JP2005141138A - Method for manufacturing rod lens plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method capable of efficiently manufacturing a rod lens plate high in precision. <P>SOLUTION: The method for manufacturing the rod lens plate 12, on which rod lenses 2 are arranged two-dimensionally, comprises steps of: arranging a plurality of rod lenses in parallel to each other between two substrates; injecting an adhesive 8 into the space between the substrates and the rod lenses to form a rod lens array 1; releasing the substrates from the rod lens array to obtain a rod lens arrangement body 10 connected by the adhesive; and adhering the rod lens arrangement body with the end faces placed on one plane to form a rod lens plate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a rod lens plate, and more particularly to a method for manufacturing a rod lens plate configured by two-dimensionally arranging a large number of rod lenses.

  A cylindrical rod lens is known as one of micro lenses. In addition to being used alone, such a rod lens is a rod lens array in which a plurality of rod lenses are arranged in parallel, as an optical component for an image sensor used in a scanner or the like, or a writing device such as a printer It is used as.

Further, the rod lens is a rod lens plate in which a large number of rod lenses are two-dimensionally arranged, and is also used as an optical component such as a display or a two-dimensional image sensor such as a fingerprint sensor.

Here, the rod lens array refers to a rod lens having 1 to 4 rows of rod lenses arranged therein, whereas the rod lens plate is a rod lens plate having 5 rows or more of rod lenses arranged therein. Insert.

As a method for manufacturing such a rod lens plate, a short rod lens is placed upright in the frame, pressed from the side to arrange the rod lens, and an adhesive is poured to bond the rod lenses together. A method of using a rod lens plate is known (for example, see Patent Document 1).
JP-A-8-248206

However, since the above-described prior art method arranges a number of short rod lenses standing in a frame, the accuracy of the thickness uniformity of the rod lens plate manufactured with a disordered arrangement is lowered. Since it is manufactured using a short rod lens, it has disadvantages such as increased loss.
The present invention has been made in view of such problems, and it is an object of the present invention to provide a method of manufacturing a rod lens plate that can efficiently manufacture a highly accurate rod lens plate.

  According to the present invention, a rod lens plate manufacturing method in which rod lenses are two-dimensionally arranged, a step of arranging a plurality of rod lenses in parallel so as to be parallel to each other between two substrates; A step of injecting an adhesive into a space between the substrate and the rod lens to form a rod lens array; and a method of separating the substrate from the rod lens array and connecting the rod lens array connected by the adhesive A rod lens plate comprising: a step of obtaining a rod lens plate by adhering the rod lens array to each other such that end surfaces thereof are located on the same plane. A method is provided.

  According to such a configuration, since the rod lens plate is manufactured using the rod lens array, it is possible to manufacture a highly accurate rod lens plate.

According to another preferred aspect of the present invention, the method includes a step of applying a release agent to the surface of the substrate prior to the step of arranging in parallel.
According to such a configuration, since the substrate can be easily peeled from the rod lens array, the production efficiency is improved and the peeling surface is not roughened, so that the accuracy of the rod lens plate is also improved.

According to the other preferable aspect of this invention, the said board | substrate contains the mold release agent.
According to such a configuration, since the substrate can be easily peeled from the rod lens array, the production efficiency is improved and the peeling surface is not roughened, so that the accuracy of the rod lens plate is also improved.

  According to another aspect of the present invention, there is provided a method of manufacturing a rod lens plate in which rod lenses are two-dimensionally arranged, and a plurality of rod lenses are arranged in parallel so as to be parallel to each other between two substrates. A step of forming a rod lens array by injecting an adhesive into a space between the substrate and the rod lens, and adhering the rod lens array to each other with their end faces positioned on the same plane. And a step of forming a rod lens plate. A method of manufacturing a rod lens plate is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the rod lens plate which can manufacture a highly accurate rod lens plate efficiently is provided.

Hereinafter, a rod lens plate manufacturing method according to a preferred embodiment of the present invention will be described in detail.
First, the configuration of the rod lens used in the rod lens plate manufacturing method of the present embodiment will be described.
The rod lens used in the present embodiment is a plastic rod lens having a cylindrical shape, and the refractive index continuously decreases from the central axis toward the outer periphery. The rod lens is preferably manufactured by a monomer interdiffusion method.

Further, the rod lens has a refractive index distribution in the range of 0.3r to 0.7r at least from the central axis toward the outer periphery when the radius is r in a cross section perpendicular to the central axis by the following formula (1). It is preferable to approximate with a specified quadratic curve distribution.
_{n (L) = n 0 {} 1- (g 2/2) L 2} (1)
(N ₀ is the refractive index at the central axis of the rod lens (central refractive index), L is the distance from the central axis of the rod lens (0 <L <r), g is the refractive index distribution constant of the rod lens, n (L) Is the refractive index at a distance L from the central axis of the rod lens.)

The radius r of the rod lens is not particularly limited, but is generally about 0.01 mm to 1 mm.
From the viewpoint of downsizing the optical system, r is preferably 0.5 mm or less, more preferably 0.3 mm or less, and from the viewpoint of ease of handling during processing, it is preferably 0.00. The thickness should be 05 mm or more, more preferably 0.1 mm or more.

The refractive index distribution constant g at the operating wavelength of the rod lens is not particularly limited, but is generally about 0.1 mm ⁻¹ to 5 mm ⁻¹ .
From the viewpoint of compacting the optical system, g is preferably 0.2 mm ⁻¹ or more, more preferably 0.5 mm ⁻¹ or more, and the viewpoint of ensuring the working distance of the optical system and ease of handling. Is preferably 3 mm ⁻¹ or less, more preferably 2 mm ⁻¹ or less.

  Furthermore, in order to remove flare light and crosstalk light and improve the lens performance, the rod lens has a cross section perpendicular to the central axis within a range of 100 μm from the outer peripheral surface of the lens toward the central axis, and 0. It is preferable that a light absorber-containing layer containing a light absorber that absorbs light in at least a part of the wavelength region of the visible light and near infrared light regions is formed in the outer range of 6r or more.

  The light absorber-containing layer is formed on the outer periphery of the rod lens as described above, and this is caused by an irregular portion of the refractive index distribution formed on the outer periphery of the rod lens without significantly reducing the amount of emitted light. Crosstalk when using flare light or a rod lens plate can be prevented.

  As the light absorber to be used, various dyes, pigments and pigments capable of absorbing light having a wavelength used in an optical system in which a rod lens is used can be used. These light absorbers are light absorbers that absorb only a specific wavelength range, and two or more kinds of light absorbers that absorb different wavelengths may be used in combination.

Moreover, it is preferable that a light absorber exists in the light absorber containing layer substantially uniformly. In that case, it is preferable that the light absorber molecules are uniformly dispersed or bonded in the polymer constituting the light absorber-containing layer.
Moreover, 0.001-10 mass% is preferable and, as for content in the light absorber content layer of a light absorber, 0.01-1 mass% is more preferable.

  Further, a configuration may be adopted in which a portion containing a light absorber is formed in a region including the central axis of the central portion of the lens so that only a target wavelength is transmitted and a filter function is provided. Further, a light absorber-containing layer may be formed on the outer peripheral portion of the lens, and a portion containing the light absorber may be formed in a region including the central axis of the central portion of the lens. In this case, the light absorbent in the outer peripheral portion of the lens and the light absorbent in the region including the central axis of the central portion of the lens may be the same or different.

Next, a method for manufacturing a rod lens will be described.
First, N types of uncured materials having a refractive index n after curing having a relationship of n ₁ > n ₂ >...> _{N N} (N> 3) are sequentially applied from the center toward the outer periphery. So that the refractive index distribution between the respective layers of the filamentous body is continuous, and is shaped into an uncured laminated body (hereinafter referred to as “filamentous body”) that is concentrically laminated. While performing the interdiffusion treatment of the substances between the adjacent layers or after the mutual diffusion treatment, the filamentous body is cured to obtain a raw yarn to be a rod lens.

  Next, the obtained raw yarn is heated and stretched, and then subjected to a relaxation treatment and cut into a predetermined length to obtain a rod lens used in the present embodiment.

Examples of the substance constituting the uncured material include a radical polymerizable vinyl monomer, or a composition comprising a radical polymerizable vinyl monomer and a polymer soluble in the monomer.
In order to easily adjust the viscosity of the uncured product when forming the filament from these uncured products and to have a continuous refractive index distribution from the center to the outer periphery of the filament, It is preferable to comprise a composition of a monomer and a polymer soluble in this (soluble polymer).

  In order to cure the uncured product, the filamentous material containing the thermosetting catalyst and / or the photocuring catalyst is subjected to heat treatment or photocuring treatment. When the uncured product contains both a thermosetting catalyst and a photocuring catalyst, both heat treatment and photocuring treatment can be performed.

The photocuring treatment can be carried out by irradiating an uncured material containing a photocatalyst with ultraviolet rays from the surroundings. Examples of the light source used for the photocuring treatment include a carbon arc lamp that generates light having a wavelength of 150 to 600 nm, a high-pressure mercury lamp, a medium-pressure mercury lamp, a low-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a chemical lamp, a xenon lamp, and a laser beam. Further, these light sources may be used in appropriate combination in order to increase the polymerization rate.
The thermosetting treatment can be performed by heat-treating an uncured product containing a thermosetting catalyst for a predetermined time in a curing processing section such as a heating furnace controlled at a constant temperature.

The lens raw yarn obtained by curing the filament may be continuously sent to the heating and stretching process as it is, or may be wound once on a bobbin and then sent to the heating and stretching process. The heat stretching may be performed in a batch manner or continuously. Moreover, the heating and stretching step and the relaxation step may be performed continuously or may be performed separately for each step.
The lens raw yarn thus obtained may be continuously cut to a desired length as it is, or may be cut after being wound on a bobbin or the like.

Next, the manufacturing method of the rod lens plate according to the first embodiment of the present invention will be described.
In the manufacturing method of this embodiment, first, the rod lens array 1 (FIG. 1) is manufactured using the plastic rod lens as described above.
The rod lens array 1 used in this embodiment has a configuration in which a plurality of rod lenses 2 are arranged in a line between two substrates 4 and 6 so that the optical axis directions are parallel to each other. The space between the rod lens 2 and the substrates 4 and 6 is filled with an adhesive 8, and the rod lens 2 and the substrates 4 and 6 are fixed. The adjacent rod lenses 2, 2 may be in contact with each other as shown in FIG. 1, or may be arranged with a certain distance, but the distance between the rod lenses 2, 2 is not limited. It is preferable that is constant.

  The material of the substrates 4 and 6 is not particularly limited, but is preferably a material that can be easily processed in the process of manufacturing the rod lens array. As a material for the substrate, various thermoplastic resins, various thermosetting resins and the like are preferable, and acrylic resin, ABS resin, polyimide resin, liquid crystal polymer, epoxy resin and the like are particularly preferable. Moreover, you may use a fiber and paper as a base material of a board | substrate and a reinforcing material. You may add a mold release agent, dye, a pigment, etc. to a board | substrate.

  Further, in the illustrated example, the substrates 4 and 6 are flat plates with flat surfaces. However, in order to arrange the rod lenses 2 at regular intervals, grooves such as a U shape and a V shape that accommodate the rod lenses 2 are provided. May be provided.

In manufacturing the rod lens array 1 having such a configuration, first, a release agent is applied to one side of the substrates 4 and 6. As the mold release agent, known ones used for mold release at the time of molding of a thermoplastic resin or a thermosetting resin are used, but the silicone mold release agent containing dimethyl silicone or a derivative thereof affects the rod lens 2. It is particularly preferable because it is excellent in peelability. As a method for applying the release agent, a known method is used, but a spray coating method is preferable because the release agent can be easily and uniformly applied.
Instead of the release agent, a compound having the same function as the release agent and a peelable adhesive may be applied.

Next, a plurality of rod lenses 2 cut to a certain length are arranged and fixed between two substrates 4 and 6 arranged so that the surfaces to which the release agent is applied face each other. The rod lenses 2 are arranged in parallel so that the side surfaces are in contact with each other. In this state, an adhesive 8 containing a light shielding agent such as carbon black is injected into a gap formed between the rod lens 2 and the substrates 4 and 6, and the adhesive 8 is cured to complete the rod lens array 1. To do.
Thereafter, the rod lens array 1 is cut into a desired length. Thereafter, if necessary, the end surface may be mirror-finished by a method such as cutting with a diamond blade.

Next, the two substrates 4 and 6 are peeled from the rod lens array 1, and a rod lens array (rod lens array) 10 (FIG. 2) in which a plurality of arranged rod lenses 2 are fixed by an adhesive 8 is obtained. obtain.
As a method of peeling the two substrates 4 and 6, the rod lens array 1 is fixed and one substrate 4 (or 6) is pulled and peeled, or the substrate 4 (or 6) is fixed with an adhesive. For example, a thin blade or the like is inserted between the rod lens rows 10 to separate the interface. In the present embodiment, a release agent such as a silicone-based release agent is applied in advance to the surfaces of the substrates 4 and 6, so the rod lens array 1 is fixed and one substrate 4 (or 6) is fixed. The substrate 4 (or 6) can be easily peeled from the rod lens array 1 by pulling.

  Next, a plurality of rod lens arrays 10 are bonded to each other at the side surfaces from which the substrate 4 (or 6) has been peeled off to obtain a rod lens plate 12 as shown in FIG. At this time, the rod lens arrays 10 are arranged so that the rod lenses 2 are parallel and the end surfaces perpendicular to the optical axis of the rod lenses 2 are substantially the same plane.

In the present embodiment, the end surfaces of the rod lens arrays 10 are made to be the same plane by bringing the adjacent rod lens arrays 10 and 10 into close contact with each other in a state in which one end surface of each rod lens array 10 is in contact with a flat plate. Yes.
In the present embodiment, as shown in FIG. 3, the rod lenses 2 of the adjacent rod lens rows 10 have a stacked positional relationship in which the rod lenses 2 are shifted by the radius of the lens. A rod lens plate 12 ′ (FIG. 4) in which the rod lens rows 10 are arranged so as to have a four-sided positional relationship in which the ten rod lenses 2 are aligned may be used.
After the rod lens rows 10 are arranged in the shape of a rod lens plate by arranging a large number of rod lens rows fixed by an adhesive, a method of contacting the side surfaces of the rod lens rows 10 with adhesive applied to the side surfaces, Bonding is performed by, for example, injecting a liquid adhesive having a low viscosity into the gap between the side surfaces of the rod lens array 10.

  After the rod lens plate is manufactured in this way, post-processing such as making the end surface a mirror surface by optical polishing or cutting with a diamond blade, or attaching an antireflection film to the end surface may be performed as necessary.

Next, a method for manufacturing the rod lens plate according to the second embodiment of the present invention will be described.
The second embodiment also uses the same rod lens array 1 as in the first embodiment. In this embodiment, a rod lens plate 14 (FIG. 5) is manufactured by connecting a plurality of rod lens arrays 1 without peeling off the substrates 4 and 6.
In the rod lens array 1, the substrates 4 and 6 are bonded to each other so that the rod lenses 2 are parallel to each other and the end surfaces perpendicular to the optical axis of the rod lens 2 are substantially the same plane. The method for aligning the end faces of the rod lens array is the same as in the first embodiment.

As in the first embodiment, the rod lens arrays 1 are arranged by arranging a large number of rod lens arrays 1 fixed by an adhesive or a method of bringing the side surfaces of the rod lens array 1 applied with adhesive onto the side surfaces. After the rod lens plate is formed, it is bonded by a method of injecting a liquid adhesive having a low viscosity into the gap between the side surfaces of the rod lens array 10.
Similarly to the first embodiment, the rod lenses 2 of the adjacent rod lens array 1 may have a four-sided positional relationship.

  As in the first embodiment, after manufacturing the rod lens plate, the end surface is made into a mirror surface by optical polishing or cutting with a diamond blade, or post-processing such as attaching an antireflection film to the end surface is performed as necessary. Also good.

  In the second embodiment, it is preferable to make the substrates 4 and 6 of the rod lens array 1 thin, for example, a thickness of 0.3 mm or less.

The rod lens plate manufactured by the manufacturing method of the first embodiment and the second embodiment is different from the conventional manufacturing method, and the rod lens plate is manufactured using the rod lens array. Since the accuracy of the lens length can be made comparable to the dimensional accuracy of the lens array, an extremely high accuracy can be obtained.
This is because the rod lens array is usually in the form of one or two lines, so the accuracy on the line can be easily adjusted for the mirror finish of the end face, and mass production of such an array with the same external dimensions is easy. This is because it can.

  In addition, since a large rod lens plate can be manufactured by sequentially connecting rod lens arrays, a large array device that matches the size of the rod lens plate that was necessary in the conventional manufacturing method. It is possible to manufacture a large rod lens plate with a small manufacturing apparatus without using the above.

The present invention is not limited to the above-described embodiment, and various changes or modifications can be made within the scope of the matters described in the claims.
In the above embodiment, the rod lens plate is manufactured by using the rod lens array 1 in which one row of rod lenses is arranged between the substrates. However, a plurality of rows (2 to 4 rows) of rod lenses are provided between the substrates. A rod lens array 16 in which are stacked and arranged may be used (FIG. 6). In this case, it is preferable that the rod lenses are arranged in a stacked manner as shown in FIG. 6 or in a four-sided manner so that the gap is minimized.

  In the above embodiment, the rod lens is made of plastic, but the present invention can also be applied to a glass rod lens. The glass rod lens is preferably manufactured by an ion exchange method. Further, the configuration of the refractive index distribution and the like of the rod lens is not limited to the above embodiment, and can be appropriately changed according to the application.

  Furthermore, although the said embodiment was the structure which apply | coats a mold release agent etc. to the surface of a board | substrate for making peeling of a board | substrate easy, a board | substrate itself is made to contain a mold release agent or a compound with the function similar to it. The structure which uses the board | substrate which consists of a structure or a poor adhesiveness with an adhesive agent may be sufficient.

  Hereinafter, the present invention will be described specifically by way of examples. In the examples, the refractive index distribution was measured by a known method using an Interfaco interference microscope manufactured by Carl Zeiss.

  For first layer formation, 52 parts by weight of polymethyl methacrylate, 35 parts by weight of benzyl methacrylate, 13 parts by weight of methyl methacrylate, 0.25 parts by weight of 1-hydroxycyclohexyl phenyl ketone and 0.1 parts by weight of hydroquinone are heated and kneaded at 70 ° C. The stock solution was used.

  48 parts by weight of polymethyl methacrylate, 10 parts by weight of benzyl methacrylate, 35 parts by weight of methyl methacrylate, 7 parts by weight of 2,2,3,3,4,4,5,5-octafluoropentyl methacrylate, 0-hydroxyhydroxyphenyl ketone 1 25 parts by mass and 0.1 part by mass of hydroquinone were heated and kneaded at 70 ° C. to obtain a second layer forming stock solution.

  47 parts by mass of polymethyl methacrylate, 30 parts by mass of methyl methacrylate, 23 parts by mass of 2,2,3,3,4,4,5,5-octafluoropentyl methacrylate, 0.25 parts by mass of 1-hydroxycyclohexyl phenyl ketone, hydroquinone 0.1 parts by mass was heated and kneaded at 70 ° C. to obtain a third layer forming stock solution.

  40 parts by weight of polymethyl methacrylate, 18 parts by weight of methyl methacrylate, 42 parts by weight of 2,2,3,3,4,4,5,5-octafluoropentyl methacrylate, 0.25 parts by weight of 1-hydroxycyclohexyl phenyl ketone, hydroquinone 0.1 parts by mass was heated and kneaded at 70 ° C. to obtain a fourth layer forming stock solution.

  37 parts by mass of polymethyl methacrylate, 4 parts by mass of methyl methacrylate, 59 parts by mass of 2,2,3,3,4,4,5,5-octafluoropentyl methacrylate, 0.25 parts by mass of 1-hydroxycyclohexyl phenyl ketone, hydroquinone 0.1 parts by mass was heated and kneaded at 70 ° C. to obtain a fifth layer forming stock solution.

  In addition, in order to suppress crosstalk light and flare light, the dye Blue ACR (manufactured by Nippon Kayaku Co., Ltd.) is used for the entire stock solution in each stock solution for the third layer, the fourth layer, and the fifth layer before heating and kneading. ) 0.12% by mass, dye MS Yellow HD-180 (manufactured by Mitsui Toatsu Dye Co., Ltd.) 0.10% by mass, dye MS Magenta HM-1450 (manufactured by Mitsui Toatsu Dye Co., Ltd.) 0.08% by mass Was added.

  These five types of stock solutions were sequentially arranged from the center so that the refractive index after curing was lowered and simultaneously extruded from a concentric five-layer composite spinning nozzle. The temperature of the composite spinning nozzle was 40 ° C. The ejection ratio of each layer is converted into the ratio of the thickness of each layer in the radial direction of the lens (the radius in the first layer). First layer / 2nd layer / 3rd layer / 4th layer / 5th layer = 35/38/20/6/1.

  Next, the filaments extruded from the composite spinning nozzle are taken up by a nip roller (300 cm / min), passed through a 30 cm-long interdiffusion treatment unit, and subsequently 18 chemical lamps having a length of 120 cm and 40 W are provided on the central axis. First curing processing unit (first light irradiation unit) disposed at equal intervals around the second curing processing unit (second light) having three 2 kW high-pressure mercury lamps disposed at equal intervals around the central axis The filamentous body was sequentially passed over the center of the irradiation section) and cured. The nitrogen flow rate in the interdiffusion treatment part was 72 L / min. The radius of the obtained lens yarn was 0.24 mm.

  The lens yarn was stretched 2.2 times in an atmosphere of 125 ° C., and subjected to relaxation treatment so that the relaxation rate was 10/11 in an atmosphere of 140 ° C.

The obtained rod lens has a radius of 0.17 mm, a center refractive index of 1.513, and a refractive index distribution approximated by the formula (1) in the range of 0.2r to 0.8r from the central axis toward the outer periphery, and is 525 nm. The refractive index distribution constant g at a wavelength of 1.51 mm ⁻¹ was 1.51 mm ⁻¹ .

  In addition, a layer having a thickness of about 47 μm from the outer peripheral surface of the rod lens toward the central portion and a substantially uniform mixture of dyes was formed.

  The obtained rod lenses (cut to a length of 200 mm) were closely arranged in a row between two phenolic resin substrates (thickness 0.3 mm, length 200 mm × width 227 mm). A plurality of the obtained arrays are stacked, and the gap between the rod lens and the substrate is filled with an adhesive (Epiform with carbon black (2% by mass) added). The agent was cured. The rod lens array original plate thus produced is cut perpendicularly to the optical axis direction of the lens to form a lens array having a lens length of 3 mm, and both end surfaces thereof are mirror-cut with a diamond blade, and the lens length is 2.52 mm. A lens array of A4 size (width 227 mm) with both end surfaces mirrored was manufactured. Before producing the lens array, a release agent (KF-96 (dimethyl silicone oil) manufactured by Shin-Etsu Silicone) was spray-coated on the surface of the substrate in contact with the lens.

  The conjugate lengths (Tc) of these lens arrays at 470 nm, 525 nm, and 630 nm were 4.79 mm, 5.03 mm, and 5.33 mm, respectively, and the difference in Tc between 630 nm and 470 nm was 0.54 mm. The overlapping degree m at 525 nm was 1.11.

  The substrate was peeled from these lens arrays to obtain a rod lens array fixed with an adhesive. After removing the mold release agent adhering to the side surfaces of these rod lens rows, 900 rod lens rows are arranged so that the end surfaces thereof are on the same plane, and the end portion of the rod lens row width is They were arranged in close contact so as to be aligned. Thereafter, an instantaneous adhesive was applied to the side surface of each rod lens array, and the side surfaces of the adjacent rod lens arrays were adhered to each other to obtain a rod lens plate of about A4 paper size (227 mm × 306 mm). In this rod lens plate, the rod lenses were arranged in a four-sided stack. Both sides of this rod lens plate were mirror-finished, and the variation in thickness (lens length) within the rod lens plate was ± 5 μm or less.

  An antireflection film (Arc Top manufactured by Asahi Glass Co., Ltd.) was attached to both surfaces of the rod lens plate of Example 1. When the reflected light was measured, it was reduced by 90% or more as compared to before applying the antireflection film.

  A lens array was produced in the same manner as in Example 1 except that the release agent was not spray-coated on the surface of the substrate in contact with the lens. These 900 lens arrays were arranged so that the end surfaces of the rod lenses were on the same plane, and were arranged in close contact so that the end portions of the rod lens array were aligned. Thereafter, an instantaneous adhesive was applied to the side surfaces of the respective substrates, and the substrate side surfaces of the adjacent rod lens arrays were adhered to each other to obtain a rod lens plate having a size of 227 mm × 855 mm. In this rod lens plate, the rod lenses were arranged in a four-sided stack. Both sides of this rod lens plate were mirror-finished, and the variation in thickness (lens length) within the rod lens plate was ± 5 μm or less.

  An antireflection film (Asahi Glass Arc Top) was attached to both surfaces of the rod lens plate of Example 3 (both end surfaces perpendicular to the optical axis of the rod lens). When the reflected light was measured, it was reduced by 90% or more as compared to before applying the antireflection film.

  A rod lens plate of about A4 paper size (227 mm × 306 mm) having a lens length of 3 mm was obtained in the same manner as in Example 1 except that both end faces of the lens array were used without being mirror-cut. In this rod lens plate, the rod lenses were arranged in a four-sided stack. Both surfaces of this rod lens plate were polished with a No. 8000 water-resistant polishing sheet to obtain a rod lens plate having a lens length of 2.52 mm and mirror-treated on both surfaces. Variation in thickness (lens length) in the rod lens plate was ± 5 μm or less.

  Antireflection films (Ark Top manufactured by Asahi Glass Co., Ltd.) were attached to both surfaces (both end surfaces perpendicular to the optical axis of the rod lens) of the rod lens plate of Example 5. When the reflected light was measured, it was reduced by 90% or more as compared to before applying the antireflection film.

  A rod lens having a radius of 0.294 mm was obtained in the same manner as in Example 1 except that the take-up speed with the nip roller was changed to 200 cm / min and no stretching-relaxation was performed.

The center refractive index of the obtained rod lens is 1.513, and the refractive index distribution is approximated by the formula (1) in the range of 0.2r to 0.8r from the central axis toward the outer peripheral portion, and the refractive index distribution at a wavelength of 525 nm. The constant g was 0.89 mm ⁻¹ .

  In addition, a layer having a thickness of about 79 μm from the outer peripheral surface of the rod lens toward the central portion, in which the dye is almost uniformly mixed, was formed.

  The obtained rod lenses (cut to a length of 200 mm) were closely arranged in a row between two phenolic resin substrates (thickness 0.3 mm, length 200 mm × width 236 mm). A plurality of the obtained arrays are stacked, and the gap between the rod lens and the substrate is filled with an adhesive (Epiform with carbon black (2% by mass) added). The agent was cured. The rod lens array original plate thus produced is cut perpendicularly to the optical axis direction of the lens to form a lens array having a lens length of 5 mm, and both end faces thereof are mirror-cut with a diamond blade, and the lens length is 4.10 mm. A lens array of A4 size (width 236 mm) with both end surfaces mirrored was manufactured. Before producing the lens array, a release agent (KF-96 (dimethyl silicone oil) manufactured by Shin-Etsu Silicone) was spray-coated on the surface of the substrate in contact with the lens.

  The Tc of this lens array at 470 nm, 525 nm, and 630 nm were 9.2 mm, 9.8 mm, and 10.6 mm, respectively, and the difference in Tc between 630 nm and 470 nm was 1.4 mm. The overlapping degree at 525 nm was 1.72.

  The substrate was peeled from these lens arrays to obtain a rod lens array fixed with an adhesive. After removing the mold release agent adhering to the side surfaces of these rod lens rows, 540 rod lens rows are arranged so that the end surfaces thereof are on the same plane, and the rod lenses are arranged in a stacked manner. Thus, every other end of the width of the rod lens array was shifted by half the lens arrangement pitch and aligned and closely aligned. Thereafter, an instantaneous adhesive was applied to the side surfaces of the rod lens rows, and the side surfaces of the adjacent rod lens rows were bonded to each other. The end of this rod lens plate was cut to 227 mm to obtain a rod lens plate of about A4 paper size (227 mm × 318 mm). In this rod lens plate, the rod lenses were arranged in a stack. Both sides of this rod lens plate were mirror-finished, and the variation in thickness (lens length) within the rod lens plate was ± 5 μm or less.

[Comparative Example 1]
A large number of rod lenses (cut to a length of 200 mm) obtained in Example 1 were arranged in a frame of length 227 mm × width 300 mm × height (length) 200 mm, but the lens was flexible. Because of that it could not be arranged well.

[Comparative Example 2]
A large number of rod lenses obtained in Example 7 cut to a length of 5 mm were packed in a frame of 227 mm length × 300 mm width × height (length) 5 mm and arranged in a stack. The gap was filled with an adhesive and cured, and the end surface was cut and polished with a diamond blade to obtain a rod lens plate having a thickness (lens length) of 4.10 mm.

  In this rod lens plate, the rod lenses were arranged in a substantially stacked manner, but there was an arrangement disorder that was not partially stacked. This rod lens plate was mirror-treated on both sides, but the variation in thickness (lens length) within the rod lens plate was ± 20 μm.

It is a schematic sectional drawing which shows the structure of the rod lens array used by the embodiment of this invention. It is a schematic sectional drawing which shows the structure of the rod lens row | line | column used in the embodiment of this invention. It is a schematic sectional drawing which shows the structure of the rod lens plate manufactured by the method of the 1st embodiment of this invention. It is a schematic sectional drawing which shows the structure of the rod lens plate manufactured by the modification of the method of the 1st embodiment of this invention. It is a schematic sectional drawing which shows the structure of the rod lens plate manufactured by the method of the 2nd embodiment of this invention. It is a schematic sectional drawing which shows the structure of the modification of the rod lens array used by the embodiment of this invention.

Explanation of symbols

1: Rod lens array 2: Rod lens 4, 6: Substrate 8: Adhesive 10: Rod lens array 12: Rod lens plate 14: Rod lens plate

Claims (4)

A rod lens plate manufacturing method in which rod lenses are two-dimensionally arranged,
Arranging a plurality of rod lenses between two substrates in parallel so as to be parallel to each other;
Injecting an adhesive into the space between the substrate and the rod lens to form a rod lens array;
Peeling the substrate from the rod lens array to obtain a rod lens array connected by the adhesive; and
Bonding the rod lens array to each other such that end surfaces thereof are located on the same plane to form a rod lens plate;
A method for producing a rod lens plate, comprising: A step of applying a release agent to the surface of the substrate prior to the step of arranging in parallel,
The manufacturing method of the rod lens plate of Claim 1. The substrate contains a release agent;
The manufacturing method of the rod lens plate of Claim 1. A rod lens plate manufacturing method in which rod lenses are two-dimensionally arranged,
Arranging a plurality of rod lenses between two substrates in parallel so as to be parallel to each other;
Injecting an adhesive into the space between the substrate and the rod lens to form a rod lens array;
Bonding the rod lens array to each other such that end surfaces thereof are located on the same plane to form a rod lens plate;
A method for producing a rod lens plate, comprising:

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