JP2019145205A - Lighting device - Google Patents

Abstract

To provide a lighting device for making compatible both high lighting efficiency and small luminance unevenness.SOLUTION: A lighting device 1 comprises: a casing 10 exerting a bottomed shape, and reflecting light by an inner wall face 100 including an inner bottom face 120; a light source 20 held to the inner bottom face 120, and radiating light; and a dimmer 30 arranged while covering an opening 11 of the casing 10. The lighting device lights an object by light which is adjusted in a luminance distribution through the dimmer 30. The dimmer 30 has a permeation part 31 for making light permeate therethrough, and a reflection part 32 being the reflection part 32 for reflecting light in which a reflection direction of light by a reflection protrusion 322 is set while avoiding the light source 20 by forming the reflection protrusion 322 which protrudes toward the light source 20 side in an acute shape, and is protrusively curved to an external peripheral side in a confronting region 320 confronting the light source 20.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to a lighting device.

  2. Description of the Related Art Conventionally, illumination devices that illuminate an object with light whose luminance distribution has been adjusted are widely known, for example, surface illumination devices. As a kind of such an illuminating device, Patent Document 1 discloses a device that generates light with a luminance distribution adjusted through a light control body.

  In this disclosed apparatus, a light control body is disposed so as to cover the bottomed opening in a bottomed casing in which a light source that emits light is held on an inner bottom surface. Here, the light control body has a transmission part that transmits light and a reflection part that reflects light. Thereby, a part of the light from the light source reaches the transmitting part directly and is transmitted. On the other hand, the remaining portion of the light from the light source is reflected by the reflecting portion, and further reflected once or a plurality of times by the inner wall surface including the inner bottom surface of the casing, and then reaches the transmitting portion and is transmitted therethrough. As a result of these light guide actions, the luminance distribution of the light transmitted through the transmission part can be adjusted uniformly.

JP 2008-27886 A

  Patent Document 1 discloses a form in which a reflection convex portion protrudes in a sharp shape toward the light source side in a facing region that faces the light source as one form of the reflection portion. However, the reflective convex part of this disclosed form has a conical shape with apex angles between straight generatrices. When light from the light source is reflected by such a conical reflection convex portion, the direction of the reflection is easily separated from the light source. Therefore, although it is possible to avoid a decrease in illumination efficiency due to the reflected light recursively incident on the light source, the occurrence of uneven brightness due to insufficient light incident on the inner surface of the casing near the light source It becomes difficult to avoid.

  The subject of this indication is providing the illuminating device which makes high illumination efficiency and little brightness nonuniformity compatible.

  Hereinafter, technical means of the present disclosure for solving the problem will be described. The reference numerals in parentheses described in the claims and in this section indicate the correspondence with specific means described in the embodiments described in detail later, and limit the technical scope of the present disclosure. Not what you want.

  A first aspect of the present disclosure includes a casing (10) that has a bottomed shape and reflects light by an inner wall surface (100) including an inner bottom surface (120), and a light source (20) that is held on the inner bottom surface and emits light. ) And a dimmer (30) disposed so as to cover the opening (11) of the casing, and the illumination device (1) for illuminating the object with the light whose luminance distribution is adjusted through the dimmer The dimmer is a transmissive part (31) that transmits light and a reflective part (32) that reflects light, and projects in a sharp shape toward the light source in a facing region (320) that faces the light source. By forming the reflective convex portion (322) that is convexly curved toward the outer peripheral side, the reflective portion is set such that the light reflection direction by the reflective convex portion is set to avoid the light source.

  In the facing region that directly faces the light source in the reflection portion of the first aspect, a reflection convex portion that protrudes sharply toward the light source side is formed, so that the reflection direction of light by the reflection convex portion changes the light source. Set to avoid. As a result, even if the light from the light source is reflected by the sharp tip of the reflection convex portion and the surrounding portion, it is difficult to recursively enter the light source. In addition, in the reflection part of the first aspect, the reflection direction of the light from the light source is as close as possible to the same light source within a range that avoids the light source due to the reflection convex part that is curved to the outer peripheral side among the sharp shapes. Can do.

  According to the first aspect as described above, the light utilization efficiency is reduced due to the recurrent incidence on the light source, and the light quantity incident on the vicinity of the light source is insufficient on the inner bottom surface of the bottomed casing where the light source is arranged. Any bias in the luminance distribution can be suppressed. Therefore, it is possible to achieve both high illumination efficiency by suppressing a decrease in light utilization efficiency and small luminance unevenness by suppressing the unevenness of the luminance distribution.

  According to the second aspect of the present disclosure, the light source includes a base material (21) attached to the inner bottom surface, and a light emitting diode (22) that is mounted on the base material and emits light, In the projection view in the facing direction between the facing region and the light source, the reflecting convex portion falls within the protruding source side contour (322b).

  In a projection view in the facing direction between the facing region and the light source in the reflective portion of the second aspect, the light emitting diode that emits light by being mounted on the base material mounted on the inner bottom surface of the casing of the light source is the reflective convex portion. It fits within the projecting side contour. Thereby, the light from the light emitting diode can be reduced in reflection by the surrounding portions of the reflective convex portion in the facing region of the reflective portion. Therefore, it is possible to improve the reliability of the achievement effect of high illumination efficiency by avoiding the recurrence of the reflected light to the light source due to the surrounding area of the reflective convex portion, and hence the reduction of the light utilization efficiency due to the recurrence. It is.

It is sectional drawing which shows the illuminating device of one Embodiment. It is the II-II sectional view taken on the line of FIG. It is a perspective view which expands and shows the reflective convex part of FIG. It is a schematic diagram for demonstrating the light reflection condition in the illuminating device of one Embodiment. It is a perspective view which shows the modification of FIG. It is a perspective view which shows the modification of FIG. It is sectional drawing which shows the modification of FIG. It is sectional drawing which shows the modification of FIG. It is sectional drawing which shows the modification of FIG.

  The illuminating device 1 of one Embodiment shown in FIG. 1 is used in order to illuminate objects, such as a liquid crystal panel or an organic electroluminescent panel, for example. The lighting device 1 includes a casing 10, a light source 20, and a light control body 30.

  The casing 10 has a bottomed rectangular cylindrical shape composed of one bottom wall 12 and four side walls 13 as a bottomed shape with an opening 11 open. In the casing 10, each side wall 13 is erected substantially perpendicular to the bottom wall 12. Therefore, in the following, directions along the two sides of the bottom wall 12 are referred to as an X direction and a Y direction, and a direction perpendicular to the bottom wall 12 is referred to as a Z direction. The inner wall surface 100 of the casing 10 includes the inner surface 130 of each side wall 13 together with the inner bottom surface 120 of the bottom wall 12. Each of these inner bottom surface 120 and each inner side surface 130 reflects light as a reflecting surface.

  In order to realize such a configuration, the casing 10 may be a molded product in which the bottom wall 12 and the side walls 13 are integrally molded from a reflective material such as white resin or metal. Alternatively, the casing 10 may be a composite product in which a reflective material such as a metal is laminated by sputtering or vapor deposition on the inner wall surface of a bottomed base material formed of, for example, resin or metal.

  As shown in FIG. 1, the light source 20 includes a base material 21 and a light emitting diode (hereinafter referred to as LED) 22. The substrate 21 is, for example, a print substrate or a lead frame. The base material 21 has a rectangular plate or rectangular column shape. The mounting surface 210 of the base material 21 is mounted on the inner bottom surface 120 of the bottom wall 12 by, for example, adhesion. The geometric center Ca of the mounting surface 210 in the X direction and the Y direction overlaps the geometric center Cb of the inner bottom surface 120 in the Z direction, as shown in FIGS. Thereby, the base material 21 is held on the same surface 120 in a state where it is aligned with the inner bottom surface 120 in the casing 10. The base material 21 is electrically connected to the outside through a lead (not shown) that penetrates the bottom wall 12.

  The LED 22 has a rectangular chip shape. The fixing surface 220 of the LED 22 is mounted and fixed to the mounting surface 211 facing the Z direction opposite to the mounting surface 210 in the base material 21. Thus, the LED 22 has the light emitting surface 221 opposite to the fixing surface 220 facing the opening 11 side of the casing 10. The light emission center Cl substantially coincident with the geometric center of the light emitting surface 221 in the X direction and the Y direction overlaps with the geometric centers Cb and Ca of the surfaces 120 and 210 described above in the Z direction. Thereby, LED22 is also hold | maintained through the base material 21 in the same surface 120 in the state aligned with the inner bottom face 120 in the casing 10. FIG. The LED 22 is electrically connected to the base material 21 through wire bonding (not shown). The LED 22 emits light of a predetermined color, particularly white light in the present embodiment, when energized from the outside through the base material 21. Here, the directivity of emitting light in the Z direction is given to the LED 22 of the present embodiment.

  The light control body 30 has a sheet shape or a plate shape with a rectangular outline as a whole. The four sides of the light control body 30 are respectively attached to the side walls 13 of the casing 10 by adhesion or the like. Thereby, the light control body 30 is arrange | positioned in the attitude | position in alignment with a X direction and a Y direction in the state which opened the light guide space 301 between the bottom walls 12 of the casing 10, and has covered the opening 11. FIG. The inner surface of the light control body 30 facing the inner bottom surface 120 side of the casing 10 reflects light as the reflection surface 300. The geometric center Cr in the X direction and Y direction of the reflecting surface 300 overlaps the geometric centers Cb, Ca, Cl of the surfaces 120, 210, and 221 described above in the Z direction.

  The light control body 30 includes a transmission part 31 and a reflection part 32. The transmission part 31 is composed of a large number of through holes 310 that penetrate the light control body 30 along the Z direction. These through holes 310 are classified into any of a plurality of hole groups 310a, 310b, and 310c. Each of the hole groups 310a, 310b, and 310c is formed by arranging a predetermined number of through holes 310 on a plurality of virtual frame lines Fa, Fb, and Fc concentrically assumed around the geometric center Cr of the reflecting surface 300. . In the present embodiment, the virtual frame lines Fa, Fb, and Fc are assumed to have a rectangular frame shape that is similar to each other and similar to the contour of the dimmer 30. Thereby, the through holes 310 on the virtual frame lines Fa, Fb, and Fc, that is, the through holes 310 of the hole groups 310a, 310b, and 310c are arranged along the X direction or the Y direction. In addition, the through holes 310 of the hole groups 310a, 310b, and 310c in the present embodiment are formed with a diameter that increases as the distance from the geometric center Cr concentric with the corresponding virtual frame lines Fa, Fb, and Fc increases. Has been. In FIG. 2, the provision of reference numerals 310, 310a, 310b, and 310c is omitted for some through holes 310.

  As shown in FIGS. 1 and 2, the reflecting portion 32 is configured from the remaining portion of the dimmer 30 excluding the through portions of the through holes 310 that form the transmitting portion 31. Thereby, in the reflective surface 300 which the reflection part 32 forms around each through-hole 310, the facing area | region 320 is set in the virtual frame line Fa nearest to the geometric center Cr. The directly facing region 320 means a region where the reflecting surface 300 faces the light source 20 in the Z direction. Therefore, the facing area 320 is a range (in other words, a range in which the base material 21 forming the outermost contour of the light source 20 in this embodiment is projected onto the reflecting surface 300 in the Z direction that is the facing direction between the reflecting surface 300 and the light source 20 (that is, , A range within a two-dot chain line frame in FIG. 2). With this definition, the geometric center Cr of the reflecting surface 300 is synonymous with the geometric center Cr of the facing region 320.

  As shown in FIGS. 1 to 3, the reflective portion 32 in the facing region 320 is provided with a reflective convex portion 322. The reflection convex portion 322 protrudes in a sharp shape from the reflection surface 300 of the facing region 320 toward the light source 20 side in the Z direction, and is convexly curved toward the outer peripheral side around the Z direction. As a result, the reflective convex portion 322 has a curved side surface 322c that bulges outwardly around the Z direction. Here, in the present embodiment, the reflection convex portion 322 in which the projecting-source-side contour 322b has a circular shape in a plan view viewed from the Z direction increases in the diameter reduction rate per unit length in the Z direction toward the light source 20 side. A curved side surface 322c is formed in a semi-spindle shape. In the present embodiment, the protrusion height of the reflection convex portion 322 in the Z direction of the facing region 320 is smaller than the thickness of the reflection portion 32 around the reflection convex portion 322 (for example, a thickness of 0.5 mm). However, it may be set to a height higher than the thickness.

  As shown in FIGS. 1 and 2, the sharp tip 322 a that is the center vertex of the sharp shape in the reflective convex portion 322 is in the geometric direction Cb, Ca, Cl, Cr and the Z direction of each surface 120, 210, 221, 300 described above. overlapping. Thereby, in the projection view of the Z direction which is the facing direction of the directly facing area | region 320 and the light source 20, in the state which the point 322a of the reflective convex part 322 aligned with the light source 20, the protrusion origin side of the reflective convex part 322 The entire LED 22 is within the outline 322b.

  In order to realize the above-described configuration, the light control body 30 is formed by integrally forming the reflection portion 32 including the reflection convex portion 322 together with the transmission portion 31 from a reflective material such as a fine foam resin, a white resin, or a metal. It may be a product (see FIG. 1). Alternatively, the light control body 30 is formed of, for example, resin or metal, and a convex body that is the inner surface serving as the reflective surface 300 and the reflective convex portion 322 in the sheet-like base material or plate-like base material through which the plurality of through holes 310 penetrate. It may be a composite product in which a reflective material such as metal is laminated on the surface of the substrate by sputtering or vapor deposition. Or the light control body 30 forms the reflective convex part 322 with respect to the inner surface used as the reflective surface 300 in the sheet-like base material or plate-shaped base material which was formed, for example from resin or a metal, and the several through-hole 310 penetrated. It may be a composite product in which convex reflectors such as metals are joined by adhesion or the like.

  In the lighting device 1 described so far, as shown in FIG. 4, the LED 22 of the light source 20 emits light in the light guide space 301 between the bottom wall 12 and the light control body 30 in the casing 10. As a result, part of the light from the LED 22 reaches the transmission part 31 and passes through each through hole 310. On the other hand, the remaining portion of the light from the LED 22 is reflected by the reflecting surface 300 of the reflecting portion 32 and the curved side surface 322c of the reflecting convex portion 322, and further by the inner wall surface 100 including the inner bottom surface 120 of the casing 10 once or a plurality of times. After being reflected, it reaches the transmission part 31 and passes through each through hole 310. In this latter case, in particular, light is reflected in a direction away from both the LED 22 and the base material 21 by the reflection convex portion 322 having a sharp shape (specifically, a semi-spindle shape) convexly curved toward the outer peripheral side. . That is, the reflection direction of the light from the light source 20 by the reflection convex portion 322 is set so as to avoid substantially the entire light source 20.

  As described above, in the light guide action through the light control body 30, the light distribution from the light source 20 is transmitted directly or indirectly through the transmission unit 31, so that the luminance distribution of the transmitted light that becomes the illumination light to the object is obtained. Is adjusted to be substantially uniform, for example.

(Function and effect)
The operational effects of the present embodiment as described above will be described below.

  In the facing region 320 that faces the light source 20 in the reflecting portion 32 of the present embodiment, a reflective convex portion 322 that protrudes sharply toward the light source 20 side is formed, so that the light by the reflective convex portion 322 is transmitted. The reflection direction is set to avoid the light source 20. Thereby, even if the light from the light source 20 is reflected by the sharp tip 322a and the outer peripheral side surface 322c of the reflection convex portion 322, it is difficult to recursively enter the light source 20. Moreover, in the reflection part 32 of the present embodiment, the reflection direction of the light from the light source 20 is set to the same light source 20 within a range that avoids the light source 20 by the reflection convex part 322 having a sharp curved shape, particularly in the sharp shape. Can be as close as possible.

  According to the present embodiment as described above, the light utilization efficiency is reduced due to the recurring incidence on the light source 20, and the light enters the vicinity of the light source 20 on the inner bottom surface 120 where the light source 20 is arranged in the bottomed casing 10. Any deviation in luminance distribution due to insufficient light quantity can be suppressed. Therefore, it is possible to achieve both high illumination efficiency by suppressing a decrease in light utilization efficiency and small luminance unevenness by suppressing the unevenness of the luminance distribution.

  Further, in the reflection part 32 of the present embodiment, the light reflection direction by the sharp tip 322a centered on the light source 20 in the reflection convex part 322 and the curved side surface 322c on the outer peripheral side thereof avoids the light source 20 accurately. It becomes easy to set. According to this, it is possible to improve the reliability of the effect of achieving high illumination efficiency by avoiding recursive incidence from the reflective convex portion 322 to the light source 20 leading to a decrease in light utilization efficiency.

  Furthermore, in the reflection part 32 of the present embodiment, in the projection view in the facing direction between the facing region 320 and the light source 20, the light is mounted on the base material 21 mounted on the inner bottom surface 120 of the casing 10 of the light source 20 to emit light. The emitted LED 22 is accommodated within the protrusion-side contour 322b of the reflective convex portion 322. As a result, the light from the LED 22 can be reduced from being reflected by the surrounding portions of the reflective convex portion 322 in the directly facing region 320 of the reflective portion 32. Therefore, the reliability of the effect of achieving high illumination efficiency can be improved by avoiding the recursive incidence of the reflected light on the light source 20 due to the surrounding area of the reflective convex portion 322, and hence the reduction in the light use efficiency due to the recursive incidence. Is possible.

  In addition, in the transmission part 31 of the present embodiment, light is transmitted through the through-hole 310 that penetrates the dimmer 30 with a larger diameter as the distance from the geometric center Cr of the facing region 320 facing the light source 20 in the reflection part 32 increases. It is done. According to this, even if it is the transmission part 31 in which the light from the light source 20 becomes difficult to reach so that it leaves | separates from the facing area | region 320, the transmission amount of the said light can increase by the larger diameter through-hole 310. FIG. Therefore, it is possible to reduce the unevenness of the luminance distribution depending on the distance from the light source 20 to the transmission part 31 and suppress the luminance unevenness.

(Other embodiments)
Although one embodiment has been described above, the present disclosure is not construed as being limited to the embodiment, and can be applied to various embodiments without departing from the gist of the present disclosure.

  Specifically, in the light control body 30 of the first modification, in the translucent base material that does not penetrate the through hole 310 and is partially shielded by the reflecting material, the reflecting portion 32 is formed from the light shielding portion and the light shielding is performed. The transmissive part 31 may be formed from a translucent part other than the part. The light control body 30 of the modification 1 becomes the inner surface which becomes the reflective surface 300, and the reflective convex part 322, for example in the sheet-like base material or plate-shaped base material formed from transparent resin etc. without the through-hole 310. It may be a composite product in which a reflective material such as metal is laminated on the surface of the convex body by sputtering or vapor deposition. Or the light control body 30 of the modification 1 has the reflective convex part 322 with respect to the inner surface used as the reflective surface 300 in the sheet-like base material or plate-shaped base material formed, for example from transparent resin etc. without the through-hole 310. It may be a composite product in which convex reflectors such as metal to be formed are joined by adhesion or the like.

  In the light control body 30 according to the second modification, a part of the LED 22 is eaten from the protrusion-side outline 322b of the reflection convex portion 322 in a projected view in the directly facing direction (that is, the Z direction) between the facing region 320 and the light source 20. You may stick out. In the light control body 30 of the modification 3, as shown in FIG. 5, the protrusion origin side outline 322b exhibits a rectangle in a plan view viewed from the Z direction, and toward the outer peripheral side in both the X direction and the Y direction. The reflection convex part 322 may be formed in the sharp shape which has the four curved side surfaces 322c which bulged convexly. In the light control body 30 of the modification 4, as shown in FIG. 6, the light control body 30 has a rectangular shape in a plan view when viewed from the Z direction, and swells in a convex shape toward the outer peripheral side only in one of the X direction and the Y direction. The reflection convex part 322 may be formed in the sharp shape which has the two curved side surfaces 322c.

  The light control body 30 of the modification 4 may be convexly curved toward the inner bottom surface 120 side of the casing 10 or the opposite side in the Z direction. In Modification 5, as shown in FIGS. 7 and 8, a plurality of sets of elements 10, 20, and 30 may be arranged side by side in at least one of the X direction and the Y direction. In Modification 6, as shown in FIG. 9, a translucent light guide 40 that guides light is additionally disposed between the bottom wall 12 and the light control body 30 in the casing 10. Also good.

  In Modification 7, the LED 22 in the light source 20 may emit chromatic light other than white. In such a modified example 7, it is possible to suppress the color shift caused by the recurrent incidence of light to the light source 20 and to ensure the desired visibility with respect to the object.

DESCRIPTION OF SYMBOLS 1 Illuminating device, 10 casing, 11 opening, 12 bottom wall, 20 light source, 21 base material, 22 LED, 30 light control body, 31 permeation | transmission part, 32 reflection part, 100 inner wall surface, 120 inner bottom surface, 310 through-hole, 320 Directly facing region, 322 reflective convex part, 322a pointed end, 322b protruding origin side contour, 322c curved side surface, Ca, Cb, Cl, Cr geometric center

Claims (4)

A casing (10) having a bottomed shape and reflecting light by an inner wall surface (100) including an inner bottom surface (120);
A light source (20) that is held on the inner bottom surface and emits light;
A dimmer (30) disposed over the opening (11) of the casing,
An illuminating device (1) for illuminating an object with light adjusted in luminance distribution through the dimmer,
The dimmer is
A transmission part (31) that transmits light;
A reflection part (322) that reflects light and that projects in a sharp shape toward the light source side and is convexly curved toward the outer peripheral side in the facing region (320) that faces the light source is formed. A reflection part in which the reflection direction of the light by the reflection convex part is set to avoid the light source,
Lighting device having.   2. The illumination device according to claim 1, wherein the sharp tip (322 a) of the reflection convex portion is aligned with the light source. The light source is
A base material (21) attached to the inner bottom surface;
A light emitting diode (22) that emits light when mounted on the substrate;
Including
The light emitting diode is
3. The illumination device according to claim 1, wherein the illumination device fits within a projecting-source-side contour (322 b) of the reflective convex portion in a projected view in a facing direction between the facing region and the light source. The transmission part is
The through hole (310) which penetrates the said light control body so that it is so large that it leaves | separates from the geometric center (Cr) of the said facing area | region, and permeate | transmits light is comprised. Lighting equipment.

Images