JP7231195B2 - Resin lens, resin lens array, and method for manufacturing resin lens - Google Patents

Description

The present invention relates to a resin lens made of resin, a resin lens array formed by arranging resin lenses, and a method of manufacturing a resin lens.

Conventionally, techniques for forming lenses with resin are known. In the case of forming a lens from a resin, it has often been the case that a half-finished lens is cast and then cut and polished to produce a product. In this manufacturing method, a considerable portion of the molded lens is discarded during cutting, and at the same time, the added expensive additives are also discarded, resulting in a lot of waste. In addition, it is necessary to cut and polish each lens one by one, which limits the cost reduction of the product.

As a technique related to this resin lens, for example, a base lens is used as a first mold, and a second mold is arranged on one side or both sides of the first mold so as to have a substantially constant predetermined gap. A cavity is formed by sealing a peripheral gap between the first and second molds with taping or a gasket, and a functional resin layer is cast-molded by injecting a liquid resin raw material containing a functionality-imparting agent into the cavity. In the method of manufacturing a resin lens in which the base lens and the functional resin layer are integrated, the base lens having an adhesive layer of a thermoplastic elastomer formed on the side surface on which the functional resin layer is formed is formed in the first lens. A method of manufacturing a resin lens characterized by molding is known (see, for example, Patent Document 1).

According to this technology, the resin lens produced not only has excellent adhesion during machining, but also has excellent adhesion in hot water resistance and hot water resistance tests, and is expected to improve durability in use under high temperature and high humidity conditions. However, it did not improve the process of manufacturing resin lenses, which requires resin molding and machining.

Further, for a resin lens array in which lens surfaces are arranged on a plane, a method of manufacturing a lens array sheet by molding the surface of a resin sheet so as to arrange the lens surfaces is often used. However, in the above case, the lens surface is formed only on one side of the sheet, and it has been difficult to form both the lens front surface and the lens rear surface that function as lenses. As a technology related to this resin lens array, a plate with a hole made of a light-shielding material and having a plurality of through holes and a plurality of resin convex lenses corresponding to the through holes are provided on the surface of the through hole side. A resin lens array comprising a resin lens array sheet having a flat surface, wherein the plate with holes and the lens array sheet are fixed with the optical axes of the lenses and the through holes aligned with each other. is publicly known (see Patent Document 2).

According to this, the resin layer that bonds the transparent flat substrate and the plate with holes is pushed out into the openings of the through holes in the plate with holes, whereby each lens is formed into a lens array sheet. and the optical axis of each through-hole are completely aligned, eliminating the need for adjustment. However, even in this technique, the lens surface is formed only on one side of the sheet, and it is difficult to form lenses with higher functions in the lens array at low cost.

JP 2014-156067 A Japanese Patent Application Laid-Open No. 2004-110069

The present invention has been made in view of the circumstances as described above, and an object of the present invention is to provide a technique capable of realizing a resin lens or a resin lens array with lower cost and higher performance.

The present invention for solving the above-mentioned problems is a resin lens characterized by comprising a substantially spherical resin base material and a liquid that is absorbed in the entirety of the resin base material and swells the resin base material.

That is, in the present invention, the liquid is absorbed in the entire substantially spherical resin base material, and the resin base material is swollen to form a lens. Here, it is considered that the swelling pressure acts uniformly toward the outside of the swollen resin substrate. Therefore, in the resin lens obtained by swelling the resin base material, the sphericity is improved and the surface roughness is reduced as compared with the resin base material before swelling. As a result, it is possible to obtain a resin lens having a shape sufficiently usable as an optical element.

According to this, compared with the case where the resin lens is formed by machining a resin material or by resin molding, the manufacturing cost can be reduced and the optical performance can be further improved. The above resin base material can be resin-molded using a low-cost mold with lower precision than a high-precision mold capable of directly molding an optical component. Alternatively, for example, it is also possible to manufacture by a mold-free manufacturing method in which a resin material is injected, melted, and cooled.

Further, the resin lens according to the present invention is formed by swelling the resin base material, so that it is very flexible and deformable. Therefore, it is possible to change the focal length by deforming the resin lens itself by applying a load. Moreover, since the lens can be deformed in a direction perpendicular to the optical axis, it is possible to change the optical axis by deforming the resin lens itself. Furthermore, by interposing the resin lens according to the present invention as a buffer between the object to be photographed and the objective lens of an imaging device such as a camera, the space between the objective lens and the object to be photographed is filled with a substance having a desired refractive index, Usage such as increasing the working distance is also possible.

Further, when the resin lens according to the present invention is interposed as a buffer between the object to be photographed and the objective lens of the photographing device, the resin lens is deformed by moving the objective lens in the optical axis direction, thereby zooming and focusing. It is possible to Further, scanning can be performed by moving the objective lens in a direction perpendicular to the optical axis.

As the resin base material in the present invention, a transparent one may be used, but a colored resin may be used depending on the wavelength of the target light. Moreover, it does not necessarily have to be formed of a material that transmits visible light. In the present invention, the shape of the resin base material is substantially spherical, and the substantially spherical shape referred to here is a shape that becomes a spherical shape with high sphericity that can be used as a lens by swelling. Therefore, if this condition is satisfied, a three-dimensional shape such as a polygon may be used.

Further, the present invention may be a resin lens array formed by arranging the above resin lenses on a predetermined tray.

According to this, it is possible to obtain a resin lens array with a simpler structure by simply arranging the resin lenses on the tray. In addition, in the conventional resin lens array, since a plurality of lens surfaces are formed on the surface of a plate-shaped member that serves as a base, each lens has a lens surface that functions as a lens on either the front surface or the rear surface. However, the degree of freedom of the obtained optical characteristics was low. On the other hand, in the resin lens array of the present invention, since the independent spherical lenses are arranged side by side, the ratio of the lens surfaces in the surface of the resin lens array can be increased. It is possible to effectively use the optical properties of both rear surfaces. As a result, it is possible to realize a resin lens array with higher optical performance.

Further, in the present invention, a resin lens array may be formed by arranging a plurality of types of resin lenses having different diameters.

According to this, it is possible to more easily realize a multi-focus resin lens array having a plurality of focal lengths. Also, by changing the arrangement of resin lenses having different diameters, it is possible to freely change the focus distribution in the resin lens array.

Further, the present invention may be a method of manufacturing a resin lens, characterized in that the resin lens is obtained by causing a substantially spherical resin base material to absorb liquid in its entirety to swell the resin base material.

In addition, the present invention provides a storage step of storing a plurality of the resin base materials in a container having a predetermined size;
a swelling step of forming a resin lens by swelling the plurality of resin base materials housed in the container by immersing them in a liquid in the container;
has
In the swelling step, the plurality of resin base materials are in contact with each other in the container and are swollen until they cannot move under their own weight. good too.

Here, in the present invention, the entire resin base material is allowed to absorb liquid to swell the resin base material. The substrates are in contact with each other, and the contact pressure resists the swelling pressure, thereby restricting further swelling. Therefore, it is possible to control the size of the resin lens by the size of the container and the number of resin substrates to be accommodated. This makes it possible to more easily define the size of the resin lens and the number of resin lenses manufactured in one swelling process.

It should be noted that the means for solving the above problems can be used in combination as much as possible.

According to the present invention, it is possible to realize a resin lens or a resin lens array with lower cost and higher performance.

1 is a diagram showing a resin base material and a resin lens according to Example 1 of the present invention; FIG. It is a figure which illustrates the usage aspect of the resin lens which concerns on Example 1 of this invention. It is a figure which shows the manufacturing method of the resin lens which concerns on Example 1 of this invention. 4 is a flow chart showing a process of a method for manufacturing a resin lens according to Example 1 of the present invention; It is a figure which shows the 1st and 2nd aspect of the resin lens array which concerns on Example 1 of this invention. FIG. 5 is a diagram showing an example of an imaging state by the resin lens array according to Example 1 of the present invention; It is a figure which shows the 3rd and 4th aspect of the resin lens array which concerns on Example 1 of this invention. FIG. 6 is a diagram showing a resin lens array according to Example 2 of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. The components described in the following examples are not intended to limit the technical scope of the invention only to them unless otherwise specified.

<Example 1>
First, Example 1 of the present invention will be described. FIG. 1 is a conceptual diagram of a resin base material 1a and a resin lens 1 in this embodiment. The resin lens 1 is formed by allowing a substantially spherical resin base material 1a made of a water-absorbent resin to absorb water from the outside and swell the base material. The material of the resin substrate 1a has the property of taking in a large number of water molecules into the network structure formed by the polymer to form a gel. Hydrolyzate of graft polymer, neutralized starch-acrylic acid graft polymer, saponified vinyl acetate-acrylic acid ester copolymer, carboxymethyl cellulose crosslinked product, hydrolysis of acrylonitrile copolymer or acrylamide copolymer or a crosslinked product thereof, a crosslinked product of a cationic monomer, a crosslinked isobutylene-maleic acid copolymer, a crosslinked product of 2-acrylamido-2-methylpropanesulfonic acid and acrylic acid, or the like. Also, silicon-based resin may be used.

As shown in FIG. 1, the resin base material 1a has a substantially spherical shape, but the shape is not necessarily a perfect sphere. In addition, the surface roughness is so rough that it cannot be used as a lens as it is. However, by absorbing water to some extent and swelling, the inner pressure increases, which increases the sphericity and smoothes the surface roughness, making it possible to obtain a shape that can be used as a lens. The size of the resin base material 1a may be about φ0.1 mm to 10 mm. Also, the size of the resin lens 1 may be about φ1 mm to 50 mm.

FIG. 2 shows, as an example of the usage of the resin lens 1 in this embodiment, how to use the resin lens 1 as a buffer when photographing an object O with an imaging device such as a camera-equipped microscope. In this example, the resin lens 1 of this embodiment is interposed between the objective lens barrel 2 of the photographing apparatus and the photographing object O, and the photographing object O is photographed through the resin lens 1 .

FIG. 2(a) shows an example of photographing an object O by moving the objective lens barrel 2 back and forth in the optical axis direction in the above state and utilizing the zoom effect and focusing effect of the resin lens 1. is illustrated. FIG. 2(b) shows an example of scanning the shooting point by moving the objective lens barrel 2 in the direction perpendicular to the optical axis in the above state. Further, by selecting the material so that the refractive index of the resin lens 1 becomes a desired refractive index, it is possible to fill the space between the objective lens and the photographing object O with a medium having a desired refractive index. It is possible to adjust to the desired distance. Thus, by using the resin lens 1 in this embodiment as a buffer, it is possible to increase the degree of freedom in photographing.

Next, a method for manufacturing the resin lens 1 in this embodiment will be described with reference to FIG. In this embodiment, first, as shown in the left diagram of FIG. 3, a container 5 having a cylindrical side surface and a bottom surface is filled with water and a resin base material 1a. This step corresponds to the accommodation step in this embodiment. Here, the container 5 may contain the water first and then the resin base material 1a, or conversely, the water may be contained after containing the resin base material 1a. In this state, variations in the shape and size of the resin base material 1a are large. After the water and the resin base material 1a are placed in the container 5, the container 5 is left for a predetermined period of time, and the entire resin base material 1a absorbs the water and swells. This step corresponds to the swelling step in this embodiment.

Then, in the container 5, the resin base material 1a swells and becomes larger. Then, the resin lenses 1 are formed by swelling to the limit that can be accommodated in the container 5. At this time, the resin lenses 1 come into contact with each other in the container 5 and are arranged in a close-packed manner. When the resin lenses 1 are arranged in the container 5 at the highest density, each resin lens 1 is pressed from the outside by the surrounding resin lenses 1 or the inner wall of the container 5 . At that time, the swelling pressure, which is the internal pressure of the resin lens 1, and the contact pressure from the outside are balanced, and further swelling of the resin lens 1 is restricted. Formation of the resin lens 1 is completed in this state.

Here, the size of the resin lens 1 is determined by the inner dimension of the container 5 and the number of resin substrates 1a. Therefore, if the inner dimension of the container 5 and the number of the resin substrates 1a are determined, the swellable size of the resin lens 1 is determined. In FIG. 3, the container 5 has a circular cross-section when viewed from above, but the cross-sectional shape of the container when viewed from above may be other shapes such as a polygon. In addition, although the container 5 has a form in which the front surface of the upper surface is open, a form may be employed in which a cover is added to the upper surface to restrict swelling more firmly in the vertical direction.

FIG. 4 shows a flow chart of the manufacturing process of the resin lens 1 in this embodiment. When this process is executed, first, the size of the resin lens 1 to be obtained is determined in S101. Also, in S102, the number of resin lenses 1 to be manufactured by one swelling process is determined. Then, the size of the container 5 is determined in S103. Therefore, in S103, a container 5 having an appropriate size and shape is further selected. Next, in S104 and S105, the resin base material 1a and water are placed in a container (of course, the order of S104 and S105 may be different).

Then, in S106, the entire resin base material 1a is made to absorb water and swell. In S106, the resin lens 1 is completed when the resin lens 1 does not move by its own weight in the container 5 even if the container 5 is tilted or turned upside down. When the material of the resin base material 1a is selected, in the process of S106, the resin base material 1a swells, and the substantially spherical shape can be maintained even when the resin lenses 1 are densely arranged in the container 5. A material having a certain degree of gel strength is selected. As a result, a resin lens 1 having a more stable spherical shape can be manufactured. In the above, S104 and S105 correspond to the containing step, and S106 corresponds to the swelling step.

As described above, according to this example, the resin lens was manufactured by swelling the entire resin base material 1a made of a water-absorbent resin by absorbing water. However, the resin lens of the present invention is not limited to this aspect. A resin that swells by absorbing an organic solvent may be selected as the material of the resin base material 1a, and the resin lens 1 may be manufactured by allowing the resin base material 1a to absorb the organic solvent. Other combinations of the resin base material 1a and the liquid to be absorbed may be used.

The resin lens 1 manufactured by swelling the resin base material 1a by absorbing water in this embodiment can be used for a long period of time, for example, by being used in water. In this case, if further swelling during use is more reliably prevented, it may be used together with a frame for suppressing enlargement of the size of the resin lens 1 due to swelling. On the other hand, when used in the air, the size may change due to drying, so it may be used for a short period of time or may be provided with some kind of humidification means.

In the present embodiment, an example was described in which the resin base material 1a made of a water-absorbing resin is allowed to absorb only water and swell. However, the degree of swelling may be adjusted by appropriately adding a surfactant or the like. do not have.

<Example 2>
Next, Example 2 of the present invention will be described. In this embodiment, a resin lens array in which the resin lenses described in the first embodiment are arranged on a tray will be described.

FIG. 5 illustrates the resin lens array 10 in this embodiment. In this embodiment, as shown in FIG. 5A, a resin lens array 10 is formed by arranging the resin lenses 1 on a transparent tray 7 . According to this, the resin lens array 10 can be formed by simply arranging the resin lenses 1 on the tray 7, and the manufacturing cost can be greatly reduced and the manufacturing process can be simplified. Moreover, since the spherical resin lenses 1 are simply arranged, it is possible to manufacture a resin lens array 10 of a larger size. By manufacturing the resin lens array 10 of such a large size, an optical system capable of collectively forming an image on a plane of a larger size (for example, a light receiving surface of an image sensor) and scanning that does not require the movement of the objective lens. It becomes possible to realize a mechanism and the like.

As for the resin lens array 10 in this embodiment, as shown in FIG. 5B, the resin lenses 1 arranged on the tray 7 are pressed from above with a transparent plate 8, thereby focusing the resin lenses 1. Alternatively, zooming may be performed. This makes it possible to perform imaging and measurement with a higher degree of freedom. When the tray 7 having side walls and a function of containing liquid as shown in FIG. 5 is used, the tray 7 may be filled with water. FIG. 6 shows an example of an imaging state by the resin lens array 10. As shown in FIG. As shown in FIG. 6( a ), it is possible to image a large number of objects according to the number of resin lenses 1 . Then, as shown in FIG. 6(b), by pressing each resin lens 1 from above with a plate 8, it is possible to change the focal length and change the imaging state.

Next, FIG. 7 shows a case where a resin lens array is formed using a tray having a lens receiving portion on which each resin lens 1 can be placed, instead of the tray 7 with side walls as shown in FIG. Illustrate.

FIG. 7(a) shows the case of using a tray 9 having a lens receiving portion 9a formed by a substantially hemispherical recess. When the resin lens array 20 is formed using such a tray 9, the arrangement of the resin lenses 1 in the resin lens array 20 can be easily changed by appropriately adjusting the arrangement of the lens receiving portions 9a. It is possible. FIG. 7(b) shows a case where a tray 11 having a lens receiving portion 11a formed by a circular hole into which the resin lens 1 is fitted is used. When the resin lens array 30 is formed using such a tray 11, the lens surfaces of the resin lenses 1 can be arranged directly on both the upper and lower surfaces of the resin lens array 30, thereby exhibiting higher optical performance. becomes possible.

In this embodiment, as the shape of the lens receiving portion, a substantially hemispherical depression or a circular hole was exemplified, but the shape of the lens receiving portion is not limited to the above. Square or honeycomb-shaped recesses or holes may also be used.

<Example 3>
Next, Example 3 of the present invention will be described. In the present embodiment, an example of a resin lens array using the resin lenses described in the first embodiment, in which resin lenses of different types are mixed will be described.

FIG. 8 illustrates the resin lens array 40 in this embodiment. In this embodiment, a resin lens array 40 is formed by arranging resin lenses 1x and 1y having two different diameters on a transparent tray 7. FIG. According to this, a multifocal resin lens array 40 can be formed simply by arranging resin lenses 1 having two diameters on the tray 7 . As a result, it is possible to greatly reduce the manufacturing cost of the multifocal resin lens array and simplify the manufacturing process. In FIG. 8, an example in which two types of resin lenses 1x and 1y with different diameters are alternately arranged has been described. Thus, the distribution of focal lengths on the resin lens array 40 can be freely changed.

Also, in this embodiment, a resin lens array may be formed by distributing and arranging resin lenses of a plurality of colors on the transparent tray 7 . This makes it possible to give the resin lens array a compound color filter function. Also in this case, the resin lenses 1 of different colors may be alternately arranged, or may be arranged with a desired distribution.

DESCRIPTION OF SYMBOLS 1... Resin lens 1a... Resin base material 2... Objective lens barrel 5... Container 7, 9, 11... Tray 10, 20, 30, 40... Resin lens array

Claims (4)

The diameter before swelling is φ0.1 mm or more and φ10 mm or less, and the partially neutralized crosslinked product of polyacrylic acid, the hydrolyzate of starch-acrylonitrile graft polymer, the neutralized product of starch-acrylonitrile graft polymer, the vinyl acetate- saponified acrylic acid ester copolymer, carboxymethyl cellulose crosslinked product, hydrolyzate of acrylonitrile copolymer or acrylamide copolymer, or crosslinked product thereof, crosslinked product of cationic monomer, crosslinked isobutylene-maleic acid copolymer, a resin base material containing either a crosslinked product of 2-acrylamido-2-methylpropanesulfonic acid and acrylic acid or a silicone resin ;
A liquid that is absorbed by the entire resin base material, swells the resin base material , and remains in the gelled resin base material even after swelling ,
It is a spherical shape that can be deformed by the action of an external force,
A resin lens having a diameter of φ1 mm or more and φ50 mm or less before deformation after swelling . 2. A resin lens array, wherein the resin lenses according to claim 1 are placed and arranged on a predetermined arraying tray having a positioning mechanism for the resin lenses. 3. The resin lens array according to claim 2, wherein a plurality of types of resin lenses having different diameters are arranged on the arraying tray . 2. The method for manufacturing a resin lens according to claim 1, wherein the resin lens is formed by causing the resin base material to absorb a liquid to swell the resin base material,
an accommodating step of accommodating a plurality of the resin substrates, the number of which is determined by a value obtained by dividing the inner dimension of the swelling container by the diameter of the resin lens to be manufactured, in a cylindrical swelling container having a predetermined size;
a swelling step of forming a resin lens by swelling the plurality of resin base materials housed in the swelling container by immersing them in a liquid in the swelling container;
has
The method for manufacturing a resin lens, wherein in the swelling step, the plurality of resin base materials are swollen until they are in contact with each other in the swelling container and cannot move under their own weight.

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