatly inclined from the front direction nd, the light L6 is not incident on the polarizer 41, but rather is air between the deflecting optical sheet 50 and the polarizer 41. The utilization efficiency from the light source 25 increases when the layer is interposed and reflected at the interface between the deflecting optical sheet 50 and the air layer (light L6b in FIG. 6).

  On the other hand, if the deflecting optical sheet 50 has the unit optical element 60 capable of exhibiting the light collecting function as in the above-described form, the light from the light source 25 can be emitted without causing the above-described problems. The utilization efficiency can be improved more stably. The inventors of the present invention have made extensive studies, and as a result, the angular distribution of luminance caused by the light condensed by the unit optical element 60 and traveling through the deflecting optical sheet 50, and the arrangement direction of the unit optical elements 60 and The half-value angle (in the direction in which half the peak luminance is measured and the sheet surface of the deflecting optical sheet 50) in the angular distribution of the luminance in the plane along both the normal direction nd to the sheet surface of the deflecting optical sheet 50 Is equal to or less than the total reflection critical angle of light traveling from the deflecting optical sheet 50 to the air layer through the light exit surface 50a on the assumption that the deflecting optical sheet 50 is adjacent to the air layer. In this case, the utilization efficiency of the light source light can be improved extremely effectively by bonding the deflecting optical sheet 50 to the polarizer 41.

  In the above-described example, the deflection optical sheet 50 having a light control function (a function of changing the traveling direction of light) is stably supported by being joined to the polarizer 41. On the other hand, in the form shown in FIG. 30, it is necessary to hold each of the light collecting sheet B and the diffusion sheet C in a state of being positioned with respect to the other components. For this reason, the display device 10 and the liquid crystal display device 15 described above are excellent in resistance to various problems caused by vibrations and changes in environmental conditions (temperature, humidity, etc.) of the installation location during handling such as transportation. Will come to present. For this reason, it is possible to effectively prevent the top portion of the unit-shaped element 60 having a delicate structure from being lost, and the deflecting optical sheet 50 can exhibit the expected optical function.

  Various modifications can be made to the above-described embodiment. Hereinafter, an example of modification will be described with reference to the drawings as appropriate. In the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above-described embodiment are used, and redundant descriptions are omitted.

  In the above-described embodiment, the deflecting optical sheet 50 includes a main part 59a made of a resin material, a light diffusion layer 51a made of a diffusion component 59b dispersed in the main part 59a, and a resin material only without containing the diffusion component 59b. And a resin layer 51b made of In other words, the diffusion component 59b is dispersed only in a part of the deflection optical sheet 50. However, the diffusing component 59b may be dispersed throughout the deflection optical sheet 50. In such an example, the deflecting optical sheet 50 is composed of only a light diffusion layer 51a having a main portion 59a made of a resin material and a diffusion component 59b dispersed in the main portion 59a. The unit optical element 60 is configured as a part of the light diffusion layer 51a. In this case, the degree of the light diffusion function of the deflecting optical sheet 50 can be further freely adjusted.

  On the other hand, it is necessary to impart a light diffusing function to the deflecting optical sheet 50 in accordance with optical characteristics required for the optical module 20 and the display device 10, configurations of other components of the optical module 20 and the display device 10, and the like. Absent. That is, the diffusing component 59b may not be dispersed in the deflecting optical sheet 50, and the deflecting optical sheet 50 may be configured only by the resin layer 51b made of only the resin material.

  Further, in the above-described embodiment, the example in which the cross-sectional shape of the main cutting surface of the unit optical element 60 of the deflection optical sheet 50 is a triangular shape is shown, but the present invention is not limited to this, and the unit optical element of the deflection optical sheet 50 The cross-sectional shape of the 60 main cutting planes can be designed in various shapes. For example, the triangular top portion forming the cross-sectional shape of the unit optical element 60 on the main cutting surface of the deflecting optical sheet 50 may be chamfered. Further, as shown by a two-dot chain line in FIG. 2, at the main cutting plane of the deflecting optical sheet, at least one of the two sides extending from the triangular main body 55 described above is a curve that bulges outward. You may deform | transform so that it may become.

  Further, as shown in FIG. 7, the unit optical element 60 may have a curved outer contour on the main cut surface of the deflection optical sheet 50. That is, the light incident surface of the unit optical element 60 may be configured as a curved surface. As an example of a specific shape, the unit optical element 60 has a shape corresponding to a part of an ellipse (a semi-ellipse as an example) or a part of a circle (a semi-circle as an example) on the main cut surface of the deflection optical sheet 50. You may make it have. Further, as shown in FIG. 8, the unit optical element 60 may have a shape obtained by removing the triangular top portion of the main cutting surface described above on the main cutting surface of the deflection optical sheet 50. As an example of a specific shape, the unit optical element 60 may have an isosceles trapezoidal shape as shown in FIG. 8 on the main cutting surface of the deflecting optical sheet 50, or the isosceles trapezoidal shape. You may make it have the shape formed by changing the upper base of to a curve. Note that the deflection optical sheet 50 shown in FIG. 7 and FIG. 8 can be manufactured by extrusion molding in the same manner as the deflection optical sheet 50 of the above-described embodiment.

  9 and 10 show a modification of the unit optical element 60 included in the deflection optical element 50. FIG. Here, this modified example will be described with reference to FIGS. 9 and 10. 9 and 10 are different from the above-described embodiment only in the cross-sectional shape of the unit optical element 60, and other configurations such as the arrangement of the unit optical elements 60 are the same. Can be configured.

  The outer contour 62 of the unit optical element 60 described here has a shape formed by connecting a plurality of different parabolas in a cross section orthogonal to the longitudinal direction. In particular, in the example shown in FIGS. 9 and 10, in the cross section orthogonal to the longitudinal direction of the unit optical element 60 (the cross section corresponding to the main cutting surface described above), the outer contour 62 of the unit optical element 60 is the main body portion 55. Are separated into the side of the top portion 61a farthest from the side and the side of the base end portion 61b connected to the main body portion 55, and extend along two different parabolas. Specifically, the top side section 62a including the top 61a of the outer contour 62 of the unit optical element 60 as a center extends along the parabola P1, and includes the proximal end portion 61b of the outer contour of the unit optical element 60. A pair of base end side sections 62b extends along the parabola P2.

  According to this configuration, the intersection 61c of the parabola P1 and the parabola P2 exists between the top part 61a and the base end part 61b on the outer contour 62 of the unit optical element 60. The intact intersection defined by the parabola P1 and the parabola P2 is a pointed outside point that cannot be differentiated. However, from the viewpoint of smoothing the angular distribution of luminance, the intersection point is a region including the intersection of the parabola P1 and the parabola P2. In addition, the outer contour 62 of the unit optical element 60 is along a line segment that is differentiably connected to the parabola P1 and the parabola P2, for example, a part of a circle, an ellipse, a parabola, a hyperbola, a spline curve, and other free curve segments. May extend.

  In addition, the range of the line segment which connects the parabola P1 and the parabola P2 can be 50% or less of the height H1 of the unit optical element 60 in the front direction. And, “the outer contour of the unit optical element extends along the parabola” means that the outer contour of the unit optical element smoothly connects the two parabolas at the connection part of two different parabolas. As mentioned above, it extends along a line segment other than a parabola in a range that is 50% or less of the height H1 of the unit optical element 60 in the front direction.

Next, the parabolas P1 and P2 that define the outer contour 62 of the unit optical element 60 shown in FIGS. 9 and 10 will be described. First, as shown in FIG. 10, in the cross section along the longitudinal direction of the unit optical element 60, the coordinate axis using the X axis parallel to the light incident side surface 55 b of the main body 55 and the Z axis orthogonal to the X axis is shown. Define. In the coordinate system defined by the X-axis and the Z-axis, the position of the apex 61a of the unit optical element 60 is the origin O of the X-axis and the Z-axis, and the side of the main body 55 viewed from the origin O is the Z-axis. Negative side. When this coordinate system is used, the parabola P1 defining the top side section 62a is represented by “Z = −aX ² ”, and the parabola P2 defining the base end side section 62b is “Z = −bX ² + h”. Is represented. Here, “a”, “b”, and “h” in the formula satisfy the following formulas (x) and (y).
0 <a <b Formula (x)
0 <h Formula (y)
As an example, when the unit optical element 60 is designed with the units of the variables “X” and “Y” in the parabolas P1 and P2 being [μm], the coefficient a of the function representing the parabola P1 is set to 0.01 or more and 0.06. It can be set to a numerical value in the following range, for example, 0.02. Similarly, when the unit optical element 60 is designed with the units of the variables “X” and “Y” in the parabolas P1 and P2 being [μm], the coefficient b of the function representing the parabola P2 is set to 0.01 or more and 0.06. It can be set to a numerical value in the following range, for example, 0.05.

  The intersection 61c between the parabola P1 and the parabola P2 is 25 to 75% of the height H1 of the unit optical element 60 along the front direction nd from the light incident side surface 55b of the main body 55 in the Z-axis direction (in the front direction). It may be located within the range. The coefficient h in the function that specifies the parabola P2 is set so that the parabola P1 and the parabola P2 intersect each other. The position of the intersection between the parabolas can be changed by the values of the coefficients a, b, and h in the function specifying the parabola P1 and the parabola P2.

  Further, the cross-sectional shape of the unit optical element 60 shown in FIGS. 9 and 10 is set so that the width W1 and the height H1 of the unit optical element 60 satisfy “(W1) / 2 ≧ (H1)”. Preferably it is. However, from the viewpoint of securing a wide viewing angle, the cross-sectional shape of the unit optical element 60 shown in FIGS. 9 and 10 is such that the width W1 and the height H1 of the unit optical element 60 are “(W1) / 2 ≦ ( H1) ”is preferably set. Note that the unit optical elements 60 are preferably arranged without a gap from the viewpoint of preventing omission, and in this case, the arrangement pitch of the unit optical elements 60 and the width W1 of the unit optical elements 60 are equal.

  As an example of the dimensions of the unit optical elements shown in FIGS. 9 and 10 as described above, the width W1 can be 20 to 200 μm and the height H1 can be 10 to 100 μm.

  The “parabola” for specifying the contour outside the cross section of the unit optical element shown in FIGS. 9 and 10 is not limited to a parabola in a strict sense as a mathematical concept. A parabola in the strict sense with a slight modulation is also included in the parabola here. For example, (1) a tangential approximation of a parabola in a strict sense, specifically, (1-1) discrete points (preferably 10 or more) arranged on a parabola, adjacent points (1-2) A polygon inscribed in a parabola (preferably a decagon or more). (1-3) Polygon circumscribing the parabola (preferably a decagon or more); (2) The parabola is slightly displaced by deformation in one or all sections of the parabola (preferably within 5% of each coordinate value). A curved line, and the like. Optical characteristics and optical action of the deflecting optical sheet including the unit optical element specified by the parabola-modulated line in the strict sense, including the unit optical element specified by the strict parabola When the optical characteristic and optical action have no significant difference in practical use, a line obtained by modulating a parabola in a strict sense is regarded as a “parabola”.

  According to the deflection optical sheet 50 shown in FIGS. 9 and 10 as described above, since the outer cross-sectional contour of the unit optical element 60 is defined by a plurality of parabolas, the luminance in the front direction is appropriately maintained. Further, the viewing angle can be enlarged.

  Next, another modification will be described. In the above-described embodiment, the example in which the unit optical elements 60 are configured identically has been described. However, the present invention is not limited to this. For example, as illustrated in FIG. 11, the unit optical elements 60 are included between the unit optical elements 60 included in the deflection optical sheet 50. Thus, the cross-sectional shapes may be different. As can be understood from FIG. 2, the traveling direction of the light entering the deflecting optical sheet 50 from the light emitting unit 26 of the light source 25 is the deflecting optical sheet from the light emitting unit 26 to the incident position on the deflecting optical sheet 50. It varies according to the distance along the sheet surface of 50. In the view shown in FIG. 11, the cross-sectional shape of the unit optical element 60 changes according to the distance from the light emitting unit 26 to each unit optical element 60, and as a result, a plurality of units included in the deflection optical sheet 50. A so-called Fresnel lens is formed by the optical element 60. In such a modification, the Fresnel lens formed by the unit optical element 60 is formed as a circular Fresnel lens as shown in FIGS. 18 and 19 to be referred to later, depending on the arrangement of the light emitting portions 26. Alternatively, it may be formed as a linear Fresnel lens.

  Further, in the above-described embodiment, the example in which the light collecting function is exhibited by the unit optical element 60 changing the traveling direction of light by total reflection has been described, but the present invention is not limited thereto. For example, as shown in FIG. 12, each unit optical element 60 may be configured to change the traveling direction of light by refraction. Further, a part of the plurality of unit optical elements 60 included in one deflecting optical sheet 50 changes the traveling direction of light by refraction, and the other unit optical elements change the traveling direction of light by reflection. May be. Furthermore, as shown in FIG. 13, one unit optical element 60 may have both a function of reflecting light and a function of refraction.

  Furthermore, in the above-described embodiment, an example in which the deflection optical sheet 50 is made of an extruded material obtained by extrusion molding has been described, but the present invention is not limited thereto. It is also possible to use a deflecting optical sheet manufactured by other manufacturing methods such as injection molding. Here, FIGS. 14 to 17 show, as an example, an example of a deflection optical sheet 50 that can be produced by molding a resin applied on the base film 53, for example, ionizing radiation, into a desired shape. ing. The deflecting optical sheet 50 shown in FIG. 14 can be produced by molding a resin containing a diffusing component 59b on a base film 53. In the deflection optical sheet 50 shown in FIG. 14, the unit optical element 60 forming the light incident side surface 50b is formed as a part of the light diffusion layer 51a, and the resin made of the base film 53 on the light output side of the light diffusion layer 51a. A layer 51b is provided.

  The deflection optical sheet 50 shown in FIG. 15 can be manufactured by molding a resin on the base film 53 that contains the diffusion component 59b and forms the light diffusion layer 51a. For example, an extruded material can be used as the base film 53 including the diffusion component 59b, and the base film 53 constitutes the light diffusion layer 51a.

  In the example shown in FIG. 16, the unit optical element 60 is formed by molding a resin on the base film 53, but the light exit side surface 50a where the unit optical element 60 of the base film 53 is not formed. A mat layer 54 having an uneven surface is formed. The mat layer 54 is composed of a diffusion component 59b and a resin material that functions as a binder resin (for example, an ionizing radiation resin). The resin material as the binder resin functions as the main portion 59a, so that the light diffusion layer is formed. 51a is configured. The mat layer 54 can be formed on the base film 53 either before or after the unit optical element 60 is molded.

  In the example shown in FIG. 17, a mat layer 54 made of a resin material (main part 59a) functioning as a diffusion component 59b and a binder resin is formed between the base film 53 and the resin material constituting the unit optical element 60. Is formed. In the embodiment shown in FIG. 17, the mat layer 54 is formed on the base film 53, and the unit optical element 60 is shaped on the mat layer 54.

  In addition, when forming the deflection | deviation optical sheet 50 by shape | molding the resin apply | coated on the base film 53, as shown in FIGS. 14-17, resin apply | coated on the base film 53 is shown. In addition to the plurality of unit optical elements 60, a land portion 52 that is disposed between the base film 53 and the unit optical element 60 and covers the base film 53 may be formed. In this case, the land portion 52 constitutes a part of the main body portion 55 of the deflection optical sheet 50.

  In the above-described embodiment, the example in which the arrangement direction of the unit optical elements 60 of the deflection optical sheet 50 is parallel to the first direction d1 is shown, but the present invention is not limited to this. The arrangement of the unit optical elements 60 of the deflecting optical sheet 50 may be changed as appropriate in accordance with optical characteristics required for the optical module 20 and the display device 10. For example, in the above-described embodiment, the example in which the unit optical element 60 of the deflecting optical sheet 50 extends linearly is shown. However, the present invention is not limited to this. For example, as shown in FIGS. 60 may extend in a curved line. Furthermore, the unit optical element 60 is not limited to a linear element arranged one-dimensionally, but may be a dot-like element arranged two-dimensionally to constitute a microlens (fly eye lens).

  Furthermore, the light diffusion function of the deflecting optical sheet 50 in the above-described embodiment may be an isotropic light diffusion function or an anisotropic light diffusion function. When the deflection optical sheet 50 has an anisotropic light diffusion function, the deflection optical sheet 50 may exhibit a stronger light diffusion function in the second direction d2 than in the first direction d1, or in the second direction. A stronger light diffusion function may be exhibited in the first direction d1 than in d2. Furthermore, the deflection optical sheet 50 may exhibit the strongest light diffusion function in directions other than the first direction d1 and the second direction d2. According to such a configuration, for example, optical characteristics (for example, viewing angle characteristics) required for the display device 10 can be realized with a higher degree of freedom.

  As an example, as shown in FIG. 20, the diffusion component 59b having the longitudinal direction ld is arranged in the light diffusion layer 51a of the deflecting optical sheet 50 so as to have an orientation in a predetermined direction od. An isotropic light diffusion function can be imparted to the deflecting optical sheet 50. Here, the longitudinal direction of the diffusion component 59b can be specified as the direction in which the target diffusion component 59b has the longest length. Further, “the diffusion component 59b having the longitudinal direction ld has an orientation in the predetermined direction od” means that the angle formed by the longitudinal direction ld of each diffusion component 59b with respect to the predetermined direction od is 0 ° or more and 45 This means that the diffusion component 59b is arranged with directional regularity with reference to the predetermined direction od.

  The light diffusion layer 51a of the deflecting optical sheet 50 shown in FIG. 20 is manufactured by extruding a diffusion component 59b having a longitudinal direction as a raw material together with a resin material that forms the main portion 59a. obtain. The diffusion component 59b having the longitudinal direction is directed so that the longitudinal direction ld is along the extrusion direction (machine direction) under high pressure when passing through the die of the extruder together with the resin material. Thereby, the diffusion component 59b in the extruded material is dispersed in the deflection optical sheet 50 so as to have an orientation in a specific direction od.

  As the shape of the diffusing component 59b having the longitudinal direction ld, various shapes such as a plate shape, a granular shape (rice granular shape), a needle shape, a scale shape, and a fine plate shape can be adopted as an example. As a specific example, the average aspect ratio (the average value of the ratio of the length of the diffusion component 59b along the longitudinal direction ld to the length of the diffusion component 59b along the direction orthogonal to the longitudinal direction ld) is And bubbles having an average particle size of 1.5 to 50 μm and an average particle size of the diffusing component 59b (particle size calculated by the volume equivalent method, ie, arithmetic average of volume equivalent diameter, the same applies hereinafter) of 0.5 μm to 100 μm The diffusion component 59b having the longitudinal direction ld can be used. Moreover, the diffusion component 59b which consists of heat resistant organic fibers, such as the diffusion component 59b which consists of organic fibers, for example, an aramid fiber, a wholly aromatic polyester fiber, a polyimide fiber, can also be used. Moreover, the diffusion component 59b which consists of fibrous fillers, such as glass fiber, a silica fiber, an alumina fiber, a zirconia fiber, for example can also be used for the diffusion component 59b which consists of inorganic fibers. Furthermore, a diffusion component 59b made of a thin plate filler (mica) can also be used. Furthermore, a diffusing component 59b made of an amorphous filler, for example, a diffusing component 59b made of an inorganic white pigment such as silica, calcium carbonate, magnesium hydroxide, clay, talc, or titanium dioxide can be used.

  The diffusion component 59b having the longitudinal direction ld exhibits a stronger light diffusion function in a direction perpendicular to the longitudinal direction than in a direction parallel to the longitudinal direction. For example, in the embodiment described above, the light source 25 is configured by arranging a large number of light emitting units 26 in the second direction d2. The brightness distribution along the second direction d2 is influenced by the configuration of the light source 25a, for example, the arrangement pitch of the light emitting units 26.

  Therefore, in the above-described embodiment, when the distribution of brightness along the second direction d2 is sufficiently uniformed by the configuration of the light source 25, it is preferable to mainly diffuse in the first direction d1. From this point, it is preferable that the orientation direction od of the diffusing component 59b having the longitudinal direction ld is parallel to the second direction which is the arrangement direction of the light emitting units 26 forming the light source 25. In this case, it is possible to effectively prevent the light incident on the deflecting optical sheet 50 from being diffused more than necessary, and to effectively use the light.

  On the other hand, as in the examples shown in FIGS. 18 and 19, when the number of the light emitting units 26 is small, uneven brightness may occur along the second direction d2. In this case, the orientation direction od of the diffusing component 59b having the longitudinal direction ld is parallel to the first direction d1 orthogonal to the second direction d2 in which the light emitting portions 26 forming the light source 25 are arranged, and the diffusing component 59b is It is preferable to diffuse mainly in two directions d2. When the light diffusing layer 51a of the optical sheet 50 has an anisotropic diffusing function that exhibits a stronger light diffusing ability in the second direction d2 perpendicular to the first direction d2 than the light diffusing ability in the first direction d1. The light component along the second direction d2 can be intensively diffused while maintaining the traveling direction of the light component along the first direction d1 collected by the unit optical element 60. Accordingly, the brightness according to the configuration (array) of the light emitting unit 26 is increased by the anisotropic diffusion function caused by the light diffusion layer 51a while simultaneously increasing the luminance in the front direction by the light collecting function caused by the unit optical element 60. It is also possible to eliminate this variation.

  Furthermore, in the above-described embodiment, the example in which the deflection optical sheet 50 is bonded to the polarizer 41 by water bonding is shown, but the present invention is not limited to this, and the adhesive layer is interposed between the deflection optical sheet 50 and the polarizer 41. It may be arranged. In this modification, the adhesive layer may include an adhesive and a diffusion component dispersed in the adhesive. In this case, the degree of the light diffusion function by the adhesive layer can be appropriately adjusted independently of the presence or absence of the light diffusion function in the deflection optical sheet 50 or the degree of the light diffusion function of the deflection optical sheet 50. Thereby, the degree of the light diffusion function that the lower polarizing plate 40 can exhibit can be designed more freely. In addition, what was illustrated as the diffusion component 59b which can be contained in the deflection | deviation optical sheet 50 can be similarly used for the diffusion component contained in an contact bonding layer. In addition, the degree of the light diffusion function by the adhesive layer can be appropriately adjusted by the same method as the degree of the light diffusion function in the deflection optical sheet 50. Furthermore, the light diffusing function of the adhesive layer may be isotropic or anisotropic. When the light diffusion function of the adhesive layer is anisotropic, the adhesive layer has the strongest light in any direction other than the first direction d1, the second direction d2, the first direction d1, and the second direction d2. You may make it exhibit a spreading | diffusion function.

  Furthermore, in the above-described embodiment, an example in which the lower polarizing plate 40 includes the polarizer 41 and the functioning deflection optical sheet 50 bonded to the polarizer 41 from the light incident side is shown. I can't. For example, a protective sheet made of a TAC film or the like may be provided on the light output side of the polarizer 41. In addition, a phase difference plate for compensating for the phase difference of light may be provided between the lower polarizing plate 40 and the liquid crystal cell 11, but in this case, the protective sheet on the light output side of the lower polarizing plate 40 is You may make it also serve as the protective sheet of the light-incidence side of a phase difference plate.

  In addition, as an intermediate film between the deflecting optical sheet 50 and the polarizer 41, a polarization separation film having a function of transmitting a specific polarization component and reflecting other polarization components back to the light source side is provided. It may be. According to this example, by providing the polarization separation film, light of a polarization component that can be transmitted through the polarizer 41 can be selectively incident on the polarizer 41 and other light can be returned to the light source side. The light returned to the light source side can be incident again on the polarization separation film while changing the polarization state by subsequent reflection or the like. “DBEF” (registered trademark) available from 3M USA can be used as a polarized light separation film that can be useful for improving luminance. In addition to “DBEF”, a high-intensity polarizing sheet “WRPS” available from Shinwha Intertek, Korea, a wire grid polarizer, or the like can be used as the polarization separation film.

  Furthermore, a light diffusing sheet having a light diffusing function may be provided as an intermediate film between the polarizer 41 of the lower polarizing plate 40 and the deflecting optical sheet 50, or a simple resin film, for example, a pair A triacetyl cellulose film (TAC film) having a parallel main surface may be provided.

  Further, various changes can be made to the reflection sheet 21. For example, in the above-described embodiment, the example in which the reflection sheet 21 has the flat reflection surface 22 parallel to the deflecting optical sheet 50 has been described. For example, as in the example shown in FIG. 21, the normal direction from the reflecting surface 22 of the reflecting sheet 21 to the light incident side surface 55 b of the main body portion 55 of the deflecting optical sheet 50 to the light incident side surface 55 b of the main body portion 55. The distance sd may be changed so as to decrease in the first direction d1 from the one edge 50c1 side (one side) toward the other edge 50c2 side (the other side). According to such a modified example, the density of light incident on the liquid crystal display panel 15 is increased in a region away from the light emitting unit 26 that tends to reduce the amount of light, that is, in a region on the other side in the first direction d1. Can be made. Thereby, the distribution of the amount of light incident on each position along the first direction d1 of the liquid crystal display panel 15 can be made uniform.

  In the modification shown in FIG. 21, a region on one side of the reflecting surface 22 of the reflecting sheet 21 in the first direction d <b> 1 is formed as a flat surface parallel to the light incident side surface 55 b of the main body 55. The other area | region of the 21 reflective surfaces 22 is formed as a curved surface. However, from the viewpoint of changing the distance sd from the reflection surface 22 of the reflection sheet 21 to the main body portion 55 of the deflection optical sheet 50, the reflection surface 22 of the reflection sheet 21 is the light incident side surface of the main body portion 55 of the deflection optical sheet 50. It may be configured only from a flat surface arranged to be inclined with respect to 55b, the entire area of the reflective surface 22 of the reflective sheet 21 may be configured as a curved surface, and further, the reflective sheet 21 The reflective surface 22 may be configured as a bent surface.

  In the example shown in FIG. 21, the auxiliary reflecting element 31 is not provided. In this example, the optical axis pd of the light emitted from the light source 25 may be directed to a position on the reflection sheet 21 or may be directed to a position on the deflection optical sheet 50. In the example shown in FIG. 21, the other side edge portion in the first direction of the reflection sheet 21 and the other edge portion 50 c 2 of the deflecting optical sheet 50 are close to each other and irradiated from the light emitting unit 26. It is possible to effectively prevent light from leaking from between the reflective sheet 21 and the deflecting optical sheet 50 on the other side in the first direction d1 and being unable to be used for forming an image.

  Further, various modifications can be made to the auxiliary reflecting element 31. For example, as shown in FIG. 22, the reflection surface of the auxiliary reflection element 31 may be configured as a curved surface, particularly a convex curved surface. According to the example shown in FIG. 22, the light emitted from the light emitting unit 26 of the light source 25 can be diffused and reflected in a certain angular range. As a result, the amount of light incident on each position along the first direction d1 of the liquid crystal display panel 15 can be made more uniform.

  Further, in the above-described embodiment, the light emitted from the light emitting unit 26 of the light source 25 is directly projected onto the region between the deflection optical sheet 50 and the reflecting sheet 21, that is, the light emitting unit 26 of the light source 25. Although the example in which the light emitted in (1) is projected onto the region between the deflecting optical sheet 50 and the reflecting sheet 21 without passing through other members has been shown, the present invention is not limited to this example. As shown in FIGS. 31 to 33, an optical element 84 that receives light emitted from the light emitting unit 26 of the light source 25 and directs it to a region between the deflection optical sheet 50 and the reflection sheet 21 may be provided. The optical element 84 is used for various purposes, for example, to direct the traveling direction of the light emitted from the light emitting unit to the region between the deflecting optical sheet 50 and the reflecting sheet 21 or the directivity characteristics of the light emitting unit 26 ( It is provided for the purpose of adjusting the light amount distribution of light traveling to the region between the deflecting optical sheet 50 and the reflecting sheet 21 by eliminating or correcting the light distribution characteristic, in other words, the angle (direction) distribution of luminous intensity). Can be. As an optical element 84 for changing the traveling direction of light from the light emitting unit 26 or adjusting the directivity of the light emitting unit 26, as shown in FIGS. 31 to 33, a lens, a prism, a reflecting mirror, or the like may be used. it can. Further, as shown in FIGS. 31 and 32, the optical element formed of the reflecting mirror may have a curved reflecting surface or a flat reflecting surface. Further, when the light emitting units 26 are arranged in the second direction d2 or when the light emitting units 26 extend along the second direction d2, the optical element may also extend in the second direction d2. Alternatively, a plurality of optical elements may be arranged in the second direction d2.

  As an example, in the example shown in FIG. 25, the light source 25 is arranged on the base 81 extending along the second direction d2 (the depth direction of the paper surface in FIG. 25) and on the base 81 along the second direction d2. And a plurality of light emitters 26 and an optical element 85 extending along the second direction d2. The light emitted from the light emitter 26 passes through the optical element 85 and proceeds to a region between the deflection optical sheet 50 and the reflection sheet 21. In the example shown in FIG. 25, the space between the base 81 and the optical element 85 is surrounded by the reflective sheet 21 and the reflective material 83 disposed at a position facing the reflective sheet 21 from the front direction. Thus, the light emitted from the light emitter 26 is prevented from leaking in an unintended direction.

  In the example shown in FIG. 25, the optical element 85 may have a unit optical element such as a unit lens or a unit prism. For example, the optical element 85 may have a large number of unit optical elements arranged along the second direction d2. When the unit optical elements of the optical element 85 extend in a direction orthogonal to the arrangement direction (second direction d2), that is, in the direction connecting the deflection optical sheet 50 and the reflection sheet 21, the optical element 85 is It becomes possible to adjust the brightness distribution along the second direction d2. In other words, the optical element 85 can make the unevenness of brightness caused by the arrangement of the light emitters 26, for example, the light and dark unevenness appearing in a striped pattern inconspicuous. As the cross-sectional shape of the unit optical element provided in the optical element 85, various shapes can be adopted. As an example, the unit optical elements having the cross-sectional shape shown in FIGS. 9 and 10 are arranged at a pitch of 50 μm. An optical element 85 can be used.

  In the example shown in FIG. 25, the reflection sheet side end of the optical element 85 is on the deflection optical sheet of the optical element 85 in the cross section orthogonal to the second direction d2, that is, on the main cut surface of the deflection optical sheet. It is located outward along the first direction d1 from the side end. In other words, the normal line direction of the optical element 85 is inclined so as to face the reflective sheet 21 side with respect to the first direction d1. Although the illustrated inclination of the optical element 85 is merely an example, the direction of the optical axis pd of the light emitted from the light source 25 can be adjusted by adjusting the direction of the optical element 85. When the present inventors repeated the experiment, when the normal direction of the optical element 85 is directed toward the reflection sheet 21 with respect to the first direction d1, the optical axis pd of the light emitted from the light source 25 is the reflection sheet 21. When the normal direction of the optical element 85 is directed toward the deflecting optical sheet 50 with respect to the first direction d1, the optical axis pd of the light emitted from the light source 25 is the deflecting optical sheet. There was a tendency to be easily directed to the 50 side.

  In the above description, an example in which the unit optical element of the optical element 85 forms a lenticular lens is shown. However, the present invention is not limited to this, and elements that can exhibit various optical functions can be used. These unit optical elements may be two-dimensionally arranged to constitute a fly-eye lens (microlens).

  As another example, the optical element 85 extending in the second direction d2 has a function of transmitting a specific polarization component and reflecting the other polarization component to return to the light emitter 26 again. A polarization separation film may be used. At this time, the optical element 85 configured as a reflective polarization separation film is configured to transmit a polarization component that can be transmitted by the polarizer 41. For example, when the transmission axis of the polarizer 41 of the liquid crystal display panel 15 is parallel to the first direction d1, the transmission axis of the optical element 85 is a direction orthogonal to the second direction d2, that is, a deflection optical sheet. What is necessary is just to make it the direction which ties 50 and the reflective sheet 21. FIG. According to such a form, the light source 25 itself exhibits a light recycling function, and the light use efficiency in the optical module 20 can be improved. Moreover, according to such a form, compared with the case where a reflection type polarization separation film is arrange | positioned in parallel with the polarizer 41 of the liquid crystal display panel 15, the usage area of a comparatively expensive polarization separation sheet is decreased. be able to. As the reflective polarization separation film, “DBEF” (registered trademark) available from 3M USA can be used. In addition to “DBEF”, a high-intensity polarizing sheet “WRPS” available from Shinwha Intertek, Korea, a wire grid polarizer, or the like can be used as the polarization separation film.

  In the example shown in FIG. 25, the auxiliary reflecting element 31 is provided at a position facing the light source 25 along the first direction d1. In the example shown in FIG. 25, in the cross section orthogonal to the second direction d2, that is, on the main cut surface of the deflection optical sheet, the reflection sheet side end of the auxiliary reflection element 31 is the deflection optical sheet of the auxiliary reflection element 32. It is located inward along the first direction d1 from the side end. In other words, the normal direction of the auxiliary reflecting element 32 is inclined so as to face the deflecting optical sheet 50 side with respect to the first direction d1, and the reflected light is directed to the deflecting optical sheet 50 side. Yes.

  As another example, the light source 25 may be provided with two or more optical elements. For example, an optical element having a unit optical element and an optical element made of a reflective polarization separation film may be incorporated in one light source 25.

  Furthermore, a modified example regarding the light source 25 will be described. In the above-described embodiment, the optical axis pd of the light emitted from the light source 25 is directed to the position on the reflection surface 32 of the auxiliary reflecting element 31, and the optical axis pd of the light emitted from the light source 25 is the unit optical element. The direction was parallel to the arrangement direction d1 of 60. However, the optical axis pd of the light emitted from the light source 25 may be inclined with respect to the arrangement direction d1 of the unit optical elements 60, and is further directed or deflected to a position on the reflection surface 22 of the reflection sheet 21. You may make it face in the position on the optical sheet 50. FIG.

  Moreover, in embodiment mentioned above, although LED was illustrated as the point light emission part 26 of the light source 25, it is not restricted to this, You may use another point light emission part. For example, a laser light source that generates laser light may be used as the point light emitting unit. In the above-described embodiment, as shown in FIG. 3, an example in which the light emitting units 26 are arranged side by side along the entire length of one edge of the liquid crystal display panel 15 has been described. Not limited. For example, in the case of using a high-output light emitter (light emitting section) as typified by a laser light source, the number of light emitters 26 constituting the light source 25 is reduced as shown in FIGS. Can do.

  Here, FIGS. 18 and 19 are plan views showing the light source 25 together with the deflecting optical sheet 50. In the example shown in FIG. 18, the light source 25 is formed by a single light emitter 26. In the example shown in FIG. 18, the deflection optical sheet 50 has a plurality of unit optical elements 60 extending concentrically around a single light emitter 26 that forms the light source 25 in the observation from the front direction. On the other hand, in the example shown in FIG. 19, a light source 25 is formed by three point-like light emitters 26 arranged in a second direction d2 orthogonal to the first direction d1. In the example shown in FIG. 19, the deflecting optical sheet 50 has a plurality of unit optical elements 60 extending on a concentric circle centered on the middle light emitter among the three light emitters 26 when viewed from the front. . The innermost unit optical element 60 is formed so as to extend on a circle having a size that surrounds all the three light emitters 26 in a plan view.

  Furthermore, the light emitter 26 of the light source 25 is not limited to a point light emitter, and for example, a linear light emitter such as a cold cathode tube may be used.

  Furthermore, in the above-described embodiment, the light that travels from the one edge 50c1 side (one side) of the deflection optical sheet 50 toward the other edge 50c2 side (the other side) in the first direction d1 is deflected optical sheet 50. In this example, only the light source 25 that irradiates the region between the reflecting sheet 21 and the reflecting sheet 21 is provided. However, as shown in FIG. 23, the light that travels from the other edge 50c2 side (other side) of the deflecting optical sheet 50 toward the one edge 50c1 side (one side) in the first direction d1 is deflected optical sheet 50. A second light source 27 for irradiating a region between the reflecting sheet 21 and the reflecting sheet 21 may be further provided. That is, a pair of light sources 25 and 27 each having the light emitting portions 26 and 28 may be provided corresponding to both the edge portions 50c1 and 50c2 in the first direction of the deflecting optical sheet 50, respectively.

  In the example shown in FIG. 23, a second auxiliary reflecting element 33 extending between the deflecting optical sheet 50 and the reflecting sheet 21 is provided at a position facing the second light source 27 along the first direction d1. It has been. The auxiliary reflection element 31 and the second auxiliary reflection element 33 are provided between the first light source 25 and the second light source 27 along the first direction d1, and are reflected from the liquid crystal display panel 15 along the front direction nd. It is located between the sheet 21. In the example shown in FIG. 23, the first light source 25 and the second light source 27, and the first auxiliary reflection element 31 and the second auxiliary reflection element 33 are center axes (center planes) parallel to the front direction nd. ) Around the center.

  Similar to the auxiliary reflective element 31 described above, from the viewpoint of uniforming the brightness distribution along the first direction d1, the second auxiliary reflective element 33 is the second auxiliary reflective element 33 measured in accordance with JISZ8741. The specular glossiness is equal to or greater than the specular glossiness of the reflective sheet 21 measured according to JISZ8741 using incident light that travels in a plane parallel to the first direction and is incident at an incident angle of 60 °. It is preferable.

  In the example shown in FIG. 23, each of the light sources 25 and 27 has one or more light emitting portions 26 and 28, and the light sources 25 and 27 have an optical axis pd of light emitted from the light source, which is a deflecting optical sheet. 50 and the reflection sheet 21 so as to extend to the corresponding positions on the auxiliary reflection elements 31 and 33. Further, the reflecting surfaces 32 and 34 of the auxiliary reflecting elements 31 and 33 are inclined with respect to the first direction d1, and each auxiliary reflecting element 31 and 33 deflects the light traveling in the first direction d1 by the deflecting optical sheet 50. Reflects to the upper position. According to such a configuration, the brightness distribution along the first direction d1 can be effectively uniformed as in the above-described embodiment.

  Further, in the above-described embodiment, the example in which the deflection optical sheet 50 is bonded to the polarizer 41 to form a part of the liquid crystal display panel 15 has been described, but the present invention is not limited thereto. The deflection optical sheet 50 may be provided separately from the liquid crystal display panel 15. In this example, an optical sheet such as a polarization separation film, an isotropic light diffusing sheet, an anisotropic isotropic light diffusing sheet, and a condensing sheet may be provided between the liquid crystal display panel 15 and the deflecting optical sheet 50.

  Similarly, although the liquid crystal display panel has shown the example which consists of a pair of polarizing plates 12 and 40 and the liquid crystal cell 11 located between a pair of polarizing plates 12 and 40, it is not restricted to this. For example, various functional optical sheets such as an antireflection film, an antiglare film, an antistatic film, and a hard coat film may be provided on the liquid crystal display panel 15.

  As an example, FIG. 24 discloses an example in which the liquid crystal display panel 15 includes a light control member 70 disposed on the light output side of the upper polarizing plate 12. The light control member 70 is a member having a function of changing the traveling direction of light, and includes a light transmission part (main part) 71 and an intermediate part (filling part) 72. In the example shown in FIG. 24, the intermediate portion 72 is formed in a columnar shape and extends to the back / near side of the paper surface of FIG. The light transmission part 71 is provided adjacent to both sides of the intermediate part 72 and has a substantially trapezoidal cross section and extends in a columnar shape.

  The light transmission part 71 is a part whose main function is to transmit light. As shown in FIG. 24, the cross-sectional trapezoidal shape of the light transmitting portion 71 is arranged such that the long lower base faces the light incident side and the short upper base faces the light outgoing side. The light transmission parts 71 are arranged at predetermined intervals along the panel surface of the liquid crystal display panel 15. An intermediate portion 72 having a substantially triangular cross section is formed between two adjacent light transmission portions 71. Therefore, the cross-sectional triangular shape formed by the interspace 72 has a base on the upper base side of the cross-sectional trapezoidal shape formed by the light transmitting portion 71 and a vertex on the lower base side of the cross-sectional trapezoidal shape formed by the light transmitting portion 71. Have.

  Such a light control member can be manufactured as follows. First, an ionizing radiation curable resin is molded on the transparent base material 73 to form the light transmission part 71. Next, an intermediate portion 72 is formed by applying and curing an ionizing radiation curable resin between the light transmitting portions 71. As a result, the light control member 70 having the transparent base material 73 and the light transmission part 71 and the intermediate part 72 formed on the transparent base material 73 is obtained.

  The light control member 70 has a light diffusing function caused by reflection or refraction at the interface between the light transmitting portion 71 and the intermediate portion 72 by forming the light transmitting portion 71 and the intermediate portion 72 from materials having different refractive indexes. Will be expressed.

  The cross-sectional shape of the intermediate portion 72 can be changed to various shapes without being limited to the triangular shape, and the cross-sectional shape of the light transmitting portion 71 is changed from a trapezoidal shape according to the cross-sectional shape of the intermediate portion 72. It may be changed. For example, the cross-sectional shape of the intermediate portion 72 may be a trapezoidal shape, or the hypotenuse of the intermediate portion 72 forming the side portion of the trapezoidal cross-sectional shape may be a polygonal line or a curved line.

  Although several modifications to the above-described embodiment have been described above, a plurality of modifications can be applied in appropriate combination.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to this Example.

  The optical modules according to Examples 1 to 3 and the optical module according to Comparative Example 1 were actually manufactured, and the brightness distribution along the first direction was investigated. Each optical module was manufactured by arranging a light source, a reflection sheet, a deflection optical sheet, and an auxiliary reflection element in the same manner as in the above-described embodiment. That is, the deflecting optical sheet and the reflecting sheet are disposed so as to face each other, and the light source and the auxiliary reflecting element are disposed on the sides of the deflecting optical sheet and the reflecting sheet. Each display device is different only in the reflection sheet, and other than the reflection sheet is configured in the same manner.

  In Examples 1 to 3, a reflection sheet that reflects the light with reflection characteristics having directivity depending on the incident direction of light is used. In Comparative Example 1, a reflection sheet that completely diffuses and reflects incident light is used. . More specifically, in Example 1, a reflective sheet having a specular reflectivity and having a reflective surface formed of silver was used. In Example 2, Example 3, and Comparative Example 1, a reflection sheet made of white PET in which a diffusing component was mixed was used. The internal diffusion capacity of the reflection sheet used in Comparative Example 1 was set stronger than the diffusion capacity of the reflection sheets used in Examples 2 and 3.

  The length along the first direction of each optical module was about 400 mm, and the length along the second direction of each optical module was about 700 mm. The thickness along the front direction of each optical module was set to approximately 30 mm.

  The deflecting optical sheet was an optical sheet in which linear unit optical elements having an isosceles triangular shape with a width W1 of 50 μm and an apex angle θ1 of 66 ° were linearly arranged without gaps. Similar to the deflecting optical sheet shown in FIG. 5, this optical sheet is composed of a resin layer including unit optical elements and a light diffusion layer positioned on the light output side of the resin layer.

  The light source included LEDs arranged side by side in the second direction and a cap covering the LEDs. The width along the second direction of the LED was 3 mm, and the width along the second direction of the cap was 23 mm. The LEDs were arranged at a pitch of 25 mm along the second direction. The auxiliary reflective element had a reflective surface made of a silver vapor deposited film. The optical axis of light emitted from a light source including an LED is directed in a direction parallel to the first direction. The auxiliary reflecting element was arranged so as to reflect the light incident from the direction along the optical axis of the LED toward the deflecting optical sheet.

  Table 1 shows the measurement results obtained by measuring the specular gloss and surface roughness of the reflective sheet incorporated in each optical module. The specular gloss is measured according to JISZ8741, and the incident light used for the measurement is parallel to both the first direction (the arrangement direction of the unit optical elements of the deflecting optical sheet) and the normal direction of the reflecting sheet. The light that travels in the plane and is incident on the target reflection sheet at incident angles of 60 ° and 20 °. IG-331 made by HORIBA was used for the measurement of specular gloss. In Table 1, a reflective sheet having a specular glossiness exceeding 199 (%) is displayed as over 199. On the other hand, the surface roughness measured ten-point average roughness Rz and arithmetic average roughness Ra based on JIS B0601. The measuring instrument used for the measurement was KOSAKA LAB. Surfcorder SE1700α was manufactured. In addition, about the reflective surface of the reflective sheet used in Example 1, the surface was smooth and the surface roughness could not be measured.

  Further, in FIGS. 26 to 29, the luminance in the front direction measured for the optical modules according to Examples 1 to 3 and Comparative Example 1 (the luminance measured from the normal direction to the sheet surface of the deflecting optical sheet), respectively. The in-plane distribution of is shown. 26 to 29, the area surrounded by the rectangular frame is centered along the length 400 mm along the second direction of the light exit side surface of the deflecting optical sheet of each optical module along the second direction. This corresponds to a region having a length of 180 mm along the second direction. 26 to 29 show the positions of the light sources.

  In FIG. 26 to FIG. 29, the value of the front direction luminance measured at each position on the light output side surface of the deflecting optical sheet as a ratio to the highest front direction luminance measured on the light output side surface of the deflecting optical sheet of each optical module. Evaluated. In FIG. 26 to FIG. 29, an area where the front direction luminance of 90% to 100% of the maximum front direction luminance value measured by each optical module is shown as S1, and the highest measured by each optical module is shown as S1. A region where the front direction luminance of 80% or more and less than 90% of the front direction luminance value is measured is shown as S2, and the front direction luminance of 70% or more and less than 80% of the maximum front direction luminance value measured by each optical module is shown. The measured area is indicated as S3, and the area where the front direction luminance of 60% or more and less than 70% of the maximum front direction luminance value measured by each optical module is indicated as S4, and measured by each optical module. An area where the front direction luminance of 50% or more and less than 60% of the maximum front direction luminance value is measured is shown as S5, and the maximum front direction luminance value measured by each optical module is shown. Front direction luminance of less than 0% indicates the measured area as S6.

  Further, when the distribution of brightness on the light exit side of the deflecting optical sheet of each optical module was visually confirmed, in the optical modules according to Example 1 and Example 2, unevenness in brightness could not be detected, In the optical module according to Example 3, unevenness in brightness that can be finally sensed by careful observation has occurred, but this is practically acceptable. On the other hand, in the optical module according to Comparative Example 1, uneven brightness was clearly detected.

DESCRIPTION OF SYMBOLS 10 Display apparatus 11 Liquid crystal cell 15 Liquid crystal display panel 20 Optical module 21 Reflection sheet 22 Reflection surface 25 Light source 26 Light emission part 27 Light source, 2nd light source 28 Light emission part 31 Auxiliary reflection element 32 Reflection surface 33 Auxiliary reflection element, 2nd auxiliary reflection element 34 Reflective surface 40 Polarizing plate, lower polarizing plate 40b Light incident side surface 41 Polarizer 50 Polarizing optical sheet, protective film, optical sheet 50a Light emitting side surface 50b Light incident side surface 51a Light diffusion layer 51b Resin layer 52 Land portion 54 Mat layer 55 Main body portion 59a Main part 59b Diffusing component 60 Unit optical element 81 Base 82 Cap 83 Reflecting material 85 Optical element

Claims (16)

A reflection sheet that reflects the light with a reflection characteristic having directivity depending on the incident direction of light;
A deflecting optical sheet disposed at a position facing the reflecting sheet, and a sheet-like main body portion, and a plurality of unit optical elements arranged on the main body portion and projecting toward the reflecting sheet. A deflection optical sheet having
An optical module comprising: a light source that projects light from one side to the other side in a direction parallel to the arrangement direction of the unit optical elements onto a region between the deflection optical sheet and the reflection sheet.   The specular gloss of the reflective sheet measured in accordance with JISZ8741 using incident light that travels in a plane parallel to the arrangement direction of the unit optical elements and is incident at an incident angle of 60 ° is 24 or more. The optical module according to claim 1.   The optical module according to claim 1, wherein a surface of the reflective sheet that faces the deflecting optical sheet is a smooth surface.   The optical module according to claim 3, wherein the reflection sheet contains a diffusing component therein.   The optical module according to claim 1, further comprising an auxiliary reflecting element disposed at a position facing the light source along a direction parallel to an arrangement direction of the unit optical elements.   The specular glossiness of the auxiliary reflecting element measured according to JISZ8741 conforms to JISZ8741 using incident light that travels in a plane parallel to the arrangement direction of the unit optical elements and is incident at an incident angle of 60 °. The optical module according to claim 5, which is equal to or higher than the specular gloss of the reflecting sheet measured in the above.   The light source is configured such that an optical axis of light emitted from the light source extends between the deflecting optical sheet and the reflective sheet and is directed to a position on the auxiliary reflective element. 7. The optical module according to 6.   The surface of the auxiliary reflection element facing the light source is inclined with respect to a direction parallel to the arrangement direction of the unit optical elements, and the auxiliary reflection element is in a direction parallel to the arrangement direction of the unit optical elements. The optical module according to claim 7, wherein the traveling light is reflected to a position on the deflecting optical sheet.   A second light source that irradiates a region between the deflection optical sheet and the reflection sheet with light traveling from one side to the other side in a direction parallel to the arrangement direction of the unit optical elements. The optical module according to any one of the above.   10. The optical module according to claim 9, further comprising a second auxiliary reflection element disposed at a position facing the second light source along a direction parallel to the arrangement direction of the unit optical elements.   The specular glossiness of the second auxiliary reflecting element measured according to JISZ8741 is JISZ8741 using incident light that travels in a plane parallel to the arrangement direction of the unit optical elements and is incident at an incident angle of 60 °. The optical module according to claim 10, which is equal to or higher than the specular gloss of the reflecting sheet measured in accordance with the above.   The second light source and the auxiliary reflection so that an optical axis of light emitted from the second light source extends between the deflecting optical sheet and the reflection sheet and is directed to a position on the second auxiliary reflection element. The optical module according to claim 10 or 11, wherein the element is configured.   The surface of the second auxiliary reflection element facing the second light source is inclined with respect to a direction parallel to the arrangement direction of the unit optical elements, and the second auxiliary reflection element is arranged in the arrangement of the unit optical elements. The optical module according to claim 12, wherein light traveling in a direction parallel to a direction is reflected to a position on the deflecting optical sheet.   The optical according to any one of claims 1 to 13, further comprising a polarizer provided on a side opposite to the side facing the reflection sheet of the deflection optical sheet and bonded to the deflection optical sheet. module.   A display apparatus provided with the optical module as described in any one of Claims 1-14.   The display device according to claim 15, wherein the deflection optical sheet forms a surface on the most incident light side of the liquid crystal display panel.

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