JP6704270B2 - Light distribution control element holding structure and surface light source device including the same - Google Patents

Description

The present invention relates to a lighting device and a surface light source device used as a backlight light source of a display for image display, and more particularly to a technique for stably holding a substrate on which a point light source is mounted and a light distribution control element.

In recent years, in a surface light source device mainly used for a backlight light source, it is mainstream to use an LED element as a point light source. In a direct type surface light source device in which substrates on which a plurality of LED elements are mounted are arranged on the back surface of a product, a light distribution control element is provided on the LED elements to diffuse light and illuminate a liquid crystal panel. ..

In addition, the light distribution control element is roughly classified into a method of arranging a plurality of LED elements arranged side by side on a straight line and a method of arranging so as to cover the entire plurality of LED elements. There is (for example, see Patent Documents 1 and 2).

In any of the above methods, the positional relationship between the LED element and the light distribution control element is broken, which leads to luminance deterioration and color unevenness. Therefore, it is important to provide a holding structure for the light distribution control element that does not lose the positional relationship between the two. Is. In order to surely obtain the bonding strength with respect to the mounting board without breaking the positional relationship between the LED element and the light distribution control element, it is common to bond the light distribution control element to the mounting board using a dedicated jig. ..

For example, in the technique described in Patent Document 2, an example in which a light distribution control element is provided with a flange shape and is fixed to a mounting board by using a screw, and a light distribution control element is provided with a claw portion and is fixed to a mounting board provided with holes An example of doing so is disclosed. In addition, a convex shape that covers the outer shape of the LED element is provided for positioning with respect to the point light source.

Further, for example, in the technique described in Patent Document 3, a substrate having an LED element mounted on the light distribution control element itself is mounted by extrusion molding without using a member such as a screw or an adhesive, and a holding structure that can be fixed is provided. The light distribution control element is held by being provided. Further, although injection molding can be performed, in the case of extrusion molding, the same cross section can be used for large and small backlights.

JP, 2006-286608, A JP 2007-48883 A Japanese Utility Model Publication No. 6-38267

The technique described in Patent Document 1 discloses only the optical performance of a light distribution control element that is linear and long, and a holding structure for a mounting substrate on which an LED element is mounted and a light distribution control element is disclosed. Not disclosed.

When the light distribution control element is held by adhesion, a jig for positioning the substrate on which the LED element is mounted and the light distribution control element is required. Further, it is difficult to remove the light distribution control element and replace the mounting board after the adhesion, and the cost for repairing becomes high. Further, in a long light distribution control element, when the light distribution control element is bonded to the mounting substrate, deformation or distortion occurs when thermally expanded or thermally contracted, and the position of the LED element and the light distribution control element It is very likely that the relationship will break.

In the techniques described in Patent Documents 2 and 3, by providing the holding structure on the light distribution control element itself, there is an effect that the need for adhesion and screwing can be eliminated and the number of steps can be reduced. However, the method of positioning by providing a convex shape that covers the outer shape of the LED element causes damage to the LED element. Further, when the shape is fixed by inserting the substrate into the light distribution control element by extrusion molding, the position of the light distribution control element in the longitudinal direction cannot be determined. Furthermore, the substrate may scrape the light distribution control element when the substrate is inserted, and scraps may adhere to the LED element.

Therefore, the present invention stably holds the substrate and the light distribution control element without breaking the positional relationship between the point light source and the light output portion of the light distribution control element without providing a holding structure in the light distribution control element. The purpose is to provide a technology that can.

The light distribution control element holding structure according to the present invention has a long substrate on which a plurality of point light sources are mounted in an array and has a plurality of notches, and each of the point light sources mounted on the substrate. disposed thereon, and the light distribution control element recesses that are provided in the light exit portion, the plurality of arranged at a position corresponding to the notch portion, and a holding member for holding the said substrate and said light distribution control device wherein the holding member is shall comprise insertable protrusion into the recess.

According to the present invention, the holding structure of the light distribution control element has a long substrate on which a plurality of point light sources are mounted in an array and has a plurality of notches, and each point light source mounted on the substrate. The light distribution control element is arranged on the upper side, and a holding member which is arranged at a position corresponding to the plurality of notches and holds the substrate and the light distribution control element.

Therefore, the substrate and the light distribution control element can be stably held without breaking the positional relationship between the point light source and the light emitting portion of the light distribution control element without providing a holding structure on the light distribution control element.

FIG. 3 is an exploded perspective view of the light distribution control element holding structure according to the first embodiment. FIG. 3 is a perspective view of a light distribution control element holding structure according to the first embodiment. FIG. 3 is a cross-sectional view of a mounting board on which the LED element is mounted and a light distribution control element according to the first embodiment. FIG. 3 is a perspective view of a mounting board according to the first embodiment. FIG. 5 is a perspective view of a holding member according to the first embodiment. FIG. 3 is a plan view of a light distribution control element holding structure according to the first embodiment. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. FIG. 6 is an exploded perspective view of a light distribution control element holding structure according to a second embodiment. FIG. 6 is a perspective view of a light distribution control element holding structure according to a second embodiment. FIG. 9 is a perspective view of a holding member according to the second embodiment.

<Embodiment 1>
Embodiment 1 of the present invention will be described below with reference to the drawings. 1 is an exploded perspective view of a holding structure for a light distribution control element 1 according to Embodiment 1, FIG. 2 is a perspective view of a holding structure for a light distribution control element 1, and FIG. 3 is an LED element 2a. FIG. 3 is a cross-sectional view of a mounting substrate 2 and a light distribution control element 1 on which is mounted. Note that, for ease of explanation, XYZ coordinate axes are shown in the drawing as appropriate. Here, the +X direction and the -X direction are collectively referred to as the X axis direction, the +Y direction and the -Y direction are collectively referred to as the Y axis direction, and the +Z direction and the -Z direction are collectively referred to as the Z axis direction.

As shown in FIGS. 1 and 2, the holding structure of the light distribution control element 1 includes a light distribution control element 1, a mounting substrate 2, and a holding member 3. As shown in FIGS. 1 to 3, the light distribution control element 1 is formed in a linear shape and a long shape, and covers the upper side of a mounting board 2 on which a plurality of LED elements 2a (point light sources) are mounted in an array. Is arranged on each LED element 2a. Since the light distribution control element 1 diverges the light emitted from the LED element 2a, the light output portion is provided with a concave portion 1a and the light input portion is provided with a concave portion 1b. The concave portions 1a and 1b are arranged in the longitudinal direction (X It is formed along the (axial direction).

Here, the holding structure of the light distribution control element 1 is incorporated into a surface light source device used for a backlight light source. The surface light source device includes a plurality of holding structures for the light distribution control element 1, and the holding structures for the plurality of light distribution control elements 1 are arranged in parallel at intervals to output planar light. The surface light source device may further include a planar light guide plate. Further, if the planar light guide plate can output the planar light in a well-balanced manner without the planar light guide plate, the planar light guide plate may be omitted.

Next, the mounting substrate 2 will be described with reference to FIGS. 1, 2, and 4. FIG. 4 is a perspective view of the mounting board 2. The mounting substrate 2 is formed in a linear shape and a long shape, and a plurality of LED elements 2a are arranged at predetermined intervals along the X-axis direction. A plurality of notches 2b are formed at both ends of the mounting substrate 2 in the longitudinal direction (X-axis direction). More specifically, notches 2b cut out from both sides in the width direction (Y-axis direction) are formed at both ends in the longitudinal direction (X-axis direction) of the mounting board 2, respectively.

Next, the holding member 3 will be described with reference to FIGS. 1, 2, and 5. FIG. 5 is a perspective view of the holding member 3. The holding member 3 is made of resin. The holding member 3 is arranged at a position corresponding to the cutout portion 2b of the mounting board 2 to hold the mounting board 2 and the light distribution control element 1, and to position the mounting board 2 and the light distribution control element 1. Is done.

The holding member 3 includes a main body portion 3a, a convex portion 3b, a convex portion 3c, a contact portion 3d, a contact portion 3e, a claw portion 3f, and a claw portion 3g. The main body 3a is formed so as to extend in the Y-axis direction, and contacts the upper surface of the light distribution control element 1 to hold the upper side (+Z direction) of the light distribution control element 1. The convex portion 3b and the convex portion 3c are formed so as to protrude downward (-Z direction) from the central portion of the main body portion 3a. The protrusion 3b is formed thicker than the protrusion 3c, and the protrusion 3c is formed wider than the protrusion 3b.

The contact portion 3d and the contact portion 3e are formed so as to extend downward (in the −Z direction) from both ends of the body portion 3a, and are arranged at positions facing each other. The contact portions 3d and 3e are elastically deformable in the Y-axis direction. The contact portions 3d and 3e hold the width direction (Y-axis direction) of the mounting substrate 2 by contacting both ends in the width direction (Y-axis direction) of the mounting substrate 2.

The claw portion 3f and the claw portion 3g are formed so as to project from the lower ends of the contact portions 3d and the contact portion 3e in an inwardly bent state, and the tips thereof face upward (+Z direction). The claw portion 3f and the claw portion 3g hold the back surface of the mounting substrate 2 (the surface opposite to the surface on which the LED element 2a is mounted).

Next, the holding of the mounting substrate 2 and the light distribution control element 1 by the holding member 3 will be described with reference to FIGS. 6, 7, and 8. 6 is a plan view of the holding structure of the light distribution control element 1, FIG. 7 is a sectional view taken along the line AA of FIG. 6, and FIG. 8 is a sectional view taken along the line BB of FIG.

Since the cutouts 2b are arranged at both ends of the light distribution control element 1 in the X-axis direction, the holding structure for the light distribution control element 1 according to the first embodiment includes two holding members 3. The two holding members 3 are arranged at both ends of the light distribution control element 1 in the X-axis direction. The holding member 3 is attached so as to cover the light distribution control element 1 and the mounting substrate 2 from the +Z direction, and the contact portions 3d and 3e contact the cutout portion 2b in the Y-axis direction. The holding member 3 has a shape along the cutout portion 2b of the mounting substrate 2. More specifically, the cutout portion 2b is formed to be slightly larger than the outer dimensions of the contact portion 3d and the contact portion 3e in the X-axis direction, and is a holding member for the mounting substrate 2 and the light distribution control element 1. It fulfills the positioning function of the X axis direction.

As shown in FIGS. 5 and 7, the convex portion 3 b of the holding member 3 has a shape along the concave portion 1 a of the light distribution control element 1. The concave portion 1a is formed to be slightly larger than the outer dimensions of the convex portion 3b in the Y-axis direction and the Z-axis direction. Therefore, by disposing the light distribution control element 1 on the mounting substrate 2 and attaching the holding member 3 from the +Z direction, the convex portion 3b of the holding member 3 is accommodated in the concave portion 1a of the light distribution control element 1, and the mounting substrate 2 The light distribution control element 1 can be positioned in the Y-axis direction with respect to.

Further, as shown in FIGS. 1, 2, 5, and 8, the convex portion 3c of the holding member 3 is formed in a shape larger than the concave portion 1a of the light distribution control element 1 in the Z-axis direction and the Y-axis direction. ing. Therefore, the convex portion 3c of the holding member 3 is in contact with the end portion of the light distribution control element 1 in the X axis direction, and the light distribution control element 1 can be positioned with respect to the mounting substrate 2 in the X axis direction.

As shown in FIGS. 5 and 7, the holding member 3 is attached to the light distribution control element 1 and the mounting substrate 2 from the +Z direction, so that the claw portions 3f and 3g are provided on the rear surface of the mounting substrate 2. It abuts from the −Z direction, and the convex portion 3b is inserted into the concave portion 1a from the +Z direction. Thereby, the mounting substrate 2 and the light distribution control element 1 can be positioned in the Z-axis direction.

Further, since the contact portion 3d, the contact portion 3e, the claw portion 3f, and the claw portion 3g have elastic force, it is easy to attach and detach the holding member 3 to and from the mounting substrate 2 and the light distribution control element 1. Therefore, the holding member 3 can be easily repaired after being attached, and the light distribution control element 1 can be held even if it has a complicated shape. Although the light distribution control element 1 is described as one, the light distribution control element may be divided into, for example, two in the X-axis direction. In this case, two holding members 3 are attached to each of the two light distribution control elements.

As described above, in the holding structure for the light distribution control element 1 according to the first embodiment, the elongated mounting substrate 2 in which the plurality of LED elements 2a are mounted in an array and which has the plurality of notches 2b. And the light distribution control element 1 arranged on each LED element 2a mounted on the mounting board 2 and the positions corresponding to the plurality of cutouts 2b, and the mounting board 2 and the light distribution control element 1 And a holding member 3 for holding and.

Therefore, the mounting substrate 2 and the light distribution control element 1 can be stably held without breaking the positional relationship between the LED element 2a and the light output portion of the light distribution control element 1 without providing a holding structure on the light distribution control element 1. can do. From the above, the yield of the holding structure of the light distribution control element 1 can be improved.

Further, by holding the mounting board 2 and the light distribution control element 1, it is possible to handle the mounting board 2 and the light distribution control element 1 as one unit. Since the operator can handle this unit without directly touching the LED element 2a, it is possible to reduce the risk of causing external damage and dirt to the LED element 2a. Further, since the light distribution control element 1 need not be provided with a holding structure and the light distribution control element 1 can be manufactured in consideration of only the optical characteristics, both the injection molding and the extrusion molding manufacturing methods are possible. In molding, the same cross-sectional shape can be used for a small backlight and a large backlight.

The light distribution control element 1 is formed in a long shape, the light emitting portion is provided with the concave portion 1a, and the holding member 3 is provided with the convex portion 3b which can be inserted into the concave portion 1a. The element 1 can be positioned in the Z-axis direction. Further, since the light distribution control element 1 is arranged at positions corresponding to both ends of the light distribution control element 1 in the longitudinal direction (X-axis direction), it is possible to obtain appropriate holding strength.

The concave portion 1a of the light distribution control element 1 is formed over the longitudinal direction (X-axis direction) of the light distribution control element 1, and the convex portion 3b of the holding member 3 has a shape along the concave portion 1a. The light distribution control element 1 can be positioned in the Y-axis direction with respect to.

Since the holding member 3 further includes the contact portion 3d and the contact portion 3e having a shape along the cutout portion 2 of the mounting substrate 2, the mounting substrate 2 can be positioned in the Y-axis direction.

Since the holding member 3 further includes a claw portion 3f and a claw portion 3g that hold the surface of the mounting substrate 2 opposite to the surface on which the LED element 2a is mounted, the holding member 3 of the mounting substrate 2 and the light distribution control element 1 is provided. Positioning in the Z-axis direction can be performed.

Since the surface light source device includes a plurality of holding structures for the light distribution control element 1 and the holding structures for the plurality of light distribution control elements 1 are arranged in parallel at intervals, the above-mentioned effect is obtained. Therefore, the emitted light can be output with the mounting substrate 2 and the light distribution control element 1 positioned. Thereby, the surface light source device can output the surface light in a stable state.

<Second Embodiment>
Next, a holding structure of the light distribution control element 1 according to the second embodiment will be described. 9 is an exploded perspective view of the holding structure of the light distribution control element 1 according to the second embodiment, FIG. 10 is a perspective view of the holding structure of the light distribution control element 1, and FIG. It is a perspective view. In the second embodiment, the same components as those described in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

When the surface light source device is used as a backlight light source for a large-sized display, the dimension of the light distribution control element 1 in the X-axis direction becomes large. Therefore, by only holding the mounting substrate 2 and both ends of the light distribution control element 1, There is a possibility that adequate holding strength may not be obtained. Therefore, in the second embodiment, as shown in FIGS. 9 and 10, the holding member 4 is further arranged at a position corresponding to the central portion of the light distribution control element 1 in the X-axis direction. In order to dispose the holding member 4, the cutout portion 2b of the mounting substrate 2 is also formed in the central portion in the X-axis direction.

As shown in FIG. 11, the holding member 4 is made of resin similarly to the holding member 3. The holding member 4 is arranged at a position corresponding to the cutout portion 2b of the mounting board 2 to hold the mounting board 2 and the light distribution control element 1, and to position the mounting board 2 and the light distribution control element 1. Is done.

The holding member 4 includes a main body portion 4a, a convex portion 4b, a contact portion 4d, a contact portion 4e, a claw portion 4f, and a claw portion 4g. The body portion 4a is formed so as to extend in the Y-axis direction, and contacts the upper surface of the light distribution control element 1 to hold the upper side (+Z direction) of the light distribution control element 1. The convex portion 4b is formed so as to protrude downward (-Z direction) from the central portion of the main body portion 4a.

The contact portion 4d and the contact portion 4e are respectively formed so as to extend downward (-Z direction) from both ends of the body portion 4a, and are arranged at positions facing each other. Further, the contact portion 4d and the contact portion 4e are elastically deformable in the Y-axis direction. The contact portions 4d and 4e hold the mounting board 2 in the width direction (Y-axis direction) by contacting both ends in the width direction (Y-axis direction) of the mounting board 2.

The claw portion 4f and the claw portion 4g are formed so as to project from the lower ends of the abutting portions 4d and 4e in an inwardly bent state, and the tips thereof face upward (+Z direction). The claw portions 4f and 4g hold the back surface of the mounting board 2 (the surface opposite to the surface on which the LED elements 2a are mounted).

Here, holding member 4 does not have a convex portion corresponding to convex portion 3c of holding member 3 in the first embodiment. This means that, if the holding member 3 is arranged at a position corresponding to the central portion of the light distribution control element 1 in the X-axis direction, the external dimensions of the convex portions 3c in the Y-axis direction and the Z-axis direction are the same. Since it is larger than the size of the concave portion 1a, it interferes with the light distribution control element 1 and the holding member 3 cannot be attached.

As described above, in the holding structure for the light distribution control element 1 according to the second embodiment, the holding member 4 is further arranged at a position corresponding to the central portion of the light distribution control element 1 in the longitudinal direction (X-axis direction). Therefore, even when the surface light source device is used as a backlight light source for a large display, it is possible to obtain an appropriate holding strength.

It should be noted that in the present invention, the respective embodiments can be freely combined, or the respective embodiments can be appropriately modified or omitted within the scope of the invention.

1 light distribution control element, 1a concave portion, 2 mounting substrate, 2a LED element, 2b cutout portion, 3 holding member, 3b convex portion, 3d abutting portion, 3e abutting portion, 3f claw portion, 3g claw portion, 4 holding Element.

Claims (7)

A plurality of point light sources are mounted in an array, and a long substrate having a plurality of notches,
Disposed on each said point light source mounted on the substrate, and a light distribution control device that recesses are provided in the light exit portion,
A holding member which is arranged at a position corresponding to the plurality of cutout portions, and which holds the substrate and the light distribution control element,
Equipped with
The holding member, the Ru with insertable projections on the recess, the holding structure of the light distribution control device. The light distribution control element is formed in a long shape ,
The holding member is disposed at a position corresponding to the both ends in the longitudinal direction before Symbol light distribution control device, the holding structure of the light distribution control device according to claim 1, wherein. The recess of the light distribution control element is formed over the longitudinal direction of the light distribution control element,
The light distribution control element holding structure according to claim 2, wherein the convex portion of the holding member has a shape along the concave portion. The light distribution control element holding structure according to claim 2, wherein the holding member is further arranged at a position corresponding to a central portion in the longitudinal direction of the light distribution control element. The light distribution control element holding structure according to any one of claims 1 to 4, wherein the holding member further includes an abutting portion having a shape along the cutout portion of the substrate. The light distribution according to any one of claims 1 to 5, wherein the holding member further includes a claw portion that holds a surface of the substrate opposite to a surface on which the point light source is mounted. Control element holding structure. A plurality of holding structures for the light distribution control element according to any one of claims 1 to 6 are provided,
A surface light source device that outputs planar light by arranging the holding structures of the plurality of light distribution control elements in parallel at intervals.

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