JP6647026B2 - Light distribution control element holding structure and surface light source device - Google Patents

Description

  The present invention relates to a surface light source device used as a lighting device and a backlight light source of a display as an image display, and more particularly to a technique capable of stably holding a light distribution control element provided in the surface light source device.

  In recent years, in a surface light source device mainly used as a backlight light source, an LED element is mainly used as a light source. In a direct-type surface light source device in which a plurality of LED elements are arranged on the bottom surface of a housing (corresponding to the rear surface), a light distribution control element is provided on the LED elements to diffuse light and irradiate a liquid crystal panel. ing.

  The light emission control elements are roughly classified into a method in which the light emission control elements are arranged so as to cover each one of the plurality of LED elements arranged in a straight line, and a method in which the light emission control elements are arranged so as to cover the entirety of the plurality of LED elements. (See, for example, Patent Documents 1 to 3).

  In any of the above methods, since the positional relationship between the LED element and the emission control element is broken, which leads to luminance degradation and color unevenness, it is important to provide a holding structure that does not break the positional relationship between the two. In order to surely obtain the bonding strength to the housing without breaking the positional relationship between the LED element and the light emission control element, a method of bonding the light emission control element to the mounting board using a dedicated jig is generally used.

  For example, in the technology described in Patent Literature 4, an example in which a light emitting control element is provided with a flange shape and fixed to a mounting substrate using screws, and an example in which a light emitting control element is provided with a claw portion and fixed to a mounting substrate provided with holes Is disclosed. In addition, a convex shape that covers the outer shape of the LED element is provided for positioning.

  For example, in the technology described in Patent Literature 5, the light distribution control element itself holds the mounting substrate by extrusion molding without using members such as screws or adhesives. In addition, although it can be molded by injection molding, in the case of extrusion molding, the same cross section can be used in large and small backlights.

JP 2009-192915 A JP 2006-286608 A JP 2008-216540 A JP 2007-048883 A JP-A-6-38267

  The technologies described in Patent Documents 1 and 2 disclose only the optical performance of a light distribution control element that is elongated linearly, and hold a mounting board on which an LED element is mounted and a light distribution control element. The structure is not disclosed.

  According to the technique described in Patent Document 3, when holding by bonding, a jig for positioning the mounting board having the LED element and the light distribution control element is required, and it is difficult to replace the mounting board after bonding. And high cost of repair.

  In the techniques described in Patent Literature 4 and Patent Literature 5, the provision of the holding structure in the light distribution control element itself eliminates the need for bonding and screwing, and has the effect of reducing man-hours. However, since the light distribution control element does not have a shape considering only the optical characteristics, but has a holding structure in the light distribution control element, the light diffusion path becomes complicated and optical loss occurs. For this reason, there is a high possibility of leading to luminance degradation or color unevenness.

  Therefore, the present invention stably holds the substrate and the light distribution control element without bonding the light distribution control element to the substrate on which the light source is mounted, or providing the light distribution control element with a holding structure. The aim is to provide a technology that can.

A light distribution control element holding structure according to the present invention includes a substrate on which a light source is mounted, a light distribution control element disposed on the light source, and having a concave portion in a light incident portion, and an arrangement on which the substrate is disposed. A housing having a surface, a horizontal portion of the substrate and the light distribution control element with respect to the arrangement surface of the housing , and a convex portion having a shape along the concave portion of the light distribution control element; And a holding portion projecting from the arrangement surface of the body to the side where the substrate is arranged, and holding the substrate and the light distribution control element.

  According to the present invention, the light distribution control element holding structure includes a substrate on which the light source is mounted, a light distribution control element that is disposed on the light source, and has a concave portion in the light incident portion, and an arrangement in which the substrate is disposed. A housing having a surface, and a holding portion that protrudes from the arrangement surface of the housing to a side on which the substrate is arranged, and that holds the substrate and the light distribution control element.

  Therefore, the substrate and the light distribution control element can be stably held without adhering the substrate on which the light source is mounted and the light distribution control element or providing a holding structure in the light distribution control element. Further, since it is not necessary to provide a holding structure in the light distribution control element, it is possible to manufacture a light distribution control element in consideration of only optical characteristics.

FIG. 3 is an exploded perspective view of a light distribution control element holding structure according to the first embodiment. FIG. 3 is a perspective view of a holding structure of the light distribution control element according to the first embodiment. FIG. 3 is a cross-sectional view of a mounting board on which the LED elements are mounted and a light distribution control element according to the first embodiment. FIG. 2 is an enlarged perspective view of a mounting board according to the first embodiment. FIG. 3 is a perspective view of a holding component according to the first embodiment. FIG. 3 is a perspective view of a housing according to the first embodiment. FIG. 3 is a plan view of a holding structure of the light distribution control element according to the first embodiment. FIG. 8 is a sectional view taken along line AA of FIG. 7. FIG. 8 is a sectional view taken along line BB of FIG. 7. FIG. 10 is an exploded perspective view of a light distribution control element holding structure according to Embodiment 2. FIG. 9 is a perspective view of a light distribution control element holding structure according to a second embodiment. FIG. 13 is an enlarged perspective view of a housing according to the second embodiment. 13 is an exploded perspective view of a light distribution control element holding structure according to Embodiment 3. FIG. FIG. 13 is a perspective view of a light distribution control element holding structure according to Embodiment 3. FIG. 14 is a perspective view of a holding component according to the third embodiment. It is a perspective view of the holding structure of the mounting board which has the light distribution control element based on a base technology.

<First Embodiment>
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a holding structure of the light distribution control element 1 according to Embodiment 1, FIG. 2 is a perspective view of a holding structure of the light distribution control element 1, and FIG. FIG. 2 is a cross-sectional view of the mounting board 2 and the light distribution control element 1 on which is mounted. Note that, for ease of explanation, XYZ coordinate axes are shown in the drawings 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, a surface light source device mainly used for a backlight light source includes a structure for holding a light distribution control element 1. The holding structure of the light distribution control element 1 includes a mounting board 2 (substrate), the light distribution control element 1, a housing 4, and a holding component 3. FIG. 3 is a cross-sectional view of the mounting board 2 on which the LED element 2a is mounted and the light distribution control element 1. The positional relationship between the concave portion 1a of the light distribution control element 1 and the mounting board 2 on which the LED element 2a is mounted. Is shown.

  As shown in FIGS. 1 to 3, the light distribution control element 1 is formed in a rod shape, and is mounted on the LED element 2 a so as to cover the upper side (+ Z direction) of the mounting substrate 2 on which the LED element 2 a (light source) is mounted. Are located. The light distribution control element 1 has a concave portion 1a in the light incident portion for diffusing light emitted from the LED element 2a, and the concave portion 1a extends in the longitudinal direction (X-axis direction) of the light distribution control element 1. Is formed. In FIG. 3, the holding component 3 is not shown for easy viewing of the drawing.

  Next, the mounting substrate 2 will be described with reference to FIGS. FIG. 4 is an enlarged perspective view of the mounting board 2. The mounting substrate 2 is formed so as to extend in the X-axis direction, and a plurality of (for example, four) LED elements 2a are arranged on the mounting substrate 2 at predetermined intervals. Holes 2b and 2c are formed on both ends in the longitudinal direction of the mounting board 2 in order from the end side.

  Next, the holding component 3 will be described with reference to FIGS. 1, 2 and 5. FIG. 5 is a perspective view of the holding component 3. The holding portion 3b of the holding component 3 protrudes from the arrangement surface of the housing 4 to the side where the mounting board 2 is arranged, and holds the mounting board 2 and the light distribution control element 1. The holding component 3 is formed of, for example, a resin, and includes a circular design portion 3a, a pair of holding portions 3b, and convex portions 3e, 3f, and 3g in plan view. The pair of holding parts 3b and the convex parts 3e, 3f, 3g are integrally molded with the design part 3a so as to protrude in the + Z direction from the design part 3a. The design part 3a is attached to the surface of the housing 4 opposite to the surface on which the mounting substrate 2 is arranged. The design portion 3a is formed in a shape larger than the opening 4b so as to cover the opening 4b formed in the housing 4, and is given a similar color to the housing 4.

  The pair of holding portions 3b are formed in a U-shape, and are arranged to face each other. The pair of holding parts 3b both have a claw part 3c formed on the opposite side and an engaging part 3d protruding on the opposite side of the claw part 3c. In the pair of holding parts 3b, the side where the engaging part 3d is formed is connected to the design part 3a, and the side where the claw part 3c is formed has a predetermined gap from the design part 3a. 3c is configured to be elastically deformable in the Y-axis direction.

  Next, the housing 4 will be described with reference to FIGS. 1, 2 and 6. FIG. 6 is a perspective view of the housing 4. The housing 4 is formed of, for example, metal so as to have a heat radiation function of the mounting board 2. The housing 4 is formed so as to extend in the X-axis direction and open in the + Z direction, and has an arrangement surface on which the mounting board 2 is arranged. A pair of long holes 4e and holes 4c and 4d are formed at both ends of the arrangement surface of the housing 4 in order from the end side, and a pair of engaged portions 4a and a pair of openings 4b are sandwiched between the holes 4c. Are formed one by one. The pair of engaged portions 4a are formed at positions adjacent to the pair of openings 4b.

  Since the holding component 3 is disposed at each of both ends of the light distribution control element 1 in the longitudinal direction, the pair of holding parts 3b and the projections 4c are formed at both ends of the light distribution control element 1 in the design part 3a. It is arranged at a position corresponding to the section. The pair of openings 4b of the housing 4 is formed so as to be rotatable in the horizontal direction in a state where the pair of holding portions 3b of the holding component 3 are inserted, and has a shape larger than the outline of the pair of holding portions 3b in plan view. The engaging portions 3d of the pair of holding portions 3b are arranged in the design portion 3a at positions where they can be engaged with the pair of engaged portions 4a of the housing 4. The elongated holes 4e, 4c, and 4d of the housing 4 are formed in a shape larger than the convex portions 3f, 3e, and 3g so that the convex portions 3f, 3e, and 3g of the holding component 3 can be inserted therethrough.

  Next, holding of the light distribution control element 1 and the mounting board 2 by the holding component 3 will be described with reference to FIGS. 7, 8 and 9. FIG. 7 is a plan view of a holding structure of the light distribution control element 1, FIG. 8 is a cross-sectional view taken along line AA of FIG. 7, and FIG. 9 is a cross-sectional view taken along line BB of FIG.

  The holding component 3 is attached from the −Z side of the housing 4, and by rotating the holding component 3 in the horizontal direction about the hole 4 c and the convex portion 3 e with respect to the housing 4, the engagement of the pair of holding portions 3 b is performed. The portion 3d is engaged with the pair of engaged portions 4a of the housing 4, and the holding component 3 is mounted. The hole 4d and the convex portion 3g serve to prevent the holding component 3 from rotating back.

  As shown in FIGS. 1, 2, 7, 8, and 9, the protrusion 3 e of the holding component 3 positions the mounting board 2 and the light distribution control element 1 in the horizontal direction with respect to the arrangement surface of the housing 4. Is going. More specifically, the convex portion 3e has a shape along the concave portion 1a of the light distribution control element 1, and the convex portion 3e is inserted through the hole 4c of the housing 4 and the hole 2c of the mounting board 2. The positioning of the mounting board 2 and the light distribution control element 1 with respect to the arrangement surface of the housing 4 in the horizontal direction is performed by inserting the light distribution control element 1 into the concave portion 1 a of the light distribution control element 1. Thus, the positions of the mounting board 2 in the X and Y directions and the position of the light distribution control element 1 in the Y direction are maintained. In addition, since the protrusion 3e does not approach the LED element 2a, the LED element 2a is not damaged. Further, since the convex portion 3e has a shape along the concave portion 1a, it is possible to reliably hold the light distribution control element 1 in the Y-axis direction.

  Further, as shown in FIG. 9, the light distribution is achieved by bringing the protrusion 3 f of the holding component 3 into contact with the longitudinal end of the light distribution control element 1 while being inserted through the hole 2 b and the elongated hole 4 e. The control element 1 can be positioned in the X-axis direction.

  The claw portions 3c of the pair of holding portions 3b position the mounting board 2 and the light distribution control element 1 in the vertical direction (Z-axis direction) with respect to the arrangement surface of the housing 4. More specifically, when the holding component 3 is mounted, the claw portions 3c of the pair of holding portions 3b abut on the ends in the width direction of the light distribution control element 1 from the + Z direction, and the arrangement surface of the housing 4 is formed. Of the mounting board 2 and the light distribution control element 1 with respect to the vertical direction. Since the claw portion 3c has an elastic force, repair after assembly is easy, and it is possible to hold the light distribution control element 1 even if it has a complicated shape.

  As described above, the holding structure of the light distribution control element 1 according to the first embodiment includes the mounting board 2 on which the LED element 2a is mounted, the concave part 1a disposed on the LED element 2a, and the light incident part. A light distribution control element 1, a housing 4 having an arrangement surface on which the mounting substrate 2 is arranged, and a projection protruding from the arrangement surface of the housing 4 to the side on which the mounting substrate 2 is arranged, and the mounting substrate 2 and the light distribution And a holding unit 3b for holding the control element 1. Further, the surface light source device includes a holding structure for the light distribution control element 1.

  Therefore, the mounting board 2 and the light distribution control element 1 can be connected to each other without bonding the mounting board 2 on which the LED elements 2a are mounted and the light distribution control element 1 or providing the light distribution control element 1 with a holding structure. It can be stably held. Further, since it is not necessary to provide a holding structure in the light distribution control element 1, it is possible to manufacture the light distribution control element 1 in consideration of only the optical characteristics.

  The light distribution control device 1 further includes a convex portion 3e for positioning the mounting substrate 2 and the light distribution control element 1 in the horizontal direction with respect to the arrangement surface of the housing 4, the light distribution control element 1 is formed in a rod shape, and the holding portion 3b and the convex portion 3e The light distribution control elements 1 are arranged at positions corresponding to both ends in the longitudinal direction. Therefore, the horizontal positions of the mounting board 2 and the light distribution control element 1 can be more stably held at two places.

  Since the convex portion 3e has a shape along the concave portion 1a of the light distribution control element 1, it is possible to reliably hold the light distribution control element 1 in the Y-axis direction. Since the holding portion 3b has the claw portion 3c for positioning the mounting board 2 and the light distribution control element 1 in the vertical direction with respect to the arrangement surface of the housing 4, the holding of the light distribution control element 1 in the vertical direction is ensured. It can be carried out.

  As shown in FIG. 16, in the base technology, the housing 103 is generally formed of metal in order to have a heat radiation function of the mounting substrate 102, and a light distribution control element is provided on the housing 103 side. There is a case where the holding portion 103a of the mounting substrate 102 having (held by a conventional technique such as bonding) is provided. In this case, since the opening 103b is formed in the design surface of the casing 103 in the cut-and-raised shape, light leakage occurs from the arrangement surface side of the casing 103, and the design property is further impaired. FIG. 16 is a perspective view of a holding structure of a mounting substrate 102 having a light distribution control element according to the prerequisite technique (held by a conventional technique such as bonding).

  On the other hand, in Embodiment 1, the holding portion 3b is integrally molded with the design portion 3a fixed to the surface of the housing 4 opposite to the surface on which the mounting substrate 2 is disposed. The opening 4b can be covered by the design portion 3a. Thereby, light leakage can be prevented. Moreover, since the design part 3a covers the opening 4b formed in the housing 4 and is given a similar color to the housing 4, a surface light source device that does not impair the design can be realized.

<Embodiment 2>
Next, a holding structure of the light distribution control element 1 according to the second embodiment will be described. FIG. 10 is an exploded perspective view of a holding structure of the light distribution control element 1 according to Embodiment 2, FIG. 11 is a perspective view of a holding structure of the light distribution control element 1, and FIG. FIG. 4 is an enlarged perspective view of FIG. In the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  As shown in FIGS. 10, 11 and 12, the holding structure of the light distribution control element 1 according to the second embodiment includes a mounting board 2, a light distribution control element 1, and a housing 5. In the first embodiment, the housing 4 (see FIG. 1) is made of metal in order to provide the heat dissipation function of the mounting board 2, but in the second embodiment, the housing 5 is made of resin. In the holding structure of the light distribution control element 1 according to the second embodiment, instead of including the holding component 3 (see FIG. 1), the resin housing 5 includes the pair of holding portions 5b and the convex portions 5d and 5e. Have.

  The pair of holding portions 5b and the protrusions 5d and 5e are arranged at both ends in the longitudinal direction of the housing 5, and the pair of holding portions 5b, the protrusions 5d and 5e and the housing 5 are integrally formed. The pair of holding portions 5b are formed in a U-shape, and are arranged to face each other. The pair of holding portions 5b have both claw portions 5c formed on opposing sides. In the pair of holding portions 5b, the side opposite to the side where the claw portion 5c is formed is connected to the arrangement surface 5a of the housing 5, and the side where the claw portion 5c is formed is from the arrangement surface 5a of the housing 5. There is a predetermined gap, and the claw portion 5c is configured to be elastically deformable in the Y-axis direction.

  The protrusions 5d and 5e position the mounting board 2 and the light distribution control element 1 in the horizontal direction with respect to the placement surface 5a of the housing 5, and the claw portions 5c of the pair of holding portions 5b serve as the positioning surfaces of the housing 5. The vertical positioning of the mounting board 2 and the light distribution control element 1 with respect to 5a is performed.

  As described above, in the holding structure of the light distribution control element 1 according to the second embodiment, since the holding portion 5b and the housing 5 are integrally formed, the number of components can be reduced as compared with the case of the first embodiment. It is possible to suppress the manufacturing cost of the surface light source device.

<Embodiment 3>
Next, a holding structure of the light distribution control element 1 according to the third embodiment will be described. FIG. 13 is an exploded perspective view of the holding structure of the light distribution control element 1 according to the third embodiment, FIG. 14 is a perspective view of the holding structure of the light distribution control element 1, and FIG. It is a perspective view of. In the third embodiment, the same components as those described in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted.

  When the surface light source device is used as a backlight light source for a large display, the length of the light distribution control element 1 in the longitudinal direction (X-axis direction) is extended, so that only the both ends of the light distribution control element 1 in the longitudinal direction are used. Retention alone may not provide adequate retention strength. Therefore, in the third embodiment, as shown in FIGS. 13 and 14, the holding component 6 is further arranged at a position corresponding to the central portion of the light distribution control element 1 in the longitudinal direction. In FIG. 13, three holding parts 3 and only one holding part 6 are shown, but actually, as shown in FIG. 14, four holding parts 3 and two holding parts 6 are provided. One is used.

  As shown in FIG. 15, the holding component 6 is formed of, for example, a resin and includes a design portion 6a, a pair of holding portions 6b, and convex portions 6e and 6f. The pair of holding portions 6b and the convex portions 6e and 6f are integrally formed with the design portion 6a so as to project from the design portion 6a in the + Z direction. The design part 6a is fixed to a surface of the housing 4 opposite to the surface on which the mounting substrate 2 is disposed.

  The pair of holding portions 6b are formed in a U-shape, and are arranged to face each other. The pair of holding portions 6b both have a claw portion 6c formed on the opposite side and an engaging portion 6d protruding on the opposite side of the claw portion 6c. In the pair of holding parts 6b, the side where the engaging part 6d is formed is connected to the design part 6a, and the side where the claw part 6c is formed has a predetermined gap from the design part 6a. 6c is configured to be elastically deformable in the Y-axis direction.

  Holding component 6 does not include a projection corresponding to projection 3f of holding component 3 in the first embodiment. This is because if the holding component 3 is disposed at a position corresponding to the central portion of the light distribution control element 1 in the longitudinal direction, the convex portion 3f has a dimension in the Z-axis direction larger than that of the concave portion 1a of the light distribution control element 1. This is because it interferes with the light distribution control element 1 and the mounting of the holding component 3 is impossible. Note that it is also possible to provide a pair of holding portions and two convex portions at the center in the longitudinal direction of the housing 5 in the second embodiment.

  As described above, in the holding structure of the light distribution control element 1 according to the third embodiment, the holding portion 6b is further arranged at a position corresponding to the central portion of the light distribution control element 1 in the longitudinal direction. An appropriate holding strength can be obtained even when the device is used as a backlight source for a large display.

  In the present invention, each embodiment can be freely combined, or each embodiment can be appropriately modified or omitted within the scope of the invention.

  Reference Signs List 1 light distribution control element, 1a concave portion, 2 mounting substrate, 2a LED element, 3a design portion, 3b holding portion, 3c claw portion, 3e convex portion, 3f convex portion, 4 housing, 4b opening, 5 housing, 5b holding Part, 5c nail part, 5d convex part, 5e convex part, 6b holding part, 6c nail part, 6e convex part.

Claims (8)

A substrate on which the light source is mounted,
A light distribution control element disposed on the light source, and having a concave portion in the light incident portion,
A housing having an arrangement surface on which the substrate is arranged,
The horizontal position of the substrate and the light distribution control element with respect to the arrangement surface of the housing, and a convex portion having a shape along the concave portion of the light distribution control element,
A holder that projects from the arrangement surface of the housing to a side where the substrate is arranged, and that holds the substrate and the light distribution control element,
The light distribution control element holding structure, comprising: Before Symbol light distribution control element is formed into a rod,
2. The light distribution control element holding structure according to claim 1, wherein the holding section and the projection are arranged at positions corresponding to both ends in the longitudinal direction of the light distribution control element. 3.   The holding structure for a light distribution control element according to claim 2, wherein the holding unit is further arranged at a position corresponding to a central portion in a longitudinal direction of the light distribution control element. The holding portion includes a claw portion for performing vertical positioning of the substrate and the light distribution control device for the arrangement surface of the housing, the holding structure of the light distribution control device according to claim 2 or claim 3 . A substrate on which the light source is mounted,
A light distribution control element disposed on the light source, and having a concave portion in the light incident portion,
A housing having an arrangement surface on which the substrate is arranged,
A holder that projects from the arrangement surface of the housing to a side where the substrate is arranged, and that holds the substrate and the light distribution control element,
With
The light distribution control element holding structure, wherein the holding portion is integrally molded with a design portion fixed to a surface of the housing on a side opposite to the arrangement surface on which the substrate is arranged. The light distribution control element holding structure according to claim 5 , wherein the design portion covers an opening formed in the housing and is given a similar color to the housing. The holding portion and the housing are integrally molded, the holding structure of the light distribution control device according to claim 1, any one of claims 4. To claims 1 any one of claims 7 comprises a holding structure of a light distribution control device according, the surface light source device.

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