JP6093548B2 - Holder and lighting device - Google Patents

Description

  The present invention relates to a lighting device that uses a light emitting element as a light source and can be used in place of a fluorescent tube, and a holder used therefor.

  In recent years, lighting devices (for example, LED bulbs and LED fluorescent tubes) that use light-emitting diodes (hereinafter also referred to as “LEDs”) as light sources have been used as lighting devices to replace light bulbs and fluorescent tubes from the viewpoint of energy saving and environmental conservation. It has come to be. As such an illuminating device, an illuminating device in which an LED is disposed at an end of a light emitting region has been proposed (see, for example, Patent Document 1). FIG. 1 is a cross-sectional view of the lighting device described in Patent Document 1. As shown in FIG.

  As shown in FIG. 1, the illumination device 10 described in Patent Document 1 includes a light emitting unit 12 on which an LED serving as a light source is mounted, a cylindrical light guide member 14 made of a transparent material, and a light transmissive material. And a support 18 that supports the light guide member 14. The light guide member 14 is supported by the support portion 18 so that one end surface thereof faces the LED.

JP 2011-96592 A

  In general, the light guide member 14 is formed of a material having high light transmittance such as acrylic resin. For this reason, the light guide member 14 usually includes emission means for directing light traveling along the axial direction of the light guide member 14 toward the outer peripheral surface of the light guide member 14. Examples of the emitting means include scatterers dispersed in the light guide member 14.

  Light that has entered the light guide member 14 from the end surface (incident surface) of the light guide member 14 travels along the axial direction of the light guide member 14 as indicated by an arrow in FIG. 14 is emitted from the outer peripheral surface. For this reason, the area A at the light emitting unit 12 side end portion of the cover 16 is difficult to reach light, and tends to be a dark portion. For this reason, light and dark unevenness may occur in the cover 16. In the region A, the larger the area of the incident surface of the light guide member 14 relative to the light emission area of the LED, or the greater the amount of emitted light per unit length in the axial direction of the light guide member 14, the more Prone to dark areas.

  As a means for preventing the occurrence of a dark part in the region A, it is conceivable to perform a process that greatly disturbs the optical path at the end of the light guide member 14 on the incident surface side. However, when such processing is performed, the region A becomes a bright portion, light does not sufficiently reach the portion on the side opposite to the incident surface of the light guide member 14, and unevenness in brightness and darkness may occur in the cover 16. is there.

  The objective of this invention is providing the holder which can prevent generation | occurrence | production of the dark part in the edge part by the side of the light emitting element of a cover. Another object of the present invention is to provide an illumination device having this holder.

The holder according to the present invention is a holder having light transmittance for holding the light guide member with respect to the light emitting element in the lighting device having the light emitting element and the light guide member,
A first recess having a first opening of a size surrounding the light emitting element; a second recess having a second opening into which the light guide member is to be inserted;
The first concave portion and the second concave portion are formed in a portion closer to the first opening portion than the position of the end surface of the light guide member when the light guide member is inserted into the second concave portion on the peripheral walls of the first concave portion and the second concave portion. An incident surface that is configured by at least a part of a rotationally symmetric surface with the central axis of the recess as a rotation axis, and that makes the emitted light from the light emitting element enter the holder;
It is formed on the outer side in the circumferential direction from the first recess and the second recess, and is at least a part of a rotationally symmetric surface with the central axis as a rotation axis, from the position of the first opening in the central axis direction. 2 a total reflection surface that is configured by a surface whose distance from the central axis gradually increases toward the opening, and totally reflects light that has arrived from the incident surface;
An exit surface configured to be at least part of a rotationally symmetric surface having the central axis as a rotation axis on the second opening side in the central axis direction from the total reflection surface; ,
The structure which has is taken.

  The illumination device according to the present invention includes at least one light emitting element, a light guide member, the holder according to the present invention that holds the light guide member with respect to the light emitting element, and light emitted from the holder and the light guide member. And a cover that allows permeation while diffusing.

  According to the present invention, in the lighting device, it is possible to prevent the occurrence of a dark portion at the end of the cover on the light emitting element side. Therefore, it is possible to provide a lighting device having a wide effective light emitting area and uniform luminance in the effective light emitting area.

It is sectional drawing of the illuminating device of patent document 1. 2A is a plan view of the lighting apparatus according to Embodiment 1, FIG. 2B is a cross-sectional view taken along line BB shown in FIG. 2A, and FIG. 2C is a side view of the lighting apparatus. 3A is a plan view of the holder according to Embodiment 1, FIG. 3B is a front view of the holder, FIG. 3C is a bottom view of the holder, and FIG. 3D is shown in FIG. 3A. It is sectional drawing of a DD line. FIG. 4A is a cross-sectional view of a first comparative holder, and FIG. 4B is a diagram schematically showing an optical path of light in this holder. FIG. 5A is a cross-sectional view of the holder according to Embodiment 1, and FIG. 5B is a diagram schematically showing an optical path of light in this holder. FIG. 6 is a diagram schematically illustrating an optical path of emitted light from the holder and the light guide rod according to the first embodiment. 7A is a plan view of a holder according to Embodiment 2, FIG. 7B is a front view of the holder, FIG. 7C is a bottom view of the holder, and FIG. 7D is shown in FIG. 7A. It is sectional drawing of a DD line. FIG. 8 is an enlarged view of a region A shown in FIG. 7D. FIG. 9 is a diagram schematically showing an optical path of light in the second comparative holder. 10A is a plan view of a holder according to Embodiment 3, FIG. 10B is a front view of the holder, FIG. 10C is a bottom view of the holder, and FIG. 10D is shown in FIG. 10A. It is sectional drawing of a DD line. FIG. 11 is a diagram schematically illustrating an optical path of light in the holder having the second inclined surface. 12A is a partial cross-sectional view of the lighting apparatus according to Embodiment 4, and FIG. 12B is an enlarged view of region B shown in FIG. 12A. FIG. 13 is a perspective view illustrating a main part in a state where a cover of the lighting apparatus according to Embodiment 4 is removed. FIG. 14 is a perspective view of a holder according to the fourth embodiment. 15A is a plan view of a holder according to Embodiment 4, FIG. 15B is a front view of the holder, FIG. 15C is a rear view of the holder, and FIG. 15D is a side view of the holder. FIG. 15E is a cross-sectional view taken along the line EE shown in FIG. 15A. FIG. 16 is a diagram illustrating light distribution characteristics of the light guide rod used in the example. FIG. 17A is a diagram illustrating the relative luminance of the cover when light is emitted from only one light emitting element of the lighting device used in the example, and FIG. 17B is a diagram illustrating light emitted from the light emitting elements at both ends of the lighting device. It is a figure which shows the relative luminance of a cover when it radiate | emits. FIG. 18A is a diagram schematically showing a cross-sectional shape of a main part of a comparative holder, and FIG. 18B shows a case where light is emitted only from a light emitting element on one end side of a comparative illumination device having the holder. It is a figure which shows the relative luminance of a cover. FIG. 19A is a diagram illustrating the relative luminance of the cover when light is emitted from only the light emitting element on one end side in the illumination device used in the example and the comparative illumination device, and FIG. 19B is a diagram illustrating these illumination devices. It is a figure which shows the relative brightness | luminance of a cover when light is radiate | emitted from the light emitting element of both ends.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, a lighting device that can be used in place of a fluorescent tube will be described as a representative example of the lighting device of the present invention.

(Embodiment 1)
[Configuration of lighting device]
FIG. 2A is a plan view of lighting apparatus 100 according to Embodiment 1 of the present invention. 2B is a cross-sectional view taken along line BB shown in FIG. 2A. FIG. 2C is a side view of the lighting device 100.

  As illustrated in FIG. 2, the lighting device 100 includes a light emitting element 110, a heat sink 120, a holder 130, a light guide rod 140, and a cover 150. The light emitting element 110, the heat sink 120, and the holder 130 constitute a set of light emitting units. In the lighting device 100, a pair of light emitting units are disposed with the light guide rod 140 interposed therebetween.

  The light emitting element 110 is a light source of the lighting device 100 and is disposed on a substrate 125 attached to the heat sink 120. The light emitting element 110 is a light emitting diode (LED) such as a white light emitting diode.

  The heat sink 120 is disposed at both ends of the lighting device 100 and has a function of cooling the light emitting element 110. The heat sink 120 is formed with a circuit for connecting the light emitting element 110 and an external power supply circuit. The heat sink 120 is manufactured using, for example, a metal having high thermal conductivity such as aluminum or copper. The substrate 125 is also formed of a metal having high thermal conductivity such as aluminum or copper. When the substrate 125 does not require high thermal conductivity, a resin substrate in which a glass nonwoven fabric is impregnated with an epoxy resin may be used as the substrate 125.

  The holder 130 surrounds the light emitting element 110 at one end side and holds the light guide rod 140 at the other end side. The holder 130 will be described in detail later.

  The light guide rod 140 is a light-transmissive columnar light guide member. The light guide rod 140 causes the light emitted from the light emitting element 110 to enter from the end face. That is, the end surface of the light guide rod 140 functions as an incident surface. The light that has entered the light guide rod 140 travels through the light guide rod 140 by a predetermined distance, and then is emitted from the outer peripheral surface (side surface) of the light guide rod 140. That is, the outer peripheral surface of the light guide rod 140 functions as an exit surface.

  In the present embodiment, the shape of the light guide rod 140 is a columnar shape, but the shape of the light guide rod 140 is not particularly limited as long as it is a columnar shape having an end surface and an outer peripheral surface. Also good. In addition, when a plurality of arc-shaped light guide members are used, an annular illumination device can be configured. The length and thickness of the light guide rod 140 are appropriately set according to the application and the intensity of light emitted from the light emitting element 110.

  The light guide rod 140 is formed by, for example, injection molding, extrusion molding, cast molding, or the like. The material of the light guide rod 140 is not particularly limited as long as it can transmit light having a desired wavelength. For example, the material of the light guide rod 140 is a light transmissive resin such as polymethyl methacrylate (PMMA), polycarbonate (PC), or epoxy resin (EP); or glass. Further, scatterers such as beads may be dispersed in the light transmissive resin or glass. Forward scattering characteristics can be imparted to the light guide rod 140 by dispersing the scatterers at an appropriate concentration in the light guide rod 140. Moreover, you may perform a light-diffusion process (for example, roughening process) to the outer peripheral surface of the light guide rod 140. FIG.

  The cover 150 is formed in a cylindrical body, for example. The cover 150 covers the outer peripheral surface of the light guide rod 140 by, for example, the edge of the cover 150 being fitted into the opening of the heat sink 120. The cover 150 has light transmittance and light scattering properties. The cover 150 diffuses light reaching the cover 150 from the outer peripheral surface of the light guide rod 140 and the exit surface of the holder 130 and transmits the light to the outside.

  The shape of the cover 150 is not particularly limited as long as it can cover the holder 130 and the light guide rod 130 as described above. For example, the shape of the cover 150 may be a rectangular tube shape or a flat plate shape.

  The material of the cover 150 is not particularly limited as long as it has light transparency. Examples of the material of the cover 150 include light transmissive resins such as polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), and styrene / methyl methacrylate copolymer resin (MS). Also, the means for imparting light diffusing power to the cover 150 is not particularly limited. For example, light diffusion treatment (for example, roughening treatment) may be performed on the inner surface or outer surface of the cover 150, or scatterers such as beads may be dispersed in the light transmissive resin.

[Configuration of Holder 130]
3A is a plan view of the holder 130, FIG. 3B is a front view of the holder 130, FIG. 3C is a bottom view of the holder 130, and FIG. 3D is a DD line shown in FIG. 3A. FIG.

  The holder 130 is formed, for example, in a substantially disc shape having light transmittance. The holder 130 may be formed of the same transparent material as that of the light guide rod 140, for example. The holder 130 usually does not contain emission means such as scatterers in the material.

  The holder 130 has a through hole 131. The through-hole 131 has a first opening 131a on one end side and a second opening 131b on the other end side. The first opening 131a is formed in a size that surrounds the light emitting element 110, and the second opening 131b is formed in a size in which the light guide rod 140 can be inserted. The holder 130 is usually made of a transparent material and does not block the incidence of light on the light guide rod 140. For this reason, you may form a partition wall between the 1st opening part 131a and the 2nd opening part 131b. In this case, a first recess on the first opening 131a side and a second recess on the second opening 131b side are formed. The bottom surface of the recesses of the first recess and the second recess may be a flat surface or a curved surface. For example, the convex lens may be formed by the bottom surface of the first concave portion and the bottom surface of the second concave portion, and the incident light to the light guide rod 140 may be condensed, or the concave lens may be formed by the bottom surface of the first concave portion and the bottom surface of the second concave portion. In order to compensate for the brightness near the light emitting element 110, light may be emitted. In the present embodiment, holder 130 has a structure in which the first recess communicates with the second recess, that is, through hole 131. When the holder 130 has the through hole 131, light loss at the interface and slight light absorption by the holder material can be suppressed as compared with the case where the holder 130 has a partition wall, and the holder 130 can be reduced in weight. Can be planned.

  The holder 130 further has a first inclined surface 132 outside the through hole 131 in the circumferential direction. The first inclined surface 132 is a rotationally symmetric surface having the central axis CA as a rotation axis. Further, the first inclined surface 132 is configured by a surface whose distance from the central axis CA gradually increases from the position of the first opening 131a in the direction of the central axis CA toward the second opening 131b. The bus line of the first inclined surface 132 may be a straight line or a curved line. The “bus line” generally means a straight line that describes a ruled surface, but in the present invention, it is used as a word including a curve for drawing a rotationally symmetric surface. When the first inclined surface 132 is a curved surface, the inclination angle of the first inclined surface 132 is an angle of the tangent line of the first inclined surface 132 with respect to the central axis CA. Between the 1st opening part 131a and the 1st inclined surface 132, the 1st end surface 133 which is an annular | circular shaped plane surrounding the 1st opening part 131a is formed.

  The holder 130 is further connected to the outer peripheral surface 134 and the cylindrical outer peripheral surface 134 connected to the first inclined surface 132 on the second opening 131b side in the central axis CA direction from the first inclined surface 132. And a second end surface 135 that is an annular plane surrounding the two openings 131b. Both the outer peripheral surface 134 and the second end surface 135 are rotationally symmetric surfaces having the central axis CA as a rotation axis.

  As shown in FIG. 2B, the holder 130 is attached to the lighting device 100 such that the first end surface 133 is bonded to the substrate 125 and the first opening 131 a surrounds the light emitting element 110. The center axis CA of the holder 130 matches the optical axis LA of the light emitting element 110. From the second opening 131 b of the holder 130, the light guide rod 140 is inserted to the vicinity of the light emitting element 110, but to a position away from the light emitting element 110. Thus, the end surface of the inserted light guide rod 140 is disposed away from the light emitting element 110. The “optical axis of the light emitting element” refers to the traveling direction of light at the center of the three-dimensional light flux from the light emitting element. In the case where there are a plurality of light emitting elements on the same plane, it refers to the traveling direction of light at the center of the three-dimensional light flux from the plurality of light emitting elements.

[optical properties]
The optical path in the holder 130 will be described. First, an optical path in the comparative holder 530 having the same structure except that the first inclined surface 132 is not provided will be described. FIG. 4A is a cross-sectional view of the holder 530. FIG. 4B is a diagram showing an optical path of light emitted from the center of the first opening 131 a of the through hole 131 of the holder 530.

  Light emitted at a large angle with respect to the central axis CA of the comparative holder 530 enters the holder 530 from the peripheral wall of the through hole 131. The light that has entered the holder 530 reaches the outer peripheral surface of the holder 530 and is emitted outward from the outer peripheral surface. Light incident on the holder 530 enters the peripheral wall of the through hole 131 with a small incident angle, and light incident on the holder 530 also enters the outer peripheral surface of the holder 530 with a small incident angle. Therefore, the light that has reached the outer peripheral surface of the comparative holder 530 passes through the outer peripheral surface almost as it is and is emitted to the side of the holder 530.

  FIG. 5A is a cross-sectional view of holder 130 according to the present embodiment. FIG. 5B is a diagram illustrating an optical path of light emitted from the center of the first opening 131 a of the through hole 131 of the holder 130.

  As shown in FIG. 5B, the light emitted at a large angle with respect to the central axis CA enters the holder 130 from the peripheral wall of the through hole 131. Actually, since the light guide rod 140 is inserted into the through hole 131 from the second opening 131b, the light incident on the holder 130 is incident on the end wall of the inserted light guide rod 140 on the peripheral wall of the through hole 131. The light enters the holder 130 from a portion (136 in FIG. 5B) closer to the first opening 131a than the position. The peripheral wall of the through-hole 131 forms a rotationally symmetric surface with the central axis CA as the rotation axis. That is, the portion serves as an incident surface 136 through which light emitted from the light emitting element 110 enters the holder 130.

  The light that has entered the holder 130 from the incident surface 136 reaches the first inclined surface 132. The incident angle of the light reaching the first inclined surface 132 with respect to the surface is large, and the light reaching the first inclined surface 132 is totally reflected by the first inclined surface 132 and reaches the outer peripheral surface 134. The first inclined surface 132 is a total reflection surface that totally reflects light that has arrived from the incident surface 136.

  The incident angle of the light reaching the outer peripheral surface 134 with respect to the outer peripheral surface 134 is slightly large. Therefore, a part of the light reaching the outer peripheral surface 134 is emitted outward from the outer peripheral surface 134 and a part thereof is reflected by the outer peripheral surface 134. The emitted light from the outer peripheral surface 134 is refracted, for example, toward the second opening 131b according to the refractive index of the holder 130. A part of the light reaching the second end face 135 is emitted from the second end face 135 outward because the incident angle with respect to the second end face 135 is slightly large, and a part of the light is reflected by the second end face 135. The outgoing light from the second end surface 135 is also refracted according to the refractive index of the holder 130. As described above, the outer peripheral surface 134 and the second end surface 135 are emission surfaces that emit light that has reached from the total reflection surface to the outside.

  The light reflected by the second end surface 135 reaches and reflects the peripheral wall surface of the through hole 131, reaches the first inclined surface 132, and is emitted outward from the first inclined surface 132. Thus, most of the light incident on the holder 130 at a large angle with respect to the optical axis LA is closer to the light guide rod 140 than the holder 130 in the central axis CA direction, and more outward in the circumferential direction of the through hole 131. Exit.

  On the other hand, light emitted from the light emitting element 110 at a small angle with respect to the optical axis LA enters the light guide rod 140 from the end face of the light guide rod 140. FIG. 6 is a diagram schematically illustrating an optical path of light emitted from the holder 130 and the light guide rod 140. As shown in FIG. 6, the light guide rod 140 emits light from the outer peripheral surface of the light guide rod 140 at a predetermined angle with respect to the optical axis LA, and in the direction of the optical axis LA in the light guide rod 140. Advance light. In this case, the light emitted from the light guide rod 140 is unlikely to reach the portion indicated by A in FIG. For this reason, A part tends to become a dark part. However, in the present embodiment, as shown in FIG. 6, the emitted light from the holder 130 reaches the A part.

[effect]
The holder 130 has a first inclined surface 132. For this reason, the light that has entered the holder 130 at a large angle with respect to the optical axis LA from the light emitting element 110 is emitted from the holder 130 to the outside, and from the region where the emitted light from the light guide rod 140 reaches the cover 150. Also reaches the region on the light emitting element 110 side. Therefore, in the illuminating device 100, the effective light-emitting area extends in the direction of the optical axis LA, and the luminance in the effective light-emitting area becomes more uniform.

(Embodiment 2)
A holder 230 according to the present embodiment is shown in FIG. 7A is a plan view of the holder 230, FIG. 7B is a front view of the holder 230, FIG. 7C is a bottom view of the holder 230, and FIG. 7D is a DD line shown in FIG. 7A. FIG.

  The holder 230 has a through hole 231. Except for the through hole 231, the holder 230 is configured in the same manner as the holder 130. The same components as those of the holder 130 are denoted by the same reference numerals, and the description thereof is omitted.

  The through hole 231 includes an incident surface 236 that gradually expands from the first opening 231a. The incident surface 236 is formed on the first opening 231 a side of the peripheral wall of the through hole 231. The incident surface 236 is formed on a surface where the distance from the central axis CA gradually increases from the position of the first opening 231a in the direction of the central axis CA toward the second opening 131b. For this reason, the diameter of the first opening 231a is slightly smaller than the diameter of the second opening 131b. Note that the generatrix of the incident surface 236 may be a straight line. The inclination angle of the incident surface 236 that is a curved surface is an angle of the tangent line of the incident surface 236 with respect to the central axis CA.

  FIG. 8 is an enlarged view of the area A shown in FIG. 7D. The length L1 of the incident surface 236 in the central axis CA direction is shorter than the length L2 of the first inclined surface 132 in the central axis CA direction.

  FIG. 9 is a diagram illustrating an optical path of light in a holder having an incident surface 236. Here, a description will be given using the holder 630 for comparison. The holder 630 is configured in the same manner as the comparative holder 530 except for the through hole 231.

  Light emitted at a large angle with respect to the central axis CA of the holder 630 enters the holder 630 from the incident surface 236. The light incident on the holder 630 is slightly refracted to one end side of the holder 630 at the incident surface 236. Part of the light incident from the incident surface 236 reaches the outer peripheral surface of the holder 630 directly. The remainder of the incident light from the incident surface 236 reaches the annular end surface on the first opening 231a side, is totally reflected by the end surface, and reaches the outer peripheral surface.

  Incident light from the incident surface 236 is slightly refracted by the incident surface 236 toward the first opening 231a. For this reason, the light that directly reaches the outer peripheral surface from the incident surface 236 reaches a portion closer to the first opening 231a than the case where the incident surface 236 is not formed (see FIG. 4B). In addition, the light that enters from the incident surface 236 and reaches the outer peripheral surface after being totally reflected by the annular end surface is reflected at a large reflection angle because the incident angle with respect to the end surface is large, and again the first opening of the outer peripheral surface. A portion close to the portion 231a is reached.

  Thus, light incident on the holder 630 from the incident surface 236 has a region closer to the first opening 231a in the holder in the direction of the central axis CA than the holder 530 for comparison and the holder 130 according to the first embodiment. pass. Therefore, in the holder 230 according to the present embodiment, light can easily reach the first inclined surface 132 as compared with the holder 130. This effect is further enhanced by the fact that the length L1 of the incident surface 236 in the central axis CA direction is shorter than the length L2 of the inclined surface 132.

  As described above, the holder 230 according to the present embodiment can cause the emitted light having a larger angle with respect to the optical axis LA from the light emitting element 110 to reach the first inclined surface 132 more than the holder 130. it can. Therefore, the illuminating device to which the holder 230 is attached has the effects of the first embodiment described above, and is more effective from the viewpoint of suppressing the formation of a dark portion at the end of the cover 150. Further, the entrance surface 236 restricts the entry of the light guide rod 140 from the second opening 131b side. For this reason, the holder 230 is more effective from the viewpoint of easily determining the insertion position of the light guide rod 140. The light guide rod 140 may not be inserted up to the incident surface 236. In this case, the incident surface on which the light emitted from the light emitting element 110 is incident on the holder 230 is a part of the inner peripheral wall surface of the straight body portion connected to the incident surface 236 and the through hole 231 (from the incident surface 236 to the light guide rod 140. Part to the end). In this case, the range of the incident surface can be adjusted by inserting the light guide rod 140.

(Embodiment 3)
A holder 330 according to the present embodiment is shown in FIG. 10A is a plan view of the holder 330, FIG. 10B is a front view of the holder 330, FIG. 10C is a bottom view of the holder 330, and FIG. 10D is a DD line shown in FIG. 10A. FIG.

  The holder 330 is configured in the same manner as the holder 230 except that it has a second inclined surface 334 instead of the outer peripheral surface 134 and the second end surface 135. The same components as those of the holder 230 are denoted by the same reference numerals, and the description thereof is omitted. The second inclined surface 334 is connected to the other end side of the first inclined surface 132 in the central axis CA direction. The second inclined surface 334 is configured by a surface in which the distance from the central axis CA gradually decreases toward the second opening 131b in the central axis CA direction. The bus line of the second inclined surface 334 may be a straight line or a curved line. When the second inclined surface 334 is a curved surface, the inclination angle of the second inclined surface 334 is an angle of the tangent line of the second inclined surface 334 with respect to the central axis CA.

  FIG. 11 is a diagram illustrating an optical path of light in the holder having the second inclined surface 334. Here, in order to show the optical path more simply, a description will be given using the holder 730. The holder 730 is configured in the same manner as the holder 330 according to the present embodiment except that it does not have the incident surface 236, and is included in one embodiment of the present invention.

  Light emitted at a large angle with respect to the central axis CA of the holder 730 enters the holder 730 from the peripheral wall of the through hole 131. The light incident on the holder 730 reaches the first inclined surface 132, is totally reflected, and reaches the second inclined surface 334. The incident angle of the light reaching the second inclined surface 334 with respect to the second inclined surface 334 is sufficiently small. Therefore, although the light that has reached the second inclined surface 334 is slightly refracted by the second inclined surface 334, the light travels substantially straight and is emitted outward.

  As described above, the second inclined surface 334 emits light having the traveling direction of the light totally reflected by the first inclined surface 132 maintained substantially outward. Therefore, in each of the holders 330 and 730 according to the embodiment of the present invention, the light emitted from the holder 330 or 730 is emitted depending on conditions such as the angle, shape, and size of the first inclined surface 132 with respect to the central axis CA. The angle can be controlled. Therefore, the holders 330 and 730 can more easily control the emission angle of the emitted light than the holders 130 and 230. Further, in consideration of the refractive index of the holder 330 or 730, adjusting the direction of the emitted light from the second inclined surface 334 according to conditions such as the angle, shape, size, etc. with respect to the central axis CA of the second inclined surface 334, The outgoing angle of the outgoing light from the holder 330 or 730 can be controlled more precisely. Furthermore, the holder 330 or 730 can suppress reflection of light on the exit surface more than the holder 130 and the holder 230, and is more effective from the viewpoint of increasing the amount of emitted light. In addition, since the holder 330 has all of the incident surface 236, the first inclined surface 132, and the second inclined surface 334, the illumination device to which the holder 330 according to the present embodiment is mounted is the implementation described above. The effects of Embodiment 1 and Embodiment 2 are achieved, and in addition, it is even more effective from the viewpoint of suppressing formation of a dark portion on one end side of the cover 150.

(Embodiment 4)
A lighting device according to this embodiment is shown in FIG. FIG. 12A is a partial cross-sectional view of lighting apparatus 200 according to Embodiment 4 of the present invention. FIG. 12B is an enlarged view of region B shown in FIG. 12A. FIG. 13 is a perspective view showing a state in which the cover of the lighting device 200 is removed.

  Lighting device 200 according to the present embodiment includes light emitting element 110, substrate 225, heat sinks 220 and 260, holder 430, light guide rod 140, and cover 250. The same components as those of the lighting device 100 are denoted by the same reference numerals, and description thereof is omitted.

  The substrate 225 is formed in a substantially hexagonal flat plate in which each hexagonal top is cut out in a substantially circular shape. The substrate 225 is configured in the same manner as the substrate 125 except that its planar shape is different.

  The heat sink 220 is disposed at both ends of the lighting device 200, and the heat sink 260 is disposed at the bottom of the lighting device 200 along the longitudinal direction of the lighting device 200 (the optical axis LA direction). The heat sink 260 is fixed to the heat sink 220 with screws 270. Both the heat sinks 220 and 260 have a function of cooling the light emitting element 110. A circuit for connecting the light emitting element 110 and an external power supply circuit is formed in the heat sink 220. On the upper surface of the heat sink 260, for example, a member having a high light scattering property such as a prism may be disposed on the surface facing the light guide rod 140. The heat sinks 220 and 260 are manufactured using, for example, a metal having high thermal conductivity such as aluminum or copper.

  Holder 430 according to the present embodiment is fixed to heat sink 260 with screws 270. The holder 430 will be described in detail later.

  For example, the cover 250 is formed in a substantially cylindrical body that lacks a part of the circumferential wall of the cylinder in the circumferential direction over the entire length of the cylinder. The cover 250 is attached to the heat sink 260 by, for example, fitting the side edge of the cover 250 into a groove on the side edge of the heat sink 260. The cover 250 covers the outer peripheral surface of the light guide rod 140 away from the light guide rod 140. The cover 250 is configured in the same manner as the cover 150 except that its shape is different.

  FIG. 14 is a perspective view of the holder 430. 15A is a plan view of the holder 430, FIG. 15B is a front view of the holder 430, FIG. 15C is a rear view of the holder 430, FIG. 15D is a side view of the holder 430, and FIG. It is sectional drawing of the EE line shown in FIG. 15A.

  The holder 430 includes a pedestal 431 and a holder main body 432. The base 431 is formed in a substantially rectangular parallelepiped shape in which each side of a rectangular parallelepiped member is chamfered. A screw hole 433 is formed in the base 431. The pedestal 431 is formed so as to fit into a recess formed by the heat sinks 220 and 260 at a position where the holder main body 432 contacts the substrate 225. The screw hole 433 is formed at a position where the screw 270 is screwed when the pedestal 431 is fitted in the recess. As described above, the holder 430 is easily positioned and fixed with respect to the substrate 225 and the light emitting element 110 by the pedestal 431.

  The holder main body 432 has a through hole 434 having a circular cross-sectional shape at the center. The through hole 434 has a first opening 434a on one end side and a second opening 434b on the other end side. Around the through-hole 434, an arch-shaped (inverted U-shaped) first inclined surface 435 and a second inclined surface 436 are formed when the holder body 432 is viewed in plan. The first inclined surface 435 is configured by a surface whose distance from the central axis CA gradually increases from the periphery of the first end surface 133 surrounding the first opening 434a of the through hole 434 toward the second opening 434b. The second inclined surface 436 is connected to a portion on the second opening 434b side in the direction of the central axis CA of the first inclined surface 435, and is a surface whose distance from the central axis CA gradually decreases toward the second opening 434b side. It is configured. Each of the first inclined surface 435 and the second inclined surface 436 is formed in a semi-annular shape above the central axis CA when the holder body 432 is up and the pedestal 431 is down. It has rotational symmetry with CA as the rotation axis. Below the central axis CA, the first inclined surface 435 and the second inclined surface 436 are both formed to extend vertically downward.

  An incident surface 437 is formed inside the through hole 434. The incident surface 437 is configured in the same manner as the incident surface 236 in the above-described embodiment, except that a protrusion 438 is formed in the lower portion thereof. The ridge 438 is formed on the upper surface of the pedestal 431 so as to extend in a direction crossing the first opening 434a. The height of the ridges 438 is such that the light emitted from the light emitting element 110 is not substantially blocked (for example, about 1 mm). In the direction of the central axis CA, the length of the first inclined surface 435 is the longest, the thickness of the ridge 438 is then long, and the length of the incident surface 437 is the shortest.

  The end face of the light guide rod 140 inserted from the second opening 434b comes into contact with the ridge 438. The light guide rod 140 is held by the holder 430 at a position that does not contact the light emitting element 110 and does not contact the incident surface 437. Since the light guide rod 140 does not come into contact with the incident surface 437, the light condensing effect on the first inclined surface 435 by the incident surface 437 is sufficiently obtained. Thus, the light guide rod 140 is easily disposed at a more preferable position by the ridges 438.

  Light emitted from the light emitting element 110 at a large angle with respect to the optical axis LA enters the holder 430 from the incident surface 437, is totally reflected by the first inclined surface 435, and is reflected by the first inclined surface 435. The light is emitted outward from the second inclined surface 436 in a state where the property is substantially maintained. Then, it reaches the end of the cover 250. Since the illuminating device 200 includes the heat sink 260, the functions of light collection and emission by the holder 430 need only be expressed with respect to light directed upward and laterally in FIG. 12A. Therefore, the illumination device 200 can sufficiently widen the effective light emitting area by the holder 430 according to the present embodiment, and can make the luminance of the effective light emitting area more uniform. As described above, the positions and ranges of the first inclined surface 435 (total reflection surface) and the second inclined surface 436 (outgoing surface) in the circumferential direction are appropriately set according to the structure of the lighting device to which the holder is to be attached. It is possible. When the total reflection surface and the emission surface do not need to be provided over the entire circumference, the structure such as the base 431 and the screw hole 433 that facilitates the positioning of the holder or the holder such as the protrusion 438 is guided. A structure that facilitates positioning of the optical rod can be employed.

  Using the lighting device 200 according to Embodiment 4, the brightness of the cover was measured along the optical axis LA direction. The illumination device used in this embodiment is hereinafter referred to as “E1 illumination device”. As the holder, a holder having an incident surface, a first inclined surface, a second inclined surface, and a pedestal as shown in FIG. 15 was used. This holder is hereinafter referred to as “E1 holder”. The E1 holder is formed of transparent polycarbonate. The E1 holder is designed so that when the light emitting element is surrounded by the first opening of the E1 holder, light of 75 to 90 ° with respect to the optical axis LA of the light emitted from the light emitting element reaches the incident surface. Has been. The inner diameter of the through hole of the E1 holder is 8.1 mm. The angle of the first inclined surface with respect to the central axis of the E1 holder is 67 °. The angle of the second inclined surface with respect to the central axis of the E1 holder is 57 °.

  A substantially cylindrical light guide rod having an outer diameter of 8 mm was used as the light guide member. The end portion of the light guide rod is formed in a D-cut shape in accordance with the shape of the through hole and the base of the E1 holder. The D-cut shape refers to a shape in which the portion of the light guide rod in contact with the surface of the pedestal is formed in a straight line and the rest is formed in an arc in the cross-sectional shape of the light guide rod. The length between the D-cut shape portions of the light guide rod is about 580 mm. FIG. 16 shows the light distribution characteristics of the light guide rod when light is emitted only from the light emitting element on one end side of the light guide rod. In FIG. 16, “E” represents a relative value of illuminance on a surface at a distance of 1 m from the center of the outer peripheral surface of the light guide rod. “Θ” represents an angle with respect to the normal line of the outer peripheral surface of the light guide rod. The 90 ° point and the −90 ° point are located on the optical axis LA. The light emitting element is disposed at the end on the −90 ° side. As shown in FIG. 16, the light guide rod mainly emits light having a light distribution characteristic of 50 to 60 ° with respect to the normal line (30 to 40 ° with respect to the optical axis LA).

The brightness of the cover of the E1 lighting device equipped with the E1 holder and the light guide rod was measured. FIG. 17A is a diagram illustrating the brightness of the cover when light is emitted from only one of the light emitting elements A arranged at both ends of the E1 lighting device, and FIG. 17B is a diagram illustrating both ends of the E1 lighting device. It is a figure which shows the brightness | luminance of a cover when light is radiate | emitted from both the light emitting element A and the light emitting element B which were arrange | positioned. In FIG. 17, “L” represents a relative value of luminance. “P ₁ ” and “P ₂ ” respectively represent the measurement positions of the luminance in the cover. “P ₁ ” represents the end of the cover on the light emitting element A side, and “P ₂ ” represents the end of the cover on the light emitting element B side. As shown in FIG. 17A, light is emitted from the light guide rod to a certain degree of brightness up to a position that is about half the length of the light guide rod. Around more than half, the light emitted from the light guide rod is rapidly attenuated. Moreover, as shown in FIG. 17B, when light is incident on the light guide rod from both end faces of the light guide rod, uniform brightness can be obtained over almost the entire length of the cover.

  On the other hand, a comparative illumination device (hereinafter, this illumination device is also referred to as “C1 illumination device”) equipped with a comparative holder (hereinafter, this holder is also referred to as “C1 holder”) and the light guide rod is prepared. Then, the brightness of the cover was measured. FIG. 18A is a diagram schematically showing a cross-sectional shape of a portion of the C1 holder having rotational symmetry with the central axis as a rotation axis. In the rotationally symmetrical portion of the C1 holder, the end surface on the first opening side of the C1 holder is a substantially annular plane that does not include the inclined surface 132, and the first opening side of the through hole is the second opening. The holder 130 according to the first embodiment is different from the holder 130 according to the first embodiment in that it is a small diameter portion of a straight body having a smaller cross-sectional shape than the opening shape of the portion. The opening shape of the small-diameter portion is the same as the opening shape of the first opening portion of the through hole of the E1 holder, and the length of the small-diameter portion is the same as the length of the incident surface of the E1 holder.

FIG. 18B is a diagram illustrating a relative value of the luminance of the cover when light is emitted from only one of the light emitting elements A arranged at both ends of the C1 lighting device. Similarly to FIG. 17A, light is emitted from the light guide rod to a certain degree of brightness up to a position about half the length of the light guide rod, and the light emitted from the light guide rod abruptly exceeds this position. It is decaying. Furthermore, the C1 lighting device, of the cover, in the region A from P ₁ to the position of the peak of luminance, the luminance is lower at the end of the light emitting element side. Such a low luminance part is recognized as a dark part. In the C1 lighting device, the length of the region A is, for example, about 10 to 40 mm.

FIG. 19 shows the relative value of the luminance of the cover of the E1 lighting device and the relative value of the luminance of the cover of the C1 lighting device. In FIG. 19, the solid line represents the luminance of the cover of the E1 lighting device, and the broken line represents the luminance of the cover of the C1 lighting device. The measurement position on the horizontal axis in FIG. 19 is half of that in FIGS. 17 and 18. That is, in FIG. 19, “P _1.5 ” represents a position that is approximately half the length of the light guide rod (a position that is approximately 280 mm from one end face of the light guide rod). FIG. 19A is a diagram illustrating relative values of the luminance of the covers of the E1 lighting device and the C1 lighting device when light is emitted from only one of the light emitting devices A, and FIG. It is a figure which shows the relative value of the brightness | luminance of the cover of E1 illumination device and C1 illumination device when light is radiate | emitted from both.

  As illustrated in FIG. 19A, in the E1 lighting device, a decrease in luminance at the end of the cover on the light emitting element side is suppressed with respect to one light emitting device, as compared with the C1 lighting device. Further, in the E1 lighting device, a decrease in luminance at the center portion of the cover is suppressed as compared with the C1 lighting device. For this reason, as shown in FIG. 19B, the E1 lighting device emits light from the cover with a substantially constant luminance in the region from the end of the cover to the center when light is incident from both ends of the light guide rod. Exit. On the other hand, in the C1 lighting device, the brightness is relatively low at the end and the center of the cover, and uneven brightness occurs in the longitudinal direction of the cover. Thus, according to the E1 illuminating device to which the E1 holder is mounted, the entire area of the cover can be made an effective light emitting area with uniform luminance.

  Since the lighting device of the present invention can be used in place of a fluorescent tube or the like, it can be widely applied to various lighting devices.

DESCRIPTION OF SYMBOLS 10,100,200 Illuminating device 12 Light emission part 14 Light guide member 16,150,250 Cover 18 Support part 110 Light emitting element 120,220,260 Heat sink 125,225 Board | substrate 130,230,330,430,530,630,730 Holder 131, 231 and 434 Through-holes 131a, 231a and 434a First opening 131b and 434b Second opening 132 and 435 First inclined surface 133 First end surface 134 Outer peripheral surface 135 Second end surface 136, 236 and 437 Incident surface 140 Conduction Optical rod 270 Screw 334, 436 Second inclined surface 431 Base 432 Holder body 433 Screw hole 438 Convex CA Central axis LA Optical axis

Claims (6)

A holder having a light transmission property for holding the light guide member with respect to the light emitting element in a lighting device having a light emitting element and a light guide member,
A first recess having a first opening of a size surrounding the light emitting element; a second recess having a second opening into which the light guide member is to be inserted;
The peripheral wall of the first recess and the second recess is formed in a portion on the first opening side than the position of the end surface of the light guide member when the light guide member is inserted into the second recess, An incident surface that is configured by at least a part of a rotationally symmetric surface with a central axis of the first concave portion and the second concave portion as a rotation axis, and that makes outgoing light from the light emitting element incident on the holder;
The first concave portion and the second concave portion are formed on the outer side in the circumferential direction, and are at least part of a rotationally symmetric surface having the central axis as a rotational axis, the first opening in the central axis direction A total reflection surface that is configured by a surface whose distance from the central axis gradually increases from the position toward the second opening, and totally reflects light that has arrived from the incident surface;
Consists of at least a part of a rotationally symmetric surface having the central axis as a rotation axis on the second opening side in the central axis direction from the total reflection surface, and emits light reaching the total reflection surface to the outside An exit surface to be
A holder having   The holder according to claim 1, wherein the first recess and the second recess communicate with each other to form a through hole. The incident surface includes a surface where the distance from the central axis gradually increases from the position of the first opening in the central axis direction toward the second opening.
The holder according to claim 1 or 2. The length of the incident surface in the central axis direction is shorter than the length of the total reflection surface in the central axis direction,
The holder as described in any one of Claims 1-3. The emission surface is configured by a surface in which the distance from the central axis gradually decreases toward the second opening in the central axis direction.
The holder as described in any one of Claims 1-4. At least one light emitting element;
A light guide member;
The holder according to any one of claims 1 to 4, which holds the light guide member with respect to the light emitting element,
A cover that diffuses and transmits the light emitted from the holder and the light guide member;
A lighting device.

Images