JPH0627303A - Lens plate and its production - Google Patents

Abstract

PURPOSE:To provide the lens plate of a convex lens shape which enables the mass production of lenses of various shapes with simple processes without requiring molds and high-temp. treatments with good controllability, enables the easy change of the array positions, etc., of the lenses and has excellent fineness, fine array characteristic, opening rate, etc., and the process for production of this lens plate. CONSTITUTION:This lens plate has convex lens regions 2 consisting of a photopolymer at one or >=2 points on the surface of or inside a transparent base layer 1. A photopolymerizable lens forming material is held on the surface of or inside the transparent base layer 1 and the prescribed points thereof are irradiated with a laser beam having a light intensity distribution to polymerize the lens forming material and thereafter, the unpolymerized lens forming material is removed. As a result, the delicate adjustment of the lens shapes is possible and the array plate arrayed with the lenses having the excellent uniformity of shapes with good accuracy is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a convex lens type lens plate excellent in fineness and array property, and a manufacturing method excellent in mass productivity thereof.

[0002]

2. Description of the Related Art Conventionally, a lens formed by polishing a glass block or a resin block has been known. However, the polishing method requires complicated and complicated operations, is poor in mass productivity, and has a problem that it is difficult to form a fine lens other than a spherical shape.

On the other hand, a lens formed by molding a resin by an injection method or a molding method has been known. However, in such a method, a predetermined mold is required for each change of the lens size and shape, or the array arrangement, and thermal distortion due to molding is likely to occur, and the mold followability and the mold releasability are small. There is a problem that it is difficult to form a lens and its array body.

On the other hand, a lens formed by softening and deforming a cylindrical resin has also been known. However, such a method requires various molds as in the case of the above-mentioned molding method, requires high temperature and a complicated process, is difficult to control the shape, and is difficult to form a minute lens or its array body for mass production. There was a problem with poor sex. Therefore, in any of the above cases, it is difficult to form an array body having a narrow lens pitch and a large aperture ratio.

[0005]

SUMMARY OF THE INVENTION According to the present invention, lenses of various shapes can be mass-produced with good controllability by a simple process without the need for molds and high-temperature treatment, and the array position of lenses can be easily changed to obtain a fine structure. The objective is to develop a convex lens type lens plate having excellent fine array property, aperture ratio, etc., or a manufacturing method thereof.

[0006]

DISCLOSURE OF THE INVENTION The present invention is directed to a lens plate having a convex lens region made of a photopolymer at one or two or more locations over the surface or inside of the transparent support layer, and the surface of the transparent support layer. Alternatively, a photopolymerizable lens forming material may be retained inside, and a predetermined portion thereof may be irradiated with a laser beam having a light intensity distribution to polymerize the lens forming material and then remove the unpolymerized lens forming material. A method for producing a characteristic lens plate is provided.

[0007]

[Function] By arranging a photopolymerizable lens-forming material on the surface or inside of the transparent support layer and irradiating it with laser light,
It is possible to make a partial difference in the polymerization rate of the lens forming material based on the intensity distribution of the laser light. In that case, since the intensity distribution of the laser light exhibits a Gaussian distribution, the convex lens region can be formed based on the Gaussian distribution. Therefore, it is important that the irradiation light has a light intensity distribution, and even if the uniform intensity light is irradiated through the binary optical mask including the exposed portion and the non-exposed portion, the convex lens region cannot be formed. .

The shape of the convex lens region formed in the above can be arbitrarily controlled by the irradiation amount of laser light having a light intensity distribution, the beam position, the irradiation spot size, and the like, and scanning, and can be spherical, aspherical, or cylindrical. Lenses having various forms such as shapes and their array bodies can be easily formed, and chromatic aberration due to the shapes can be easily controlled.

Therefore, according to the above, the lens plate can be formed by irradiating the laser beam, which is excellent in mass productivity and is easy to manufacture a large area plate. In addition, since it is easy to form uniform lenses regularly, the lenses can be arrayed with high accuracy, and high density arrangement of adjacent lenses can be achieved, and a lens with a large aperture ratio can be obtained.

[0010]

EXAMPLES The lens plate of the present invention has one or more convex lens regions made of a photopolymer over the surface or inside of the transparent support layer. Examples thereof are shown in FIGS. 1 and 2. FIG. 1 illustrates a single lens plate, and FIG. 2 illustrates a lens array plate. In both cases, a biconvex lens type is shown, but in the present invention, an appropriate form such as providing an aspherical lens or a semi-cylindrical lens only on one side of the transparent support layer can be adopted. 1 in the figure
Is a transparent support layer, and 2 is a convex lens region.

The lens plate is manufactured by, for example, holding a photopolymerizable lens forming material on the surface or inside of the transparent support layer and irradiating a predetermined portion thereof with laser light having a light intensity distribution to form the lens forming material. It can be carried out by removing the unpolymerized lens-forming material after the polymerization.

The lens-forming material used is, for example, a monomer,
In the case of using a suitable material such as an oligomer, a resin, glass, or other inorganic material in a combination containing at least one kind of photopolymerizable substance, and using it as a lens according to the irradiation intensity of the laser light irradiation, Any polymer capable of forming a polymer that is transparent to wavelength light may be used. Therefore, if necessary, a photoreaction initiator, a photosensitizer or the like may be added.

As the transparent support layer, an appropriate material having transparency to wavelength light when used as a lens can be used, but such a support layer does not need to be solid at the stage of irradiating laser light, It may be solidified by an appropriate treatment such as heat treatment or exposure treatment after laser light irradiation. Therefore, the transparent support layer may also contain a photoreaction initiator, a photosensitizer, etc., if necessary. The thickness of the transparent support layer may be appropriately determined and is generally 10 μm to 10 mm.

The transparent support layer having a photopolymerizable lens-forming material on its surface or inside is formed by, for example, a method of impregnating the lens-forming material in the support layer or a layer of the lens-forming material on one or both sides of the support layer. Can be performed by an appropriate method such as a method of providing.

As an example of such a transparent support layer having a lens-forming material, a transparent support layer made of a polymer, glass, an inorganic crystal, a composite thereof, or the like is used. A lens-forming material containing the above monomers or photosensitive glass,
Examples include coated materials.

The above-mentioned photopolymerizable monomer or photosensitive glass is fixed on the surface or inside of the transparent support layer by polymerization, curing, addition, compounding or the like through irradiation of laser light with the monomers or through the transparent support layer. . If necessary, the fixing state can be reinforced by developing treatment, heat treatment, pre-exposure treatment, post-exposure treatment, solvent treatment and the like.

As described above, in the present invention, the convex lens region is formed by polymerizing the lens forming material. Laser light is used for forming the convex lens area, and the lens forming material is formed in a state having a light intensity distribution. It is performed by irradiating a predetermined place.

For the irradiation of laser light, a suitable laser oscillator can be used depending on the reaction wavelength of the lens-forming material and other photoreactive materials such as photopolymerization initiators and photosensitizers.
Preferably, it is possible to form a circular beam cross section and exhibit a 0th-order or 1st-order Gaussian distribution as the light intensity distribution. A preferable irradiation wavelength of laser light is 200 to 650.
nm, and therefore an ultraviolet laser or the like can be preferably used.

Examples of commonly used laser oscillators include those that oscillate a laser beam having a relatively short wavelength such as a helium / cadmium laser, an excimer laser, and an argon laser. Depending on the combination of the photopolymerization initiator and the photosensitizer, a helium / neon laser or the like may be used together with the coloring removing means. Further, a long-wavelength laser such as a YAG laser may be wavelength-converted into, for example, a third harmonic and used.

FIG. 3 exemplifies a manufacturing apparatus in which a laser oscillator is arranged. This is a laser oscillating unit 3, a shutter 4, a condenser unit 5 including a lens, a mirror, a filter, and the like.
An exposure subject is composed of a scanning optical system 6 composed of a mirror and the like, and 7 is an exposed body composed of a transparent support layer having a photopolymerizable lens forming material on the surface or inside thereof.

The irradiation of the laser beam (arrow) on the object 7 to be exposed is controlled by converging the laser beam oscillated by the laser oscillating section 3 through the condensing section 5 and adjusting the size of the irradiation spot. This can be performed by reflecting the light toward the object to be exposed through the scanning optical system 6. The irradiation position and the scanning locus are adjusted by the control of the scanning optical system 6. The shutter 4 is for controlling the passage of the laser light oscillated by the laser oscillator 3 to the condensing unit 5. It is preferable that the shutter can be controlled in conjunction with the condensing unit and the scanning optical system. . The control can be easily performed by a device such as a personal computer.

The lens area to be formed is controlled, for example, by controlling the irradiation time and intensity of the laser beam, the beam position of the laser beam, the size of the irradiation spot, intensity control such as dimming by a filter or a transmittance distribution type optical mask, and scanning. It can be done according to the route and speed. In the present invention, it is possible to form a convex lens type region having a smooth curve based on a Gaussian distribution or the like by irradiating for a predetermined time without scanning, or to scan a laser beam to form a region having an arbitrary shape. You can also In that case, the size of the irradiation spot is usually about 0.01 to 200 mm.

In the above-mentioned scanning method, a cylindrical region having continuous convex portions is formed according to the scanning path. In that case, the irradiation amount per unit distance can be adjusted by controlling the degree of focusing of the laser light or by controlling the scanning speed, whereby the width and sectional shape of the convex lens region formed on the scanning path can be controlled. Therefore, when the scanning paths are crossed or overlapped with each other, a convex lens region different from the other scanning parts can be formed in the overlapped part.

The form of the convex lens region formed by the irradiation of the laser light is arbitrary. Such a region may occupy the whole of the transparent support layer, or may occupy only a part thereof, or may be formed as a plurality of regions to form lenses in an array.

Therefore, the form of the lens formed as the sum of the convex lens regions can be arbitrarily determined, and for example, it can be formed as a convex lens, a cylindrical lens, a Fresnel lens, an aspherical lens, a combination lens thereof or an array body. it can. Further, the diameter and thickness of the lens to be formed, the shape such as the focal length, and the characteristics can be appropriately determined, and the form, arrangement state, arrangement number, etc. of the lenses in the array body are arbitrary. The closest packing is more advantageous than the aperture ratio. The diameter of a general lens unit formed as a single lens or a lens array plate is 0.
It is about 01 to 200 mm.

Further, the convex lens region can be formed on one side or both sides of the transparent support layer, and in the case of both sides, the shape and position of the lens, the material or the refractive index on both sides may be different. The refractive index can be arbitrarily determined depending on the diameter and thickness of the lens, performance, etc., but in general, a refractive index larger than the focal length is preferable. The refractive index in the lens does not have to be uniform, and the refractive index distribution can be arbitrarily selected.

After the polymerization treatment of the lens-forming material by irradiation of laser light is completed, as one of the above-mentioned necessary development processing, heat treatment, exposure treatment, solvent treatment, etc., the inside or the surface of the transparent support layer is treated. Then, the unpolymerized lens-forming material remaining in is removed. Such removal treatment can be performed by an appropriate method depending on the lens forming material, such as extraction treatment with a solvent or volatilization treatment by heating.

The obtained lens plate or lens array plate can be used for various purposes. In that case, the lens plate or the like can be cut out into an appropriate shape for practical use, and if necessary, a reinforcing plate, an antireflection film, an adhesive layer, or the like can be attached.

Example 1 Urethane acrylate polymer (manufactured by Dainippon Ink and Chemicals,
Unidec V4220) is formed into a film, and a transparent support layer having a thickness of 50 μm is prepared by adding 1 part (part by weight, the same applies hereinafter) of tribromophenoxyethyl acrylate (refractive index 1.56) to a photopolymerization initiator (Ciba Geigy). After dipping 1 part of Irgacure 651) manufactured by K.K. in 1 part of chloroform into a solution to impregnate it with a lens-forming material, a helium-cadmium laser of 0th transverse mode at 4.2 mW is applied to this. Irradiation for 2 seconds and then immersion in methanol for 6 hours to extract and remove unreacted tribromophenoxyethyl acrylate to obtain a lens plate.

Example 2 A lens array plate was obtained in the same manner as in Example 1 except that the irradiation spots were spaced at a center interval of 1.1 mm, each of which was irradiated at 16 vertical and horizontal 4 positions.

Example 3 A lens plate was obtained in the same manner as in Example 1 except that the irradiation time was 6 seconds.

Example 4 According to Example 1, first, after irradiation for 1 second, the spot diameter was halved through the lens and irradiation was further performed for 1 second to obtain a lens plate.

Comparative Example An ultraviolet lamp was used as the exposure means, and the ultraviolet ray of the diameter of 1.
A lens plate was obtained in the same manner as in Example 1 except that irradiation was performed for 20 seconds through a photomask having a 0 mm transmission hole.

Evaluation Test The surface shapes of the lens plates or lens array plates obtained in the examples and comparative examples were measured with a surface roughness meter. The results are shown in Example 2.
5 for the lens array plate of FIG.
It was shown to. In the figure, the height reference (0 mm position) is
It is the surface of the transparent support layer, and the distance standard (0 mm position) is
It is one end of the formed convex lens region.

As shown in FIG. 4, the convex portion having a quadric surface shape is formed in the first embodiment, the convex portion having a curved surface with a slightly flat top is formed in the third embodiment, and the convex portion is formed in the fourth embodiment. It can be seen that a curved surface shape in which a convex portion is further overlapped is formed on. On the other hand, in the comparative example, it can be seen that the curved surface shape is not formed.

When the lens characteristics were examined, Example 1 showed good convex lens characteristics with small spherical aberration, Example 3 showed aspherical lens characteristics, and Example 4
Showed good double focus. However, the comparative example showed no lens action.

On the other hand, in Example 2 of FIG. 5, four quadratic curved surface-shaped convex portions having a diameter of about 1 mm were formed vertically and laterally at a very narrow interval of about 0.2 mm. Also, the shapes such as the diameter and height of each lens were well aligned. By a separate test, it was also confirmed that various lens array plates can be easily formed by changing the intervals and diameters of irradiation spots and irradiation time.

[0038]

According to the present invention, it is possible to obtain a convex lens plate having fine and high-performance lenses whose lens shape is finely adjusted. In addition, lenses having excellent shape uniformity can be arrayed with high precision to obtain an array plate having a large aperture ratio. Furthermore, according to the manufacturing method of the present invention, various shapes of lenses and their array bodies can be easily mass-produced with good controllability by a simple process using a laser beam that does not require a mold or high-temperature treatment, and a large-area plate can be easily manufactured. Can be formed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a lens.

FIG. 2 is a sectional view illustrating a lens array plate.

FIG. 3 is an explanatory diagram of a manufacturing apparatus.

FIG. 4 is a measurement diagram of a lens shape.

FIG. 5 is a measurement diagram of another lens shape.

[Explanation of symbols]

1: Transparent Support Layer 2: Convex Lens Area 3: Laser Oscillator 4: Shutter 5: Focusing Part 6: Scanning Optical System 7: Exposed Body (Transparent Support Layer Having Photopolymerizable Lens Forming Material on Surface or Inside) )

Claims (2)

[Claims] 1. A lens plate having one or more convex lens regions made of a photopolymer over the surface or inside of a transparent support layer. 2. A transparent support layer is provided with a photopolymerizable lens forming material on the surface or inside thereof, and a predetermined portion thereof is irradiated with laser light having a light intensity distribution to polymerize the lens forming material. A method for manufacturing a lens plate, comprising removing a polymerized lens forming material.