Optical components and illumination devices

Abstract

To provide an optical member capable of achieving shortening of molding time, and capable of suppressing generation of molding failure, and to provide a luminaire.SOLUTION: An optical member (100) includes: a refraction part (21) for refracting light; reflection parts (22) arranged on both sides of the refraction part (21); and a light emission surface (23) for emitting transmission light which has transmitted the refraction part (21) and reflection light reflected at the reflection parts (22). The light emission surface (23) is divided into a plurality of divided regions (23a-23c), and steps are provided between the plurality of divided regions (23a-23c).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an optical member and a lighting device.

Background Art

[0002] Conventionally, a light source device using a lens utilizing total reflection, so-called a TIR lens, is known. The TIR lens includes a refractive portion disposed at the center and a reflective portion disposed around the refractive portion. As a document disclosing a light source device using a TIR lens, for example, Patent Document 1 is known.

[0003] 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) having the function of a collimating lens respectively disposed on the plurality of light sources, and a plurality of lens arrays disposed on the emission surface side of the plurality of optical means, and forms a plurality of different light distribution patterns. The use of the optical unit disclosed in Patent Document 1 is mainly for vehicle lamps.

[0004] The light source device as described above may be used as a lighting device (backlight) of a head-up display (hereinafter sometimes referred to as "HUD") mounted on, for example, a vehicle or the like. In the light source device used for HUD, it is particularly required to be bright and uniform, that is, to have a high brightness and a uniform brightness distribution. Since the above TIR lens can also collect light whose angle (directivity angle) with the emission axis is large and spreads outward in the emitted light from the light emitting element, it is often used as an optical means suitable for this purpose.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, conventional TIR lenses utilize both refraction at the refractive element and reflection at the reflective element, resulting in uneven lens thickness across the plane and requiring a larger overall lens thickness. This increased the time required for injection molding of TIR lenses, leading to problems such as thickness changes (so-called shrinkage) during the hardening of the lens material, and a higher likelihood of molding defects.

[0007] Therefore, the present invention has been made in view of the above-mentioned conventional problems, and aims to provide an optical component and lighting device that can shorten the molding time and suppress the occurrence of molding defects. [Means for solving the problem]

[0008] To solve the above problems, the optical member of the present invention comprises a refraction portion that refracts light, and arrangements on both sides of the refraction portion. The light is incident from the incident surface of the reflective part, and the light is reflected by the light reflective surface. It comprises a reflective section and a light-emitting surface that emits transmitted light that has passed through the refracting section and reflected light that has been reflected by the reflective section, and the light-emitting surface is divided into a plurality of divided regions. The multiple division regions include a central region that includes the center of the light-emitting surface, Steps are provided between the multiple divided regions. The boundaries of the multiple divided regions are provided with inclined portions that are tilted at a predetermined angle, and the inclined portions adjacent to the central region overlap with the incident surface of the reflective portion in a plan view. It is characterized by the following: Furthermore, in order to solve the above problems, the optical member of the present invention comprises a refraction portion that refracts light, reflective portions arranged on both sides of the refraction portion to which light is incident from the reflection portion incident surface and which reflects the light at the light reflection surface, and a light emission surface that emits transmitted light that has passed through the refraction portion and reflected light that has been reflected by the reflection portion, wherein the light emission surface is divided into a plurality of divided regions, the plurality of divided regions include a central region that includes the center of the light emission surface, steps are provided between the plurality of divided regions, inclined portions that are inclined at a predetermined angle are provided at the boundaries of the plurality of divided regions, and a projection is erected on the light emission surface at a position that overlaps with the reflection portion incident surface in a plan view.

[0009] In the optical component of the present invention, the light-emitting surface is divided into multiple divided regions, and steps are provided between the multiple divided regions. This reduces the difference in lens thickness between each divided region, thereby shortening the molding time and suppressing the occurrence of molding defects.

[0012] Furthermore, in one aspect of the present invention, the light-emitting surface is configured by dividing a single planar or curved shape into the divided region.

[0014] Furthermore, in one aspect of the present invention, the inclined portion has an inclination angle of 1 degree or more and 15 degrees or less with respect to the direction in which the step occurs.

[0015] Furthermore, in order to solve the above problems, the lighting device of the present invention is characterized by having an optical member as described in any one of the above and a light-emitting element arranged opposite to the light incident side of the refraction portion. [Effects of the Invention]

[0016] The present invention provides an optical component and a lighting device that can shorten molding time and suppress the occurrence of molding defects. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic cross-sectional view illustrating the outline of the optical member 20 and the illumination device 100 according to the first embodiment. [Figure 2] This is a partially enlarged cross-sectional view illustrating the structure of the light-emitting surface 23 of the optical component 20. [Figure 3] This is a schematic diagram illustrating the lens thickness in the divided regions 23a to 23c of the light-emitting surface 23. [Figure 4] This is a schematic cross-sectional view showing an example of the structure of the optical member 20 according to the second embodiment. [Figure 5] This is a schematic cross-sectional view showing an example of the structure of the optical member 20 according to the third embodiment. [Figure 6] This is a schematic cross-sectional view showing an example of the structure of the optical member 20 and the illumination device 100 according to the fourth embodiment. [Modes for carrying out the invention]

[0018] (First Embodiment) Embodiments of the present invention will be described in detail below with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing will be denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. Figure 1 is a schematic cross-sectional view illustrating the outline of the optical member 20 and illumination device 100 according to this embodiment. As shown in Figure 1, the illumination device 100 has a light-emitting element 10 and an optical member 20.

[0019] The light-emitting element 10 is an electronic component that is mounted on a mounting substrate (not shown) on which wiring is formed and emits light of a predetermined color when current is supplied by a drive circuit. A plurality of light-emitting elements 10 are arranged along a direction perpendicular to the plane of the paper. Although the specific structure of the light-emitting element 10 is not limited, an LED package combining a light-emitting diode (LED: Light Emitting Diode) that emits primary light and a wavelength conversion member that wavelength-converts a part of the primary light into secondary light can be used. Also, the material of the light-emitting diode is not limited, and known materials and structures can be used. As an example, a GaN-based LED that emits blue light can be used. Also, the material of the wavelength conversion member is not limited, and as an example, a YAG-based phosphor material that is excited by blue light and emits yellow light can be used. In the present embodiment, the number of arrays of the light-emitting elements 10 is one row, but it may be two rows or more. Also, the light-emitting element 10 is not limited to an LED and may be a semiconductor laser or the like.

[0020] The optical member 20 is a member for allowing the light irradiated by the light-emitting element 10 to enter, refracting and reflecting the light, and irradiating it in a predetermined direction. As shown in FIG. 1, the optical member 20 includes a refracting portion 21, a reflecting portion 22, a light exit surface 23, and an inclined portion 24. Also, the optical member 20 is formed by extending each part of the cross-sectional shape shown in FIG. 1 in a direction perpendicular to the plane of the paper, and constitutes a uniaxial TIR (Total Internal Reflection) lens.

[0021] The refracting portion 21 is disposed near the center of the optical member 20 and is a portion that refracts and transmits the incident light. A refracting portion incident surface 21a having a curved surface shape is provided on the side of the refracting portion 21 facing the light-emitting element 10. Although the shape of the refracting portion incident surface 21a is not limited, it is preferably a convex lens shape in order to make the light incident in an expanded manner from the light-emitting element 10 approach parallel light. As shown in FIG. 1, the refracting portion incident surface 21a is formed as a concave portion surrounded by the reflecting portion 22 around it and located at the center of the reflecting portion 22. Therefore, a part of the light irradiated from the light-emitting element 10 is refracted at the refracting portion incident surface 21a due to the refractive index difference between the refracting portion 21 and air, passes through the refracting portion 21, and is irradiated from the light exit surface 23.

[0022] The reflecting portion 22 is disposed on both sides of the refracting portion 21 and is a portion that reflects and irradiates the incident light. At the boundary between the reflecting portion 22 and the refracting portion 21, a reflecting portion incident surface 22a erected toward the light emitting element 10 side is provided. Further, on the outer periphery of the reflecting portion 22, a light reflecting surface 22b inclined at a predetermined angle with respect to the light emitting surface 23 is provided. The inclination angle of the light reflecting surface 22b is set to an angle at which the light from the light emitting element 10 reaches and is totally reflected at a critical angle or more due to the refractive index difference between the reflecting portion 22 and air. Therefore, a part of the light irradiated from the light emitting element 10 is incident into the reflecting portion 22 from the reflecting portion incident surface 22a, is totally reflected by the light reflecting surface 22b due to the refractive index difference between the reflecting portion 22 and air, passes through the reflecting portion 22, and is irradiated from the light emitting surface 23.

[0023] The light emitting surface 23 is a portion that irradiates the light refracted by the refracting portion 21 and the light reflected by the reflecting portion 22. In the optical member 20 of the present embodiment, as shown in FIG. 1, the light emitting surface 23 is divided into a plurality of divided regions 23a to 23c. Further, an inclined portion 24 is provided between the plurality of divided regions 23a to 23c, and a step is provided in each of the divided regions 23a to 23c. The steps of the divided regions 23a to 23c are shaped such that the central region has the largest step and the steps become smaller toward the periphery. Also, in the present embodiment, the surface shape of the divided regions 23a to 23c is flat, and has a structure in which a step shape is provided on one plane.

[0024] More specifically, as shown in Figure 1, the outermost segmented region 23c of the light-emitting surface 23 is located at the furthest distance from the light-emitting element 10. Segmented region 23a is the central region including the center of the light-emitting surface 23, and is located at the closest distance from the light-emitting element 10, with the largest step difference from segmented region 23c. Segmented region 23b is located midway between segments 23a and 23c, and the step difference from segmented region 23c is smaller than that from segmented region 23a. Furthermore, the central region, which is segmented region 23a, is provided corresponding to the refraction portion 21 in a plan view. In the example shown in Figure 1, segmented region 23b is located midway between segments 23a and 23c, but it does not necessarily have to be midway.

[0025] The inclined portion 24 is provided at the boundary of a plurality of divided regions 23a to 23c of the light-emitting surface 23 and is inclined with respect to the light-emitting surface 23. As described above, because the inclined portion 24 is provided at the boundary of each divided region 23a to 23c, a step is provided in each divided region 23a to 23c.

[0026] Figure 2 is a partially enlarged cross-sectional view illustrating the structure of the light-emitting surface 23 of the optical member 20. As shown in Figure 2, the width of the divided regions 23a to 23c is denoted by w, the step height by h, and the inclination angle by θ. Here, the reference for the inclination angle θ is the direction in which the step height occurs or the direction parallel to the direction of light irradiation. It is preferable that the width h of the divided regions 23a to 23c be 3 mm or more. If the width h is less than 3 mm, it becomes difficult to ensure the molding accuracy of the light-emitting surface 23 at the boundary between the divided regions 23a to 23c and the inclined portion 24, and unexpected light refraction or reflection may occur.

[0027] In the example shown in Figure 1, the width h of the central divided region 23a is approximately equal to the width of the refraction portion 21, and the inclined portion 24 provided at the boundary between divided regions 23a and 23b and the incident surface 22a of the reflecting portion overlap in a plan view. Furthermore, the widths of the divided regions 23b and 23c are equal divisions of the width of the reflecting portion 22. This is because the light-reflecting surface 22b of the reflecting portion 22 is inclined at approximately a constant angle, and the lens thickness in divided regions 23b and 23c is made to be approximately the same. In the example shown in Figure 1, the widths of the divided regions 23b and 23c are equal divisions of the width of the reflecting portion 22, but they do not necessarily have to be equal divisions.

[0028] The inclined portion 24 preferably has an inclination angle θ in the range of 1 degree to 15 degrees, more preferably 3 degrees to 10 degrees, and even more preferably 5 degrees to 8 degrees. Setting the inclination angle θ of the inclined portion 24 within these ranges makes it easier to remove the optical member 20 from the mold during injection molding. Furthermore, since the light reflected by the light-reflecting surface 22b of the reflective portion 22 travels while expanding at a certain angle rather than being a perfect point light source from the light-emitting element 10, the effect of refraction at the inclined portion 24 can be suppressed within these inclination angle θ ranges.

[0029] Figures 1 and 2 show examples where the inclination angle θ and step height h are the same for the inclined section 24 between divided regions 23a and 23b, and between divided regions 23b and 23c. However, the inclination angle θ and step height h may be different. Also, although the inclined section 24 is shown with a constant inclination angle θ, the inclination angle θ may change gradually.

[0030] Figure 3 is a schematic diagram illustrating the lens thickness in the divided regions 23a to 23c of the light-emitting surface 23. As shown in Figure 3, the optical member 20 divides the light-emitting surface 23 into multiple divided regions 23a to 23c and provides steps between them. This reduces the thickness of the refracting portion 21 and the reflecting portion 22 compared to when no steps are provided on the light-emitting surface 23. This makes the thickness of each divided region 23a to 23c closer to each other, shortening the molding time and suppressing the occurrence of molding defects.

[0031] When setting the step difference between the divided regions 23a to 23c, it is preferable to assume that the regions are separated at their boundaries as shown by the dashed lines in the figure, and to ensure that the assumed inscribed circles 25a to 25c in each region have roughly the same diameter. As shown by the dashed lines in Figure 3, by making the size of the virtual inscribed circles 25a to 25c roughly the same in each divided region 23a to 23c, the thickness change during hardening of the lens material will be roughly the same in each region, and deterioration of the surface shape can be suppressed.

[0032] In this embodiment, the case of a uniaxial TIR lens is shown, where the cross-sectional shape shown in Figure 1 is formed by extending perpendicularly to the plane of the paper. However, a TIR lens in which the cross-section shown in Figure 1 is rotated around a central axis may also be used. Alternatively, the inclined portion 24 may be omitted, and a step may be created by providing a wall surface parallel to the direction of light propagation (perpendicular to the light emission surface 23) at the boundary of each divided region 23a to 23c.

[0033] As described above, in the optical member 20 and illumination device 100 of this embodiment, the light-emitting surface 23 is divided into a plurality of divided regions 23a to 23c, and steps are provided between the plurality of divided regions 23a to 23c. This reduces the difference in lens thickness between each divided region 23a to 23c, thereby shortening the molding time and suppressing the occurrence of molding defects.

[0034] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to Figure 4. Details that overlap with the first embodiment will be omitted. Figure 4 is a schematic cross-sectional view showing an example of the structure of the optical member 20 according to this embodiment. In this embodiment, the number of divisions and shape of the light-emitting surface 23 differ from those of the first embodiment. Figure 4(a) shows the case where the light-emitting surface 23 is a free-form surface, Figure 4(b) shows the case where the light-emitting surface 23 is a concave surface, and Figure 4(c) shows the case where the light-emitting surface 23 is a convex surface. Furthermore, in Figures 4(a) to 4(c), the original shape without divided regions 23a to 23d and steps on the light-emitting surface 23 is shown on the left, and the optical member 20 with divided regions 23a to 23d and steps is shown on the right.

[0035] As shown in Figures 4(a) to 4(c), the divided regions 23a to 23d that constitute the light-emitting surface 23 have a structure in which a single planar or curved shape is divided. In the optical member 20, the light refracted by the refraction portion 21 and the light reflected by the reflecting portion 22 are collimated and irradiated from the light-emitting surface 23. Therefore, even when the divided regions 23a to 23d and steps are provided on the light-emitting surface 23, the influence of the inclined portion 24 and the steps is small, and the entire light-emitting surface 23 can achieve optical power equivalent to that of the original shape.

[0036] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to Figure 5. Details that overlap with the first embodiment will be omitted. Figure 5 is a schematic cross-sectional view showing an example of the structure of the optical member 20 according to this embodiment. This embodiment differs from the first embodiment in that it shows a minimal configuration in which the light-emitting surface 23 is divided into a central region and an outer peripheral region. As shown in Figure 5, the optical member 20 of this embodiment has a refraction portion 21, a reflecting portion 22, and a light-emitting surface 23, and the light-emitting surface 23 is divided into a divided region 23a, which is the central region, and a divided region 23b, which is the outer peripheral region. Furthermore, steps are provided between the divided regions 23a and 23b, and the divided region 23a has a concave shape with a recess.

[0037] In this embodiment as well, it is preferable that the central region, the divided region 23a, is formed with a width approximately the same as that of the refraction portion 21 in a plan view. As shown in Figures 1 and 5, the refraction portion 21 and the reflective portion 22 have a large change in thickness at their boundary (the position of the incident surface 22a of the reflective portion), and molding defects are likely to occur at this boundary. Therefore, by designing the incident surface 22a of the reflective portion, which is the boundary between the refraction portion 21 and the reflective portion 22, and the inclined portion 24, which is the boundary between the divided regions 23a and 23b, to overlap in a plan view, molding defects of the light emission surface 23 can be suppressed.

[0038] (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to Figure 6. Details that overlap with the first embodiment will be omitted. Figure 6 is a schematic cross-sectional view showing an example of the structure of the optical member 20 and the illumination device 100 according to this embodiment. This embodiment differs from the first embodiment in that a protrusion 26 is provided at the boundary between the divided regions 23a and 23b. As shown in Figure 6, the optical member 20 of this embodiment has a refraction portion 21, a reflecting portion 22, and a light-emitting surface 23. The light-emitting surface 23 is divided into divided regions 23a to 23c, and a protrusion 26 is provided at the boundary between the divided regions 23a and 23b.

[0039] The protruding portion 26 is a part erected on the upper surface of the divided region 23b at the boundary with the divided region 23a (the boundary with the inclined portion 24). As shown in Figure 6, the protruding portion 26 is integrally formed from the same material as the other parts of the optical member 20. Furthermore, the protruding portion 26 is provided so as to overlap, in a plan view, with the incident surface 22a of the refracting portion, which is the boundary between the refraction portion 21 and the reflecting portion 22.

[0040] In the optical component 20, light refracted by the refraction portion 21 and light reflected by the reflecting portion 22 are irradiated from the light emission surface 23. Therefore, in a plan view, in the region that overlaps with the reflecting portion incident surface 22a, which is the boundary between the refraction portion 21 and the reflecting portion 22, both the refracted and reflected light tend to be small. Consequently, even if a protrusion 26 is provided in this region, the amount of light incident on the protrusion 26 is small, so the influence of the protrusion 26 is small. In addition, the thickness of the refraction portion 21 and the reflecting portion 22 changes significantly at their boundary, and molding defects are likely to occur at this boundary. Therefore, by providing the protrusion 26 so as to overlap with the reflecting portion incident surface 22a, which is the boundary between the refraction portion 21 and the reflecting portion 22, in a plan view, the effects of molding defects can be contained within the protrusion 26, and the effects of molding defects can be suppressed from extending to the area surrounding the protrusion 26.

[0041] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0042] 100... Lighting devices 10…Light-emitting element 20…Optical components 21...Refracted section 21a... Incident surface of the refraction portion 22…Reflector 22a...Reflector entrance surface 22b…Light reflecting surface 23...Light exit surface 23a~23d…Divided area 24…Slope part 25a~25c...Imaginary inscribed circle 26...Protrusion

Claims

1. A refracting part that refracts light, Arranged on both sides of the refraction portion, the reflecting portion receives the light from the incident surface of the reflecting portion and reflects the light at the light-reflecting surface, The system includes a light-emitting surface that emits transmitted light that has passed through the refracting portion and reflected light that has been reflected by the reflecting portion, The light-emitting surface is divided into a plurality of divided regions, each of which includes a central region that includes the center of the light-emitting surface, and steps are provided between the plurality of divided regions. The boundaries of the multiple division regions are provided with inclined portions that are tilted at a predetermined angle. The optical member is characterized in that the inclined portion adjacent to the central region overlaps with the incident surface of the reflective portion in a plan view.

2. A refracting part that refracts light, Arranged on both sides of the refraction portion, the reflecting portion receives the light from the incident surface of the reflecting portion and reflects the light at the light-reflecting surface, The system includes a light-emitting surface that emits transmitted light that has passed through the refracting portion and reflected light that has been reflected by the reflecting portion, The light-emitting surface is divided into a plurality of divided regions, each of which includes a central region that includes the center of the light-emitting surface, and steps are provided between the plurality of divided regions. The boundaries of the multiple division regions are provided with inclined portions that are tilted at a predetermined angle. The optical member is characterized in that a protrusion is erected on the light-emitting surface at a position that overlaps with the incident surface of the reflective portion in a plan view.

3. An optical member according to claim 1 or 2, The optical member is characterized in that the light-emitting surface is formed by dividing a single planar or curved shape into the divided region.

4. An optical member according to claim 1 or 2, The optical member is characterized in that the inclined portion has an inclination angle of 1 degree or more and 15 degrees or less with respect to the direction in which the step occurs.

5. An optical member as described in claim 1 or 2, A lighting device characterized by having a light-emitting element positioned opposite the light-incident side of the refraction portion.

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