CN117280155A - Planar lighting device - Google Patents

Abstract

A planar lighting device (1) of an embodiment is provided with a plurality of light sources (3), a substrate (2), and a reflector (4). The light source (3) is two-dimensionally arranged on the substrate (2). The reflector (4) is provided with a section (4 d), the section (4 d) is provided with a hole (4 b) corresponding to the light source (3) and a reflecting surface (4 c) extending obliquely from the periphery of the hole (4 b), the outer wall (4 e-4 h) is arranged on the outer periphery of the whole reflector (4), and the reflector (4) is arranged on the emergent side of the substrate (2). In the section (4 d) which is disposed in the irregular portion (1 a) of the outer peripheral portion of the reflector (4) and which cannot be formed into a predetermined shape by the outer walls (4 e-4 h), recesses (4 i-4 m) for accommodating the light source (3) or adjusting the light quantity are provided on the surfaces of the outer walls (4 e-4 h) facing the substrate (2).

Description

Planar lighting device

Technical Field

The present invention relates to a planar lighting device.

Background

In a direct type surface illumination device in which a light source such as an LED (Light Emitting Diode: light emitting diode) is two-dimensionally arranged on a substrate, a reflector is often used in order to reflect light emitted from the light source in a direction inclined with respect to the normal direction of the substrate and to increase light in the normal direction of an emission surface (for example, refer to patent document 1).

The reflector has a unit configuration called segment (segment) provided for each light source, each segment having: holes through which heads (light emitting portions) of the respective light sources are inserted; and a reflecting surface extending obliquely from the periphery of the hole and surrounding the light source. In many cases, the segments are formed in a regular shape such as a rectangle or a hexagon in a plan view.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2021-12884

Disclosure of Invention

Problems to be solved by the invention

However, in the case of a planar lighting device having a special-shaped outer shape, which is not rectangular in outer shape, a section (standard section) of a predetermined shape may not be formed on the outer periphery of the special-shaped portion, and thus the section may not be arranged, leaving an incomplete area. In this case, although the area is negligible in the case of a small area where the light source cannot be arranged, the remaining area is of a size that cannot be ignored in the case where the light source cannot be arranged due to interference by an outer wall provided on the outer peripheral portion of the reflector for ensuring the intensity or the like. As a result, the following problems exist: the brightness of the outer peripheral portion of the shaped portion is reduced to form a dark portion.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a planar lighting device in which a dark portion is not easily formed even when the planar lighting device has a special-shaped outer shape.

Solution for solving the problem

In order to solve the above-described problems and achieve the object, a planar lighting device according to an aspect of the present invention includes a plurality of light sources, a substrate, and a reflector. The light sources are two-dimensionally arranged on the substrate. The reflector is provided with a section having a hole corresponding to the light source and a reflecting surface extending obliquely from the periphery of the hole, and is provided with an outer wall on the entire outer periphery thereof, and is arranged on the emission side of the substrate. In the section which is disposed in the abnormal portion of the outer peripheral portion of the reflector and which cannot be formed into a predetermined shape by the outer wall, a recess for accommodating the light source or adjusting the light quantity is provided on a surface of the outer wall facing the substrate.

According to the planar lighting device of the aspect of the present invention, the dark portion is not easily formed even when the planar lighting device has a special-shaped outer shape.

Drawings

Fig. 1 is a perspective view of a planar lighting device according to a first embodiment.

Fig. 2 is an exploded perspective view of the planar lighting device.

Fig. 3 is an enlarged perspective view of the vicinity of the notch portion of the reflector.

Fig. 4 is an enlarged perspective view of the vicinity of the notch portion of the reflector as seen from another angle.

Fig. 5 is a view of the vicinity of the notch portion of the planar illumination device when viewed from the direction facing the emission surface.

Fig. 6 is a perspective view showing an example in which a concave portion is provided so as not to penetrate the outer wall of the reflector.

Fig. 7 is a perspective view of the planar lighting device of the second embodiment.

Fig. 8 is an exploded perspective view of the planar lighting device.

Fig. 9 is an enlarged perspective view of the vicinity of the notch portion of the reflector.

Fig. 10A is a plan view showing the vicinity of the notch of the planar lighting device.

Fig. 10B is a view showing an example of the luminance distribution of the planar lighting device of fig. 10A.

Fig. 11A is a plan view showing the vicinity of the notch portion of the planar lighting device of the comparative example (modification).

Fig. 11B is a view showing an example of the luminance distribution of the planar lighting device of fig. 11A.

Fig. 12A is a plan view showing the vicinity of a notch portion of the planar lighting device according to the third embodiment.

Fig. 12B is a view showing an example of the luminance distribution of the planar lighting device of fig. 12A.

Fig. 13 is a perspective view showing the vicinity of a notch portion of the planar lighting device according to the fourth embodiment.

Fig. 14 is a plan view of the planar lighting device of the fifth embodiment.

Fig. 15A is a plan view showing an example of the case where the rotation angle in the plane of the light source of the planar lighting device is 0 °.

Fig. 15B is a diagram showing luminance distribution characteristics in the case of the arrangement of fig. 15A.

Fig. 16A is a plan view showing an example of the case where the rotation angle in the plane of the light source of the planar lighting device is 45 °.

Fig. 16B is a diagram showing luminance distribution characteristics in the case of the arrangement of fig. 16A.

Fig. 17 is a plan view showing an example of the case where the rotation angle in the plane of all the light sources of the planar lighting device is 0 °.

Fig. 18 is a plan view showing an example of the case where the rotation angle in the plane of all the light sources of the planar lighting device is 45 °.

Fig. 19 is a plan view showing an example of the case where the rotation angle in the plane of the light source at the corner of the entire planar lighting device is 0 ° and the rotation angle in the plane of the other light source is 45 °.

Fig. 20 is a plan view (1) showing an example of the shape of the reflecting surface of the reflector segment.

Fig. 21 is a plan view (2) showing an example of the shape of the reflecting surface of the reflector segment.

Fig. 22 is a plan view (3) showing an example of the shape of the reflecting surface of the reflector segment.

Fig. 23 is a plan view (4) showing an example of the shape of the reflecting surface of the reflector segment.

Detailed Description

The planar lighting device according to the embodiment will be described below with reference to the drawings. The present invention is not limited to the present embodiment. In addition, dimensional relationships of elements, proportions of elements, and the like in the drawings may sometimes be different from actual ones. Sometimes, the drawings also include portions having different dimensional relationships and proportions from each other. The same applies to the other embodiments and modifications in principle as described in the description of one embodiment and modifications.

(first embodiment)

Fig. 1 is a perspective view of a planar lighting device 1 according to a first embodiment. For convenience, the longitudinal direction of the planar lighting device 1 is the X-axis direction, the short-axis direction is the Y-axis direction, and the thickness direction is the Z-axis direction, but the posture at the time of use is arbitrary.

In fig. 1, a planar lighting device 1 includes: a substrate 2; and a reflector 4 fixed to the upper side of the substrate 2 in the figure by a double-sided tape or the like. A notch portion 1a is provided on the left side in the drawing of the substrate 2 and the reflector 4, and the notch portion 1a has a special-shaped outer shape. The irregular shape may be a straight defect such as the notch portion 1a, a circular arc defect, or a defect having a complicated shape.

Fig. 2 is an exploded perspective view of the planar lighting device 1. In fig. 2, light sources 3 such as LEDs (Light Emitting Diode: light emitting diodes) are two-dimensionally arranged on a substrate 2, and wiring (not shown) is also provided for each light source 3. In the illustrated example, the substrate 2 and the reflector 4 are formed in a flat plate shape, but may be formed by a curved substrate 2 and reflector 4 having a convex curved surface, a concave curved surface, or the like. In this case, the two-dimensional configuration is assigned to be placed on a curved surface, for example, to be placed at a position represented by two independent coordinate axes on a curved surface based on cylindrical coordinates, spherical coordinates, or the like. The light source 3 has an optical axis in the normal direction of the substrate 2. The portion of the substrate 2 not covered by the reflector 4 (portion exposed from the hole 4b described later) or the entire surface is subjected to a treatment for improving the reflectance of light.

As a practical product, in many cases, various optical sheets are disposed on the upper side (emission side) of the reflector 4 in the drawing, in addition to the lens array and the diffuser, and the entire optical sheet is accommodated in a frame made of metal, resin, or the like (an opening is provided on the emission side). As the optical sheet, there are a prism sheet (prism film), a brightness enhancing sheet (brightness enhancing film), a louver sheet (louver film), and the like.

Fig. 3 is an enlarged perspective view of the vicinity of the notch portion 1a of the reflector 4. Fig. 4 is an enlarged perspective view of the vicinity of the notch portion 1a of the reflector 4 from another view angle. Fig. 5 is a view of the vicinity of the notch portion 1a of the planar lighting device 1 when viewed from a direction facing the emission surface.

In fig. 3 to 5, the reflector 4 has outer walls 4e, 4f, 4g, and 4h (the outer wall 4h is not shown) as outer peripheral portions. The recess 4n in fig. 4 is a portion in which a double-sided tape for attaching the reflector 4 to the substrate 2 is disposed.

In fig. 3 to 5, the reflector 4 has a section 4d provided corresponding to each light source 3 (fig. 2). Section 4d has: a hole 4b through which the head of the light source 3 is inserted; and a reflecting surface 4c extending obliquely from the periphery of the hole 4b and surrounding the light source 3. In the illustrated example, the section 4d is rectangular, and the reflection surface 4c is divided into four. That is, the light source 3 has a substantially rectangular outer shape in a plan view, the predetermined shape of the segment is substantially rectangular in a plan view, the hole 4b in the predetermined shape of the segment has a substantially rectangular outer shape in a plan view, and the reflection surface 4c in the predetermined shape of the segment is constituted by four planes. It should be noted that some or all of the reflection surfaces may be composed of two or more surfaces. For example, in the case where all the reflection surfaces are each constituted by two surfaces, eight surfaces in total.

In the notched portion 1a having the irregular outer shape, six rows of non-arranged segments are arranged from the upper side of the figure in the segment row extending in the longitudinal direction at the left end of fig. 3, and the two rows below are arranged with segments, although not in a regular predetermined shape. In these sections, recesses 4l and 4m for accommodating the light source 3 are provided on the surface (the rear surface in fig. 3) of the outer wall 4g of the reflector 4 facing the substrate 2. The recesses 4l, 4m are provided so as to penetrate the outer wall 4g, and even when the thickness of the outer wall 4g is insufficient, the recesses 4l, 4m having an appropriate width enough to accommodate the light sources 34, 35 (fig. 5) can be provided.

In the second column from the left end of fig. 3, the two rows from the top of the drawing are not arranged with the segments, and the three rows below are not in a regular predetermined shape, but are arranged with the segments. In these sections, recesses 4i, 4j, and 4k are provided on a surface (a rear surface in fig. 3) of the outer wall 4g of the reflector 4 facing the substrate 2. Two of the three recesses 4i, 4j are provided for accommodating the light sources 31, 32 (fig. 5). The remaining recess 4k is provided for adjusting the light quantity.

That is, in the section where the concave portion 4k is provided, the outer wall 4g does not interfere with the arrangement of the light source 33 (fig. 5), but since the area of the section is reduced, the light quantity per unit area becomes large and becomes bright if the area is kept as it is, and therefore, a part of the light is consumed by the concave portion 4k to adjust the light quantity. In this regard, although the sections of the light source 36 (fig. 5) are not of a regular predetermined shape, the reduction in area of the sections is small, and the influence on the amount of light per unit area is small, so that no recess is provided.

The reflector 4 is formed of, for example, a white resin having a high reflectance, and the concave portions 4i to 4m may be formed by exposing the material as it is or by changing the reflectance by coloring or the like.

In this way, even in the deformed portion where the section (standard section) 4d of the predetermined shape cannot be arranged due to the deformed shape of the cutout portion 1a, the light sources 31, 32, 34, 35 can be arranged by providing the recesses 4i, 4j, 4l, 4m on the surface of the outer wall 4g facing the substrate 2 in the portion where the light source 3 cannot be arranged due to the obstruction of the outer wall 4g. As a result, the decrease in brightness of the outer peripheral portion of the deformed portion can be eliminated, and the formation of the dark portion can be prevented.

Instead of providing the concave portions 4i, 4j, 4l, 4m, etc., it is conceivable to eliminate the outer wall 4g itself, but the intensity of the reflector 4 is lowered, and the light from the light sources 31, 32, 34, 35, etc. is too strong, which may adversely impair the uniformity of the luminance. That is, the concave portions 4i, 4j, 4l, 4m block light emitted directly above the light sources 31, 32, 34, 35, thereby reducing luminous efficiency per unit area and improving uniformity in the light emitting surface.

The outer wall 4g does not interfere with the arrangement of the light source 33 like the section of the light source 33, but the concave portion 4k is used as described above in order to adjust the light amount per unit area.

In order to compensate for the shortage of the amount of light caused by the region which is not completely left as the region above the light source 34 in the figure, the concave portion 4l in the region of the light source 34 may be enlarged to the upper side of the figure. In this case, the light is guided from the light source 34 to the area where the segments cannot be arranged and remains incompletely, and the shortage of the light quantity can be compensated.

Fig. 6 is a perspective view showing an example in which the concave portions 4i to 4m are provided so as not to penetrate the outer wall 4g of the reflector 4. Fig. 6 is a view from the same angle as fig. 4. In fig. 6, the outer wall 4g of the reflector 4 is formed thicker, and therefore the concave portions 4i, 4j, 4k, 4l, 4m do not penetrate the outer wall 4g.

Since the concave portions 4i, 4j, 4k, 4l, and 4m do not penetrate the outer wall 4g, the thickness of the outer wall 4g is maintained, and the strength of the reflector 4 can be prevented from being lowered. Other effects are the same as those of the above-described configuration example. The space for disposing the light source is also provided above the drawing of the concave portion 4i and above the drawing of the concave portion 4l, and therefore, the section and the concave portion may be provided at this portion. In this case, when the thickness of the outer wall 4g is insufficient, the recess may penetrate the outer wall 4g as shown in fig. 4.

In the example of fig. 1 to 6, the surface (grid surface) of the reflector 4 on the non-emission side is arranged on the substrate 2 so as to be in contact with it, but the portion in contact with the substrate 2 may be the outer walls 4e to 4h of the reflector 4 or a part thereof, and the hole 4b of the segment 4d may be suspended from the substrate 2. In this case, the head of the light source 3 disposed on the substrate 2 may be inserted into the hole 4b of the section 4d or may be not inserted. When the head of the light source 3 is not inserted into the hole 4b of the section 4d, the reflector 4 and the light source 3 can be prevented from interfering with each other even when the reflector 4 and the light source 3 expand and contract due to a temperature change. When the head of the light source 3 is not inserted into the hole 4b of the section 4d, the hole 4b of the section 4d may have a size larger than the light emitting portion of the light source 3 in plan view (for example, a rectangular light emitting portion provided inside the rectangular outer shape of the light source 3), and may be smaller than the outer shape of the light source 3. In this case, even if the arrangement pitch of the light sources 3 is small and the sections 4d of the reflector 4 are arranged at a high density, the manufacturing of the reflector 4 by injection molding or the like becomes easy, the wall of the reflection surface 4c constituting the section 4d can be increased (the thickness in the Z-axis direction is increased), the reflection efficiency can be improved, and the light emission to the adjacent section 4d can be suppressed and the contrast at the time of area dimming can be improved. The structure of the reflector 4 can be similarly applied to the following embodiments.

(second embodiment)

Fig. 7 is a perspective view of the planar lighting device 1 of the second embodiment. For convenience, the longitudinal direction of the planar lighting device 1 is the X-axis direction, the short-axis direction is the Y-axis direction, and the thickness direction is the Z-axis direction, but the posture at the time of use is arbitrary.

In fig. 7, the planar lighting device 1 includes: a substrate 2; and a reflector 4 fixed to the upper side of the substrate 2 in the figure by a double-sided tape or the like. In fig. 7, the illustration of the light source (3) on the substrate 2 is omitted. A notch portion 1a is provided on the upper left side in the drawing of the substrate 2 and the reflector 4, and the notch portion 1a has a special-shaped outer shape. The irregular shape may be a straight defect such as the notch portion 1a, a circular arc defect, or a defect having a complicated shape.

Fig. 8 is an exploded perspective view of the planar lighting device 1. In fig. 8, light sources 3 such as LEDs (Light Emitting Diode: light emitting diodes) are two-dimensionally arranged on a substrate 2, and wiring (not shown) is also provided for each light source 3. In the illustrated example, the substrate 2 and the reflector 4 are formed in a flat plate shape, but may be formed by a curved substrate 2 and reflector 4 having a convex curved surface, a concave curved surface, or the like. In this case, the two-dimensional configuration is assigned to be placed on a curved surface, for example, to be placed at a position represented by two independent coordinate axes on a curved surface based on cylindrical coordinates, spherical coordinates, or the like. The light source 3 has an optical axis in the normal direction of the substrate 2. The portion of the substrate 2 not covered by the reflector 4 (portion exposed from the hole 4b described later) or the entire surface is subjected to a treatment for improving the reflectance of light.

As a practical product, in many cases, various optical sheets are disposed on the upper side (emission side) of the reflector 4 in the drawing, in addition to the lens array and the diffuser, and the entire optical sheet is housed in a frame made of metal, resin, or the like (an opening is provided on the emission side). As the optical sheet, there are a prism sheet (prism film), a brightness enhancing sheet (brightness enhancing film), a louver sheet (louver film), and the like.

Fig. 9 is an enlarged perspective view of the vicinity of the notch portion 1a of the reflector 4. Fig. 10A is a plan view showing the vicinity of the notch portion 1a of the planar lighting device 1.

In fig. 9 and 10A, the reflector 4 has outer walls 4e, 4f, 4g, 4h (outer wall 4h is not shown) as outer peripheral portions. The reflector 4 further has a section 4d provided in correspondence with each light source 3. Section 4d has: a hole 4b through which the head of the light source 3 is inserted; and a reflecting surface 4c extending obliquely from the periphery of the hole 4b and surrounding the light source 3. The outer walls 4e, 4f, 4g, and 4h need not be provided over the entire periphery of the entire outer periphery, and may be provided locally or may not be provided at all.

In the illustrated example, the section 4d is rectangular, and the reflection surface 4c is divided into four. The light source 3 has a substantially cubic outer shape. That is, the light source 3 has a substantially rectangular outer shape in a plan view, the standard shape of the section other than the shaped portion is substantially rectangular in a plan view, the hole 4b of the section has a substantially rectangular outer shape in a plan view, and the reflecting surface 4c of the section is constituted by four planes. It should be noted that some or all of the reflection surfaces may be composed of two or more surfaces. For example, in the case where all the reflection surfaces are each constituted by two surfaces, eight surfaces in total. Hereinafter, the standard-shaped sections other than the shaped portion are also referred to as standard sections. In the present embodiment, the plurality of standard segments 4d are regularly (in a grid shape) arranged in the row direction and the column direction.

In addition, the standard segments are not arranged in the notch portion 1a having the irregular shape, and a segment group for improving uniformity is arranged. That is, for twelve columns from the left end to the right side of the first row on the upper side of the figure, the two rows of the non-shaped case are integrated by removing the middle partition wall. In other words, the irregular section 4d and the adjacent section 4d (not necessarily the standard section 4 d) are integrated by removing the partition wall (reflection surface 4 c) that forms the boundary. The shaped section 4d is a (virtual) section having at least one edge along the entire (shaped portion) shape and having a small hole 4b compared to the standard section 4d. In addition, a plurality (two) or a greater number of light sources 3 than the number of light sources 3 accommodated in the standard section 4d are accommodated in the holes 4b of each section 4d. The light sources 3 are disposed in the holes 4b of the sections 4d so as to be vertically separated. Depending on the shape and size of the irregular section 4d, the space where the partition wall (reflecting surface 4 c) is originally present can be effectively utilized as the space for accommodating the light source 3. The other section 4d is arranged so that the light emission center of the light source 3 is located at the center. The light emission center corresponds to the position of the minute light emitting chip built in the light source 3, and does not necessarily coincide with the center of the package of the light source 3. In addition, when a plurality of light emitting chips are mounted, the average position thereof is the light emitting center. Fig. 10B is a view showing an example of the luminance distribution of the planar lighting device 1 of fig. 10A. The features of which will be described later. Depending on the size of the integrated irregular section 4d, the number of the light sources 3 to be accommodated may not be increased to be larger than the number of the light sources 3 accommodated in the standard section 4d even if the position of the light sources 3 is changed. The irregular section 4d may be formed by integrating three or more sections 4d according to the size or the like, or may not be formed by integrating adjacent sections 4d.

On the other hand, fig. 11A is a plan view showing the vicinity of the notch 1A 'of the planar lighting device 1' of the comparative example (modification). In fig. 11A, a planar lighting device 1' of the comparative example is the same as fig. 10A in the following aspects: in the notch portion 1a', for twelve rows from the left end to the right side of the first row on the upper side, two rows of the non-shaped case are integrated by removing the middle partition wall. However, in the comparative example of fig. 11A, one light source 3 'is arranged at each position of the original second row in the hole of each section 4d' of the shaped portion. Fig. 11B is a view showing an example of the luminance distribution of the planar lighting device 1' of fig. 11A, in which a dark portion is formed at the outer peripheral portion of the shaped portion. That is, the abnormal portion has a portion where the area of the segment 4d ' is excessively large when the one light source 3' is covered, and as a result, a dark portion may be formed at the outer peripheral portion of the notch portion 1a ', and the luminance may be uneven.

In this regard, in the embodiment of fig. 7 to 10A, as shown in fig. 10B, the brightness is slightly higher at the left side in the drawing where the light sources 3 are closely arranged, but there is no dark portion at the peripheral portion. The dark portion cannot be corrected, but the bright portion can be corrected by an optical sheet or the like disposed on the exit surface side of the reflector 4. For example, by performing processing for reducing light transmittance on the optical sheet portion corresponding to the bright portion, the luminance of the bright portion can be reduced, and the luminance uniformity of the entire portion can be improved. Further, for example, by adjusting the current applied to the light source 3, the light emission amount is adjusted to reduce the brightness of the bright portion, thereby improving the brightness uniformity of the whole. Further, for example, by disposing a black light absorbing member in a part of the segment 4d, the luminance of the bright portion can be reduced, and the luminance uniformity of the whole can be improved.

(third embodiment)

Fig. 12A is a plan view showing the vicinity of the notch 1a of the planar lighting device 1 according to the third embodiment. In fig. 12A, the shape and size of the segment 4d disposed in a predetermined region (first to fourth rows from top to bottom) including the notch portion 1a having a special-shaped outer shape are equalized. The predetermined region to be equalized may be changed according to a special-shaped pattern, and may be the entire surface or may be a local region. Further, equalization does not mean that the shape and size are exactly the same, but means that they are adjusted to be as approximate as possible. Specifically, for example, in fig. 12A, the dimension from the upper end side of the reflector 4 including the notch portion 1a to the upper end of the fifth row downward is divided into four equal parts by the width of the outer wall, and four rows of segments 4d are arranged therein. The other structures are the same as those of fig. 7 to 9.

Fig. 12B is a view showing an example of the luminance distribution of the planar lighting device 1 of fig. 12A, and the luminance uniformity in the vicinity of the notch portion 1a is improved as compared with the first embodiment of fig. 10B.

(fourth embodiment)

Fig. 13 is a perspective view showing the vicinity of the notch 1a of the planar lighting device 1 according to the fourth embodiment, and is an improvement of the second embodiment of fig. 9. The same modification may be applied to the third embodiment of fig. 12A.

In fig. 13, in the vicinity of the notch portion 1a of the reflector 4, recesses 4i, 4j, 4k, and 4l for accommodating the light source 3 or adjusting the light amount of the light source 3 are provided in the surface (the rear surface in the figure) of the outer wall 4e facing the substrate 2, as in the first embodiment. Depending on the width of the outer wall 4e, the recesses 4i, 4j, 4k, 4l may or may not extend through to the upper end of the outer wall 4e in the drawing. The reflector 4 is formed of, for example, white resin having high reflectance, and the concave portions 4i, 4j, 4k, and 4l may be formed by exposing the material as it is or by coloring or the like to change the reflectance of the surface. The other structures are the same as those of fig. 7 to 9.

That is, when the size of the section 4d cannot be sufficiently ensured by the notch portion 1a, it may be difficult to dispose a plurality of (two) light sources 3, but the light sources 3 may be disposed so as to be partially hidden under the concave portions 4i, 4j, 4k, 4l, so that it is easy to ensure a space for disposing the light sources 3. Further, since the plurality of (two) light sources 3 are arranged in the narrow section 4d, the light amount per unit area becomes large and the luminance becomes high (as described in fig. 10B), but the light sources 3 arranged in the concave portions 4i, 4j, 4k, 4l are partially inserted, and the outer wall 4e as a cover can suppress the light amount by blocking the light emitted directly above, and can prevent the luminance from becoming high to more than necessary. As a result, luminance uniformity can be improved.

(fifth embodiment)

Fig. 14 is a plan view of the planar lighting device 1 of the fifth embodiment. The outer wall of the reflector 4 is not shown. In addition, as in fig. 7 and 8, a substrate 2 is provided on the back surface of the reflector 4, and the light source 3 is disposed on the substrate 2. Note that this embodiment is applicable to a case where a plurality of (two) light sources 3 are accommodated in the section 4d on the side of the notch portion 1a as in fig. 10A, but is also applicable to a case where one light source 3 is accommodated in the equalized section 4d as in fig. 12A.

In fig. 14, a plurality of (two) light sources 3 are accommodated in a first row of sections 4d on the notch portion 1a side of the reflector 4, as in the second embodiment of fig. 10A. Further, the light sources 3 at the four corners of the entire reflector 4 are configured as follows: in a plane parallel to the reflector 4 and the substrate (2), four sides around the light source 3 are aligned or orthogonal to the X-axis or the Y-axis, and the rotation angle is 0 °. Further, the rotation angle of the light source 3 disposed between the corners of the two ends in the first row section 4d on the notch portion 1a side is continuously changed from the corner on the right side. The other light sources 3 are arranged with a rotation angle of 45 °.

Fig. 15A is a plan view showing an example of the case where the rotation angle in the plane of the light source 3 of the planar lighting device 1 is 0 °. The outer wall of the reflector 4 is not shown. The light source 3 has a package shape of a substantially cubic shape (may be a substantially rectangular parallelepiped shape), and emits light mainly from four sides provided with a phosphor. Therefore, the direction of light emission has anisotropy, and the amount of light in the front direction of each of the four side surfaces is large. In fig. 15A, the rotation angle in the plane of the light source 3 is 0 °, and therefore the light amounts in the X-axis direction and the Y-axis direction are large. In the illustrated example, the reflection surface 4c of the segment 4d is formed of a plurality of planes divided by diagonal lines, and thus the reflection is anisotropic. As a result, light tends to be concentrated at the corners of each segment 4d, and the brightness at the corners increases. Fig. 15B is a diagram showing the luminance distribution characteristics in the case of the arrangement of fig. 15A, and the luminance of the region R1 in which the corners of the four segments 4d are concentrated becomes high, resulting in luminance unevenness.

On the other hand, fig. 16A is a plan view showing an example of the case where the rotation angle in the plane of the light source 3 of the planar lighting device 1 is 45 °. The outer wall of the reflector 4 is not shown. Fig. 16B is a diagram showing the luminance distribution characteristics in the case of the arrangement of fig. 16A, and since the relative rotation angle of the light source 3 and the reflection surface 4c is changed by 45 °, the luminance of the portion where the corners of the four segments 4d are concentrated becomes low. However, the luminance of the region R2 at the corner portion as a whole is reduced, resulting in uneven luminance. This is because the entire corner has no adjacent sections in both directions, and the luminance tends to be low originally. In this regard, in the configuration of fig. 15A, since the corner of each section 4d becomes bright, the luminance decrease is alleviated, whereas in the configuration of fig. 16A, the luminance decrease is not alleviated, and the luminance decrease becomes remarkable.

Therefore, in the planar lighting device 1 of fig. 14, in order to suppress a decrease in luminance of the entire corner, the rotation angle of the light source 3 of the entire corner is set to 0 °. In order not to increase the brightness of the portion where the corners of the four segments 4d are concentrated, the rotation angle of the light source 3 is set to 45 ° except for the notch portion 1a side. The rotation angle of the light source 3 of the section 4d, which is disposed on the notch portion 1a side except for the corner portions as a whole at both ends, is continuously changed from the light source 3 at the right end. This is because the area of the segment 4d is larger on the right side than on the left side, and the relative light quantity on the right side becomes smaller, so that the brightness of the corner of the segment 4d needs to be ensured as going to the right side.

(sixth embodiment)

The above-described change in the rotation angle in the plane of the light source 3 can be applied to the case of the irregular portion such as the non-notched portion 1 a.

Fig. 17 is a plan view showing an example of the case where the rotation angle in the plane of all the light sources 3 of the planar lighting device 1 is 0 °. The outer wall of the reflector 4 is not shown. In this case, as described in fig. 15A and 15B, the decrease in luminance at the corners of the whole is alleviated to some extent, but the luminance at the portions where the corners of the four inner segments 4d are concentrated is increased, and the luminance uniformity is lowered.

Fig. 18 is a plan view showing an example of the case where the rotation angle in the plane of all the light sources 3 of the planar lighting device 1 is 45 °. The outer wall of the reflector 4 is not shown. In this case, as described in fig. 16A and 16B, the luminance of the portion where the corners of the four inner segments 4d are concentrated is suppressed from becoming high, but the decrease in luminance of the corners as a whole becomes remarkable, and the luminance uniformity is decreased.

Fig. 19 is a plan view showing an example of the case where the rotation angle in the plane of the light source 3 at the corner of the entire planar lighting device 1 is 0 ° and the rotation angle in the plane of the other light source 3 is 45 °. The outer wall of the reflector 4 is not shown. In this case, the decrease in luminance of the corner portions as a whole is alleviated to some extent, and the luminance of the portion where the corners of the four inner segments 4d are concentrated is suppressed from becoming high.

(seventh embodiment)

The following shows a pattern of the shape of the reflecting surface 4c of the section 4d of the reflector 4. In the following drawings, the rotation angle in the plane of the light source 3 is set to 0 °, but the rotation angle of the light source 3 may be changed based on the principle described above.

Fig. 20 is a plan view showing an example of the shape of the reflecting surface 4c of the segment 4d of the reflector 4, and similarly to what has been described above, the reflecting surface 4c is constituted by a plurality of planes divided by diagonal lines of the rectangular segment 4d. The dashed lines in the figure represent contour lines of the shape.

Fig. 21 is a plan view showing another example of the shape of the reflecting surface 4c of the segment 4d of the reflector 4, in which the reflecting surface 4c is formed of a plurality of planes divided by vertical and horizontal cross lines. In this case, the relative rotation angle between the anisotropy of the light source 3 and the anisotropy of the segment 4d is the same as that of fig. 16A, and the effect is also the same.

Fig. 22 is a plan view showing another example of the shape of the reflecting surface 4c of the segment 4d of the reflector 4, and is a case where the reflecting surface 4c is formed of a conical curved surface. In this case, the anisotropy of the section 4d is lost or relaxed, leaving only the anisotropy of the light source 3.

Fig. 23 is a plan view showing another example of the shape of the reflecting surface 4c of the section 4d of the reflector 4, in which: in the reflecting surface 4c, one region divided by one diagonal line is formed of a plurality of flat surfaces divided by the other diagonal line, and the other region is formed of a conical curved surface. In this case, the anisotropy of the section 4d in the region on the other side disappears or is relaxed, and only the anisotropy of the light source 3 remains.

By combining the shape pattern of the reflecting surface 4c in fig. 20 to 23 and the rotation angle in the plane of the light source 3, various changes in brightness can be made.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist thereof.

As described above, the planar lighting device according to the embodiment includes: a plurality of light sources; a substrate on which a light source is two-dimensionally arranged; and a reflector having a section having a hole corresponding to the light source and a reflecting surface extending obliquely from the periphery of the hole, the reflector having an outer wall provided on an outer peripheral portion of the entire reflector, the reflector being disposed on the emission side of the substrate, and a concave portion for accommodating the light source or adjusting the light quantity being provided on a surface of the outer wall facing the substrate in a section which is disposed on a special-shaped portion of the outer peripheral portion of the reflector and is not formed into a predetermined shape by the outer wall. Thus, even when the shaped outer shape is provided, the dark portion is not easily formed.

The recess is provided so as to penetrate the outer wall. Thus, even in the case where the thickness of the outer wall is insufficient, a recess of an appropriate width enough to accommodate the light source can be provided.

The recess is provided so as not to penetrate the outer wall. This can cope with a case where the thickness of the outer wall is sufficient, and can prevent the strength of the reflector from decreasing.

The light source has a substantially rectangular outer shape in a plan view, the predetermined shape of the segment is substantially rectangular in a plan view, and the hole in the predetermined shape of the segment has a substantially rectangular outer shape in a plan view, and the reflection surface in the predetermined shape of the segment is constituted by a plurality of flat surfaces. This makes it possible to embody the structure of the planar lighting device.

Further, a segment group for improving uniformity is provided, and the segment group is disposed in a special-shaped portion of the outer peripheral portion of the reflector. Thus, luminance uniformity can be maintained even in the case of having a special-shaped outer shape.

In addition, in the segment group, the shaped segment is integrated with the partition member with the boundary removed between the segments adjacent to the segment. Thus, a section suitable for the shaped portion can be constituted. In addition, the space for accommodating the light source can be increased.

The present invention further includes: a plurality of light sources; a substrate on which a light source is two-dimensionally arranged; a reflector provided with a section having a hole corresponding to the light source and a reflecting surface extending obliquely from the periphery of the hole, the reflector being disposed on the emission side of the substrate; and a segment group for improving uniformity, which is disposed in the irregular part of the outer periphery of the reflector. Thus, luminance uniformity can be maintained even in the case of having a special-shaped outer shape.

In addition, in the segment group, the shaped segment is integrated with the partition member with the boundary removed between the segments adjacent to the segment. Thus, a section suitable for the shaped portion can be constituted. In addition, the space for accommodating the light source can be increased.

The present invention is not limited to the above embodiments. The present invention also includes a configuration in which the above constituent elements are appropriately combined. Further, those skilled in the art can easily derive further effects and modifications. Accordingly, the broader aspects of the present invention are not limited to the above-described embodiments, and various modifications are possible.

Description of the reference numerals

1: a planar lighting device; 1a: a notch portion; 2: a substrate; 3. 31 to 36: a light source; 4: a reflector; 4a: a base material; 4b: a hole; 4c: a reflecting surface; 4d: a section; 4 e-4 h: an outer wall; 4i to 4m: a recess.

Claims (8)

1. A planar lighting device is provided with:

a plurality of light sources;

a substrate on which the light source is two-dimensionally arranged; and

a reflector having a section having a hole corresponding to the light source and a reflecting surface extending obliquely from the periphery of the hole, the reflector having an outer wall provided on the entire outer periphery thereof, the reflector being disposed on the emission side of the substrate,

in the section which is disposed in the abnormal portion of the outer peripheral portion of the reflector and which cannot be formed into a predetermined shape by the outer wall, a recess for accommodating the light source or adjusting the light quantity is provided on a surface of the outer wall facing the substrate.

2. The planar lighting device according to claim 1, wherein,

the recess is provided so as to penetrate the outer wall.

3. The planar lighting device according to claim 1, wherein,

the recess is provided so as not to penetrate the outer wall.

4. The planar lighting device according to any one of claim 1 to 3, wherein,

the light source has a substantially rectangular outer shape in a top view,

the prescribed shape of the segment is substantially rectangular in plan view,

the aperture in the prescribed shape of the section has a generally rectangular outer shape in plan view,

the reflecting surface in the prescribed shape of the segment is constituted by a plurality of flat surfaces.

5. The planar lighting device according to any one of claims 1 to 4, wherein,

the reflector comprises a segment group for improving uniformity, wherein the segment group is arranged on a special-shaped part of the outer periphery of the reflector.

6. The planar lighting device according to claim 5, wherein,

in the segment group, the shaped segment is integrated with a partition member having a boundary removed between the segment adjacent to the shaped segment.

7. A planar lighting device is provided with:

a plurality of light sources;

a substrate on which the light source is two-dimensionally arranged;

a reflector having a section provided with a hole corresponding to the light source and a reflecting surface extending obliquely from the periphery of the hole, the reflector being disposed on the emission side of the substrate; and

and a segment group for improving uniformity, which is disposed in a special-shaped portion of the outer peripheral portion of the reflector.

8. The planar lighting device according to claim 7, wherein,

in the segment group, the shaped segment is integrated with a partition member having a boundary removed between the segment adjacent to the shaped segment.