Optical element, optical element array, light source device, and illumination device

Abstract

When creating an optical element by combining multiple lens parts, positional misalignment can be prevented. [Solution] The lens 1 comprises a first lens portion 11 having a first alignment portion 111, a second lens portion 12 having a second alignment portion 121, and a bonding layer 13 that joins the first lens portion 11 and the second lens portion 12. When aligning, the first lens portion 111 and the second lens portion 12 come into contact with each other.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an optical element, an optical element array, a light source device, and an illumination device.

BACKGROUND ART

[0002] For lenses used in illumination devices and the like, a plurality of lenses may be joined to produce a single lens in order to obtain a desired lens shape. For example, Patent Document 1 discloses a method for manufacturing a cemented lens in which a plurality of lenses are bonded together.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0003]

PATENT DOCUMENT 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] However, the lens manufacturing method of Patent Document 1 only discloses bonding a plurality of lenses with an adhesive, and there is a risk of positional misalignment occurring in the bonded lenses.

[0005] Accordingly, an object of the present disclosure is to provide an optical element, an optical element array, a light source device, and an illumination device that can prevent positional misalignment when a plurality of lens portions are combined to produce an optical element.

MEANS FOR SOLVING THE PROBLEMS

[0006] To achieve the above object, an optical element according to an embodiment of the present disclosure includes a first lens portion having a first alignment portion, a second lens portion having a second alignment portion, and a bonding layer that joins the first lens portion and the second lens portion, wherein the first and second alignment portions come into contact with each other during alignment of the first and second lens portions. [Effects of the Invention]

[0007] According to this disclosure, when creating an optical element by combining multiple lens parts, positional misalignment can be prevented. [Brief explanation of the drawing]

[0008] [Figure 1] Cross-sectional view of the lighting device according to the first embodiment. [Figure 2] A diagram showing a lens according to the first embodiment. [Figure 3] Cross-sectional view of the lighting device according to the second embodiment. [Figure 4] Cross-sectional view of the lighting device according to the third embodiment. [Figure 5] A cross-sectional view of the lighting device according to the fourth embodiment. [Figure 6] Cross-sectional view of the lighting device according to the fifth embodiment. [Figure 7] A cross-sectional view of the lighting device according to the sixth embodiment. [Figure 8] Cross-sectional view of the lighting device according to the seventh embodiment. [Figure 9] Cross-sectional view of the lighting device according to the eighth embodiment. [Figure 10] Cross-sectional view of the lighting device according to the ninth embodiment. [Figure 11] A cross-sectional view of the lighting device according to the 10th embodiment. [Figure 12] Cross-sectional view of the lighting device according to the 11th embodiment. [Figure 13] A plan view of the lens according to the 12th embodiment. [Figure 14] A diagram showing a lighting device according to the 13th embodiment. [Modes for carrying out the invention]

[0009] Embodiments of the present disclosure will be described in detail below with reference to the drawings. The following description of preferred embodiments is essentially illustrative and is not intended to limit the present invention, its applications, or its uses. In the following description, the same parts are denoted by the same reference numerals, and detailed descriptions are omitted where appropriate.

[0010] (First Embodiment) (Overall configuration of the lighting system) Figure 1(a) is a cross-sectional view of the lighting device according to the first embodiment, Figure 1(b) is an enlarged view of part A of Figure 1(a), Figure 2(a) is a plan view of the lens according to the first embodiment, Figure 2(b) is a perspective view of the first lens part according to the first embodiment, and Figure 2(c) is a perspective view of the second lens part according to the first embodiment. For convenience, the vertical direction in Figure 1(a) may be simply referred to as the vertical direction (corresponding to the first direction), and the horizontal direction in Figure 1(a) may be simply referred to as the horizontal direction (corresponding to the second direction). In Figure 1(a), the top of the drawing corresponds to one side in the first direction, and the bottom of the drawing corresponds to the other side in the first direction. Also, in Figure 1(a), the light emitted from the light source 2 is illustrated with arrows. Furthermore, each lighting device described below corresponds to a light source device.

[0011] As shown in Figure 1(a), the illumination device according to the first embodiment comprises a lens 1 (optical element) and a light source 2. When actually arranging this illumination device, it may be arranged so that the vertical direction in the drawing of Figure 1(a) coincides with the actual vertical direction, or it may be arranged so that they do not coincide. For example, in the actual arrangement, this illumination device may be arranged so that the illumination surface of the lens 1 faces upward, downward, sideways, diagonally, etc. Also, in Figure 1(a), the light source 2 is arranged below the drawing of the lens 1, but the light source 2 may be arranged diagonally below the drawing of the lens 1, etc.

[0012] Lens 1 is formed in an axisymmetric shape about the light emission center of light source 2 as the axis. Lens 1 condenses the light emitted from light source 2 and outputs the light upward (one side in the first direction). The light source 2 is, for example, a small light source configured by an LED or the like. In the present embodiment, the light source 2 is arranged such that the optical axis direction thereof is along the first direction.

[0013] Lens 1 includes a concave portion 3, a side surface 4, and an output surface 5. The concave portion 3 corresponds to the incident surface of lens 1.

[0014] The concave portion 3 is formed in the lower portion of lens 1 so as to surround light source 2. The concave portion 3 corresponds to the incident surface of lens 1. Specifically, the concave portion 3 includes a transmissive refraction surface 6 and a refraction inner wall surface 7.

[0015] The transmissive refraction surface 6 is a convex curved surface formed on the inner surface of lens 1 so as to face light source 2. The transmissive refraction surface 6 refracts the light incident from light source 2 and transmits the light upward.

[0016] The refraction inner wall surface 7 is a curved surface that extends from the opening of concave portion 3 (the end on the other side in the first direction) upward (one side in the first direction) on the inner surface of lens 1, and is formed so as to surround the outer periphery of light source 2. The refraction inner wall surface 7 has its upper end (the end on one side in the first direction) connected to the outer periphery of the transmissive refraction surface 6. The refraction inner wall surface 7 is formed such that its cross section is convex inward. The refraction inner wall surface 7 refracts the light incident from light source 2 and transmits the light in the left direction or the right direction.

[0017] The side surface 4 is a surface formed on the side of lens 1. For example, the side surface 4 is a conical surface or an elliptical curved surface. Specifically, the side surface 4 is formed such that its cross section extends in the upper left direction or the upper right direction. The side surface 4 is arranged so as to surround the refraction inner wall surface 7. The side surface 4 totally reflects the light refracted by the refraction inner wall surface 7 in the upward direction.

[0018] The output surface 5 is a flat surface formed on the upper surface of lens 1. The output surface 5 outputs the light incident from the transmissive refraction surface 6 and the side surface 4 upward.

[0019] As shown in Figure 1(a), in the lateral cross-section of lens 1, the refractive inner wall surface 7 is formed such that the lower end width S2 is smaller than the upper end width S1. The lower end width S2 is the opening width of the recess 3 in the left-right direction, that is, the distance between the lower ends of the left and right sides of the refractive inner wall surface 7 in the lateral cross-section of lens 1 (the other end in the first direction). The upper end width S1 is the distance between the left and right contact points between the transmissive refractive surface 6 and the refractive inner wall surface 7 in the lateral cross-section of lens 1, that is, the distance between the upper ends of the left and right sides of the refractive inner wall surface 7 in the lateral cross-section of lens 1 (the one end in the first direction). Therefore, the refractive inner wall surface 7 can be tilted in the same direction as the side surface 4. This allows light incident from the light source 2 to the refractive inner wall surface 7 to be refracted in the left-right direction, thus reducing the vertical length of the side surface 4. Furthermore, because the refractive inner wall surface 7 is convex inward, the light refracted by the refractive inner wall surface 7 is focused, making it possible to reduce the thickness of the lens 1.

[0020] (Lens 1 configuration) As shown in Figures 1 and 2, the lens 1 is composed of a first lens portion 11, a second lens portion 12, and a bonding layer 13.

[0021] The first lens portion 11, the second lens portion 12, and the bonding layer 13 are formed of a transparent resin such as acrylic or glass. The first lens portion 11, the second lens portion 12, and the bonding layer 13 may all be made of the same material, or some may be made of different materials. Furthermore, if some of the first lens portion 11, the second lens portion 12, and the bonding layer 13 are made of different materials, it is preferable that the difference in refractive index between them is within 0.2.

[0022] The first lens portion 11 is positioned opposite the light source 2, has a portion of the emission surface 5 at its upper end, and a transmissive refractive surface 6 at its lower end. The first lens portion 11 has a first alignment portion 111 formed from the outer peripheral end of the transmissive refractive surface 6 to the outer peripheral end of the emission surface 5. Specifically, the first alignment portion 111 has a first horizontal portion 111a which extends outward from the outer peripheral end of the transmissive refractive surface 6, and a first vertical portion 111b which extends upward from the outer peripheral end of the first horizontal portion 111a.

[0023] The second lens portion 12 is provided so as to surround the first lens portion 11 and the light source 2, and has a part of the emission surface 5 at its upper end, a refractive inner wall surface 7 at its inner circumference, and a side surface 4 at its outer circumference. The second lens portion has a second alignment portion 121 formed on the upper part of the upper end of the refractive inner wall surface 7. Specifically, the second alignment portion 121 has a second horizontal portion 121a which extends outward from the upper end of the refractive inner wall surface 7, and a second vertical portion 121b which extends upward from the outer circumference end of the second horizontal portion 121a. The second alignment portion 121 has a shape corresponding to the first alignment portion 111 so as to fit (contact) with the first alignment portion 111 when aligning the first lens portion 11 and the second lens portion 12. As a result, by bringing the first alignment part 111 and the second alignment part 121 into contact, the first lens part 11 and the second lens part 12 can be aligned, thus preventing misalignment when creating lens 1 by combining the first lens part 11 and the second lens part 12.

[0024] As shown in Figure 2(a), the bonding layer 13 is formed in a substantially circular shape in a plan view. In this embodiment, the emission surface 5 is composed of the upper surface of the first lens portion 11, the upper surface of the bonding layer 13, and the upper surface of the second lens portion 12.

[0025] As shown in Figure 1(b), the bonding layer 13 joins the first lens portion 11 and the second lens portion 12. Specifically, the bonding layer 13 is formed in the groove 14 that is created between the first lens portion 11 and the second lens portion 12 when the first lens portion 11 and the second lens portion 12 are aligned. In this embodiment, the inner circumferential end Xi of the bonding layer 13 and the outer circumferential end Xa of the second alignment portion 121 are aligned.

[0026] Here, let a be the length of the second alignment portion 121 in the left-right direction (length of the second horizontal portion 121a), let Xa be the position of the outer end of the second alignment portion 121 (second horizontal portion 121a), let Xt be the position of the inner end of the second alignment portion 121 (second horizontal portion 121a), let Xd be the position of the lower end of the side surface 4, and let Xu be the position of the upper end of the side surface 4. When Xa is inside Xd, a must be less than or equal to the length between Xd and Xt, and when Xa is outside Xd, a must be less than or equal to 0.1 times the length between Xu and Xt.

[0027] When light from the light source 2 is incident on the first alignment portion 111 and the second alignment portion 121, the air layer created between the first alignment portion 111 and the second alignment portion 121 causes the light to undergo Fresnel reflection, resulting in stray light. Therefore, by setting a to the above length, it is possible to suppress the incident of light from the light source 2 on the air layer created between the first alignment portion 111 and the second alignment portion 121.

[0028] Furthermore, when the length of the bonding layer 13 in the left-right direction is c, it is preferable that c ≥ 0.5 [mm]. This allows the resin for forming the bonding layer 13 to be injected into the groove 14 when forming the bonding layer 13 in the groove 14.

[0029] Furthermore, it is preferable that e ≥ 0.5 [mm] when the length of the outer peripheral end of the second alignment portion 121 (length of the second horizontal portion 121a) is e (i.e., when the vertical length of the first alignment portion 111 (first vertical portion 111b) is b and the vertical length of the bonding layer 13 is d, e = bd). This makes it easier to fit (contact) the first alignment portion 111 and the second alignment portion 121 when aligning the first lens portion 11 and the second lens portion 12, thereby making it easier to align the first lens portion 11 and the second lens portion 12.

[0030] The manufacturing process for lens 1 is as follows:

[0031] First, the first alignment portion 111 of the first lens portion 11 and the second alignment portion 121 of the second lens portion 12 are fitted together (brought into contact) to align the first lens portion 11 and the second lens portion 12. At this time, a groove portion 14 is formed between the first lens portion 11 and the second lens portion 12 (near the first alignment portion 111 and the second alignment portion 121).

[0032] Next, a material for joining the first lens portion 11 and the second lens portion 12 is injected into the groove 14. That is, a material for joining the first lens portion 11 and the second lens portion 12 is injected into the groove 14. This forms a bonding layer 13 in the groove 14 for joining the first lens portion 11 and the second lens portion 12. At this time, the temperature of the material for forming the bonding layer 13 is -30°C to +20°C relative to the melting temperature of the material. As a result, the inner circumferential surface of the groove 14 melts, and the first lens portion 11, the second lens portion 12 and the bonding layer 13 become one, so that the interface between the first lens portion 11 and the second lens portion 12 and the bonding layer 13 disappears. The lens 1 is manufactured through the above process.

[0033] (Second Embodiment) Figure 3(a) is a cross-sectional view of the lighting device according to the second embodiment, and Figure 3(b) is an enlarged view of part B of Figure 3(a). In the second embodiment, the positions of the inner circumferential end Xi of the bonding layer 13 and the outer circumferential end Xa of the second alignment portion 121 (first alignment portion 111) are different.

[0034] As shown in Figure 3(b), when the position of the outer end of the second alignment portion 121 is Xa, the position of the inner circumferential end of the bonding layer 13 is Xi, and the position of the outer circumferential end of the bonding layer 13 is Xo, then Xa is located outside Xi and inside Xo. This allows for the same effects as in the first embodiment to be obtained, and also suppresses the incidence of light from the light source 2 onto the bonding layer 13.

[0035] (Third embodiment) Figure 4(a) is a cross-sectional view of the lighting device according to the third embodiment, and Figure 4(b) is an enlarged view of part C of Figure 4(a). In the third embodiment, the shapes of the first lens portion 11, the second lens portion 12, and the bonding layer 13 are different compared to the first embodiment.

[0036] As shown in Figure 4(a), the first lens portion 11 is formed from the central part to the outer peripheral end of the lens 1, and the emission surface 5 of the lens 1 is formed only on the upper surface of the first lens portion 11. Specifically, the first lens portion 11 has a projection 11a formed on the outside of the first alignment portion 111. A bonding layer 13 (groove portion 14) is formed between the projection 11a of the first lens portion 11 and the upper surface of the second lens portion 12. In this case, when viewed in plan, the bonding layer 13 (groove portion 14) is formed in a donut shape extending from the outer peripheral end of the first alignment portion 111 (second alignment portion 121) to the outer peripheral end of the lens 1.

[0037] As shown in Figure 4, the boundary between the first lens portion 11 and the second lens portion 12 and the bonding layer 13 is not formed on the emission surface 5. Therefore, when the lighting device is in use, it becomes difficult for chemicals or the like to penetrate the boundary, and peeling between the first lens portion 11 and the second lens portion 12 can be suppressed.

[0038] (Fourth Embodiment) Figure 5(a) is a cross-sectional view of the lighting device according to the fourth embodiment, and Figure 5(b) is an enlarged view of part D of Figure 5(a). In the fourth embodiment, compared to the third embodiment, the protruding portion 11a is not formed on the first lens portion 11.

[0039] As shown in Figure 5(a), the bonding layer 13 (groove 14) is formed between the first alignment portion 111 of the first lens portion 11 and the upper surface of the second lens portion 12. Specifically, when viewed in plan, the bonding layer 13 (groove 14) is formed in a donut shape, extending from the outer peripheral end of the first alignment portion 111 (second alignment portion 121) to the outer peripheral end of the lens 1. In this case, the emission surface 5 of the lens 1 is formed by the upper surface of the first lens portion 11 and the upper surface of the bonding layer 13.

[0040] The configuration shown in Figure 5 can achieve the same effects as in the first embodiment.

[0041] (Fifth embodiment) Figure 6(a) is a cross-sectional view of the lighting device according to the fifth embodiment, and Figure 6(b) is an enlarged view of part E of Figure 6(a). In the fourth embodiment, a bonding layer 13 is formed on the upper part of the first lens portion 11 and the second lens portion 12.

[0042] As shown in Figure 6(a), the upper surfaces of the first lens portion 11 and the second lens portion 12 are formed to be substantially flush when aligned. The bonding layer 13 is formed along the upper surfaces of the first lens portion 11 and the second lens portion 12. Specifically, the bonding layer 13 is formed in a disc shape extending from the center of the lens 1 to the outer edge. In this case, the emission surface 5 of the lens 1 is formed only by the upper surface of the bonding layer 13.

[0043] The configuration shown in Figure 6 can achieve the same effects as in the first embodiment.

[0044] (Sixth Embodiment) Figure 7(a) is a cross-sectional view of the lighting device according to the sixth embodiment, and Figure 7(b) is an enlarged view of part F of Figure 7(a). In the sixth embodiment, a first surface 12a and a second surface 12b, which are positioned at different locations in the vertical direction, are formed on the upper part of the second lens portion 12.

[0045] As shown in Figure 7(a), the upper part of the second lens portion 12 has a first surface 12a and a second surface 12b formed above the first surface 12a. The first surface 12a and the second surface 12b are connected by a third surface 12c that extends in the vertical direction. The upper surface of the first lens portion 11 and the first surface 12a of the second lens portion 12 are formed to be substantially flush when aligned. The bonding layer 13 is formed along the upper surface of the first lens portion 11 and the first surface 12a of the second lens portion 12. Specifically, the bonding layer 13 is formed in the groove portion 14 formed by the upper surface of the first lens portion 11 and the first surface 12a and third surface 12c of the second lens portion 12. In a plan view, the bonding layer 13 is formed in the shape of a disc extending from the center of the lens 1 to the third surface 12c. In this case, the emission surface 5 of lens 1 is formed by the upper surface of the bonding layer 13 and the second surface 12b of the second lens portion 12.

[0046] The configuration shown in Figure 7 provides the same effects as the first embodiment.

[0047] (Seventh Embodiment) Figure 8(a) is a cross-sectional view of the lighting device according to the seventh embodiment, and Figure 8(b) is an enlarged view of part G in Figure 8(a). In the seventh embodiment, compared to the first embodiment, the first horizontal part 111a of the first alignment part 111 and the second horizontal part 121a of the second alignment part 121 are omitted.

[0048] With the configuration shown in Figure 8, the same effects as in the first embodiment can be obtained, and the configuration of the first alignment section 111 and the second alignment section 121 can be simplified.

[0049] (Eighth embodiment) Figure 9(a) is a cross-sectional view of the lighting device according to the eighth embodiment, and Figure 9(b) is an enlarged view of part H of Figure 9(a). In the eighth embodiment, compared to the first embodiment, the first horizontal part 111a and the first vertical part 111b of the first alignment part 111, and the second horizontal part 121a and the second vertical part 121b of the second alignment part 121 are omitted. That is, in the configuration of Figure 9, the first alignment part 111 and the second alignment part 121 correspond to the contact points between the first lens part 11 and the second lens part 12 when the first lens part 11 and the second lens part 12 are aligned.

[0050] With the configuration shown in Figure 9, the same effects as in the first embodiment can be obtained, and the configuration of the first alignment section 111 and the second alignment section 121 can be simplified.

[0051] (Ninth Embodiment) Figure 10(a) is a cross-sectional view of the lighting device according to the ninth embodiment, and Figure 10(b) is an enlarged view of part I of Figure 10(a). In the ninth embodiment, compared to the third embodiment, the first horizontal part 111a of the first alignment part 111 and the second horizontal part 121a of the second alignment part 121 are omitted.

[0052] The configuration shown in Figure 10 provides the same effects as the third embodiment, while also simplifying the configuration of the first alignment section 111 and the second alignment section 121.

[0053] (Tenth embodiment) Figure 11(a) is a cross-sectional view of the lighting device according to the 10th embodiment, and Figure 11(b) is an enlarged view of part J of Figure 11(a). In the 10th embodiment, compared with the third embodiment, the first horizontal part 111a and the first vertical part 111b of the first alignment part 111, and the second horizontal part 121a and the second vertical part 121b of the second alignment part 121 are omitted. That is, in the configuration of Figure 11, the first alignment part 111 and the second alignment part 121 correspond to the contact points between the first lens part 11 and the second lens part 12 when the first lens part 11 and the second lens part 12 are aligned.

[0054] The configuration shown in Figure 11 provides the same effects as the third embodiment, while also simplifying the configuration of the first alignment section 111 and the second alignment section 121.

[0055] In the configuration shown in Figure 11, when injecting the material for joining the first lens portion 11 and the second lens portion 12 into the groove portion 14 during the manufacturing process of the lens 1, the temperature and type of the material are adjusted so that the viscosity of the material increases, preventing the material from flowing into the recess 3 from between the first alignment portion 111 and the second alignment portion 121.

[0056] (11th embodiment) Figure 12(a) is a cross-sectional view of the lighting device according to the 11th embodiment, and Figure 12(b) is an enlarged view of part K in Figure 12(a). In the 11th embodiment, the bonding layer 13 (groove portion 14) extends in an oblique direction.

[0057] The configuration shown in Figure 12 can achieve the same effects as in the first embodiment.

[0058] (12th embodiment) Figure 13 is a plan view of the lens according to the 12th embodiment. In the 12th embodiment, a plurality (in this case, three) of protrusions 11b are formed on the outer circumference of the first lens portion 11. The second lens portion 12 has recesses 12d formed at positions corresponding to the protrusions 11b.

[0059] The configuration shown in Figure 13 provides the same effects as the first embodiment, while also facilitating alignment between the first lens portion 11 and the second lens portion 12.

[0060] (13th embodiment) Figure 14(a) is a cross-sectional view of the lighting device according to the 13th embodiment, Figure 14(b) is a plan view of the first lens portion according to the 13th embodiment, Figure 14(c) is a plan view of the second lens portion according to the 13th embodiment, and Figure 14(d) is a plan view of the bonding layer according to the 13th embodiment. In the 14th embodiment, the lighting device comprises a plurality of light sources 2 and a lens array 100 (optical element array).

[0061] As shown in Figures 14(a) to (d), the lighting device according to the 13th embodiment includes a lens array 100 in which a plurality of lenses 1 are arranged in an array. Each lens 1 is provided with a corresponding light source 2.

[0062] As shown in Figures 14(b) to (d), the first lens portion 11 and the second lens portion 12 are arranged in an array. The bonding layer 13 is formed in the groove 14 formed between the first lens portion 11 and the second lens portion 12.

[0063] With the configuration shown in Figure 14, it is possible to increase the light output of the lighting device while obtaining the same effects as in the first embodiment. [Industrial applicability]

[0064] The optical element of this disclosure is useful because it can prevent misalignment when creating an optical element by combining multiple lens parts. [Explanation of Symbols]

[0065] 1. Lens (optical element) 2 light source 3 recesses 4 Sides 5. Ejection surface 6. Transmitting refractive surface 7. Refracted inner wall surface S1 Top width S2 Bottom width 11. First lens section 11b Convex part 111 First alignment section 12. Second lens section 12a 1st page 12b Side 2 12d recess 121 Second alignment section 13 Bonding layer 14 grooves 100 Lens Arrays (Optical Element Arrays)

Claims

1. A first lens section having a first alignment section, A second lens section having a second alignment section, The device comprises a bonding layer that joins the first lens portion and the second lens portion, The first and second lens portions are optical elements that come into contact with the first and second alignment portions during alignment.

2. The optical element according to claim 1, wherein the bonding layer is formed in the groove that is created between the first lens and the second lens when the first and second lenses are aligned.

3. The optical element irradiates light from the light source to one side in the first direction, The light source side further comprises a recess having an opening, The second lens is, A refracting inner wall surface extending from the opening to one side and formed to surround the light source, It has a side surface formed so as to surround the aforementioned bent inner wall surface, The first lens has an outer circumference connected to one end of the refractive inner wall surface, and a transmissive refractive surface formed at a position facing the light source, The recess is composed of the transmissive refractive surface and the refractive inner wall surface, The optical element according to claim 1, wherein, when the optical element is viewed from the side, the refractive inner wall surface, in a second direction perpendicular to the first direction, has a wider gap between both sides in a portion of the region on one side than the gap between both sides at the other end.

4. The first alignment portion extends outward from the outer periphery of the transmissive refractive surface in the first lens portion. The optical element according to claim 3, wherein the second alignment portion extends outward from one end of the refractive inner wall surface in the second lens portion.

5. The position of the outer end of the second alignment portion is the same as the position of the outer end of the bonding layer. When the length of the second alignment portion in the second direction is a, the position of the outer end of the second alignment portion is Xa, the position of the inner end of the second alignment portion is Xt, the position of one end on the side surface is Xd, and the position of the other end on the side surface is Xu, If Xa is inside Xd, then a is less than or equal to the length between Xd and Xt. The optical element according to claim 4, wherein when Xa is outside Xd, a is less than or equal to 0.1 times the length between Xu and Xt.

6. When the position of the outer end of the second alignment portion is Xa, the position of the inner circumferential end of the bonding layer is Xi, and the position of the outer circumferential end of the bonding layer is Xo, The optical element according to claim 4, wherein Xa is located outside Xi and inside Xo.

7. The optical element according to claim 4, wherein the bonding layer is formed from the outer peripheral end of the first alignment portion to the outer peripheral end on one side of the second lens.

8. The optical element according to claim 7, wherein the bonding layer is formed between the first lens and the second lens.

9. The first and second lenses are formed such that when the first and second lenses are aligned, the surface on one side becomes flush with the surface. The optical element according to claim 4, wherein the bonding layer is formed along one of the surfaces of the first and second lenses.

10. On one side of the second lens, a first surface and a second surface are formed, whose positions in the second direction are different from each other. The first surface is formed such that it is flush with the surface on one side of the first lens when the first and second lenses are aligned. The optical element according to claim 4, wherein the bonding layer is formed along the first surface and the one side surface of the first lens.

11. The first alignment portion extends from the outer periphery of the transmissive refractive surface toward one side in the first lens portion, The optical element according to claim 3, wherein the second alignment portion extends from one end of the refractive inner wall surface toward the one end in the second lens portion.

12. The first alignment portion is provided on the outer periphery of the transmitting refractive surface in the first lens portion, The optical element according to claim 3, wherein the second alignment portion is provided at one end of the refractive inner wall surface in the second lens portion.

13. The optical element according to claim 3, wherein the bonding layer extends in a direction that is inclined with respect to the second direction when the optical element is viewed from the side.

14. The optical element according to claim 3, wherein the first lens has a plurality of protrusions formed on its outer periphery when viewed in a plan view.

15. A plurality of optical elements as described in claim 1, An optical element array in which the aforementioned optical elements are arranged in an array.

16. The optical element according to claim 1, wherein the first lens, the second lens, and the bonding layer are formed of the same material.

17. The optical element according to claim 1, wherein the first lens, the second lens and the bonding layer are formed of different materials.

18. The optical element according to claim 1, wherein the first lens and the second lens are formed of different materials.

19. The optical element according to claim 1, wherein the first lens and the second lens have a refractive index difference of 0.2 or less.

20. A method for manufacturing an optical element composed of a first lens portion and a second lens portion, The first step is to bring the first alignment portion of the first lens portion and the second alignment portion of the second lens portion into contact with each other to align the first lens portion and the second lens portion, The method comprises a second step of injecting a material for joining the first lens and the second lens portion into the first lens and the second lens portion to form a bonding layer for joining the first lens portion and the second lens portion, A method for manufacturing an optical element, wherein in the second step, the temperature at which the material is injected into the first lens and the second lens portion is between -30°C and +20°C relative to the melting temperature of the material.

21. The light source element according to claim 1, A light source device comprising the aforementioned light source.

22. A lighting device comprising the light source device described in claim 21.

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