JP2024037363A - Optical components and lighting devices - Google Patents

Abstract

[Problem] To provide an optical member and lighting device capable of reducing unevenness in brightness. [Solution] An optical member (20) comprising a refracting section (21) that refracts light, and a reflecting section (22) having protrusions (23) arranged on both sides of the refracting section (21), the protrusions (23) comprising light reflection adjustment sections (24) that adjust the reflection of light incident on the protrusions (23). [Selected Figure] Figure 1

Description

The present invention relates to an optical member and a lighting device.

2. Description of the Related Art Conventionally, a light source device using a lens that utilizes total internal reflection, a so-called TIR lens, is known. A TIR lens includes a refracting section located in the center and a reflecting section located around the refracting section. For example, Patent Document 1 is known as a document disclosing a light source device using a TIR lens.

The optical unit (light source device) disclosed in Patent Document 1 includes a plurality of light sources (light emitting elements), a plurality of optical means (TIR lenses) each having a function of a collimating lens arranged on the plurality of light sources, and a plurality of optical means. It includes a plurality of lens arrays arranged on the exit surface side of the lens, forming a plurality of different light distribution patterns. The optical unit disclosed in Patent Document 1 is mainly used as a vehicle lamp.

The light source device as described above may be used, for example, as a lighting device (backlight) of a head-up display (hereinafter sometimes referred to as "HUD") mounted on a vehicle or the like. A light source device used in a HUD is particularly required to be bright and without unevenness, that is, to have high brightness and a uniform brightness distribution. In other words, it is required that the luminous flux is used efficiently and that the light distribution is appropriate. The above-mentioned TIR lens can condense the light emitted from the light emitting element that has a large angle (directivity angle) with the emission axis and spreads outward, so it may be used as an optical means suitable for this purpose. many.

Japanese Patent Application Publication No. 2021-189306

However, in conventional TIR lenses, the light that enters the refracting section is focused with positive optical power, and the light that enters the reflecting section uses total internal reflection on the inclined reflective surface. However, it was difficult to ensure the amount of light emitted at the boundary between the refracting section and the reflecting section. When such a TIR lens is used as an optical member, there is a problem in that brightness unevenness occurs at the boundary between the refracting section and the reflecting section, making it difficult to display a good image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above conventional problems, and an object of the present invention is to provide an optical member and a lighting device that can reduce uneven brightness.

In order to solve the above problems, an optical member of the present invention includes a refracting section that refracts light, and a reflecting section that has protrusions arranged on both sides of the refracting section, and the protruding section is arranged on both sides of the refracting section. It is characterized by comprising a light reflection adjustment section that adjusts reflection of light incident on the section.

In such an optical member of the present invention, it is possible to adjust the light incident on the protruding part with the light reflection adjusting part, improve the amount of light at the boundary between the refracting part and the reflecting part, and reduce uneven brightness.

Further, in one aspect of the present invention, the light reflection adjusting section is a slope changing section that changes the slope of the reflecting section.

Further, in one aspect of the present invention, the slope changing portion extends closer to the bending portion than the inner wall of the protruding portion to form a claw-like portion.

Further, in one aspect of the present invention, the inner surface of the claw-like portion is inclined at an angle that totally reflects the light.

Further, in one aspect of the present invention, the refracting section and the reflecting section are formed to extend in a uniaxial direction, and the light reflection adjusting section has a periodic uneven shape along the uniaxial direction.

Further, in one aspect of the present invention, the uneven shape includes a plurality of predetermined conical shapes arranged along the uniaxial direction, and a region where the conical shape and the reflective surface intersect.

Further, in one aspect of the present invention, the conical shape has an apex angle of 100 degrees or more.

Moreover, in order to solve the above-mentioned problem, the illumination device of the present invention is characterized by having the optical member described in any one of the above, and a light emitting element disposed on the light incident side of the refraction part and the protrusion part. shall be.

The present invention can provide an optical member and a lighting device that can reduce uneven brightness.

FIG. 1(a) is a schematic cross-sectional view illustrating an overview of an optical member 20 and a lighting device 100 according to a first embodiment, and FIG. 1(b) shows a virtual TIR. showing the lens. 2A is a diagram schematically explaining a light path in the illumination device 100, FIG. 2A shows a light path in the optical member 20 and the illumination device 100 of the first embodiment, and FIG. 2B shows a virtual It shows the path of light through a typical TIR lens. 3A is a schematic diagram illustrating the illuminance distribution of light irradiation using the optical member 20, FIG. 3(a) shows the illuminance distribution in the optical member 20 of the first embodiment, and FIG. 3(b) shows a virtual TIR It shows the illuminance distribution on the lens. 4(a) is a cross-sectional view in the width direction, and FIG. 4(b) is a cross-sectional view in the longitudinal direction. FIG. It shows. 3 is a schematic perspective view showing the structure of an optical member 30. FIG. FIG. 3 is a schematic diagram illustrating a concavo-convex shape 34 of an optical member 30. FIG. It is a table showing the relationship between the apex angle 2θ of a virtual conical shape forming the uneven shape 34 and the illuminance distribution. FIG. 7 is a schematic perspective view showing the structure of an optical member 40 according to a third embodiment. FIG. 7 is a schematic cross-sectional view illustrating an overview of an optical member 40 and a lighting device 200 according to a modification of the third embodiment. FIG. 7 is a schematic diagram illustrating improvement in heat dissipation by convection in an optical member 40 according to a fourth embodiment.

(First embodiment)
Embodiments of the present invention will be described in detail below with reference to the drawings. Identical or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. FIG. 1 is a schematic cross-sectional view illustrating an overview of an optical member 20 and a lighting device 100 according to this embodiment, and FIG. 1(a) shows the lighting device 100 of this embodiment, and FIG. 1(b) is a virtual It shows a typical TIR lens. As shown in FIG. 1(a), the lighting device 100 includes a light emitting element 10 and an optical member 20.

The light emitting element 10 is an electronic component that is mounted on a mounting board (not shown) on which wiring is formed, and emits light in a predetermined color when a current is supplied by a drive circuit. A plurality of light emitting elements 10 are arranged along a direction perpendicular to the paper surface. Although the specific structure of the light emitting element 10 is not limited, it may be an LED package that combines a light emitting diode (LED) that emits primary light and a wavelength conversion member that converts a part of the primary light into secondary light. can be used. Further, the material of the light emitting diode is not limited either, and known materials and structures can be used. As an example, a GaN-based LED that emits blue light can be used. Further, the material of the wavelength conversion member is not limited, and for example, a YAG-based phosphor material that emits yellow light when excited by blue light can be used. Note that in this embodiment, the number of light emitting elements 10 arranged is one row, but it may be two or more rows. Further, the light emitting element 10 is not limited to an LED, but may be a semiconductor laser or the like.

The optical member 20 is a member into which the light emitted by the light emitting element 10 enters, refracts and reflects the light, and irradiates the light in a predetermined direction. As shown in FIG. 1, the optical member 20 includes a refracting section 21 and a reflecting section 22, and the reflecting section 22 is further provided with a protruding section 23 and a slope changing section 24. Further, the optical member 20 is formed such that each part of the cross-sectional shape shown in FIG. 1 extends in a direction perpendicular to the plane of the paper, and constitutes a uniaxial TIR (Total Internal Reflection) lens. As shown in FIG. 1, in the optical member 20, the refracting section 21, the reflecting section 22, the protruding section 23, and the slope changing section 24 are integrally formed of the same material.

The refracting section 21 is arranged near the center of the optical member 20 and is a section that refracts and transmits incident light. On the side of the refraction section 21 facing the light emitting element 10, a curved refraction section entrance surface 21a is provided. Although the shape of the refracting portion entrance surface 21a is not limited, it is preferably in the shape of a convex lens in order to bring the magnified light incident from the light emitting element 10 closer to parallel light. As shown in FIG. 1, the refracting portion entrance surface 21a is formed as a recessed portion surrounded by the reflecting portion 22 and located at the center of the reflecting portion 22. As shown in FIG. Therefore, a part of the light emitted from the light emitting element 10 is refracted at the refraction section entrance surface 21a due to the difference in refractive index between the refraction section 21 and air, passes through the refraction section 21, and is emitted from the light exit surface.

The reflecting section 22 is arranged on both sides of the refracting section 21 and is a section that reflects and irradiates incident light. A portion of the reflecting portion 22 that extends further toward the light emitting element 10 (downward in the figure) than the refracting portion 21 serves as a protruding portion 23 . The outer surface of the reflecting portion 22 is a reflecting surface 22a that is inclined at a predetermined angle with respect to the light exit surface.

The protruding portion 23 is a portion of the reflecting portion 22 that protrudes in the direction of the light emitting element 10 than the refracting portion 21 and extends by a height h, and a portion of its tip forms a slope changing portion 24 . The tip of the protruding part 23 is bent inward, and the inclination changing part 24 is extended to the bending part 21 side from the inner wall of the protruding part 23 to form a claw-like part. As will be described later, the inclination changing section 24 corresponds to the light reflection adjusting section of the present invention. The optical member 20 can be formed by pouring a resin material such as silicone into a mold using an injection molding technique or the like, and removing the resin material from the mold after the material hardens. At this time, the slope change part 24 is bent inward from the protrusion 23, but since the thickness of the slope change part 24 is small, the slope change part 24 is elastically deformed and can be removed from the mold.

The outer surfaces of the protruding portion 23 and the slope changing portion 24 are reflective surfaces 23a and 24a, respectively. The reflective surface 23a is a surface formed continuously from the reflective surface 22a, and is inclined at the same angle as the reflective surface 22a with respect to the light exit surface. The reflective surface 24a is inclined at a different angle from the reflective surfaces 22a and 23a with respect to the light exit surface. Further, in a plan view when the light emitting element 10 is viewed from the upper light exit surface side in FIG. 1, the protrusion entrance surface 23b is included within the range of the reflective surface 24a.

The inner surfaces of the protruding portion 23 and the slope changing portion 24 serve as a protruding portion entrance surface 23b and a slope changing portion entrance surface 24b, respectively. The protruding part entrance surface 23b is an inner wall surface formed by extending in the direction of the light emitting element 10 from the boundary between the refracting part 21 and the reflecting part 22, and a part of the light irradiated from the light emitting element 10 is transmitted to the reflecting part 22 and the protruding part. This is the part where the light enters the part 23. The slope-changing portion entrance surface 24b is an inner surface (inner surface) extending from the tip of the protruding portion entrance surface 23b, and is a portion through which a part of the light emitted from the light emitting element 10 enters the slope-changing portion 24. It is.

FIG. 1(b) assumes that in the optical member 20 shown in FIG. 1(a), the reflective surface 23a of the protruding portion 23 and the protruding portion entrance surface 23b are extended as they are without providing the slope changing portion 24. A virtual TIR lens is shown. If the virtual height of the protrusion 23 in the case where the slope change part 24 is not provided is L, then the height h of the protrusion 23 in the example shown in FIG. 1(a) satisfies L>h. Further, the height h of the protrusion 23 is preferably at least half of the virtual height L, more preferably at least ⅔. If the height h is smaller than these ranges, the area of the protrusion entrance surface 23b will become smaller and the amount of light reflected by the reflecting surfaces 22a and 23a will decrease, which is not preferable.

FIG. 2 is a diagram schematically explaining a light path in the illumination device 100, and FIG. 2(a) shows a light path in the optical member 20 and the illumination device 100 of this embodiment, and FIG. ) shows the path of light in a virtual TIR lens. The inclination angles of the reflective surfaces 22a, 23a, and 24a are such that the light from the light emitting element 10 reaches a critical angle or more due to the difference in refractive index between the reflective portion 22 and air and is totally reflected.

As shown in FIG. 2(a), a part of the light emitted from the light emitting element 10 enters the protrusion 23 from the protrusion entrance surface 23b, is totally reflected by the reflection surfaces 22a and 23a, and is completely reflected by the light exit surface. irradiated to the outside. Further, a part of the light emitted from the light emitting element 10 enters the slope change part 24 from the slope change part entrance surface 24b, is totally reflected by the reflection surface 24a, and is irradiated to the outside from the light output surface. Further, a part of the light emitted from the light emitting element 10 enters the refraction section 21, is refracted, and is emitted to the outside from the light exit surface. Further, the slope change portion entrance surface 24b is inclined at a predetermined angle with respect to the light exit surface, and a portion of the light that reaches the surface is reflected.

As shown in FIG. 2(b), in a hypothetical TIR lens without the slope change portion 24, the light incident obliquely on the protrusion 23 from the protrusion entrance surface 23b is totally reflected on the reflection surfaces 22a and 23a. be done. At this time, the light that travels from the light emitting element 10 in a substantially horizontal direction and reaches the reflective surface 23a has a small incident angle with respect to the reflective surface 23a, and the light that has reached the reflective surface 23a becomes smaller, and the light reaches the protrusion entrance surface 23b, which is the boundary between the refracting section 21 and the reflective section 22. In the vicinity, it is transmitted without being totally reflected.

However, in the optical member 20 of this embodiment shown in FIG. 2(a), the inclination changing part 24 is provided at the tip of the protrusion 23, and the inclination angle of the reflective surface 24a is different from that of the reflective surface 23a. , the angle of inclination with respect to the light exit surface is increased. Therefore, the light that has reached the reflective surface 24a has a large incident angle with respect to the reflective surface 24a, and even the light that has proceeded substantially laterally from the light emitting element 10 can be fully reflected. Further, the reflective surface 24a of the slope changing portion 24 overlaps with the protrusion entrance surface 23b when viewed from above, and the light reflected by the reflective surface 24a is irradiated to the outside from near the boundary between the refracting portion 21 and the reflective portion 22. . Therefore, the slope changing section 24 has a function of adjusting the reflection of light incident on the protruding section 23, and corresponds to the light reflection adjusting section in the present invention.

FIG. 3 is a schematic diagram illustrating the illuminance distribution of light irradiation using the optical member 20. FIG. 3(a) shows the illuminance distribution in the optical member 20 of this embodiment, and FIG. It shows the illuminance distribution with a typical TIR lens. White in the figure indicates areas with high illuminance, and black in the figure indicates areas with low illuminance. In a hypothetical TIR lens without the tilt changing part 24, as shown in FIG. (distribution) becomes uneven. On the other hand, in the optical member 20 of the present embodiment, the light reflected by the reflective surface 24a of the tilt changing section 24 is irradiated near the boundary between the refracting section 21 and the reflecting section 22. As a result, as shown in FIG. 3A, the amount of light to the boundary area between the central refracting section 21 and the reflecting sections 22 on both sides increases, and unevenness in the illuminance distribution (brightness distribution) can be suppressed.

In this embodiment, a case of a uniaxial TIR lens is shown in which the cross-sectional shape shown in FIG. 1 is formed by extending perpendicularly to the paper surface direction, but the cross-sectional shape shown in FIG. 1 is rotated around the central axis. It may also be a TIR lens.

As described above, in the optical member 20 and the illumination device 100 of the present embodiment, the light incident on the protrusion 23 is adjusted by the slope changing part 24 corresponding to the light reflection adjustment part, and the boundary between the refraction part 21 and the reflection part 22 is adjusted. It becomes possible to improve the amount of light and reduce uneven brightness.

(Modified example of the first embodiment)
In the first embodiment, the inclination angle of the inclination change part entrance surface 24b, which is the inner surface of the inclination change part 24 (claw-shaped part), is an angle that totally reflects the light from the light emitting element 10, but the inclination change part entrance surface It may be tilted at an angle that causes total reflection of light incident on a predetermined area of 24b. In this case, it is possible to increase the amount of light irradiated to the outside from a predetermined region of the slope-changing portion entrance surface 24b, and it is possible to suppress uneven brightness in the region closer to the refracting portion 21 than the protrusion entrance surface 23b. .

(Second embodiment)
Next, a second embodiment of the present invention will be described using FIGS. 4 to 7. Description of contents that overlap with those of the first embodiment will be omitted. FIG. 4 is a schematic cross-sectional view explaining the outline of the optical member 30 and illumination device 200 according to the present embodiment, FIG. 4(a) shows a cross-sectional view in the width direction, and FIG. 4(b) shows a cross-sectional view in the longitudinal direction. A cross-sectional view is shown. FIG. 5 is a schematic perspective view showing the structure of the optical member 30. As shown in FIGS. 4A and 4B and FIG. 5, the lighting device 200 includes a light emitting element 10 and an optical member 30.

The optical member 30 includes a refracting section 31 and a reflecting section 32, and the reflecting section 32 is further provided with a protruding section 33. Further, the optical member 30 is formed by extending each part of the cross-sectional shape shown in FIG. 4(a) in a uniaxial direction as shown in FIG. 4(b), thereby forming a uniaxial TIR lens. The outer surfaces of the reflective portion 32 and the protruding portion 33 serve as reflective surfaces 32a and 33a, respectively. The reflective surfaces 32a and 33a are inclined at a predetermined angle with respect to the light exit surface. The inner surface of the protrusion 33 serves as a protrusion entrance surface 33b.

Further, as shown in FIG. 4(b) and FIG. 5, periodic notches are formed along the uniaxial direction at the tip of the protrusion 33, and a periodic uneven shape 34 is formed. There is. Furthermore, a gap d (d≧0) is provided between the tip of the protrusion 33 and the light emitting element 10 in the direction perpendicular to the light exit surface (vertical direction in FIG. 4).

The shape of the periodic uneven shape 34 will be explained in more detail. As shown in FIG. 4(b), the uneven shape 34 has a structure in which one notch is formed between a plurality of light emitting elements 10 arranged along a uniaxial direction. Although FIG. 4B shows an example in which a notch is formed in a curved shape as the uneven shape 34, the specific shapes of the notch and the uneven shape 34 are not limited, and even if the notch is linear, it may be a rectangular shape. It is also possible to cut out the shape. Further, although FIGS. 4 and 5 show an example in which one notch is formed between each light emitting element 10, a plurality of notches may be formed between adjacent light emitting elements 10.

FIG. 6 is a schematic diagram illustrating the uneven shape 34 of the optical member 30. FIG. 6 shows a hypothetical shape of the protrusion 33 in the case where the uneven shape 34 is not provided. With the center of the surface of the light emitting element 10 as the origin, the light emission direction (upward in the figure) is 0 degrees, and the angle formed with the 0 degree axis direction is θ. Therefore, the width direction (horizontal direction in the figure) of the optical member 30 is 90 degrees. When the solid line arrow shown in the angle θ direction in FIG. 6 is rotated around the 0 degree axis, the solid line arrow draws a virtual conical shape with the center of the surface of the light emitting element 10 as the apex. This virtual conical shape has an apex angle of 2θ.

The notch of the uneven shape 34 has a shape obtained by cutting the virtual protrusion 33 in the case where the uneven shape 34 is not provided at a plane that intersects with this virtual conical shape. As shown in FIG. 4(b), since a plurality of light emitting elements 10 are arranged along one axis, the uneven shape 34 is formed by arranging a plurality of virtual conical shapes along one axis. A virtual TIR lens is cut along a line where the reflective surfaces 32a and 33a intersect.

This virtual conical shape has its apex at the center of the surface of the light emitting element 10, and can be regarded as a light cone indicating the spread of light emitted from the light emitting element 10. By cutting out an uneven shape 34 at the tip of the protruding part 33 using a virtual conical shape assuming this light cone, light irradiated from the light emitting element 10 at an angle larger than the apex angle 2θ is transmitted to the reflecting part 32 and the protruding part 33. does not enter. Generally, the light distribution of the light emitting element 10 is a Lagrangian distribution with the maximum in the 0 degree direction, so the amount of light emitted in the lateral direction where θ is large is relatively small. Therefore, even if the concavo-convex shape 34 cut out in a virtual conical shape is provided, the influence of the amount of light that does not enter the optical member 30 is considered to be small.

FIG. 7 is a table showing the relationship between the apex angle 2θ of the virtual conical shape forming the uneven shape 34 and the illuminance distribution. The intake angle in the table indicates the inclination angle θ from the 0 degree axial direction, and indicates the case where the uneven shape 34 is cut out in a virtual conical shape with an apex angle of 2θ. Further, the illuminance distribution in the table indicates the illuminance distribution on the light exit surface of the optical member 30. Further, the relative luminous flux utilization rate in the table indicates the relative luminous flux utilization rate, with the case where the capture angle is 90 degrees being set as 100%. Here, when the intake angle is 90 degrees, since the apex angle 2θ is 180 degrees, there is no virtual conical shape, and the uneven shape 34 is not cut out.

As shown in FIG. 7, the relative luminous flux utilization rate exceeds 80% when the capture angle is 50 degrees or more, indicating that even if the uneven shape 34 is formed, a decrease in the illuminance distribution from the optical member 30 can be suppressed. In particular, when the capture angle is 60 degrees or more, the relative luminous flux utilization rate exceeds 90%, and when the capture angle is 65 degrees or more, the relative luminous flux utilization rate reaches 97.5%. Therefore, the virtual conical shape preferably has an apex angle 2θ of 100 degrees or more (θ is 50 degrees or more), more preferably 120 degrees or more, and still more preferably 130 degrees or more.

The tip of the protrusion 33 is thinner in the width direction and is more likely to be deformed by heat than other parts. When the tip of the protrusion 33 is deformed, unexpected refraction or reflection of light occurs when light enters the protrusion entrance surface 33b or is reflected by the reflection surface 33a, resulting in uneven brightness in the irradiated light. However, in the optical member 30 and illumination device 200 of this embodiment, since the uneven shape 34 is provided at the tip of the protrusion 33, the recessed space surrounded by the refracting part entrance surface 31a and the protrusion entrance surface 33b is It communicates with the external space via the notch of the uneven shape 34. Therefore, air flow is likely to occur between the inside of the recessed space and the external space via the notches of the uneven shape 34. Thereby, even if heat is generated due to light irradiation in the light emitting element 10, heat dissipation is improved due to air flow through the uneven shape 34, and deformation of the protrusion 33 due to temperature rise can be suppressed.

In the example shown in FIGS. 4 and 5, a gap d is provided between the tip of the protrusion 33 and the apex of a virtual conical shape, thereby forming the uneven shape 34. Therefore, the recessed space and the external space communicate with each other via the uneven shape 34 and the gap d, and air flow is more likely to occur, further improving heat dissipation.

As described above, in the optical member 30 and the illumination device 200 of this embodiment, it is possible to improve the heat dissipation from the recess space surrounded by the refracting part entrance surface 31a and the protrusion part entrance surface 33b via the uneven shape 34. , brightness unevenness due to thermal deformation of the protrusion 33 can be suppressed. Further, even if the protruding portion 33 is formed with the uneven shape 34, the light from the light emitting element 10 can be irradiated satisfactorily by setting the apex angle 2θ to 100 degrees or more.

(Third embodiment)
Next, a third embodiment of the present invention will be described using FIG. 8. Descriptions of contents that overlap with those of the second embodiment will be omitted. This embodiment differs from the second embodiment in that the apex position of the virtual conical shape is changed. FIG. 8 is a schematic perspective view showing the structure of the optical member 40 according to this embodiment. As shown in FIG. 8, the optical member 40 includes a refraction section 41 and a reflection section 42, and the reflection section 42 is further provided with a protrusion 43. Furthermore, an uneven shape 44 is formed at the tip of the protrusion 43 . The outer surfaces of the reflective portion 42 and the protruding portion 43 serve as reflective surfaces 42a and 43a, respectively. The inner surface of the protrusion 43 serves as a protrusion entrance surface 43b.

In this embodiment, the apex of the virtual conical shape is set at a position closer to the bending part 41 than the tip of the virtual protrusion 43 without the uneven shape 44. Moreover, the uneven shape 44 has a shape cut at a plane where a virtual conical shape with an apex angle of 2θ and a virtual protrusion 43 intersect. As shown in FIG. 8, in the optical member 40, the acute angle at which the reflection surface 43a and the projection entrance surface 43b intersect does not exist at the tip of the projection 43, and the surface cut out with the uneven shape 44 along the uniaxial direction is Continuous. At the acute angle portion where the reflective surface 43a and the protrusion entrance surface 43b intersect, the resin is thin and easily thermally deformed, but the continuous uneven shape 44 suppresses thermal deformation at the acute angle portion. Can be done.

In this embodiment as well, it is possible to improve the heat dissipation from the recessed space surrounded by the refracting part entrance surface 41a and the protruding part entrance surface 43b via the uneven shape 44, and to prevent uneven brightness due to thermal deformation of the protruding part 43. Can be suppressed. Further, even if the protruding portion 43 is formed with the uneven shape 44, the light from the light emitting element 10 can be irradiated satisfactorily by setting the apex angle 2θ to 100 degrees or more. Further, by locating the apex of the virtual conical shape at a position close to the refracting section 41, the optical member 40 can be made thinner and lighter.

(Modification of third embodiment)
FIG. 9 is a schematic cross-sectional view illustrating an overview of an optical member 40 and a lighting device 200 according to a modification of the third embodiment. A broken line extending obliquely from the surface of the light emitting element 10 indicates a virtual conical shape. In order to cut out the concavo-convex shape 34 from the protruding part 33 in a virtual conical shape, in this modification, the widths of the refracting part 41 and the refracting part entrance surface 41a are widened, and the gap d between the light emitting element 10 and the tip of the protruding part 43 is widened. is provided to make the recess space surrounded by the refracting part entrance surface 41a and the protruding part entrance surface 43b shallow.

In this modification, by widening the widths of the refracting section 41 and the refracting section entrance surface 41a, the optical member 40 can be further made thinner and lighter, and the size of the uneven shape 44 can be reduced. Thereby, the possibility of occurrence of molding defects can be suppressed in the concavo-convex shape 44 that requires complex and precise moldability. In particular, when the gap d is set to a predetermined value or more, there is no need to provide the uneven shape 44. Further, by reducing the height of the protrusion entrance surface 43b and increasing the width of the refracting portion 41, heat dissipation through the uneven shape 44 can be improved, and brightness unevenness due to thermal deformation can be suppressed.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described using FIG. 10. Description of contents that overlap with those of the first embodiment will be omitted. FIG. 10 is a schematic diagram illustrating improvement in heat dissipation by convection in the optical member 40 according to the fourth embodiment. The vertical direction in the figure indicates the direction of gravity, and the horizontal direction in the figure indicates the horizontal direction. Further, a recessed space 45 is formed surrounded by the refracting part entrance surface 41a and the protruding part entrance surface 43b, and a gap d is provided between the light emitting element 10 and the tip of the protruding part 43.

In the example shown in FIG. 10(a), the light emitting element 10 and the optical member 40 are arranged horizontally, and light is irradiated rightward in the figure. When the temperature of the optical member 40 increases due to light irradiation from the light emitting element 10, convection occurs and air flows from below to above the gap d. At this time, the air existing in the recessed space 45 is also affected by convection, flows out through the gap d, and heat is radiated.

In the example shown in FIG. 10(b), the light emitting element 10 and the optical member 40 are arranged diagonally downward, and light is irradiated in the lower right direction in the figure. In this case as well, when the temperature of the optical member 40 rises due to light irradiation from the light emitting element 10, convection occurs and air flows upward from below the gap d. At this time, the air existing in the recessed space 45 is also greatly affected by convection, flows out to the outside through the gap d, and heat is effectively radiated.

Also in the optical member 40 and illumination device 200 of this embodiment, the heat dissipation from the recessed space 45 can be improved through the gap d, and uneven brightness due to thermal deformation of the protrusion 43 can be suppressed.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. are also included within the technical scope of the present invention.

100,200...Lighting device 10...Light emitting element 20,30,40...Optical member 21,31,41...Refraction part 22,32,42...Reflection part 23,33,43...Protrusion part 24...Inclination change part 34,44 ...Uneven shape 45...Concave space 21a, 31a, 41a...Refraction part entrance surface 22a, 23a, 24a, 32a, 42a, 43a...Reflection surface 23b, 33b, 43b...Protrusion part entrance surface 24b...Inclination change part entrance surface

Claims (8)

a refracting section that refracts light;
a reflecting section having protrusions arranged on both sides of the refracting section;
The optical member is characterized in that the protrusion includes a light reflection adjusting section that adjusts reflection of light incident on the protrusion. The optical member according to claim 1,
The optical member is characterized in that the light reflection adjusting section is an inclination changing section in which the inclination of the reflecting section changes. The optical member according to claim 2,
The optical member is characterized in that the slope changing portion extends closer to the bending portion than the inner wall of the protruding portion to form a claw-like portion. The optical member according to claim 3,
An optical member characterized in that the inner surface of the claw-like portion is inclined at an angle that totally reflects the light. The optical member according to claim 1,
The refracting portion and the reflecting portion are formed to extend in a uniaxial direction,
The optical member is characterized in that the light reflection adjustment portion has a periodic uneven shape along the uniaxial direction. The optical member according to claim 5,
The optical member is characterized in that the uneven shape includes a plurality of predetermined conical shapes arranged along the uniaxial direction, and a region where the conical shape and the reflective surface intersect. The optical member according to claim 6,
The optical member is characterized in that the conical shape has an apex angle of 100 degrees or more. The optical member according to any one of claims 1 to 7,
An illumination device comprising a light emitting element disposed on a light incident side of the refraction section and the protrusion.

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