JP2024048005A - Optical unit and method for manufacturing the same - Google Patents

Abstract

[Problem] To provide an optical unit that causes few problems and a method for manufacturing said optical unit. [Solution] The optical unit comprises an optical functional part having a recess that is an optically functional surface, a substrate disposed opposite the opening of the recess, and an adhesive layer disposed between the entire periphery of the opening of the recess and the substrate, bonding the optical functional part and the substrate, the thickness of the adhesive layer being thinner the closer it is to the edge of the opening. [Selected Figure] Figure 1

Description

The present invention relates to an optical unit and a method for manufacturing an optical unit.

Patent documents 1 and 2 disclose a camera module that includes a lens assembly in which multiple lenses are stacked, and a sensor assembly.

Patent No. 6529455 JP 2010-519881 A

In the technology disclosed in Patent Documents 1 and 2, adhesive is dropped onto the adhesive surface of the optically functional surface of a first lens, and a second lens is placed on the adhesive surface, and the adhesive is spread over the adhesive surface using capillary action to bond the two lenses together. During this process, air bubbles may remain on the adhesive surface, which may prevent the adhesive from spreading across the entire adhesive surface. If there are areas where the adhesive does not spread due to the generation of air bubbles, there is a risk of problems such as reduced optical performance and reduced durability, such as light rays not guided to the lens being diffused in these areas.

The present invention has been made in consideration of the above, and aims to provide an optical unit that is less prone to defects and a method for manufacturing such an optical unit.

In order to solve the above problems and achieve the object, the optical unit according to the present invention comprises an optical functional component having a recess that is an optically functional surface, a substrate arranged opposite the opening of the recess, and an adhesive layer provided between the entire periphery of the opening of the recess and the substrate, bonding the optical functional component to the substrate, the thickness of the adhesive layer being thinner the closer it is to the edge of the opening.

The optical unit according to the present invention is the above invention, in which the cross section of the adhesive layer in the thickness direction is formed into a wedge shape.

The optical unit according to the present invention is the above invention, in which another optical functional component is disposed on the back side of the surface of the substrate adjacent to the adhesive layer.

The optical unit according to the present invention is the above invention, in which another substrate is adhered to the adhesive surface provided around the opening of the recess of the other optical functional component.

The optical unit according to the present invention, in the above invention, further comprises another optically functional component having a recess that is an optically functional surface that is the same as or similar to the optically functional surface, and the bottom surface of the other optically functional component is adhered to an adhesive surface provided around the opening of the recess of the optically functional component.

In the optical unit according to the present invention, at least the portion of the substrate that faces the opening of the recess is formed transparent.

The optical unit according to the present invention is the above invention, in which the optical functional components are made of energy curable resin.

In the optical unit according to the present invention, in the above invention, the back surface of the substrate adjacent to the adhesive layer is inclined with respect to the surface adjacent to the adhesive layer.

In the optical unit according to the present invention, in the above invention, the surface of the substrate adjacent to the adhesive layer is one surface of the prism.

The optical unit according to the present invention is the above invention, in which other optical functional components are arranged on other surfaces of the prism.

The optical unit according to the present invention is the above invention, in which the optical functional components are arranged on a flat plate.

The optical unit according to the present invention is the above invention, in which a plurality of other optically functional components having recesses that are optically functional surfaces are arranged on the flat plate along a direction perpendicular to the optical axis of the optically functional surface.

In the optical unit according to the present invention, the optical functional surface of the other optical functional component and the optical functional surface of the optical functional component have the same optical function.

In the optical unit according to the present invention, at least the portion of the flat plate facing the opening of the recess is formed transparent.

In the optical unit according to the present invention, in the optical functional component, the height of the outer edge of the adhesive surface on which the adhesive layer is provided is 2 to 5 μm lower than the height of the inner edge of the adhesive surface. Also, the thickness of the adhesive layer on the inner edge side of the adhesive surface is 0 to 25 μm.

In order to solve the above problems and achieve the object, the optical unit according to the present invention comprises a plurality of optical functional components having a recess that is an optical functional surface and arranged along a direction perpendicular to the optical axis of the optical functional surface, a substrate arranged opposite the opening of each of the recesses in the plurality of optical functional components, and an adhesive layer provided between the entire periphery of the opening of the recess and the substrate, bonding the optical functional components to the substrate, the thickness of the adhesive layer being thinner the closer it is to the edge of the opening.

In order to solve the above-mentioned problems and achieve the object, the manufacturing method of the optical unit according to the present invention forms an adhesive surface for applying adhesive on at least one surface, outside the recess that is the optical functional surface of the optical functional component, facing the substrate to which the optical functional component is adhered, forms the distance between the portion of the adhesive surface close to the edge of the opening and the substrate to be smaller than the distance between the portion of the adhesive surface far from the edge of the opening and the substrate, applies adhesive to the adhesive surface, places the substrate on the adhesive surface, and spreads the adhesive over the adhesive surface to form an adhesive layer between the optical functional component and the substrate.

In order to solve the above-mentioned problems and achieve the object, the manufacturing method of the optical unit according to the present invention creates an optical functional component having a recess that is an optically functional surface and an adhesive surface in which the height of the portion farther from the edge of the opening of the recess is lower than the height of the portion closer to the edge of the opening of the recess, applies an adhesive to the adhesive surface, places a substrate on the adhesive surface, and spreads the adhesive over the adhesive surface to form an adhesive layer between the optical functional component and the substrate.

In the method for manufacturing an optical unit according to the present invention, the thickness of the adhesive layer is made thinner the closer it is to the edge of the opening.

The manufacturing method of the optical unit according to the present invention is the above invention, in which the optical functional component is made of energy curable resin.

The optical unit and manufacturing method of the optical unit according to the present invention can provide an optical unit that is less prone to malfunction.

FIG. 1 is a cross-sectional view showing an example of a configuration of an optical unit according to a first embodiment of the present invention. FIG. 2 is a diagram showing an outline of a coating process in the method for manufacturing the optical unit according to the first embodiment of the present invention. FIG. 3 is a diagram showing an outline of a bonding step in the manufacturing method of the optical unit according to the first embodiment of the present invention. FIG. 4 is a flowchart showing a flow of a manufacturing method for an optical unit according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing an example of a configuration of an optical unit according to the second embodiment of the present invention. FIG. 6 is a cross-sectional view showing an example of a configuration of an optical unit according to the third embodiment of the present invention. FIG. 7 is a cross-sectional view showing an example of the configuration of an optical unit according to the fourth embodiment of the present invention. FIG. 8 is a cross-sectional view showing an example of the configuration of an optical unit according to the fifth embodiment of the present invention. FIG. 9 is a cross-sectional view showing an example of the configuration of an optical unit according to the sixth embodiment of the present invention. FIG. 10 is a cross-sectional view showing an example of the configuration of an optical unit according to the seventh embodiment of the present invention. FIG. 11 is a cross-sectional view showing an example of the configuration of an optical unit according to the eighth embodiment of the present invention. FIG. 12 is a cross-sectional view showing an example of the configuration of an optical unit according to a ninth embodiment of the present invention. FIG. 13 is a cross-sectional view showing an example of the configuration of an optical unit according to a tenth embodiment of the present invention. 14 is a cross-sectional view showing an example of the configuration of an optical unit according to an eleventh embodiment of the present invention. FIG. 15 is a cross-sectional view showing an example of the configuration of an optical unit according to a twelfth embodiment of the present invention. 16 is a cross-sectional view showing an example of the configuration of an optical unit according to a thirteenth embodiment of the present invention.

Below, an embodiment of an optical unit and a method for manufacturing an optical unit according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiment, and the components in the following embodiment include those that are replaceable and easy for a person skilled in the art, or those that are substantially the same.

[First embodiment]
The configuration of an optical unit according to a first embodiment of the present invention will be described with reference to Figures 1 to 3. The optical unit 1 according to this embodiment is an optical component mounted on, for example, the tip of an endoscope, and has a structure in which an optical functional component and a substrate are bonded together.

Specifically, the optical unit 1 includes an optical functional component 11, a substrate (first substrate) 12, a substrate (second substrate) 13, and an adhesive layer 14.

The optical functional component 11 is made of, for example, a transparent energy curable resin. The optical functional component 11 is disposed on a substrate 12 made of a flat plate. The optical functional component 11 also has a recess 111 and an adhesive surface 112.

The recess 111 functions as an optically functional surface of the optically functional component 11. When viewed from the side as shown in FIG. 2, the recess 111 is formed in a curved shape. When viewed from the top as shown in FIG. 3, the recess 111 is formed in a circular shape. Note that the planar shape of the recess 111 is not limited to a circular shape, and may be formed in, for example, a rectangular shape, another polygonal shape, or an irregular frame shape.

In addition, in FIG. 3, the shape of the opening of recess 111 (the shape of the inner edge of adhesive surface 112) and the shape of the outer edge of adhesive surface 112 are similar, i.e., both are circular, but they may also be similar squares or polygons, for example. Also, the shape of the opening of recess 111 and the shape of the outer edge of adhesive surface 112 may be non-similar. For example, the shape of the opening of recess 111 may be "circular" and the shape of the outer edge of adhesive surface 112 may be "polygonal", or vice versa.

The adhesive surface 112 is a portion onto which adhesive 141 (see FIG. 2) is dropped during the manufacturing process of the optical unit 1. As shown in FIG. 1, this adhesive surface 112 is disposed opposite the lower surface of the substrate 13 across the adhesive layer 14. Also, as shown in FIG. 3, the adhesive surface 112 is formed in a ring shape when viewed from above. Also, the adhesive surface 112 is located outside the recess 111, which is the optically functional surface of the optically functional component 11.

As shown in FIG. 1, the adhesive surface 112 is not parallel to the bottom surface of the substrate 13, but is inclined in the radial direction. In other words, the adhesive surface 112 is shaped so that its height decreases as it moves radially outward. In other words, the distance between the outer periphery of the adhesive surface 112 and the bottom surface of the substrate 13 is set to be greater than the distance between the inner periphery of the adhesive surface 112 and the bottom surface of the substrate 13.

As a result, when adhesive 141 is dropped onto adhesive surface 112 and substrate 13 is placed on it, as shown in FIG. 2, adhesive 141 spreads from the drop area indicated by the symbol E in FIG. 3(a) and fills the adhesive surface 112 from the inner periphery side first, as shown in FIG. 3(b). Then, as shown in FIG. 3(c), adhesive fills up to the outer periphery side of adhesive surface 112, and spreads around the entire periphery of adhesive surface 112.

That is, when the adhesive 141 spreads between the upper surface of the adhesive surface 112 and the lower surface of the substrate 13, a capillary phenomenon occurs due to the surface tension of the adhesive 141, and the adhesive 141 fills the narrow part of the gap first. As a result, the adhesive 141 fills the inner periphery of the adhesive surface 112 first, so no air bubbles are generated in the adhesive layer 14. In this way, by inclining the adhesive surface 112, the generation of air bubbles can be suppressed without increasing the number of processes. Therefore, it is possible to obtain an optical unit 1 that is less susceptible to defects such as a decrease in optical performance and a decrease in durability, since the optical functional component 11 can be sealed while the generation of unbonded portions between the optical functional component 11 and the substrate 13 can be suppressed.

Here, the width (outer diameter) A of the optical functional component 11 shown in FIG. 1 is preferably in the range of φ2 to 5 mm, for example. The width B of the adhesive surface 112 is preferably in the range of 0.6 to 1.5 mm, for example. The difference C in height between the inner and outer periphery sides of the adhesive surface 112 is preferably 2 to 5 μm, for example. In other words, the height of the outer edge of the adhesive surface 112 is preferably 2 to 5 μm lower than the height of the inner edge of the adhesive surface 112. In this way, the adhesive surface 112 is inclined in μm units. The adhesive surface 112 may be configured as a smooth surface without steps or the like, or may have gentle steps, unevenness, etc., and the height may decrease as it goes radially outward.

The substrate 12 is a flat plate on which the optical functional component 11 is disposed. Examples of the substrate 12 include a glass substrate, a semiconductor substrate, and a MEMS (Micro Electro Mechanical Systems). In addition, at least the portion of the substrate 12 that corresponds to the opening of the recess 111 of the optical functional component 11 is formed to be transparent.

In addition, multiple optical functional components 11 are arranged on the substrate 12 along a direction perpendicular to the optical axis O of the optical functional surface (recess 111) of the optical functional component 11. In addition, the optical functional surfaces (recess 111) of the multiple optical functional components 11 arranged on the substrate 12 each have the same optical function. In other words, the shape, size, etc. of the optical functional surface (recess 111) of each optical functional component 11 are the same. Note that in this embodiment, the same optical functional components 11 are formed, but the shape, size, etc. of the optical mechanical surfaces (recess 111) of these optical functional components 11 do not necessarily have to be formed to be the same.

The substrate 13 is a flat plate to be bonded to the optical functional component 11. As with the substrate 12, examples of the substrate 13 include a glass substrate, a semiconductor substrate, and a MEMS. The substrate 13 is disposed opposite the opening of the recess 111 of the optical functional component 11. At least the portion of the substrate 13 that faces the opening of the recess 111 of the optical functional component 11 is formed to be transparent.

The adhesive layer 14 is a layer that is interposed between the optical functional component 11 and the substrate 13 and serves to bond the two together. In other words, the adhesive layer 14 is provided between the substrate 13 and the entire periphery of the opening of the recess 111 of the optical functional component 11, and bonds the optical functional component 11 and the substrate 13 together.

The cross section of the adhesive layer 14 in the thickness direction is formed into a wedge shape. That is, the thickness of the adhesive layer 14 is formed to be thinner the closer it is to the edge of the opening of the recess 111. In other words, the thickness of the adhesive layer 14 is set to be thinner in the portion close to the edge of the opening of the recess 111 (inner edge) than in the portion farther from the edge of the opening (outer edge).

The thickness D of the adhesive layer 14 shown in FIG. 1 is preferably a thickness that allows control of the wetting and spreading behavior due to capillary action. The thickness D of the adhesive layer 14 is preferably, for example, from about 1 μm to 1 mm or less, and it is more preferable that the thickness of the inner edge is in the range of 0 to 25 μm. The smaller the thickness D of the adhesive layer 14, the stronger the effect of capillary action, and especially when the thickness D is 10 μm or less, the capillary action becomes dominant over gravity.

As in this embodiment, by inclining the adhesive surface 112 and expanding the distance between the adhesive surface 112 and the lower surface of the substrate 13 radially outward, the adhesive 141 preferentially penetrates into the inner periphery of the adhesive surface 112 and then spreads to the outer periphery. Therefore, even if the viscosity of the adhesive 141 changes, it is possible to reliably form an adhesive layer 14 between the adhesive surface 112 and the lower surface of the substrate 13. Therefore, as shown in FIG. 1, by inclining the adhesive surface 112, it is possible to improve the bonding between the optical functional component 11 and the substrate 13. In addition, by shortening the distance between the inner edge of the opening of the recess 111 of the optical functional component 11 and the substrate 13, it becomes easier to control the thickness of the adhesive layer 14 (it becomes easier to make the thickness of the adhesive layer 14 constant).

The manufacturing method of the optical unit according to the first embodiment of the present invention will be described with reference to FIG. 4. In the manufacturing method of the optical unit, a component creation process (step S1), a coating process (step S2), and a bonding process (step S3) are performed in this order.

(Parts manufacturing process)
In the component creation process, the optical functional component 11 is created. Specifically, in the component creation process, the optical functional component 11 is created having a recess 111, which is an optically functional surface, and an adhesive surface 112. In addition, in the component creation process, the height of the adhesive surface 112 at a portion (outer edge) far from the edge of the opening of the recess 111 is formed lower than the height of the portion (inner edge) close to the edge of the opening of the recess 111. In other words, in the component creation process, the optical functional component 11 is created having an adhesive surface 112 that is inclined in the radial direction.

In the component creation process, for example, an adhesive surface 112 for applying adhesive 141 is formed on at least one surface, outside the recess 111, facing the substrate 13 to which the optical functional component 11 is attached. Then, the distance between the portion of the adhesive surface 112 close to the edge of the opening (inner edge) and the substrate 13 is formed so that it is smaller than the distance between the portion of the adhesive surface 112 far from the edge of the opening (outer edge) and the substrate 13.

The specific method for forming the adhesive surface 112 is not particularly limited. For example, when the optical functional component 11 is produced using a mold, the inclined adhesive surface 112 may be formed at the same time. Alternatively, after producing the optical functional component 11 having parallel adhesive surfaces 112, etching or other processing may be performed to form the radially inclined adhesive surface 112.

(Coating process)
In the application process, the adhesive 141 is applied to the adhesive surface 112 of the optical functional component 11. The application of the adhesive 141 can be performed, for example, by using a syringe connected to a dispenser (a device for discharging a fixed amount of liquid). The method of applying the adhesive 141 in the application process is not particularly limited, and for example, as shown in FIG. 3, the adhesive 141 may be applied in one spot on the adhesive surface 112, in multiple spots, in a line, or injected from a side surface. Regardless of how the adhesive 141 is applied to the adhesive surface 112, the adhesive 141 fills the inner periphery of the adhesive surface 112 first, and the adhesive 141 spreads over the entire adhesive surface 112. This action is the same.

As the adhesive 141, a UV-curable adhesive or a light-curable adhesive such as a visible light-curable adhesive can be used. As the adhesive 141, in addition to a UV-curable or light-curable adhesive, a heat-curable or radiation-curable adhesive can also be used.

The adhesive 141 may be selected for its properties such as viscosity and hardness after curing according to the area of the adhesive surface 112 and the required thickness of the adhesive layer 14 after curing. However, if the viscosity of the adhesive 141 is too low, it will spread too much on the adhesive surface 112 before the optical functional component 11 and the substrate 13 are bonded together, which may result in air bubbles being trapped during bonding, so it is preferable to select an adhesive with an appropriate viscosity.

(Bonding process)
In the bonding process, the optical functional part 11 and the substrate 13 are bonded together. In the bonding process, the substrate 13 is placed on the bonding surface 112 of the optical functional part 11, and the adhesive 141 is spread over the bonding surface 112 to form an adhesive layer 14 between the optical functional part 11 and the substrate 13. In the bonding process, the adhesive 141 is hardened using a hardening mechanism constituted by, for example, a UV irradiation head, to form the adhesive layer 14. In the bonding process, the thickness of the adhesive layer 14 is formed thinner as it approaches the edge of the opening of the recess 111. In other words, the adhesive layer 14 is formed so that the part (inner edge) close to the edge of the opening of the recess 111 is thinner than the part (outer edge) far from the edge of the opening of the recess 111.

As described above, by using an optical functional component 11 having a radially inclined adhesive surface 112, it is possible to suppress the generation of air bubbles without increasing the number of steps. Therefore, it is possible to suppress the generation of unbonded areas between the optical functional component 11 and the substrate 13 while sealing the optical functional component 11. As a result, it is possible to obtain an optical unit 1 that is less susceptible to defects such as a decrease in optical performance and durability.

[Embodiment 2]
The configuration of an optical unit according to a second embodiment of the present invention will be described with reference to Fig. 5. In the optical unit 1A according to this embodiment, another optical functional part 15 is disposed on the back side of the surface of the substrate 13 adjacent to the adhesive layer 14 in the optical unit 1 according to the first embodiment. Also, another substrate 16 is adhered to the adhesive surface of the recess 151 of the other optical functional part 15.

Specifically, the optical unit 1A includes an optical functional component (first optical functional component) 11, a substrate (first substrate) 12, a substrate (second substrate) 13, an adhesive layer (first adhesive layer) 14, an optical functional component (second optical functional component) 15, a substrate (third substrate) 16, and an adhesive layer (second adhesive layer) 17.

Optical functional component 15 has a similar configuration to optical functional component 11. Furthermore, substrate 16 has a similar configuration to substrate 13. Furthermore, adhesive layer 17 has a similar configuration to adhesive layer 14.

In the optical unit 1A according to the present embodiment, by using optical functional components 11 and 15 having radially inclined adhesive surfaces 112 and 152, it is possible to suppress the generation of air bubbles without increasing the number of steps. Therefore, while sealing the optical functional components 11 and 15, it is possible to suppress the generation of unadhesive portions between the optical functional component 11 and the substrate 13, and between the optical functional component 15 and the substrate 16. As a result, it is possible to obtain an optical unit 1A that is less susceptible to defects such as a decrease in optical performance and a decrease in durability. Furthermore, by stacking multiple optical functional components, the degree of freedom in optical design is increased, and since air bubbles are not generated on each adhesive surface 112 and 152, optical performance can be guaranteed.

[Embodiment 3]
The configuration of an optical unit according to a third embodiment of the present invention will be described with reference to Fig. 6. In the optical unit 1B according to this embodiment, another optical functional component 18 is disposed on the back side of the surface of the substrate 16 adjacent to the adhesive layer 17 in the optical unit 1A according to the second embodiment.

The optical unit 1B specifically includes an optical functional component (first optical functional component) 11, a substrate (first substrate) 12, a substrate (second substrate) 13, an adhesive layer (first adhesive layer) 14, an optical functional component (second optical functional component) 15, a substrate (third substrate) 16, an adhesive layer (second adhesive layer) 17, and an optical functional component (third optical functional component) 18.

Optical functional components 15 and 18 have the same configuration as optical functional component 11. Furthermore, substrate 16 has the same configuration as substrate 13. Furthermore, adhesive layer 17 has the same configuration as adhesive layer 14.

In the optical unit 1B according to the present embodiment, by using optical functional components 11 and 15 having radially inclined adhesive surfaces 112 and 152, it is possible to suppress the generation of air bubbles without increasing the number of steps. Therefore, while sealing the optical functional components 11 and 15, it is possible to suppress the generation of unbonded areas between the optical functional component 11 and the substrate 13, and between the optical functional component 15 and the substrate 16. As a result, it is possible to obtain an optical unit 1B that is less susceptible to defects such as a decrease in optical performance and a decrease in durability. Furthermore, by stacking multiple optical functional components, the degree of freedom in optical design is increased, and since air bubbles are not generated on each adhesive surface 112 and 152, optical performance can be ensured.

[Fourth embodiment]
The configuration of an optical unit according to a fourth embodiment of the present invention will be described with reference to Fig. 7. The optical unit 1C according to this embodiment further includes another optical functional component 15 having a recess 151 which is an optical functional surface that is the same as or similar to the optical functional surface of the optical functional component 11 in the optical unit 1 according to the first embodiment. Also, in the optical unit 1C, the substrate bonded to the bonding surface 112 by the adhesive layer 14 in the optical unit 1 is formed by the bottom surface of the other optical functional component 15.

Specifically, the optical unit 1C includes an optical functional component (first optical functional component) 11, a substrate (first substrate) 12, an adhesive layer 14, and an optical functional component (second optical functional component) 15.

The optical functional component 15 has a similar configuration to the optical functional component 11. In addition, the bottom surface of the optical functional component 15 is adhered to the adhesive surface 112 of the optical functional component 11, and an adhesive layer 14 is interposed between the optical functional component 15 and the optical functional component 11.

In the optical unit 1C according to this embodiment, by using an optical functional component 11 having a radially inclined adhesive surface 112, it is possible to suppress the generation of air bubbles without increasing the number of steps. Therefore, it is possible to suppress the generation of unadhered portions between the optical functional component 11 and the substrate 13 while sealing the optical functional component 11. As a result, it is possible to obtain an optical unit 1C that is less susceptible to defects such as reduced optical performance and reduced durability. Furthermore, by not interposing a substrate between the optical functional components, the manufacturing process is simplified. Furthermore, by not interposing a substrate between the optical functional components, it is possible to shorten the distance in the optical axis O direction, and therefore it is possible to make the optical unit 1C itself thinner (smaller).

[Embodiment 5]
The configuration of an optical unit according to a fifth embodiment of the present invention will be described with reference to Fig. 8. In the optical unit 1D according to this embodiment, a substrate 13 is bonded to the bonding surface 152 of the optical functional component 15 in the optical unit 1 according to the fourth embodiment.

Specifically, the optical unit 1D includes an optical functional component (first optical functional component) 11, a substrate (first substrate) 12, a substrate (second substrate) 13, an adhesive layer (first adhesive layer) 14, an optical functional component (second optical functional component) 15, and an adhesive layer 17 (second adhesive layer).

The optical functional component 15 has a similar configuration to the optical functional component 11. In addition, the bottom surface of the optical functional component 15 is adhered to the adhesive surface 112 of the optical functional component 11, and an adhesive layer 14 is interposed between the optical functional component 15 and the optical functional component 11. In addition, the adhesive layer 17 has a similar configuration to the adhesive layer 14.

In the optical unit 1D according to the present embodiment, by using the optical functional components 11 and 15 having radially inclined adhesive surfaces 112 and 152, it is possible to suppress the generation of air bubbles without increasing the number of steps. Therefore, while sealing the optical functional components 11 and 15, it is possible to suppress the generation of unadhesive portions between the optical functional components 11 and 15, and between the optical functional component 15 and the substrate 13. As a result, it is possible to obtain an optical unit 1D that is less susceptible to defects such as a decrease in optical performance and a decrease in durability. Furthermore, by not interposing a substrate between the optical functional components, the manufacturing process is simplified. Furthermore, by not interposing a substrate between the optical functional components, it is possible to shorten the distance in the optical axis O direction, and therefore it is possible to make the optical unit 1D itself thinner (smaller).

Sixth Embodiment
The configuration of an optical unit according to a sixth embodiment of the present invention will be described with reference to Fig. 9. The optical unit 1E according to this embodiment uses an optical functional component 11A instead of the optical functional component 11 in the optical unit 1 according to the first embodiment. Also, adhesive surfaces 112 are formed on both sides of the optical functional component 11A, and substrates 12 and 13 are adhered to the adhesive surfaces 112 on both sides, respectively.

Specifically, the optical unit 1E includes an optical functional component 11A, a substrate (first substrate) 12, a substrate (second substrate) 13, an adhesive layer (first adhesive layer) 14, and an adhesive layer (second adhesive layer) 17.

The optical functional component 11A has two recesses 111 and two adhesive surfaces 112. The adhesive layer 17 has the same configuration as the adhesive layer 14.

In the optical unit 1E according to the present embodiment, by using an optical functional part 11A having a radially inclined adhesive surface 112, it is possible to suppress the generation of air bubbles without increasing the number of steps. Therefore, it is possible to suppress the generation of unadhered parts between the optical functional part 11A and the substrates 12 and 13 while sealing the optical functional part 11A. As a result, it is possible to obtain an optical unit 1E that is less susceptible to defects such as a decrease in optical performance and a decrease in durability. Furthermore, by not interposing a substrate between the two recesses 111 of the optical functional part 11A, the manufacturing process is simplified. Furthermore, by not interposing a substrate between the two recesses 111, it is possible to shorten the distance in the optical axis O direction, and therefore it is possible to make the optical unit 1E itself thinner (smaller).

[Embodiment 7]
The configuration of an optical unit according to a seventh embodiment of the present invention will be described with reference to Fig. 10. An optical unit 1F according to this embodiment uses a substrate 13A instead of the substrate 13 in the optical unit 1A according to the second embodiment.

Specifically, the optical unit 1F includes an optical functional component (first optical functional component) 11, a substrate (first substrate) 12, a substrate (second substrate) 13A, an adhesive layer (first adhesive layer) 14, an optical functional component (second optical functional component) 15, a substrate (third substrate) 16, and an adhesive layer (second adhesive layer) 17.

The thickness of the substrate 13A is not constant, and one surface (the upper surface) is inclined. That is, in the optical unit 1F, the back surface of the surface of the substrate 13A adjacent to the adhesive layer 14 is inclined with respect to the surface adjacent to the adhesive layer 14. The optical functional component 15 has a similar configuration to the optical functional component 11. The substrate 16 has a similar configuration to the substrate 13. The adhesive layer 17 has a similar configuration to the adhesive layer 14.

In the optical unit 1F according to the present embodiment, by using the optical functional components 11 and 15 having radially inclined adhesive surfaces 112 and 152, it is possible to suppress the generation of air bubbles without increasing the number of steps. Therefore, while sealing the optical functional components 11 and 15, it is possible to suppress the generation of unbonded parts between the optical functional component 11 and the substrate 13A, and between the optical functional component 15 and the substrate 16. As a result, it is possible to obtain an optical unit 1F that is less susceptible to defects such as a decrease in optical performance and a decrease in durability. Furthermore, by using the substrate 13A with one surface inclined, it is possible to incline the optical axis O1 of the optical functional component 15. In other words, it is possible to incline the optical axis of the optical unit 1F consisting of a plurality of stacked optical functional components 11 and 15 midway.

[Embodiment 8]
The configuration of an optical unit according to an eighth embodiment of the present invention will be described with reference to Fig. 11. An optical unit 1G according to this embodiment uses a substrate 13B made of a right-angle prism instead of the substrate 13 in the optical unit 1A according to the second embodiment. That is, in the optical unit 1G, the surface of the substrate adjacent to the adhesive layer 14 in the optical unit 1A is formed by one surface of the substrate 13B. In addition, in the optical unit 1G, another optical functional component 15 is disposed on the other surface of the substrate 13B.

Specifically, the optical unit 1G includes an optical functional component (first optical functional component) 11, a substrate (first substrate) 12, a substrate 13B (second substrate), an adhesive layer (first adhesive layer) 14, an optical functional component (second optical functional component) 15, a substrate (third substrate) 16, and an adhesive layer (second adhesive layer) 17.

Substrate 13B is a right-angle prism having a surface that is bonded to adhesive surface 112 of optical functional component 11 and a surface that is bonded to adhesive surface 152 of optical functional component 15. Optical functional component 15 has the same configuration as optical functional component 11. Substrate 16 has the same configuration as substrate 13. Adhesive layer 17 has the same configuration as adhesive layer 14.

In the optical unit 1G according to this embodiment, by using optical functional components 11, 15 having radially inclined adhesive surfaces 112, 152, the generation of air bubbles can be suppressed without increasing the number of steps. Therefore, the generation of unbonded portions between the optical functional components 11, 15 and the substrate 13B can be suppressed while sealing the optical functional components 11, 15. As a result, an optical unit 1G can be obtained that is less susceptible to problems such as reduced optical performance and reduced durability. Furthermore, by using the substrate 13B made of a right-angle prism, it is possible to bend the optical axis O by 90°.

Ninth Embodiment
The configuration of an optical unit according to a ninth embodiment of the present invention will be described with reference to Fig. 12. In the optical unit 1H according to this embodiment, an optical functional component 11 having a radially inclined bonding surface 112 and an optical functional component 15 having a radially inclined bonding surface 152 are bonded together by an adhesive layer 14.

Specifically, the optical unit 1H includes an optical functional component 11, a substrate (first substrate) 12, a substrate (second substrate) 13, an adhesive layer 14, and an optical functional component 15.

Optical functional component 15 has a similar configuration to optical functional component 11.

In the optical unit 1H according to the present embodiment, by using the optical functional parts 11, 15 having radially inclined adhesive surfaces 112, 152, it is possible to suppress the generation of air bubbles without increasing the number of steps. Therefore, it is possible to suppress the generation of unadhesive parts between the optical functional parts 11 and 15 while sealing the optical functional parts 11, 15. As a result, it is possible to obtain an optical unit 1H that is less susceptible to defects such as a decrease in optical performance and a decrease in durability. Furthermore, by not interposing a substrate between the recesses 111, 151 of the optical functional parts 11, 15, the manufacturing process is simplified. In addition, by not interposing a substrate between the recesses 111, 151, it is possible to shorten the distance in the optical axis O direction, and therefore it is possible to make the optical unit 1H itself thinner (smaller).

[Embodiment 10]
The configuration of an optical unit according to a tenth embodiment of the present invention will be described with reference to Fig. 13. In the optical unit 1I according to this embodiment, an optical functional component 11B having a bonding surface 112 parallel to a substrate 12 and an optical functional component 15 having a bonding surface 152 inclined in the radial direction are bonded together by an adhesive layer 14.

Specifically, the optical unit 1I includes an optical functional component 11B, a substrate (first substrate) 12, a substrate (second substrate) 13, an adhesive layer 14, and an optical functional component 15.

Optical functional component 11B has an adhesive surface 112 that is not inclined in the radial direction and is parallel to substrate 12. In addition, optical functional component 15 has a configuration similar to that of optical functional component 11.

In the optical unit 1I according to this embodiment, by using an optical functional part 15 having a radially inclined adhesive surface 152, it is possible to suppress the generation of air bubbles without increasing the number of steps. Therefore, it is possible to suppress the generation of unadhesive parts between the optical functional parts 11B and 15 while sealing the optical functional parts 11B and 15. As a result, it is possible to obtain an optical unit 1I that is less susceptible to defects such as a decrease in optical performance and a decrease in durability. Furthermore, by not interposing a substrate between the recesses 111 and 151 of the optical functional parts 11B and 15, the manufacturing process is simplified. In addition, by not interposing a substrate between the recesses 111 and 151, the distance in the optical axis O direction can be shortened, and therefore it is possible to make the optical unit 1I itself thinner (smaller).

[Embodiment 11]
The configuration of an optical unit according to an eleventh embodiment of the present invention will be described with reference to Fig. 14. In the optical unit 1J according to this embodiment, an optical functional component 11B having a bonding surface 112 parallel to a substrate 12 and a substrate 13C having an inclined surface 131 inclined in the radial direction are bonded together by an adhesive layer 14.

Specifically, the optical unit 1J includes an optical functional component 11B, a substrate (first substrate) 12, a substrate (second substrate) 13C, and an adhesive layer 14.

The optical functional component 11B has an adhesive surface 112 that is not inclined in the radial direction and is parallel to the substrate 12. The substrate 13C has an inclined surface 131 that is inclined in the radial direction. An adhesive layer 14 is interposed between the adhesive surface 112 of the optical functional component 11B and the inclined surface 131 of the substrate 13C.

In the optical unit 1J according to this embodiment, by using a substrate 13C having an inclined surface 131 inclined in the radial direction, the generation of air bubbles can be suppressed without increasing the number of steps. Therefore, the generation of unbonded portions between the optical functional component 11B and the substrate 13C can be suppressed while sealing the optical functional component 11B. As a result, an optical unit 1J can be obtained that is less susceptible to defects such as reduced optical performance and reduced durability. Furthermore, by using an optical functional component 11B having an adhesive surface 112 parallel to the substrate 12, the manufacturing process of the optical functional component 11B is simplified.

[Embodiment 12]
The configuration of an optical unit according to a twelfth embodiment of the present invention will be described with reference to Fig. 15. In the optical unit 1K according to this embodiment, an optical functional component 11B having a bonding surface 112 parallel to a substrate 12 and a substrate 13D having an inclined surface 131 inclined in the radial direction are bonded together by an adhesive layer 14.

Specifically, the optical unit 1K includes an optical functional component 11B, a substrate (first substrate) 12, a substrate (second substrate) 13D, and an adhesive layer 14.

The optical functional component 11B has an adhesive surface 112 that is not inclined in the radial direction and is parallel to the substrate 12. The substrate 13D also has an inclined surface 131 that is inclined in the radial direction. That is, the surface of the substrate 13D that faces the recess 111 of the optical functional component 11B is curved. This curved surface forms the inclined surface 131.

In the optical unit 1K according to this embodiment, by using a substrate 13D having an inclined surface 131 inclined in the radial direction, the generation of air bubbles can be suppressed without increasing the number of steps. Therefore, the generation of unbonded portions between the optical functional component 11B and the substrate 13D can be suppressed while sealing the optical functional component 11B. As a result, an optical unit 1K can be obtained that is less susceptible to defects such as reduced optical performance and reduced durability. Furthermore, by using an optical functional component 11B having an adhesive surface 112 parallel to the substrate 12, the manufacturing process of the optical functional component 11B is simplified.

[Embodiment 13]
The configuration of an optical unit according to a thirteenth embodiment of the present invention will be described with reference to Fig. 16. In the optical unit 1L according to this embodiment, an optical functional component 11B having a bonding surface 112 parallel to a substrate 12 and a substrate 13E having an inclined surface 131 inclined in the radial direction are bonded together by an adhesive layer 14.

Specifically, the optical unit 1L includes an optical functional component 11B, a substrate (first substrate) 12, a substrate (second substrate) 13E, and an adhesive layer 14.

The optical functional component 11B has an adhesive surface 112 that is not inclined in the radial direction and is parallel to the substrate 12. The substrate 13E has an inclined surface 131 that is inclined in the radial direction. That is, the surface of the substrate 13E that faces the recess 111 of the optical functional component 11B is formed in a tapered shape. The inclined surface 131 is formed by this tapered surface.

In the optical unit 1L according to this embodiment, by using a substrate 13E having an inclined surface 131 inclined in the radial direction, the generation of air bubbles can be suppressed without increasing the number of steps. Therefore, the generation of unbonded portions between the optical functional component 11B and the substrate 13E can be suppressed while sealing the optical functional component 11B. As a result, an optical unit 1L can be obtained that is less susceptible to defects such as reduced optical performance and reduced durability. Furthermore, by using an optical functional component 11B having an adhesive surface 112 parallel to the substrate 12, the manufacturing process of the optical functional component 11B is simplified.

The optical unit and the manufacturing method of the optical unit according to the present invention have been specifically described above using the embodiments for carrying out the invention, but the spirit of the present invention is not limited to these descriptions and must be interpreted broadly based on the claims. Furthermore, it goes without saying that various changes and modifications based on these descriptions are also included in the spirit of the present invention.

For example, the size of each component of optical units 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, and 1L may be appropriately selected according to the required specifications and design.

The diameter of the opening of the recesses 111, 151, which are optically functional surfaces, can be appropriately selected as a design for the required specifications. From the perspective of mass production, the diameter of the opening of the recesses 111, 151 is preferably about 500 μm to 20 mm. In addition, it is preferable to select the width of the adhesive surfaces 112, 152 of the optically functional components 11, 15 to a size that provides appropriate adhesive strength depending on the required degree of durability.

The optical functional components 11, 11A, 11B, 15, and 18 may be molded in an array on a large substrate by repeatedly molding each optical functional component, or may be molded in a batch using an array-shaped mold. In addition, in this embodiment, concave lenses are used as the optical functional components 11, 11A, 11B, 15, and 18, but they are not limited to concave lenses, and various optical elements such as convex lenses, Fresnel lenses, and holographic lenses can be used.

In addition, from the viewpoint of productivity, it is preferable to use an energy-curable resin as the material for the optical functional components 11, 11A, 11B, 15, and 18 and the adhesive 141. Examples of energy-curable resins include, but are not limited to, UV-curable resins.

The viscosity of the adhesive 141 is also important because it utilizes the capillary phenomenon. Although it depends on the thickness of the adhesive layer 14 and the wettability of the substrates 13, 13A, 13B, 13C, 13D, 13E, 16 with the adhesive surfaces 112, 152, it is preferable for the viscosity of the adhesive 141 to be low, for example, 10,000 mPa·s or less, and it is particularly preferable for it to be about 3,000 to 1,000 mPa·s.

The wettability of the substrates 13, 13A, 13B, 13C, 13D, 13E, 16 and the adhesive surfaces 112, 152 is particularly preferable since it affects not only the capillary phenomenon but also adhesion and durability. If the wettability is poor, the adhesion will decrease and the wetting and spreading speed will decrease, resulting in a decrease in productivity and the quality of the optical units 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L.

In order to improve the wettability between the substrates 13, 13A, 13B, 13C, 13D, 13E, 16 and the bonding surfaces 112, 152, it is preferable to perform physical surface treatment such as UV treatment or plasma treatment, or chemical treatment using a primer or the like on the bonding surfaces 112, 152. It is also useful to coat the bonding surfaces 112, 152 with an inorganic oxide ( _SiO2 , etc.) to also serve as an anti-reflection coat for the optical surfaces. An appropriate combination of these properties may be selected based on the requirements of the application and verification in the actual molding process.

The substrates 12, 13, 13A, 13B, 13C, 13D, 13E, and 16 are preferably made of glass, ceramic, resin, or the like, and preferably have high transmittance in the desired optical wavelength range.

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L Optical unit 11, 11A, 11B Optical functional component (first optical functional component)
111 Recess 112 Adhesive surface 12 Substrate (first substrate)
13, 13A, 13B, 13C, 13D, 13E Substrate (second substrate)
131 Inclined surface 14 Adhesive layer (first adhesive layer)
141 Adhesive 15 Optical functional part (second optical functional part)
151 Recess 152 Adhesive surface 16 Substrate (third substrate)
17 Adhesive layer (second adhesive layer)
18 Optical functional parts (third optical functional parts)
O, O1 Optical axis

Claims (21)

an optical functional component having a recess that is an optically functional surface;
a substrate disposed opposite the opening of the recess;
an adhesive layer provided between the substrate and the entire periphery of the opening of the recess, the adhesive layer adhering the optical functional component to the substrate;
Equipped with
The thickness of the adhesive layer is thinner closer to the edge of the opening.
Optical unit. The optical unit according to claim 1, wherein the cross section of the adhesive layer in the thickness direction is formed into a wedge shape. The optical unit according to claim 1, wherein another optical functional component is disposed on the back side of the surface of the substrate adjacent to the adhesive layer. The optical unit according to claim 3, wherein another substrate is adhered to an adhesive surface provided around the opening of the recess of the other optical functional component. Further, another optical functional component having a recess that is an optically functional surface that is the same as or similar to the optically functional surface,
a bottom surface of the other optical functional component is bonded to an adhesive surface provided around an opening of the recess of the optical functional component;
The optical unit according to claim 1 . The optical unit according to claim 1, wherein at least the portion of the substrate facing the opening of the recess is formed transparent. The optical unit according to claim 1, wherein the optical functional components are made of energy curable resin. The optical unit according to claim 1, wherein the back surface of the substrate adjacent to the adhesive layer is inclined with respect to the surface adjacent to the adhesive layer. The optical unit according to claim 1, wherein the surface of the substrate adjacent to the adhesive layer is one surface of the prism. The optical unit according to claim 9, wherein other optical functional components are arranged on other surfaces of the prism. The optical unit according to claim 1, wherein the optical functional components are arranged on a flat plate. The optical unit according to claim 11, wherein a plurality of other optically functional components having recesses that are optically functional surfaces are arranged on the flat plate along a direction perpendicular to the optical axis of the optically functional surface. The optical unit according to claim 12, wherein the optical functional surface of the other optical functional component and the optical functional surface of the optical functional component have the same optical function. The optical unit according to claim 11, wherein at least the portion of the flat plate facing the opening of the recess is formed transparent. The optical unit according to claim 1, wherein the height of the outer edge of the adhesive surface on which the adhesive layer is provided in the optical functional component is 2 to 5 μm lower than the height of the inner edge of the adhesive surface. A plurality of optically functional components having a recess that is an optically functional surface and arranged along a direction perpendicular to an optical axis of the optically functional surface;
a substrate disposed opposite to the openings of the recesses of each of the optical functional components;
an adhesive layer provided between the substrate and the entire periphery of the opening of the recess, the adhesive layer adhering the optical functional component to the substrate;
Equipped with
The thickness of the adhesive layer is thinner closer to the edge of the opening.
Optical unit. forming an adhesive surface for applying an adhesive on at least one surface of the optical functional component facing a substrate to which the optical functional component is bonded, the adhesive surface being outside a recess that is an optical functional surface of the optical functional component;
The adhesive surface is formed such that a distance between a portion of the adhesive surface close to an edge of the opening and the substrate is smaller than a distance between a portion of the adhesive surface far from the edge of the opening and the substrate;
Applying an adhesive to the adhesive surface;
the substrate is placed on the adhesive surface, and the adhesive is spread on the adhesive surface to form an adhesive layer between the optical functional component and the substrate;
A manufacturing method of an optical unit. creating an optically functional component having a recess as an optically functional surface and an adhesive surface having a height that is lower at a portion farther from an edge of an opening of the recess than at a portion closer to the edge of the opening of the recess;
Applying an adhesive to the adhesive surface;
a substrate is placed on the adhesive surface, and the adhesive is spread on the adhesive surface to form an adhesive layer between the optical functional component and the substrate;
A manufacturing method of an optical unit. The method for manufacturing an optical unit according to claim 17 or 18, in which the thickness of the adhesive layer is made thinner as it approaches the edge of the opening. The method for manufacturing an optical unit according to claim 17 or claim 18, wherein the optical functional component is made of an energy curable resin. The optical unit according to claim 15, wherein in the optical functional component, the thickness of the adhesive layer on the inner edge side of the adhesive surface is 0 to 25 μm.

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