JPS617802A - Method and device for producing distributed index lens - Google Patents

Abstract

PURPOSE:To permit the mass production of rod lenses by constituting a titled device in such a manner that the irradiating part of light by the light transmitting part on a shielding plate expands from the lower to the upper part of a vessel and that conveying part moves from the inlet toward the outlet of a vessel installing part under rotation. CONSTITUTION:The light irradiating part 1 is disposed with a prescribed number of light sources 4 such as UV lamps on both sides of the conveying part 2 and ais provided with the shielding plate 5 between the part 2 and the light sources 4. The plate 5 has the triangular light transmitting part 8 having the side 8a extending so as to rise from the inlet 1a side toward the outlet 1b side of the part 1 and the side 8b extending in a horizontal direction. The light from the light sources 4 is irradiated through such part 8 to the transparent vessel 3 which is rotated and conveyed at a prescribed speed by the part 2 and in which a raw material monomer mixture is filled in such a manner that the part irradiated with said light expands gradually from the lower part toward the upper part. The rod lens is thus continuously formed and the mass production thereof is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing a gradient index lens and an apparatus for manufacturing a gradient index lens used in the method.

[Prior art]

Recently, research and development has been carried out on the Ron F lens, which has a refractive index that changes in proportion to the square of the distance from the central axis, as a gradient index microlens. Its field of application as a one-to-one image conversion element is rapidly expanding.

As one of the methods for manufacturing plastic rod lenses used in such applications, a manufacturing method using a photocopolymerization method using vinyl monomers, acrylic monomers, etc. as raw materials is known. In the production of rod lenses by the copolymerization method, conventional methods 1, for example, "image information (I) 11
18215.6J, page 50, as shown in FIG. 4, was commonly used. In manufacturing rod lenses using the apparatus shown in Fig. 4,
First, set the glass tube 9 filled with the predetermined mixture in the vertical direction, and move it in the direction of arrow 17 (or the opposite direction).
to rotate. Then, light from a light source 4 such as an ultraviolet lamp is irradiated from the side surface of the glass tube 9 through a slit 10 with a predetermined interval A provided at −7 to the lamp force. During the progress of copolymerization due to this light irradiation, the motor 12, gear 13, and threaded support 14
By raising the light source 4 at a constant speed V, light is irradiated from the bottom to the top of the monomer mixture in the glass tube 9. By doing so, the copolymerization proceeds throughout the heptamer mixture in the glass tube 9, and the heptamer is extinguished. In this process, the glass tube 9 rotates and the light is irradiated from the bottom to the top of the glass tube 9, so the monomer mixture moves from the inner wall of the glass tube 9 toward the center of the glass tube 9. As a result, a copolymer whose composition changes continuously becomes a copolymer, and a rod lens precursor is formed. This top-rise rate V varies depending on the type, composition, etc. of the monomer mixture, but is selected to be such that the seven-mer mixture in the center of the glass tube 9 is copolymerized and solidified throughout the entire area from the bottom to the top.

Next, the rod lens precursor in the glass tube 9 in which the seven-pointed lens has almost disappeared is heated. This is because, if only the light irradiation was performed previously, some upper layer would remain in the rod lens precursor, so this was completely polymerized and solidified by applying thermal energy.

Furthermore, this heating also has the effect of eliminating distortion in the manufactured rod lens. By such a method, the center axis 15 is separated from the periphery.
A rod lens having a refractive index gradient 16 as shown in FIG. 5a or FIG. 5b, in which the refractive index gradually increases or decreases toward the end, was obtained.

However, such conventional rod lens manufacturing equipment is not equipped with a heating device, so a separate heating device is required. Therefore, it was necessary to remove the glass tube 9 filled with the loft lens precursor from the light irradiation device shown in FIG. 4 and transfer it to the heating device. Also the fourth
The conventionally known apparatus shown in the figure is not suitable for continuous manufacturing, and it is difficult to mass-produce rod lenses.

[Object of the Invention]' The present invention has been made in view of the problems of the prior art as described above, and makes it possible to manufacture a gradient index lens in one step, and to simplify the steps in manufacturing such a lens. It is an object of the present invention to provide a manufacturing method capable of reducing the number of products and the manufacturing time per product, and an apparatus used in the method.

[Structure of the invention]

The above-mentioned objects are achieved by the method and apparatus for manufacturing a gradient index lens of the present invention, which will be described below. That is, in the method for manufacturing a gradient index lens of the present invention, a transparent container filled with a monomer mixture that is a raw material for a gradient index lens is rotated, and the portion of the transparent container that is irradiated with light is moved from the top to the bottom. The present invention is characterized in that it includes a step of conveying the light at a predetermined speed near a fixed light source that can emit light so as to gradually expand toward the target. Further, the manufacturing device for a gradient index lens used in this method includes a transport section and a light source disposed on one or both sides of the transport section, and a shielding plate is provided between the transport section and the light source. A manufacturing apparatus for a gradient index lens having a light emitting section arranged therein, wherein the shielding plate extends upwardly from the entrance side to the exit side of the emitting section and the side of the light emitting section. The container has a translucent part having a part of its outer periphery with a side extending in a substantially horizontal direction from the entrance side to the exit side, and the transport part has a container installation part in which the container can be installed and rotated on its axis. and the container installation part can be moved from the entrance to the exit of the light irradiation part.

Hereinafter, the method for manufacturing a gradient index lens of the present invention and the apparatus used in this method will be explained in detail with reference to the drawings.

FIG. 1 is a schematic plan view showing an embodiment of an apparatus used in the method of manufacturing a gradient index lens of the present invention, and FIG. 2 is a schematic front view of the apparatus.

This apparatus basically consists of a light irradiation section 1 and a conveyance section 2, and is an apparatus that can manufacture plastic acid rod lenses in one step using a photocopolymerization method.

The light irradiation section 1 functions to irradiate light onto a monomer mixture that is a raw material for a rod lens, convert the monomer into a copolymer, and form a rod lens.

The transport section 2 functions to transport the transparent container 3 filled with the monomer mixture from the entrance 1a of the light irradiation section 1 to the exit 1b.

The light irradiation section 1 has a predetermined number of light sources 4 such as ultraviolet lamps disposed on both sides of a conveyance section 2, and a shielding plate 5 is disposed between the conveyance section 2 and the light sources 4. Note that the light source 4 may be disposed only on one side of the transport section 2.

Furthermore, if necessary, a reflector 6 is installed on the side of the light source 4 opposite to the shielding plate, and a lamp cover 7 is provided so as to surround the light source 4 and the reflector 6. .

In the apparatus shown in FIG.
A triangular light-transmitting part 8 has a side 8a that extends upward from the entrance 1a side toward the exit lb side of the light irradiation part 1, and a side 8b that extends horizontally from the entrance la side of the light irradiation part 1 to the exit lb side. have The transparent container 3 filled with the raw material mixture is transported by the transport section 2 at a predetermined speed through the light-transmitting section 8, and the portion irradiated with light gradually expands from the bottom to the top. The light from the light source 4 is irradiated in this way. However, it is not necessary to irradiate the transparent container 3 with light so that the portion of the transparent container 3 that is irradiated with light is constantly enlarged throughout the entire process of irradiation with light.

Therefore, as long as such light irradiation is possible, the shape of the light-transmitting portion 8 may be any shape and is not limited to the above-mentioned triangular shape. That is, the side that extends upward from the entrance 1a side of the light irradiation section 1 toward the exit lb side and the side that extends almost horizontally from the entrance 1a side of the light irradiation section 1 toward the exit lb side are defined as one part of the outer periphery. Any transparent portion 8 having a shape similar to that shown in FIG. The former side is preferably a straight line in order to keep the copolymerization rate constant.

The latter side can be used as long as the lowest part of the monomer mixture filled in the transparent container 3 can be irradiated with light at the entrance 1a of the light irradiation part 1.
It may be extended downward from the side toward the exit lb side, but this is meaningless since it has no effect on the light irradiation effect on the transparent container 3.

Other examples of the shape of the transparent portion 8 are shown in FIGS. 3a, 3b, and 3.
Although shown in FIG. c, various modifications can be made without being limited to these examples. In these figures, 8a corresponds to the side extending upward from the entrance 1a side of the light irradiation section 1 toward the exit lb side, and 8b corresponds to the side extending almost horizontally from the entrance 1a side of the light irradiation section 1 toward the exit lb side. Corresponds to the extended side. This light-transmitting portion 8 is made of a void or a light-transmitting material. If necessary, a slit may be provided in the light-transmitting portion 8 so that the light does not diverge in unnecessary directions. When the transparent part 8 is made of a transparent material, the monomer mixture in the transparent container 3 can be effectively photocopolymerized by the light irradiated from the light source 4 through the transparent part 8. need to be selected.

The reflecting plate 6 serves to effectively irradiate the monomer mixture within the transparent container 3 with the light from the light source 4 .

The transport section 2 has a container installation section in which a desired number of transparent containers 3 can be installed, and this container installation section has means for rotating the transparent containers 3 on its axis. This transport section 2 may be configured to be able to install transparent containers 3 in two or more rows.

A method for continuously manufacturing a gradient index lens of the present invention using the above-described apparatus will be described below.

First, the transparent container 3 is filled with additives such as monomers and catalysts constituting the seven-mer mixture, which is a raw material for rod lenses, so as to have a predetermined composition.

As the rod lens raw material and its composition, raw materials having the same composition as those used in the conventional photocopolymerization method can be used. For example, the monomers constituting the monomer mixture may be vinyl benzoate and methyl methacrylate, vinyl chlorobenzoate and trifluoroethyl methacrylate, and the catalyst may be a benzoin ether compound, an organic peroxide, or the like.

Next, the transparent container 3 filled with this monomer mixture is placed in the transport section 2, and is moved at a constant speed V° from the entrance 1a to the exit 1b of the light irradiation section 1 while rotating. In this way, the monomer mixture in the transparent container 3 becomes a copolymer whose composition changes continuously from the periphery toward the center of the transparent container 3.

In the apparatus of the present invention, the portion of the monomer mixture that is irradiated with light is gradually expanded from the bottom to the top, so that the monomer mixture also moves from the bottom to the top, forming a copolymer layer with some residual upper layer. be done.

The copolymer layer thus formed, in which some of the monomer remains, continues to be irradiated with light.

Since the light source 4 also emits light having a heating effect, such as infrared rays, the monomer remaining in the copolymer layer disappears and solidifies due to the subsequent irradiation with the light. Therefore, manufacturing of the rod lens is completed without requiring a separate heating process unlike the conventional rod lens manufacturing method. The light source 4 is selected from sources that can provide the light energy necessary for photocopolymerization depending on the monomer mixture and also contain light of a wavelength capable of producing a heating effect, such as infrared rays.

As the reaction temperature, a temperature at which the photocopolymerization reaction proceeds, usually room temperature, is sufficient.

Further, the moving speed v', the light intensity of the light source, the number of light sources 4, and the interval between each light source 4 vary depending on the size of the transparent section 8 of the light irradiation section 1 and the size of the rod lens to be manufactured.
An appropriate selection is made depending on the photopolymerization reactivity of the monomer mixture so that the monomer mixture in the center of the transparent container 3 forms a copolymer layer from the bottom to the entire top. However, even if the transparent container 3 reaches the right end of the transparent part 8, if the 7-mer mixture filled in it (especially the upper part, which is exposed to less irradiation time) is not sufficiently polymerized and solidified, as shown in Fig. 3. In this way, a trapezoidal transparent portion 8 may be formed to increase the light irradiation time.

Note that depending on the type of 7-mer mixture, optical distortion may occur during the manufacturing process, and this optical distortion may not be completely removed by this apparatus. In this case, a heating device having heating means may be disposed after one device, and the transparent containers 3 may be continuously carried into this heating device by the conveying section 2 and heated.

〔Effect of the invention〕

With the above-described method and apparatus for producing a gradient index lens of the present invention, a refractive IfX lens can be produced without a special heating step. To this end, it is possible to reduce the number of manufacturing steps for gradient index lenses and reduce the manufacturing time per lens.

At the same time, mass production of gradient index lenses became possible.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

〔Example〕

Two rows of light sources 6 each having 10 UV lamps arranged in a straight line (the interval between the UV lamps in each row is 30 cm)
+a, the spacing between rows is 40c, each UV lamp is 8
0w/ct), a transparent part 8 in the shape of a right triangle (horizontal side 300 cm, vertical side 20 cm, hypotenuse 30
A rod lens was manufactured as described below using a gradient index lens manufacturing apparatus consisting of a light irradiation section 1 consisting of two shielding plates 5 having a diameter of 1 cm), a reflector 6 and a lamp cover 7, and a transport section 2. .

First, 1.55 g of vinyl chlorobenzoate (0,008 aol
) and 4.65 g of methyl methacrylate (0,048 IC
11) and a mixture containing 1% by weight of benzoyl perbutylation and 0.1% by weight of benzoin ethyl ether were charged into the catalyst. This transparent container 3 is moved at a constant speed (2cm/5in)
The transport section 2 is moved from the entrance 1a of the light irradiation section 1 to the exit 1b by
The lens was conveyed while rotating on its own axis, and a rod lens was formed.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing an embodiment of an apparatus for continuously manufacturing a gradient index lens according to the present invention, and FIG. 1 is a schematic front view of the apparatus. FIG. 3 is a schematic front view showing another embodiment of the continuous production apparatus for gradient index lenses of the present invention;
FIGS. 3a, 3b, and 3c are diagrams showing examples of the shape of the transparent portion. FIG. 4 is a schematic diagram of a conventional gradient index lens manufacturing apparatus, and FIG. 5 is a diagram showing a part of a rod lens. 1: Light irradiation section la: Inlet of light irradiation section 1b: Exit of light irradiation section 22 Transport section 3: Transparent container 4: Light source 5: Shielding plate 6: Reflection plate 7: To lamp cover - 8: Transparent section 8a: A side 8 which extends upwardly from the inlet side of the light irradiation section of the light transmitting section toward the exit side.A side 9 which extends in an almost horizontal direction from the inlet side of the light irradiation section of the two-dimensional light toward the exit side.Niglass tube 10 Nislit 12: Motor 13: Gear 14: Threaded support 15: Central axis 16: Refractive index gradient curve 17: Arrow 18 indicating the direction of rotation 2 Arrows indicating the direction Red 3 Figure

Claims (1)

[Claims] 1) In a method for manufacturing a gradient index lens, a transparent container filled with a monomer mixture serving as a raw material for a gradient index lens is rotated, and a portion of the transparent container that is irradiated with light is A method for manufacturing a gradient index lens, comprising the step of transporting at a predetermined speed near a fixed light source that can irradiate light so as to gradually expand from the top to the bottom. 2) A refractive index distribution type comprising a transport section and a light source disposed on one or both sides of the transport section, and a light emitting section with a shielding plate disposed between the transport section and the light source. In the lens manufacturing apparatus, the shielding plate has a side extending upwardly from the entrance side to the exit side of the irradiation section, and a side extending in a substantially horizontal direction from the entrance side to the exit side of the light irradiation section. a translucent part having a shape having a part of the outer periphery, and the conveying part has a container installation part in which a container can be installed and rotated,
An apparatus for manufacturing a gradient index lens, characterized in that the container installation section can be moved from the entrance to the exit of the light irradiation section.