JPH05423A - Manufacture of composite optics - Google Patents

Abstract

PURPOSE:To obtain the excellent productivity of composite optics in which resin layers are formed on both surfaces of a lens blank by only radiating ultraviolet ray from its one side. CONSTITUTION:A lens blank 6 is caused to intervene between a transparent mold 1 and the mold 2 oppositely arranged on the same axis. Ultraviolet ray 3 is radiated on said lens by an ultra high pressure mercury lamp 4, whereby each resin 5a, 5b caused to intervene between one surface of the lens blank 6 and the transparent mold 1 and between the other surface of the lens blank and the mold 2, is cured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a composite optical element in which a lens blank is provided with an ultraviolet-curable resin polymerization layer.

[0002]

2. Description of the Related Art In recent years, aspherical lenses have attracted attention for the purpose of improving performance and compactness of camera lenses and optical pickups. As a method of manufacturing this aspherical lens, a technique of molding an aspherical surface with an organic polymer resin layer on a lens blank such as glass has been proposed.

In such a composite type optical element, it is necessary to align the optical axis of the lens blank and the optical axis of the resin layer with high accuracy as a structural problem, but it is necessary to align the optical axis with high accuracy. Is very difficult to manufacture.

The following inventions have been proposed to solve the above problems.

For example, in the invention described in Japanese Patent Laid-Open No. 62-272203, a method has been proposed in which a thermosetting resin layer is provided on both surfaces of a lens blank at the same time.

This is because even if the optical axis of the lens blank and the optical axis of the resin layer deviate from each other, if the optical axes of the two resin layers provided on the respective surfaces of the lens blank coincide with each other, the lens blank will serve as a lens. It has a single core, and is achieved by ensuring the positional accuracy of the mold for forming the resin layer on the lens flank.

Further, in the invention described in JP-A-62-62716, as shown in FIG.
1 is provided with an ultraviolet-curable resin layer 12 on both sides, a transparent mold 13 made of a highly transparent material such as glass is brought into close contact, and ultraviolet rays 14 are simultaneously irradiated from both sides. By being able to use a resin,
This makes it possible to greatly improve productivity.

[0008]

However, the above-mentioned prior art has the following drawbacks.

That is, in the invention disclosed in JP-A-62-272203, a thermosetting resin is used. It takes 30 minutes for the resin to cure, and 24 hours or more for the resin to cure. It takes time and productivity is extremely low.

Further, in the invention disclosed in Japanese Patent Laid-Open No. 62-62716, curing can be performed in a short time by using an ultraviolet curable resin and a transparent resin, but ultraviolet rays must be irradiated from both sides of the lens blank. This necessitates the use of two light sources, which increases equipment costs. Further, the irradiation of ultraviolet rays from both sides of the lens blank has a drawback that the molding apparatus is structurally complicated.

Here, the ultraviolet curable resin is composed of a base resin and a photopolymerization initiator, and in order to cure the resin, the radiation wavelength range from the light source and the absorption wavelength range of the photopolymerization initiator (functional wavelength) Area) is required.

On the other hand, since the base resin, the lens blank and the transparent type also absorb light and absorb the ultraviolet rays in the low wavelength region, generally, the wavelength region and the photopolymerization initiator in which the light absorption by the base resin is small. The wavelength required for curing reaches the photopolymerization initiator by overlapping with the absorption wavelength region of.

Therefore, when the resin layer is thick or is irradiated with ultraviolet rays through a member that absorbs light in the functional wavelength range, the resin itself, the lens blank and the transparent mold absorb the ultraviolet rays, and the second layer The resin layer is not sufficiently cured or the time until curing is significantly extended.

That is, if the same resin is used as the resin on both sides of the lens blank (including the photopolymerization initiator added),
If the resin itself or the lens blank absorbs ultraviolet rays and the resin of the second layer is not sufficiently cured,
Very slow curing speed.

When the curing speed of the resin on both surfaces of the lens blank is remarkably different, the contraction of the resin may be different on both surfaces and the lens blank may be distorted.

Therefore, the present invention was developed in view of the above-mentioned drawbacks of the prior art, and an object thereof is to provide a composite type optical element which is excellent in shape accuracy and can be manufactured in a short time with inexpensive equipment.

[0017]

Means for Solving the Problems The present invention provides a method for producing a composite optical element, wherein ultraviolet curable resin polymer layers are provided on both sides of a lens blank, and the resin polymer layer is irradiated with ultraviolet rays through a transparent mold. An ultraviolet lamp is arranged only on one side of the transparent mold, and the resin polymerization layer on one surface of the lens blank surface is longer than the functional wavelength required for curing the resin polymerization layer on the other ultraviolet lamp side surface. Is a method of irradiating with the ultraviolet lamp, using a resin-polymerized layer that is cured at.

Specifically, a photopolymerization initiator having a functional wavelength longer than the functional wavelength of the photopolymerization initiator added to the resin on the ultraviolet lamp side of the lens blank is added to the resin on the other surface.

[0019]

In the present invention, a resin polymer layer that cures at a functional wavelength longer than the functional wavelength that cures the resin polymer layer on the other side of the ultraviolet lamp is used as the resin polymer layer on one side of the lens blank surface. As a result, the light rays required for curing reach the resin polymerization layer on the one surface sufficiently, and the resin polymerization layers on both surfaces of the lens blank can be cured in a short time.

It should be noted that the lens blank and the transparent mold should be made of a material that does not absorb ultraviolet rays as much as possible, but even if this is not possible, it is possible to deal with this by using a resin polymerization layer having a long functional wavelength. is there.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing this embodiment.

Reference numeral 1 is an aspherical transparent mold made of glass (BK-7), and 2 is a mold made of stainless steel created on the aspherical surface. The transparent mold 1 and the mold 2 are arranged so as to face each other. An ultra-high pressure mercury lamp 4 that emits ultraviolet rays 3 is installed above the transparent mold 1.

In the manufacturing method, first, an appropriate amount of the second layer resin 5a is put on the mold 2, and φ made of the material BK-7 is placed thereon.
A 26 mm lens blank 6 is overlaid and the second layer resin 5a is pushed out.

Next, an appropriate amount of the first layer resin 5b is applied onto the lens blank 6, and the transparent mold 1 is placed thereon so that the central axis of the transparent mold 1 and the central axis of the mold 2 are aligned with each other.

After that, after the ultraviolet rays 3 are irradiated by the ultra-high pressure mercury lamp 4 to cure the respective resins 5a and 5b, the transparent mold 1 and the mold 2 are released, and the center blanks are formed on both surfaces of the lens blank 6, respectively. Thickness 300μm, maximum resin thickness difference 200μ
A composite optical element having an aspherical resin layer of m and a resin diameter of 20 mm was obtained.

As the material used in this example, a polyfunctional urethane acrylate type, a polyfunctional ester acrylate type and a polyfunctional epoxy acrylate type are used as the resin base resin, and benzophenone and benzoin are used as the photopolymerization initiator. And thioxanthone were used.

Table 1 shows combinations of the resin base resin and the photopolymerization initiator and their respective absorption wavelength ranges.

[0028]

[Table 1]

According to this example, a composite optical element having resin layers on both sides of a lens blank could be obtained with high productivity.

Although the ultra-high pressure mercury lamp is used in this embodiment, the present invention is not limited to this, and a mercury xenon lamp or the like can be used.

The material itself and the combination thereof are not particularly limited as long as the conditions are satisfied, and can be selected according to the purpose of use.

[0032]

As described above, according to the method of manufacturing a composite optical element according to the present invention, a composite optical element having resin layers provided on both surfaces of a lens blank can be obtained by irradiating ultraviolet rays from one side. Obtained with high productivity.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Transparent type 2 Mold 3 Ultraviolet ray 4 Ultra high pressure mercury lamp 5a, 5b Resin 6 Lens blank

Claims (1)

Claim: What is claimed is: 1. A method for producing a composite optical element, comprising: providing an ultraviolet-curable resin polymerization layer on both surfaces of a lens blank, and irradiating the resin polymerization layer with ultraviolet rays through a transparent mold. An ultraviolet lamp is arranged only on one side of the mold, and the resin polymerization layer on one surface of the lens blank surface has a functional wavelength longer than the functional wavelength required for curing the resin polymerization layer on the other ultraviolet lamp side surface. A method for manufacturing a composite optical element, which comprises irradiating the ultraviolet lamp with a resin-polymerizable layer that cures.