JP5896265B2 - Optical module and display device - Google Patents

Description

  The present invention relates to an optical module having a light source, a reflector 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. 27, a conventional backlight includes light sources 25a and 25b including a light emitter 26, a reflector D for directing light source light toward the liquid crystal display panel, and a liquid crystal display panel and a reflector D. And a number of optical sheets disposed therebetween. 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. 27 is configured as an edge light type, and a light guide plate A, a deflection sheet B, and a light diffusion sheet C are sequentially provided from the reflection plate D side toward the liquid crystal display panel side. . The light emitters 26 of the light sources 25a and 25b are disposed on the side of the light guide plate A, and the light emitted from the light emitter 26 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. 27, 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. 27, the light source is arranged on the side of the optical sheet, and the light guide plate is used to uniformize the light amount distribution along the light guide direction. 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 light from the light source is larger than the width of the light emitting part of the light emitting part of the light source in order to effectively use the light from the light source, and as a result, the thickness of the other optical sheets Compared to, 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 an object thereof is to provide an optical module capable of adjusting the illuminance distribution without using a light guide plate, and a display device including the optical module. To do.

The first optical module according to the present invention comprises:
A deflection optical sheet including one edge and the other edge facing in one direction;
A reflecting plate having a reflecting surface facing the deflecting optical sheet;
A light source that emits light to a region between the deflecting optical sheet and the reflecting plate from the one edge side to the other edge side in the one direction;
The deflection optical sheet has a sheet-like main body portion, and a plurality of unit optical elements provided on the surface of the main body portion facing the reflection surface,
Along the normal direction from the reflecting surface of the reflecting plate to the surface of the deflecting optical sheet facing the reflecting surface of the body portion, the surface facing the reflecting surface of the body portion The distance decreases from the one edge side to the other edge side in the one direction.

The second optical module according to the present invention comprises:
A deflection optical sheet including one edge and the other edge facing in one direction;
A reflecting plate having a reflecting surface facing the deflecting optical sheet;
A light source that emits light to a region between the deflecting optical sheet and the reflecting plate from the one edge side to the other edge side in the one direction;
The deflection optical sheet has a sheet-like main body portion, and a plurality of unit optical elements provided on the surface of the main body portion facing the reflection surface,
The angle of inclination of the reflecting surface with respect to the one direction in the cross section along both the normal direction to the surface facing the reflecting surface of the main body and the one direction is the one edge in the one direction. It becomes larger from the side of the part toward the side of the other edge.

  In the first or second optical module according to the present invention, a surface of the deflecting optical sheet facing the reflection surface of the main body may be flat, and the reflection surface of the reflection plate may be bent.

In the first or second optical module according to the present invention,
The light source has one or more light emitters,
In a cross section along both the normal direction and the one direction to the surface of the deflecting optical sheet that faces the reflecting surface of the main body, the optical axis of the light emitter is the optical axis of the deflecting optical sheet. The light emitter may be arranged so as to incline from a direction parallel to the surface of the main body facing the reflecting surface and to face the reflecting plate.

  In the first or second optical module according to the present invention, the light source includes one or more light emitters, and the light emitters are arranged so that an optical axis thereof is directed to a position on the reflection surface of the reflector. May be.

In the first or second optical module according to the present invention,
The plurality of unit optical elements of the deflection optical sheet are arranged in the one direction, and each unit optical element extends linearly in a direction intersecting the one direction,
In the cross section orthogonal to the longitudinal direction of the unit optical element, the outer contour of the unit optical element has at least a top side and a base end of a section from the top most spaced from the main body to the base end connected to the main body. It has a shape along a parabola that is different in two sections on the part side, and in the cross section, defines an X axis parallel to the surface of the main body part facing the reflecting surface and a Z axis orthogonal to the X axis And, when the position of the top of the unit optical element is the origin of the X axis and the Z axis, and when the body portion side is the negative side of the Z axis when viewed from the origin,
The parabola on the top side is represented by “Z = −aX ² ”,
The parabola on the base end side is represented by “Z = −bX ² + h”, and
The optical module as described in any one of Claims 1-5 by which the following formula | equation (a) and Formula (b) are satisfy | filled.
0 <a <b Formula (a)
0 <h Formula (b)

In the first or second optical module according to the present invention,
The deflection optical sheet includes an anisotropic diffusion layer having an anisotropic light diffusion function,
The anisotropic diffusion layer may have a light diffusing ability stronger in a direction orthogonal to the one direction than a light diffusing ability in a direction parallel to the one direction.

  The first or second 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 plate.

  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 one direction is orthogonal to the horizontal direction, and the one edge portion of the deflection optical sheet is positioned below the other edge portion of the deflection optical sheet in the vertical direction. Thus, the optical module may be arranged.

  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, the illuminance distribution can be adjusted 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 deflection optical sheet and the light emitter of the light source. FIG. 4 is a perspective view showing the deflection optical sheet. FIG. 5 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. 6 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. 7 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 deflection optical sheet. 8 is an enlarged view of the unit optical element of the deflecting optical sheet shown in FIG. 7 in the same cross section as FIG. FIG. 9 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. 10 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. 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 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. 13 is a view corresponding to FIG. 1 and a perspective view for explaining a modification of the optical module. FIG. 14 is a diagram corresponding to FIG. 3 and a plan view for explaining another modification of the optical module. FIG. 15 is a diagram corresponding to FIG. 3 and a plan view for explaining still another modification of the optical module. FIG. 16 is a perspective view showing a light diffusion layer of the deflection optical sheet, and is a view for explaining a modification of the light diffusion layer. FIG. 17 is a diagram showing a modification of the liquid crystal display panel from the side. FIG. 18 is a side view schematically illustrating the configuration of the optical module according to the first embodiment. FIG. 19 is a side view schematically illustrating the configuration of the optical module according to the second embodiment. FIG. 20 is a side view schematically showing the configuration of the optical module according to Comparative Example 1. FIG. 21 is a graph illustrating a light amount distribution along the first direction of light incident on each position of the deflecting optical sheet of the optical module according to the first embodiment. FIG. 22 is a graph illustrating a light amount distribution along the first direction of light incident on each position of the deflecting optical sheet of the optical module according to the second embodiment. FIG. 23 is a graph showing a light amount distribution along the first direction of light incident on each position of the deflecting optical sheet of the optical module according to Comparative Example 1. FIG. 24 is a graph illustrating an angular distribution of luminance on the light exit side surface of the deflecting optical sheet of the optical module according to the first embodiment. FIG. 25 is a graph showing the angular distribution of luminance on the light exit side surface of the deflecting optical sheet of the optical module according to Comparative Example 1. FIG. 26 is a graph showing the directivity characteristics of the light emitter used in the simulation. FIG. 27 is a cross-sectional view showing a display device including a conventional surface light source device.

  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.

  1 to 4 are diagrams for explaining an embodiment according to the present 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 deflecting optical sheet and the light emitter of the light source. FIG. 4 is a perspective view showing a deflection optical element of the optical module.

  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 viewer side with respect to the liquid crystal display panel. And a light source 25 that emits light for illuminating the liquid crystal display panel 15 from the back side (in this sense, the light incident side). . The liquid crystal display panel 15 is a device that forms an image by functioning as a shutter that controls transmission or blocking of light for each pixel of the color filter.

  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. The optical module 20 is formed by the deflecting optical sheet 50 of the one polarizing plate 40, the light source 25, and the reflecting plate 21 that are located closest to the light incident side of the liquid crystal display panel 15. 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. In addition, as shown in FIGS. 1-4, in this Embodiment, a pair of polarizing plates 12 and 40 as a component which comprises the liquid crystal display panel 15, and the liquid crystal display panel 15, and the liquid crystal cell 11, Furthermore, The deflecting 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 (see FIG. 3), and as a result, each member (each configuration) The element) has two pairs of edges, a pair of edges facing the first direction d1 and another pair of edges facing the second direction d2. 1 to 3, a pair of edge portions 50c1 and 50c2 facing the first direction d1 are illustrated for the deflecting optical sheet 50. 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 emitter 26 of the light source 25 is reflected by the reflecting plate 21 or directly enters the liquid crystal display panel 15 from the back side (light incident side). Hereinafter, the reflector 21, the light source 25, and the liquid crystal display panel 15 will be described in order.

  In the present specification, the “light-emitting side” refers to a predetermined optical path, that is, the light-transmitting body 26 of the light source 25 that directly passes through the liquid crystal display panel 15 through the reflecting plate 21 or without passing through the reflecting plate 21. , The downstream side of the optical path of the light toward the observer (the right side of the paper surface in FIGS. 1 and 2), that is, the observer side. The “incident side” is the upstream side of the planned optical path. That is. 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”, “film”, and “plate” are not distinguished from each other only based on the difference in names. Therefore, for example, a “sheet” is a concept including a member that can also be called a film or a plate. As a specific example, the “deflection optical sheet” includes a member that can be called a “deflection optical film” or a “deflection optical plate”. Similarly, the “reflecting plate” includes a member that can be called a “reflective sheet” or a “reflective film”.

  Further, in this specification, the “front direction” means a normal direction to a light incident side surface (a surface facing the reflector) 55b of a main body portion 55 described later of the deflecting optical sheet 50 constituting the optical module 20. It points to 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 reflecting plate 21 will be described. The reflecting plate 21 has a reflecting surface 22 that reflects light as a surface facing the deflection optical sheet 50 of the lower polarizing plate 40 located on the most incident light side of the liquid crystal display panel 15. The reflecting plate 21 receives light emitted from the light emitter 26 that constitutes the light source 25 and reflects the light toward the light incident side surface of the liquid crystal display panel 15.

  At least the reflecting surface 22 of the reflecting plate 21 is made of a material having a high reflectance such as metal. The reflector 21 in the present embodiment has a function of regularly reflecting incident light as shown in FIG. However, the reflection on the reflecting plate 21 is not limited to regular reflection, but may be diffuse reflection (irregular reflection, scattering reflection). Further, when the reflection on the reflecting plate 21 is diffuse reflection, the reflection may be isotropic diffusion or anisotropic diffusion. For example, by forming irregularities on the reflecting surface 22 of the reflecting plate 21 by embossing or the like, the reflection on the reflecting plate 21 can be made isotropic diffusion. In addition, for example, by applying a hairline process to the reflection surface 22 of the reflection plate 21, the reflection on the reflection plate 21 can be made 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 plate 21. Due to these optical elements, the reflecting plate 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 reflector 21 is disposed at a position shifted from the liquid crystal display panel 15 in the front direction. More specifically, the reflecting plate 21 is arranged along the front direction of the liquid crystal display panel 15 with respect to the light incident side surface 50b of the deflection optical sheet 50 of the lower polarizing plate 40 located on the most incident light side of the liquid crystal display panel 15. It is arranged at a position shifted to the side away from the liquid crystal cell 11 described later (the back side opposite to the observer side). Thereby, the light reflected by the reflecting surface 22 of the reflecting plate 21 is directly incident on the light incident side surface 50b of the deflection optical sheet 50 of the lower polarizing plate 40 located on the most incident light side of the liquid crystal display panel 15, in other words. Then, it is possible to enter the light as it is without passing through another member.

  As shown in FIGS. 1 and 2, the spacing distance along the front direction between the reflector 21 and the liquid crystal display panel 15 is not constant, but varies along the first direction d1. More precisely, the distance along the normal direction from the reflecting surface 22 of the reflecting plate 21 to the light incident side surface 55b of the main body 55, which will be described later in detail, of the deflecting optical sheet 50. sd (hereinafter, also simply referred to as “the separation distance sd between the reflector 21 and the liquid crystal display panel 15”) is the other edge from the one edge 50c1 side of the deflecting optical sheet 50 in the first direction d1. It changes so that it may become small toward 50c2. In the following, as shown in FIG. 2, the side of one edge portion 50 c 1 of the deflecting optical sheet 50 in the first direction d 1 is referred to as “one side in the first direction d 1 (one side along the first direction d 1). And the other edge 50c2 side of the deflecting optical sheet 50 in the first direction d1 is also referred to as “the other side in the first direction d1 (the other side along the first direction d1)”.

  Note that, here, “the separation interval sd between the reflecting plate 21 and the liquid crystal display panel 15 is directed from the one edge portion 50c1 side of the deflecting optical sheet 50 toward the other edge portion 50c2 side in the first direction d1. The term “becomes smaller” not only means that the separation interval sd continues to change along the first direction d1, but also the separation interval sd in the first direction d1 in a part of the region on the reflection surface 22. The aspect which does not change along is also included.

  In the present embodiment shown in FIG. 2, there are places where the separation interval sd between the reflecting plate 21 and the liquid crystal display panel 15 changes so as to increase from one side to the other side in the first direction d1. Does not exist. However, in a part of the region on the reflective surface 22, more specifically, in the region on one side along the first direction d1 on the reflective surface 22, the separation interval sd between the reflective plate 21 and the liquid crystal display panel 15 is provided. Is constant along the first direction d1, and the separation interval sd between the reflector 21 and the liquid crystal display panel 15 in the other region on the reflective surface 22 along the first direction d1. Continuously changes so as to become narrower as it moves away from one side along the first direction d1.

  Further, as shown in FIGS. 1 and 2, the inclination angle of the reflecting surface 22 of the reflecting plate 21 is not constant, but changes along the first direction d1. More precisely, a cross section parallel to both the front direction nd and the first direction d1, that is, the inclination angle θr of the reflection surface 22 with respect to the first direction d1 in the cross section of FIG. θr ”) changes so as to increase from one side to the other side in the first direction d1. Here, “the inclination angle θr of the reflecting surface 22 increases from one side to the other side in the first direction d1” means that the inclination angle θr changes along the first direction d1. In addition to continuing, an aspect in which the inclination angle θr does not change along the first direction d1 in a part of the region on the reflection surface 22 is also included.

  In the present embodiment shown in FIG. 2, there is no portion that changes so that the inclination angle θr of the reflecting surface 22 decreases from one side to the other side in the first direction d1. However, in a part of the region on the reflection surface 22, more specifically, in one region along the first direction d1 on the reflection surface 22, the inclination angle θr of the reflection surface 22 is along the first direction d1. In the other region along the first direction d1 other than that on the reflection surface 22, the inclination angle θr of the reflection surface 22 is separated from one side along the first direction d1. It keeps changing as it grows gradually.

  In the illustrated embodiment, the light incident side surface 50b (light incident side surface 55b of the main body 55) of the deflection optical sheet 50 of the lower polarizing plate 40 located on the most incident light side of the liquid crystal display panel 15 is a flat surface. It is formed as. On the other hand, the reflecting surface 22 of the reflecting plate 21 is formed as a curved surface, whereby the separation interval sd between the reflecting plate 21 and the liquid crystal display panel 15 changes along the first direction d1. In addition, the inclination angle θr of the reflection surface 22 changes along the first direction d1. More specifically, in the illustrated form, one region of the reflecting surface 22 of the reflecting plate 21 in the first direction d1 is formed as a flat surface, and the light incident side surface 50b ( The main body 55 is disposed so as to be parallel to the light incident side surface 55b). On the other hand, the other region of the reflecting surface 22 of the reflecting plate 21 is formed as a curved surface and is inclined with respect to the light incident side surface 50 b of the deflecting optical sheet 50.

  However, the reflecting surface 22 of the reflecting plate 21 is not limited to the above-described configuration, and may have various configurations. For example, the reflection surface 22 of the reflection plate 21 may be configured as a flat surface that is inclined with respect to the light incident side surface 50 b of the deflecting optical sheet 50 (light incident side surface 55 b of the main body 55). In this example, the inclination angle θr of the reflection surface 22 does not change along the first direction d1, but the separation interval sd between the reflection plate 21 and the liquid crystal display panel 15 changes along the first direction d1. Moreover, the whole area | region of the reflective surface 22 of the reflecting plate 21 may be comprised as a curved surface. In this example, both the inclination angle θr of the reflection surface 22 and the separation interval sd between the reflection plate 21 and the liquid crystal display panel 15 change along the first direction d1. Furthermore, the reflecting surface 22 of the reflecting plate 21 may be configured as a bent surface. Also in this example, both the inclination angle θr of the reflection surface 22 and the separation interval sd between the reflection plate 21 and the liquid crystal display panel 15 can change along the first direction d1.

  As described above, the reflection surface 22 of the reflection plate 21 is disposed at a position shifted in the front direction from the deflection optical sheet 50 located on the most incident light side of the liquid crystal display panel 15. In particular, in the present embodiment, as shown in FIG. 2, the reflector 21 is disposed so that at least a part thereof faces the liquid crystal display panel 15 in the front direction nd. That is, at least a part of the reflecting plate 21 is disposed at a position facing the lower polarizing plate 40 located on the most incident light side of the liquid crystal display panel 15 and the front direction nd. Therefore, no other member is interposed between at least a part of the reflecting plate 21 and the lower polarizing plate 40 located on the most incident light side of the liquid crystal display panel 15, and at least a part of the reflecting plate 21. The reflected light can be directly incident on the lower polarizing plate 40.

  Similarly, as shown in FIGS. 1 and 2, each position on the reflecting surface 22 of the reflecting plate 21 is on the surface orthogonal to the front direction nd and the front direction nd from the light emitting body 26 forming the light source 25. It is shifted to at least one of the directions (for example, the first direction d1). Thereby, the light emitted from the light emitter 26 of the light source 25 can be directly incident on the reflecting surface 22 of the reflecting plate 21, in other words, can be incident as it is without passing through another member.

  In addition, in the illustrated embodiment, the reflector 21 and the light emitting body 26 that constitutes the light source 25 along the front direction nd are on the same side with respect to the liquid crystal display panel 15, specifically, both of the liquid crystal display panels 15. It is arranged on the back side. As a result, the light emitted from the light emitter 26 of the light source 25 is directly incident on the reflecting surface 22 facing the liquid crystal display panel 15 (deflection optical sheet 50) of the reflecting plate 21, and is incident on the reflecting plate 21 and The light reflected by the reflecting plate 21 turns back in the traveling direction along the front direction due to reflection by the reflecting plate 21, and is a surface (light incident surface) on the side facing the reflecting plate 21 of the liquid crystal display panel 15 (polarizing plate 40). ) Can be directly incident.

  Next, the light source will be described. As shown in FIGS. 1 to 3, the light source 25 corresponds to one edge portion of the deflection optical sheet 50 having a rectangular planar shape, and more specifically, the deflection optical sheet 50 of the liquid crystal display panel 15. Corresponding to one of the pair of edge portions 50c1 and 50c2 opposed to the first direction d1. And as shown in FIG. 3, the light-emitting body 26 radiates | emits light so that this edge part 50c1 may be crossed in planar view.

  As the light emitter 26 forming the light source 25, various known light emitters such as 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 constituted by a plurality of dot-like light emitters 26, typically a plurality of light emitting diodes (LEDs) 26. A large number of point-like light emitters 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. That is, in the present embodiment, a large number of point light emitters 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 this display device 10, the light emitter 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 emitter 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 emitter 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 emitter 26 that forms the light source 25 is disposed at a position shifted from the liquid crystal display panel 15 in the front direction. More specifically, the light emitter 26 that constitutes the light source 25 is disposed at a position shifted to the back side along the front direction from the deflecting optical sheet 50 positioned closest to the light incident side of the liquid crystal display panel 15. As shown in FIG. 3, the light emitter 26 of the light source 25 is disposed in the vicinity of one edge 50c1 of the deflecting optical sheet 50 along the first direction d1 along the edge 50c1. Then, on one side along the first direction d1, the separation interval sd between the reflector 21 and the liquid crystal display panel 15 is the widest. In the present embodiment, the light emitter 26 that constitutes the light source 25 includes the reflecting surface 22 of the reflecting plate 21 and the deflecting optical sheet 50 positioned on the most incident light side of the liquid crystal display panel 15 on one side in the first direction d1. It arrange | positions between the light-incidence side 50b and the front direction.

  By the way, the point light-emitting body 26 like LED does not emit light radially with uniform luminous intensity, but has directivity. That is, the point light emitter 26 such as an LED emits light with a different luminous intensity (unit: candela) in each direction. In general, the light emitter 26 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 emitters 26 constituting the light source 25 is determined in consideration of the directivity characteristics (light distribution characteristics, in other words, the angle (direction) distribution of luminous intensity) of the light emitters 26. 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, the optical axis pd of the light emitter 26 is viewed from a direction parallel to the light incident side surface 55 b of the main body 55 of the deflecting optical sheet 50 in a cross section parallel to both the front direction nd and the first direction d1. It is inclined so as to be directed from the deflecting optical sheet 50 side to the reflecting plate 21 side, that is, from the observer side to the back side in the front direction. Further, the light emitter 26 is arranged so that the optical axis pd thereof faces the position on the reflection surface 22 of the reflection plate 21.

  According to such an arrangement, most of the light emitted from the light emitter 26 of the light source 25 enters the liquid crystal display panel 15 after the optical path in the front direction is turned back by reflection on the reflecting plate 21. According to the present embodiment as described above, the light exhibiting the same optical characteristics as compared with the mode in which the light from the light emitter 26 is directly incident on the liquid crystal display panel 15 without being reflected by the reflecting plate 21. The module 20 and the display device 10 can be configured to be significantly thinner. Further, most of the light from the light emitter 26 travels substantially along the first direction d1, and is prevented from leaking from between the liquid crystal display panel 15 and the reflecting plate 21 on the other side in the first direction d1. be able to. That is, loss of light emitted by the light emitter 26 can be effectively prevented, and the energy efficiency of the optical module 20 and the display device 10 can be effectively improved.

  Note that, for example, when the light emitter 26 has no directivity or only weak directivity, all light emitted by the light emitter 26 is reflected by the reflecting plate 21 to be incident on the liquid crystal display panel 15. For example, as shown in FIG. 2, a part of the light emitted from the light emitter 26 (see the optical path L2b) directly enters the liquid crystal display panel 15 without passing through the reflecting plate 21. Sometimes. Further, not all the light directed to the liquid crystal display panel 15 is incident on the liquid crystal display panel 15, and a part of the light is expected to be reflected on the light incident side surface of the liquid crystal display panel 15. For this reason, as shown by a two-dot chain line in FIG. 2 separately from the reflecting plate 21 arranged at the position facing the deflecting optical sheet 50 (liquid crystal display panel 15) or as an extension of the reflecting plate 21. The reflector 23 may surround the light emitter 26 so as to close the gap between the deflecting optical sheet 50 (the liquid crystal display panel 15) and the reflector 21. According to the auxiliary reflector 23, the light that could not enter the liquid crystal display panel 15 can be directed again to the liquid crystal display panel 15, and the utilization efficiency of the light from the light source 25 can be effectively improved. it can.

  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. 3, 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.

  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.

  As shown well in FIG. 4, the deflecting optical sheet 50 includes a sheet-like main body 55 and unit optical elements 60 arranged side by side on the light incident side surface 55 b of the main body 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.

  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. When viewed from the front direction nd, the arrangement direction of the unit optical elements 60 intersects with the pixel arrangement direction of the liquid crystal cell 11 of the liquid crystal display panel 15, that is, is inclined or orthogonal to the pixel arrangement direction. It is preferable. 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 also a cross section along the both directions of the arrangement direction of the unit optical elements 60 and the normal direction to the sheet-like main body 55 (hereinafter also simply referred to as “main cut surface”). Equivalent 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 θx (see FIG. 2) of the isosceles triangle shape can be set to, for example, 15 ° to 100 ° in consideration of the light collecting function. The width W (see FIG. 2) along the arrangement direction of the isosceles triangle can be set to, for example, 5 μm or more and 250 μm or less, and the height H 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.

  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 to be 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.

  Incidentally, as shown in FIGS. 1 and 2, in the present embodiment, in the display device 10 and the optical module 20, the first direction d1 is orthogonal to the horizontal direction, and as a result, the second direction d2 is horizontal. Arranged so as to be parallel to the direction. In particular, as well shown in FIG. 2, in the present embodiment, the display device 10 and the optical module 20 are configured such that the first direction d1 is parallel to the vertical direction and the second direction d2 is parallel to the horizontal direction. It is arranged. That is, in the illustrated example, the display surface 10a of the display device 10 is orthogonal to the horizontal plane and parallel to the vertical plane. And one edge part 50c1 of the deflection | deviation optical sheet 50 is located below in the perpendicular direction rather than the other edge part 50c2. That is, one edge 50c1 of the deflecting optical sheet 50 provided near the light emitter 26 of the light source 25 extends in the horizontal direction at a position below the vertical direction.

  During the use of the display device and the optical module, heat is generated from the light emitter of the light source. In conventional display devices and optical modules, the optical sheets may be locally heated due to heat generated by the light emitter. Thermal stress is generated in the optical sheets that are locally heated, and the optical sheets are deformed such as warping and bending. At this time, in a display device and an optical molding provided with a large number of optical sheets, adjacent optical sheets may contact or rub against each other. A portion where the optical sheets are deformed and in close contact with each other can no longer exhibit the expected optical function, and the close contact may be visually recognized. In addition, when the optical sheets are rubbed with each other, the optical sheets may be scratched, and further, residue may be generated, and the display image quality is remarkably deteriorated.

  On the other hand, according to the present embodiment, as well shown in FIGS. 1 and 2, the light emitter 26 of the light source 25 is changed to the display device 10 and the display device 10 by the arrangement of the optical module 20 and the display device 10 described above. It will be located below the optical module 20. In this case, the heat generated from the light emitter 26 is diffused upward. Further, the separation interval sd between the reflecting plate 21 and the liquid crystal display panel 15 is becoming narrower from the lower side to the upper side in the vertical direction. That is, the region between the reflector 21 and the deflecting optical sheet 22 facing the light emitter 26 serving as a heat source is separated from the light emitter 26, in other words, from the lower side to the upper side along the vertical direction. As it gets smaller, it gets narrower. That is, according to the optical module 20 and the display device 10 described here, the heat caused by the heat generated by the light emitter 26 can be uniformly diffused in the region between the reflecting plate 21 and the deflecting optical sheet 22. It becomes. For this reason, the reflective plate 21, the deflecting optical sheet 50, and the reflective plate 21 are less likely to be deformed due to local heating.

  In addition, according to the present embodiment, the separation interval sd between the reflecting plate 21 and the liquid crystal display panel 15 becomes narrower from the lower side to the upper side in the vertical direction. Therefore, the reflecting plate 21 can be supported so as to lean against the deflecting optical sheet 50. For this reason, it is possible to stably support the reflecting plate 21, which has a curved reflecting surface 22, which tends to be complicated in its support structure, using the deflecting optical sheet 50. As a result, it is possible to stably ensure uniform illuminance distribution due to a desired optical action in the reflector 21 described later. The usefulness of such an effect becomes more prominent when the display device 10 is enlarged.

  In particular, according to the present embodiment, the deflection optical sheet 50 is configured as a part of the liquid crystal display panel 15. That is, the deflecting optical sheet 50 is joined to another part of the liquid crystal display panel 15 as a part of the highly rigid liquid crystal display panel 15 including the liquid crystal cell 11. For this reason, even if it is the large sized display apparatus 10, the deflection | deviation optical sheet 50 can be supported stably, without providing the special support structure for supporting the deflection | deviation optical sheet 50. FIG. Accordingly, the above-described reflector 21 can be supported while leaning against the liquid crystal display panel 15 having high rigidity. As a result, the reflector 21 is extremely stable due to the extremely simplified structure. Can be supported.

  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 emitter 26 is inclined from the light incident side surface 55 b of the main body 55 of the deflecting optical sheet 50 and is directed toward the reflecting plate 21. . In particular, in the present embodiment, the optical axis pd of the light emitter 26 is directed to the position on the reflection surface 22 of the reflection plate 21, and thus the light emission body 26 of the light source 25 is the reflection surface 22 of the reflection plate 21. Emits light toward. That is, most of the light L2a emitted from the light emitter 26 of the light source 25 enters the reflector 21 directly, that is, without entering another member, and is reflected in the traveling direction by reflection on the reflecting surface 22 of the reflector 21. Will be changed. As shown in FIG. 2, most of the light reflected by the reflecting surface 22 of the reflecting plate 21 can enter the liquid crystal display panel 15 directly, that is, without entering another member.

  In the present embodiment, the light guide plate A (see FIG. 27) for making the light quantity distribution along the irradiation direction (light guide direction) of the light from the light emitter 25 uniform is not provided. In this embodiment, in this embodiment, as shown in FIG. 2, the separation distance sd between the reflector 21 and the liquid crystal display panel 15 is changed from one side to the other side in the first direction d1, in other words. As the distance from the light emitter 26 of the light source 25 increases, the light source 25 becomes narrower. 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 emitter 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 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, and light that diffuses the light. Has a diffusion function. 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 in FIG. 2, the basic principle of the light collecting function by the unit optical element 60 having a triangular cross section is that light L2a and L2b incident from one surface (incident surface) 60b1 of the unit optical element 60 is obtained. By making total reflection on the other surface (total reflection surface) 60b2, the angle formed by 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 flat surface free from 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.

  Further, the incident angle of light incident on each position on the reflecting surface 22 of the reflecting plate 21 changes according to the distance along the first direction d1 from the light emitter 26 to the incident position. On the other hand, in the present embodiment, the inclination angle θr of the reflection surface 22 increases from one side to the other side in the first direction d1, in other words, as the distance from the light emitter 26 of the light source 25 increases. Go. Such a change in the inclination angle θr of the reflecting surface 22 serves to align the traveling directions of the light incident on the reflecting plate 21 at different incident angles after being reflected by the reflecting surface 22. That is, the variation in the incident angle of the light incident on each position of the liquid crystal display panel 15 (deflection optical sheet 50) is reduced, and the incident angle of the light incident on the liquid crystal display panel 15 (deflection optical sheet 50) is set to a narrow angle. The range can be narrowed down. As a result, the unit optical elements 60 having the same configuration arranged along the first direction d1 can exhibit an excellent light collecting 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 position of the light emitter 26 forming the light source 25 shifted from the display area in the first direction d1 in the front direction nd observation. Even if the light source 25 is not provided on the light guide plate A (see FIG. 27) and the light source 25 is provided only on one side in the first direction d1, the light quantity distribution along the first direction d1. 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. Furthermore, since only the reflecting plate 21 is disposed in the optical path of the light source light from the light emitter 26 constituting the light source 25 to the protective film 50 of the polarizing plate 40, display caused by deformation such as bending, bending or warping of the optical sheet. The degree of image quality degradation 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 emitter 26 of the light source 25 can be incident on the polarizing plate 40 of the liquid crystal display panel 15 by a single reflection on the reflection surface 22 of the reflection plate 21. For this reason, the utilization efficiency of the light emitted by the light emitter 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.

  Further, in the present embodiment, the light emitter 26 is disposed on one side in the first direction d1, and the reflector 21 and the liquid crystal display panel 15 (deflection optics) are directed from one side to the other side along the first direction d1. Light is irradiated between the sheet 50). The separation distance sd between the reflecting plate 21 and the liquid crystal display panel 15 is the widest on one side where the light emitter 26 is disposed in the first direction d1, and the other side to which the light emitted from the light emitter 26 is directed. Becomes the narrowest. Therefore, the light emitted from the light emitter 26 leaks from between the reflecting plate 21 and the liquid crystal display panel 15 (deflection optical sheet 50) on the other side in the first direction d1 and cannot be used for image formation. This can be effectively prevented. Therefore, also from such a configuration surface of the optical module 20, the utilization efficiency of the light emitted from the light emitter 26 can be effectively increased.

  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, for example, as shown in FIGS. 5 and 6, the diffusion component 59 b 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.

  Furthermore, 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 deflecting optical sheet 50 is a triangular shape has been shown. 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. In addition, as shown by a two-dot chain line in FIG. 2, at least one of the two sides extending from the above-described triangular main body 55 on the main cut surface of the protective film is a curve that bulges outward. It may be modified as follows.

  Further, as shown in FIG. 5, 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. Furthermore, as shown in FIG. 6, the unit optical element 60 may have a shape obtained by removing the triangular top 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. 6 on the main cut 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. The deflecting optical sheet 50 shown in FIGS. 5 and 6 can be produced by extrusion molding in the same manner as the deflecting optical sheet 50 of the above-described embodiment.

  7 and 8 show a modified example 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. 7 and 8 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. 8 and 9, 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 H 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 the parabola in a range that is 50% or less of the height H 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. 7 and 8 will be described. First, as shown in FIG. 8, 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 55b 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. A numerical value in the following range, for example, 0.05 can be used.

  The intersection 61c between the parabola P1 and the parabola P2 is 25 to 75% of the height H 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.

  The cross-sectional shape of the unit optical element 60 shown in FIGS. 7 and 8 is preferably set so that the width W and height H of the unit optical element 60 satisfy W / 2 ≧ H. However, from the viewpoint of securing a wide viewing angle, the cross-sectional shape of the unit optical element 60 shown in FIGS. 7 and 8 is such that the width W and the height H of the unit optical element 60 satisfy W / 2 ≦ H. It is preferable that it is set to. The unit optical elements 60 are preferably arranged without gaps from the viewpoint of preventing omissions. In this case, the arrangement pitch of the unit optical elements 60 and the width W of the unit optical elements 60 are equal.

  As an example of the dimensions of the unit optical elements shown in FIGS. 7 and 8 as described above, the width W can be 20 to 200 μm and the height H can be 10 to 100 μm.

  The “parabola” for specifying the contour outside the cross section of the unit optical element shown in FIGS. 7 and 8 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. 7 and 8 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, an example in which the deflection optical sheet 50 is made of an extruded material obtained by extrusion molding is shown, but the present invention is not limited to this. It is also possible to use a deflecting optical sheet manufactured by other manufacturing methods such as injection molding. Here, FIGS. 9 to 12 show, as an example, an example of a deflecting 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. 9 can be manufactured by molding a resin containing a diffusing component 59b on a base film 53. In the deflection optical sheet 50 shown in FIG. 9, 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 deflecting optical sheet 50 shown in FIG. 10 can be manufactured by molding a resin on the base film 53 containing the diffusing component 59b and forming the light diffusing 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. 11, 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. 12, 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 forming the unit optical element 60. Is formed. In the embodiment shown in FIG. 12, 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. 9-12, the 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 direction of the unit optical elements 60 of the deflecting optical sheet 50 intersects the first direction d1 according to the optical characteristics desired for the optical module 20 and the display device 10, for example, the first direction as shown in FIG. You may make it become orthogonal to d1 and parallel to the 2nd direction d2. 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. 16, 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 deflection optical sheet 50 shown in FIG. 16 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 diameter of 1.5 to 50 μm and an average particle diameter of the diffusion component 59b (particle diameter calculated by the volume equivalent method, ie, arithmetic average of volume equivalent diameter, the same shall apply hereinafter) 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, can also be used for the diffusion component 59b which consists of inorganic fibers, for example. 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 above-described embodiment, the light source 25 is configured by arranging a large number of light emitters 26 in the second direction d2. That is, according to the configuration of the light source 25, for example, the distribution of brightness along the second direction d2 can be controlled by the arrangement pitch of the light emitters 26. In particular, in the present embodiment, the light from the light source 25 can be controlled. Is incident on the liquid crystal display panel 15 (deflection optical sheet 50) without going through a large number of optical sheets, so that the brightness distribution due to the configuration of the light source 25 is easily maintained.

  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 emitters 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 further effectively use the light.

  On the other hand, the unit optical element 60 of the deflecting optical sheet 50 exhibits a condensing function with respect to a component along the first direction d1 of mainly incident light. In addition, when the number of the light emitters 26 is small as in the examples shown in FIGS. 14 and 15, for example, uneven brightness occurs in the second direction d2. In this case, the orientation direction od of the diffusion component 59b having the longitudinal direction ld is parallel to the first direction d1 perpendicular to the second direction d2 in which the light emitters 26 forming the light source 25 are arranged, and the diffusion component 59b is It is preferable to diffuse mainly in two directions d2. The light diffusing layer 51a of the deflecting 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. In this case, 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. . As a result, the brightness variation according to the configuration (arrangement) of the light emitters 26 is improved by the anisotropic diffusion function caused by the light diffusion layer 51a, while the front luminance is increased by the light collecting function caused by the unit optical element 60. Can also be eliminated.

  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. Further, the degree of the light diffusing function by the adhesive layer can be appropriately adjusted by the same method as the degree of the light diffusing function in the deflecting 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.

  Furthermore, various changes can be made to the reflecting plate 21. For example, in the above-described embodiment, one region of the reflecting surface 22 of the reflecting plate 21 in the first direction d1 is formed as a flat surface, and the other region of the reflecting surface 22 of the reflecting plate 21 is the other region. An example of a curved surface is shown. In this regard, as described above, the reflecting surface 22 of the reflecting plate 21 may be configured only from a flat surface that is inclined with respect to the light incident side surface 50 b of the deflecting optical sheet 50. Moreover, the whole area | region of the reflective surface 22 of the reflecting plate 21 may be comprised as a curved surface. Furthermore, the reflecting surface 22 of the reflecting plate 21 may be configured as a bent surface.

  Furthermore, as already mentioned, the reflecting plate 21 may have a diffuse reflection function (a diffuse reflection function, a scattering reflection function) instead of the regular reflection function. When the reflection plate 21 diffuses and reflects the light from the light emitter 26 of the light source 25, the light incident side surface 50b of the deflection optical sheet 50 can be illuminated with a more uniform brightness distribution. Further, when the reflection plate 21 has a diffuse reflection function, the diffusion by the reflection on the reflection plate 21 may be isotropic diffusion or anisotropic diffusion. When the diffuse reflection function of the reflection plate 21 is an anisotropic diffuse reflection function, the reflection plate 21 is any one other than the first direction d1, the second direction d2, the first direction d1, and the second direction d2. You may make it exhibit the strongest diffuse reflection function in a direction.

  Furthermore, in the above-described embodiment, an example in which light emitted from the light emitter 26 of the light source 25 is directly incident on the reflecting plate 21, that is, light emitted from the light emitter 26 of the light source 25 is another member. Although the example which injects into the reflecting plate 21 without passing through was shown, it is not restricted to this example. An optical element that receives light emitted from the light emitter 26 of the light source 25 and directs it toward the reflecting plate 21 may be provided. The optical element is used for various purposes, for example, to direct the traveling direction of the light emitted from the light emitter toward the reflector 21, or to direct only the reflector 21, or to directivity characteristics of the light emitter 26 ( It can be provided for the purpose of adjusting the light quantity distribution of light incident on each position of the reflector 21 by eliminating or correcting the light distribution characteristics, in other words, the angle (direction) distribution of luminous intensity.

  Moreover, in embodiment mentioned above, although LED was illustrated as the point light emitter 26 of the light source 25, it is not restricted to this, You may use another point light emitter. For example, a laser light source that generates laser light may be used as the point light emitter. In the above-described embodiment, as shown in FIG. 3, an example in which the light emitters 26 are arranged 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 portion) 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.

  14 and 15 are plan views showing the light source 25 together with the deflection optical sheet 50. FIG. In the example shown in FIG. 14, the light source 25 is formed by a single light emitter 26. In the example shown in FIG. 14, the deflecting optical sheet 50 includes a plurality of unit optical elements 60 extending concentrically around a single light emitter 26 that forms the light source 25 when viewed from the front. On the other hand, in the example shown in FIG. 15, the light source 25 is formed by three point-like light emitters 26 arranged in the second direction d2 orthogonal to the first direction d1. In the example shown in FIG. 15, the deflection optical sheet 50 has a plurality of unit optical elements 60 extending on a concentric circle centering on the middle light emitter among the three light emitters 26 in the observation from the front direction. . 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.

  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. In the above-described embodiment, the example in which the reflecting plate 21 is disposed at the position facing the deflecting optical sheet 50 in the front direction is shown, but the present invention is not limited thereto. Between the reflecting plate 21 and the deflecting optical sheet 50, an optical sheet such as an isotropic light diffusing sheet, an anisotropic isotropic light diffusing sheet, or a condensing sheet may be provided.

  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. 17 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. 17, the intermediate portion 72 is formed in a columnar shape and extends to the back / near side of the paper surface of FIG. 17. 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. 17, the trapezoidal cross section 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 in the cross-sectional shape of the intermediate portion 72 may be a polygonal line shape or a curved shape.

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

  As described below, optical modules according to Example 1, Example 2, and Comparative Example 1 were designed, and optical characteristics of each optical module were simulated.

[Optical module]
Each optical module to be simulated was configured to have the configuration shown in FIGS. As shown in FIGS. 18 and 19, in the optical modules according to Example 1 and Example 2, the reflecting surface 22 of the reflecting plate 21 is formed in a bent surface shape, and the unit optical element of the deflecting optical sheet 50 is used. Unlike the optical module according to the above-described embodiment, the cross-sectional shape of 60 is the same as the cross-sectional shape of the unit optical element described with reference to FIGS. The optical module according to the embodiment is configured in the same manner.

  Therefore, in the optical modules shown in FIG. 18 and FIG. 19, the separation interval sd between the reflector 21 and the liquid crystal display panel 15 is one side (lower side) along the first direction (vertical direction). It changed so that it might become small toward the other side (upper side) from. Specifically, at one side end (lower side end) along the first direction (vertical direction), the separation interval sd between the reflection plate 21 and the liquid crystal display panel 15 is 30 mm, and the first direction At the other end (upper end) along the (vertical direction), the separation interval sd between the reflecting plate 21 and the liquid crystal display panel 15 was set to 10 mm. Further, in the optical modules shown in FIGS. 18 and 19, the inclination angle θr of the reflecting surface 22 is directed from one side (lower side) to the other side (upper side) along the first direction (vertical direction). And changed to become larger. In the optical module, the light incident side surface 55b of the main body 55 of the deflecting optical sheet 50 is parallel to the vertical surface, and one side along the first direction d1 where the light emitter 26 is provided is the lower side in the vertical direction. Arranged.

  The optical module according to Example 1 and the optical module according to Example 2 were different from each other in that the bending position of the reflection surface 22 was different, and were configured identically in other points. Specifically, in the optical module according to the first embodiment, the separation distance sd between the reflecting plate 21 and the liquid crystal display panel 15 is constant in an area from one side end along the first direction to a position of 140 mm. In the optical module according to the second embodiment, the separation interval sd between the reflecting plate 21 and the liquid crystal display panel 15 is constant in an area from one side end along the first direction to a position of 160 mm. I did it.

  On the other hand, in the optical module according to the comparative example, the reflecting surface 22 of the reflecting plate 21 is a flat surface parallel to the light incident side surface 55 b of the main body 55 of the deflecting optical sheet 50. In other respects, the optical module according to the example is configured in the same manner.

  In the optical modules according to the example and the comparative example, the width W (see FIG. 8) and the arrangement pitch of the unit optical elements 60 of the deflection optical sheet 50 are set to 50 μm, and the height H of the unit optical elements 60 of the deflection optical sheet 50 (see FIG. 8) was 33.2 μm. Similarly to FIG. 8, the base angle θb of the outer contour of the unit optical element 60 of the deflecting optical sheet 50 in the cross section was set to 74 °. Other specific configurations and dimensions of the optical modules according to the example and the comparative example are as shown in FIGS. For example, in the optical modules according to the example and the comparative example, the light emitter that constitutes the light source is located 20 mm outward along the first direction from one side end in the first direction of the deflection optical sheet, It arrange | positioned in the position of 15 mm back side along the front direction from the light-incidence side of the main-body part of a sheet | seat. An angle θp formed by the optical axis pd of the light emitter with respect to the first direction is set to 8 ° so that the optical axis pd of the light emitter is directed to a position on the reflection surface 22 of the reflection plate 21. The illuminant was an LED exhibiting the directional characteristics (angle distribution of luminous intensity (candela)) shown in FIG. In each optical module, the length of the deflecting optical sheet and the reflecting plate in the first direction was 400 mm.

[Evaluation 1: Illuminance distribution]
For each optical module, in order to investigate the distribution of the incident light quantity at each position of the deflecting optical sheet, the illuminance at the position where the incident light side surface of the deflecting optical sheet is arranged was investigated. FIG. 21 is an illuminance distribution along the first direction obtained for the optical module of Example 1, and FIG. 22 is an illuminance distribution along the first direction obtained for the optical module of Example 2. FIG. 23 is an illuminance distribution along the first direction obtained for the optical module of Comparative Example 1. In the graphs shown in FIGS. 21 to 23, the ordinate indicates the illuminance, and the abscissa indicates the position where the illuminance is measured. In each of the graphs shown in FIGS. 21-23, the lowest illuminance value calculated for each optical module is plotted at 0 on the vertical axis, and the highest illuminance value is plotted at 1 on the vertical axis. Thus, the illuminance distribution at each position along the first direction is shown.

  In the optical modules according to Example 1 and Example 2, the illuminance peak was obtained at a position on the other side of the central position along the first direction. On the other hand, in the optical module according to the comparative example, the peak of illuminance was obtained at the approximate center between the center position and the one side end in the first direction. In the optical modules according to Example 1 and Example 2, illuminance more than half of the peak illuminance was obtained in more than half of the region along the first direction. On the other hand, in the optical module according to the comparative example, the region where the illuminance more than half of the peak illuminance was obtained was narrow and biased toward one side that was near the light emitter in the first direction.

[Survey 2: Brightness]
For the optical modules according to Example 1 and Comparative Example 1, the luminance on the light exit side of the deflecting optical sheet was investigated. For each optical module, a position 100 mm from one side end (lower end) along the first direction, a position 200 mm from one side end (lower end) along the first direction (center along the first direction) Position), and an angular distribution in the horizontal plane on the light exit side surface of the deflecting optical sheet (hereinafter also simply referred to as a horizontal angular distribution) at a position 300 mm from one side end (lower side end) along the first direction. ) And the angular distribution in the vertical plane (hereinafter also referred to simply as the vertical angular distribution) of the luminance on the light exit side of the deflecting optical sheet. The horizontal angle distribution of luminance is the distribution of luminance in various directions along the horizontal plane orthogonal to the vertical direction, and the vertical angle distribution of luminance is various distribution along the vertical plane orthogonal to the horizontal direction. This is the luminance distribution in the direction.

  As an example, FIG. 24 shows the horizontal angle distribution and the vertical angle distribution of luminance at a position 200 mm from one side end (lower side end) along the first direction obtained for the optical module of Example 1. Show. Further, FIG. 25 shows the horizontal angle distribution and the vertical angle distribution of the luminance at the position of 100 mm from the one side end (lower end) along the first direction obtained for the optical module of Comparative Example 1. In the graphs shown in FIG. 24 and FIG. 25, the ratio of the optical module according to Example 1 to the luminance in the front direction at the position of about 200 mm from the one side end (lower end) along the first direction, that is, the first The luminance is shown on the vertical axis as the luminance ratio (percentage:%) with respect to the luminance in the front direction of the optical module according to Example 1 at a position approximately 200 mm from one side end (lower side end) along one direction. . In addition, the horizontal axis of the graphs shown in FIGS. 24 and 25 indicates an angle of the direction in which the luminance is measured with respect to the front direction. Note that in the graphs showing the vertical angle distribution of luminance shown in FIGS. 24 and 25, the angle of the measurement direction inclined downward from the front direction is a positive value, and the measurement direction inclined upward from the front direction is taken as a positive value. The angle is negative.

  The horizontal angle distribution of luminance obtained at each position in Example 1 had the same tendency. Moreover, the horizontal angle distribution of the luminance obtained at each position in Example 1 was symmetric about the front direction, and a luminance peak appeared in the substantially front direction. The vertical angle distributions of the luminance obtained at the respective positions in Example 1 had almost the same tendency. In addition, in the luminance vertical angle distribution obtained at each position in Example 1, a luminance peak appeared in a substantially front direction.

  The horizontal angle distribution of luminance obtained at each position in Comparative Example 1 had the same tendency. Moreover, the horizontal angle distribution of the luminance obtained at each position in Comparative Example 1 was symmetric about the front direction, and a luminance peak appeared in the substantially front direction. The vertical angle distributions of the luminance obtained at the respective positions in Comparative Example 1 had almost the same tendency.

  As shown in FIG. 21, in the optical module according to Example 1, the highest illuminance in the first direction is about 200 mm from one side end (lower end) along the first direction. 23, as shown in FIG. 23, in the optical module according to Comparative Example 1, the highest illuminance in the first direction is that one side end (lower side) along the first direction. The position was approximately 100 mm from the end. And as understood from the comparison between FIG. 24 and FIG. 25, the front direction luminance of the optical module according to Example 1 at the position of approximately 200 mm from the one side end (lower end) along the first direction is It was a very high value compared with the brightness in the front direction of the optical module according to Comparative Example 1 at a position approximately 100 mm from one side end (lower side end) along the first direction.

DESCRIPTION OF SYMBOLS 10 Display apparatus 11 Liquid crystal cell 15 Liquid crystal display panel 20 Optical module 21 Reflector 22 Reflective surface 23 Auxiliary reflector 25 Light source 26 Light emitter 40 Polarizing plate, lower polarizing plate 40b Light incident side surface 41 Polarizer 50 Deflection optical sheet, protective film, Optical sheet 50a Light exit side surface 50b Light incident side surface 50c1 Edge portion 50c2 Edge portion 51a Light diffusion layer 51b Resin layer 52 Land portion 54 Mat layer 55 Main body portion 59a Main portion 59b Diffusion component 60 Unit optical element 61a Top portion 61b Base end portion 61c Intersection 62 Outer contour 62a Top side section 62b Base end side section 70 Light control member 71 Light transmission portion, main portion 72, filling portion 73 Transparent substrate

Claims (13)

A deflection optical sheet including one edge and the other edge facing in one direction;
A reflecting plate having a reflecting surface facing the deflecting optical sheet, wherein at least a part of the reflecting surface is bent ; and
A light source that emits light to a region between the deflecting optical sheet and the reflecting plate from the one edge side to the other edge side in the one direction;
The deflection optical sheet has a sheet-like main body portion, and a plurality of unit optical elements provided on the surface of the main body portion facing the reflection surface,
Each of the plurality of unit optical elements has a total reflection surface,
Along the normal direction from the reflecting surface of the reflecting plate to the surface of the deflecting optical sheet facing the reflecting surface of the body portion, the surface facing the reflecting surface of the body portion The optical module is configured such that the distance becomes smaller from the one edge side toward the other edge side in the one direction. A deflection optical sheet including one edge and the other edge facing in one direction;
A reflecting plate having a reflecting surface facing the deflecting optical sheet, wherein at least a part of the reflecting surface is bent ; and
A light source that emits light to a region between the deflecting optical sheet and the reflecting plate from the one edge side to the other edge side in the one direction;
The deflection optical sheet has a sheet-like main body portion, and a plurality of unit optical elements provided on the surface of the main body portion facing the reflection surface,
Each of the plurality of unit optical elements has a total reflection surface,
The angle of inclination of the reflecting surface with respect to the one direction in the cross section along both the normal direction to the surface facing the reflecting surface of the main body and the one direction is the one edge in the one direction. An optical module that grows from one side to the other side.   3. The optical module according to claim 1, wherein a surface of the deflecting optical sheet facing the reflecting surface of the main body is flat, and the reflecting surface of the reflecting plate is bent. The light source has one or more light emitters,
In a cross section along both the normal direction and the one direction to the surface of the deflecting optical sheet that faces the reflecting surface of the main body, the optical axis of the light emitter is the optical axis of the deflecting optical sheet. The optical module according to claim 3, wherein the light emitter is arranged so as to be inclined from a direction parallel to a surface of the main body portion facing the reflection surface and toward the reflection plate. The light source has one or more light emitters,
The optical module according to any one of claims 1 to 4, wherein the light emitter is disposed so that an optical axis thereof is directed to a position on the reflection surface of the reflection plate. The plurality of unit optical elements of the deflection optical sheet are arranged in the one direction, and each unit optical element extends linearly in a direction intersecting the one direction,
In the cross section orthogonal to the longitudinal direction of the unit optical element, the outer contour of the unit optical element has at least a top side and a base end of a section from the top most spaced from the main body to the base end connected to the main body. It has a shape along a parabola that is different in two sections on the part side, and in the cross section, defines an X axis parallel to the surface of the main body part facing the reflecting surface and a Z axis orthogonal to the X axis And, when the position of the top of the unit optical element is the origin of the X axis and the Z axis, and when the body portion side is the negative side of the Z axis when viewed from the origin,
The parabola on the top side is represented by “Z = −aX ² ”,
The parabola on the base end side is represented by “Z = −bX ² + h”, and
The optical module as described in any one of Claims 1-5 by which the following formula | equation (1) and Formula (2) are satisfy | filled.
0 <a <b Formula (1)
0 <h Formula (2) The deflection optical sheet includes an anisotropic diffusion layer having an anisotropic light diffusion function,
The anisotropic diffusion layer has a light diffusing ability stronger in a direction orthogonal to the one direction than a light diffusing ability in a direction parallel to the one direction. The optical module according to item.   The optical module according to claim 1, further comprising a polarizer provided on a side opposite to a side facing the reflection plate of the deflecting optical sheet. Each of the plurality of unit optical elements has an entrance surface;
The optical module according to claim 1, wherein the total reflection surface totally reflects light incident from the incident surface . The deflection optical sheet includes a main part made of resin and a light diffusion layer having a diffusion component dispersed in the main part, and a resin layer not containing the diffusion component,
The optical module according to claim 1, wherein the plurality of unit optical elements are included in the resin layer. A display apparatus provided with the optical module as described in any one of Claims 1-10 . An optical module, wherein the one direction is orthogonal to the horizontal direction, and the one edge portion of the deflection optical sheet is positioned below the other edge portion of the deflection optical sheet in the vertical direction. The display device according to claim 11 , wherein: The display device according to claim 11 or 12 , wherein the deflecting optical sheet forms a surface on the most incident side of the liquid crystal display panel.

Images