JP2000266907A - Resin joint type optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain necessary optical performance without laergely deviating from a desired optical surface shape by providing a hard resin layer on one surface, and providing a reflection preventing film on the other surface of a base material. SOLUTION: A lens of a composite type optical component (resin joint type optical element), is provided with a hard resin layer 4 on one surface A of a base material 1, and a reflection preventing film 3 with reflectance <1% against light of wavelength 365 nm on the other surface B of the base material 1. Namely, the lense base material 1 is prepared, and one surface (a lens surface B on the opposite side to the lens surface A forming a hard resin layer) of the lens base material 1 is coated with a reflection preventing film 3. On the other surface of the lens base material 1 (the lens surface A not coated with the reflection preventing film 3) is formed with a hard resin layer 2 to generate a non-spherical shape. Such composite type optical component (lens) is only a little deviated from the desired shape (non-spherical shape) in the optical surface shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-bonded optical element having a cured resin layer provided on a substrate (for example, a composite optical component formed by bonding a glass substrate and a resin). It is.

[0002]

2. Description of the Related Art A lens which is an optical element includes an aspherical lens having an aspherical surface. This aspherical lens is widely used because it has excellent performance that cannot be obtained with a spherical lens or the like, such as removal of spherical aberration by a spherical lens and distortion by a wide-angle lens.

As an optical part having such an aspherical shape, for example, as disclosed in Japanese Patent Application Laid-Open No. Sho 59-12412 (Minolta), a resin-bonded optical element having a resin layer formed on a glass substrate is disclosed. A composite optical component as an element has been proposed. In such a composite aspherical lens (resin-bonded optical element), a single-layer film or a multi-layer film is generally provided on a lens surface opposite to a lens surface provided with a cured resin layer as shown in FIG. A thin film for use (anti-reflection film) 3 is formed.

Here, as the antireflection film, a multilayer film having a wide band used for an optical component such as a camera is often formed, and the reflectance characteristic is shown in FIG. The performance of the broadband multi-layer film depends on the required quality, such as color balance, of optical components such as cameras, in the visible region (400 nm to 700 nm).
In m), a reflectance of 1% or less is required.

[0005] Further, since this antireflection film is generally formed by a vacuum evaporation method, the temperature of the lens surface becomes high at about 250 ° C when a thin film is formed. Therefore, an antireflection film is deposited before forming a cured resin layer on the lens surface. This is because the ultraviolet curable resin constituting the cured resin layer generally deteriorates when left in the high temperature environment as described above, and deteriorates the quality (appearance, aspherical shape, refractive index) as an optical component. Because.

FIG. 2 shows a general manufacturing process of a composite aspherical lens (resin-bonded optical element). In the first step of FIG. 2, first, a glass lens (base material) 1 is prepared. Next, in the second step, one surface of the glass lens 1 (the lens surface B opposite to the lens surface A on which the cured resin layer is formed) is coated with the antireflection film 3.

In the third step, the cured resin layer 2 is formed on the other surface of the glass lens 1 (the lens surface A not coated with the antireflection film 3) to create an aspherical shape. Here, the formation of the cured resin layer 2 is performed, for example, as follows (see FIG. 11). First, the ultraviolet curable resin liquid 52a is sandwiched between the surface A of the lens substrate 51 and the mold surface of the mold 53 having a predetermined shape.

Next, while pushing and spreading the resin liquid 52a, both are brought close to a position where the distance between the lens base material 51 and the mold 53 becomes a predetermined value or a predetermined range. With the positions of the lens substrate 51 and the mold 53 held, the resin liquid 52a is irradiated with light (ultraviolet rays) 54 from the front surface B side of the lens substrate 51 on which the antireflection film is formed, thereby forming the resin liquid. After curing, the cured resin layer 52 is formed and integrated with the lens substrate 51, and the shape of the mold surface is transferred to the surface of the cured resin layer 52 to create an aspherical shape.

The lens substrate 51 on which the cured resin layer 52 is integrally formed is peeled off from the mold surface. Finally, in a fourth step, an antireflection film 4 is coated on the cured resin layer 2 (FIG. 2). By the above steps (an example),
A conventional composite aspheric lens (resin-joined optical element) can be obtained.

[0010]

However, the conventional resin-bonded optical element (for example, a composite aspherical lens) is
A resin-bonded optical element (for example, a composite aspherical lens) that often has a shape largely deviating from a desired optical surface shape (for example, an aspherical shape) and sufficiently achieves necessary optical performance.
There was a problem that it was difficult to obtain.

The present invention has been made in view of the above problems, and has been made in view of the above circumstances, and has been made in view of a resin-bonded mold capable of sufficiently achieving required optical performance without largely deviating from a desired optical surface shape (for example, an aspherical shape). An object of the present invention is to provide an optical element (for example, a composite aspherical lens).

[0012]

Therefore, the present invention firstly provides a resin-bonded optical element having a cured resin layer provided on a substrate, wherein the cured resin layer is provided on one surface of the substrate. And a resin-bonded optical element (Claim 1) characterized in that an antireflection film having a reflectance of 1% or less for light having a wavelength of 365 nm is provided on the other surface of the substrate. .

[0013] The present invention also provides a second method. "The antireflection film has a stable measured reflectance for light having a wavelength of 365 nm even when a wavelength shift of ± 10 nm from a set spectral characteristic due to a manufacturing error such as a deposition angle condition occurs. The resin-bonded optical element according to claim 1, wherein the optical element has a spectral characteristic of 1% or less. Further, the present invention provides a third aspect, wherein the antireflection film is an alternating multilayer film of a high refractive index material and a medium refractive index material located on the substrate side, and a low refractive index formed on the alternating multilayer film. A resin-bonded optical element (Claim 3) according to claim 1 or 2, wherein the resin-bonded optical element is formed by laminating a plurality of layers with an outermost layer of a substance.

[0014] The present invention is also directed to a fourth aspect, wherein the antireflection film has a reflectance of 1% or less with respect to light in a visible region (400 to 700 nm). The present invention provides a resin-bonded optical element according to claim 4. Further, the present invention fifthly provides "an anti-reflection film having a reflectance of 1% or less for light in a visible region (400 to 700 nm) is provided on the cured resin layer. 4. A resin-bonded optical element according to any one of (4) to (5).

The present invention is also directed to a sixth aspect of the present invention wherein the optically effective diameter of the substrate surface (first surface) provided with the cured resin layer is the optical effective diameter of the substrate surface (second surface) provided with the antireflection film. Larger than the effective diameter, the periphery of the optically effective diameter portion of the second surface,
A resin-bonded optical element according to any one of claims 1 to 5, wherein the anti-reflection film is not provided with an arazuri portion.

The present invention provides a resin-bonded optical element according to any one of claims 1 to 6, wherein the material of the base material is an optical glass or a crystalline optical material. Item 7) is provided. Eighth, the present invention provides a “resin-bonded optical element according to any one of claims 1 to 7 having at least one aspherical optical surface (claim 8)”.

[0017]

DETAILED DESCRIPTION OF THE INVENTION The present inventors often find that a conventional resin-bonded optical element (for example, a complex aspherical lens) has a shape largely deviating from a desired optical surface shape (for example, an aspherical shape). The present inventors have found out the cause and made the present invention based on the cause. This will be described first.

When a curable resin layer is formed on one optical surface of a substrate (for example, a lens substrate), the material may be a photo-curable resin liquid (for example, UV-curable resin liquid) is often used. The ultraviolet light has a wavelength of 365 nm called i-line.
Is generally used, and many commercially available ultraviolet irradiation devices employ this wavelength light.

Here, the amount of ultraviolet rays when forming the cured resin layer needs to be controlled very precisely. This is because the UV-curable resin liquid undergoes a rapid curing reaction by UV irradiation (curing starts in a few seconds when irradiated with UV light).
If the amount of ultraviolet rays to be irradiated is not controlled to be the same for each substrate, the surface shape (for example, aspherical shape) of the formed cured resin layer may vary widely for each substrate. Because it becomes.

The conventional antireflection film sets the required quality of an optical component (for example, a mirror ball of a camera or the like) only in the visible region (400 nm to 700 nm), but is used when forming a resin layer. No particular attention was paid to prescribed settings for ultraviolet rays (i-line: wavelength 365 nm). Therefore, ultraviolet rays (i-line: wavelength 365 nm)
The reflectance (conversely, the transmittance) of the conventional anti-reflection film varied greatly due to film formation errors.

That is, when an anti-reflection film is formed by, for example, a vapor deposition method, a manufacturing (film forming) error occurs for each manufacturing lot due to a distance error and an angle error between a film forming substance (target) and a substrate to be formed. Then, the entire spectral characteristic of the obtained antireflection film shifts (wavelength shift). As a result, ultraviolet rays (i-line: wavelength 3
The value of the reflectance of the conventional antireflection film with respect to 65 nm) greatly fluctuated due to a film formation error.

As described above, when forming a cured resin layer on the optical surface of the substrate, the resin liquid is irradiated with ultraviolet rays (wavelength 365 nm) from the optical surface side of the substrate on which the antireflection film is formed. However, if the reflectance of the anti-reflection film for ultraviolet rays varies greatly among manufacturing lots, the transmittance of ultraviolet rays changes greatly, and the amount of ultraviolet rays per unit time reaching the resin solution is not negligible (see FIG. 11). To fluctuate.

That is, the reason that a conventional resin-bonded optical element (for example, a complex type aspherical lens) often has a shape largely deviating from a desired optical surface shape (for example, an aspherical shape) is that the base material of the optical element is used. Due to the large variation in the reflectance of the anti-reflection film formed on the substrate to ultraviolet rays (wavelength 365 nm), the amount of transmitted ultraviolet light per unit time reaching the resin liquid varies greatly, and the surface shape of the formed cured resin layer is manufactured. This is because the variation varies from lot to lot.

For example, in the case of a lens shape as shown in FIG. 4, the ultraviolet light applied to form the cured resin layer is
Ultraviolet rays 5 are transmitted through a portion D of the anti-reflection film provided on the lens surface B, and ultraviolet rays 6 are transmitted through an arazuri portion C on the outer periphery of the lens. Generally, since the anti-reflection film is not applied to the arazuri portion C, the amount of the ultraviolet rays 6 transmitted through the arazuri portion C is constant even for each lens.
The amount of the ultraviolet light 5 passing through the lens varies for each lens for the above-mentioned reason (variation in reflectance).

That is, in the case of a lens shape as shown in FIG. 4, since the balance of the amount of each ultraviolet ray transmitted through the arazuri portion C and the antireflection film portion D is greatly different for each lens, the aspherical surface of the cured resin layer The amount of variation in the shape is larger than in the case of a lens shape without an arazuri part,
It is more difficult to obtain a composite aspherical lens (resin-bonded optical element) having a desired aspherical shape.

Therefore, in the present invention, a conventional resin-bonded optical element (for example, a compound aspherical lens) often has a shape largely deviating from a desired optical surface shape (for example, an aspherical shape). The variation in the reflectance of the antireflection film formed on the substrate of the optical element with respect to ultraviolet rays (wavelength: 365 nm) is reduced so that the variation in the surface shape of the formed cured resin layer becomes negligible. .

That is, in the resin-bonded optical element according to the present invention in which a cured resin layer is provided on one surface of the substrate (claims 1 to 8), the other surface of the substrate (the cured resin layer is not formed) The reflectance of the antireflection film provided on the optical surface) to light having a wavelength of 365 nm was set to 1% or less. The resin-bonded optical element according to the present invention (claims 1 to 8) adopting such a configuration has an optical surface shape slightly deviating from a desired shape (for example, an aspherical shape), and thus sufficiently achieves necessary optical performance. be able to.

The antireflection film according to the present invention has a spectral characteristic set by a manufacturing error such as a deposition angle condition so that a resin bonded optical element having a desired optical surface shape (for example, an aspherical shape) can be stably obtained. Even if a wavelength shift of ± 10 nm occurs, it is preferable to have a spectral characteristic such that the measured reflectance for light having a wavelength of 365 nm is stably 1% or less (Claim 2).

Examples of the antireflection film according to the present invention include, for example, an alternating multilayer film of a high refractive index material and a medium refractive index material located on the substrate side, and a low refractive index material formed on the alternating multilayer film. By using the outermost layer of (1), a layer formed by laminating multiple layers can be used (claim 3). Specific examples are shown below. Substrate / M / H / M / H / M / H / M / H / L (Anti-reflective coating of 9 layers provided on the substrate) where H: High refractive index (2.0 to 2.2) substance Layer (eg TiO ₂
Layer or Zr0 ₂ layer) M: material layer of medium refractive index (1.6-1.7) (Example: Al ₂ O ₃ layer) L: The MgF ₂ layer): material layer of low refractive index (1.38 to 1.4) (Example The antireflection film according to the present invention has a visible range (400 to 400).
The reflectivity for light having a wavelength of 700 nm) may be 1% or less, so that the present invention can be applied to optical parts such as cameras that require such characteristics.

In the present invention, the reflectance of light in the visible region (400 to 700 nm) is 1 on the cured resin layer.
% Of an anti-reflection film may be further provided.
In addition, the present invention relates to a substrate surface provided with a cured resin layer (first surface).
The optical effective diameter of the surface (surface) is larger than the optical effective diameter of the substrate surface (second surface) on which the antireflection film is provided. When applied to a resin-bonded optical element that is an arazuri part that is not provided,
It is more effective (claim 6).

As the base material of the resin-bonded optical element according to the present invention, for example, an optical glass or a crystalline optical material can be used. Further, the present invention is suitable for use in a resin-bonded optical element having at least one aspherical optical surface (claim 8). Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

[0032]

Embodiment 1 In a lens which is a composite optical component (resin-bonded optical element) of this embodiment having a cured resin layer provided on a substrate, a cured resin layer 4 is provided on one surface A of the substrate 1. Provided,
On the other surface B of the substrate 1, an antireflection film 3 having a reflectance of 1% or less for light having a wavelength of 365 nm is provided.

FIG. 1 shows a composite optical component (lens) according to this embodiment. FIG. 5 shows the reflection spectral characteristics of the antireflection film. The lens substrate 1 is made of S-LAH55 (Ohara glass material), and an antireflection film 3 having the characteristics shown in FIG. The reflectance of the antireflection film 3 with respect to light having a wavelength of 365 nm is 0.1.
The reflectance is 1% or less, and the reflectance for light having a wavelength of 400 nm to 700 nm is 1% or less.

A cured resin layer 4 is formed on the lens surface A of the lens substrate 1. The composite optical component (lens) of this embodiment is manufactured by the steps shown in FIG. First, in a first step, a lens substrate 1 is prepared. Next, in the second step, one surface of the lens substrate 1 (the lens surface B opposite to the lens surface A on which the cured resin layer is formed) is coated with the antireflection film 3.

In the third step, the cured resin layer 2 is formed on the other surface of the lens substrate 1 (the lens surface A not coated with the antireflection film 3) to create an aspherical shape.
Here, the formation of the cured resin layer 2 is performed, for example, by the process shown in FIG. FIG. 7 shows the results of measuring the aspherical shape of the composite optical component (lens) of the present example manufactured as described above. The horizontal axis (X axis) represents the radial position, and the vertical axis (Y
The axis indicates the deviation from the design value.

Incidentally, there are ten lenses according to the present embodiment whose aspherical shape was measured, and the antireflection film 3 on each lens surface B was used.
Are processed in different batches. FIG.
According to the measurement result, the variation of the aspherical shape of the lens is 0.3.
It can be seen that it is less than μm and very small. FIG. 8 shows the dispersion of the reflection characteristics of the anti-reflection film coated on each lens surface B for ten lenses. According to this, it can be seen that the variation in the reflectance with respect to the light having a wavelength of 365 nm is 0.05% to 0.3%, which is sufficiently small.

As described above, the composite optical component (lens) of the present embodiment has an optical surface shape slightly deviating from a desired shape (aspherical shape), and thus can sufficiently achieve necessary optical performance. .

[0038]

Embodiment 2 In a lens which is a composite optical component (resin-bonded optical element) of this embodiment having a cured resin layer provided on a substrate, a cured resin layer 4 is formed on one surface A of a substrate 11. The other surface B of the base material 11 is provided with an antireflection film 3 having a reflectance of 1% or less for light having a wavelength of 365 nm.

FIG. 6 shows a composite optical component (lens) according to this embodiment. FIG. 5 shows the reflection spectral characteristics of the antireflection film. The lens substrate 11 is made of S-LAH55
(Ohara glass material) and its lens surface B
The antireflection film 3 having the characteristics shown in FIG. The reflectance of the antireflection film 3 for light having a wavelength of 365 nm is 0.1% or less, and the reflectance for light having a wavelength of 400 nm to 700 nm is 1% or less.

The cured resin layer 4 is formed on the lens surface A of the lens substrate 11. The composite optical component (lens) of this embodiment is manufactured by the steps shown in FIG. For ten composite optical components (lenses) of the present embodiment,
When the aspherical shapes were measured, it was found that the variation of the aspherical shape was 0.3 μm or less and was very small.

Further, for the ten lenses, the variation of the reflectance of the antireflection film 3 formed on each lens surface B with respect to light having a wavelength of 365 nm is 0.05% to 0.3%, which is sufficiently small. Was. As described above, since the composite optical component (lens) of the present embodiment has an optical surface shape slightly deviating from a desired shape (aspherical shape), it is possible to sufficiently achieve necessary optical performance.

[0042]

[Comparative Example] A lens, which is a composite optical component (resin-bonded optical element) of this comparative example in which a cured resin layer is provided on a base material, has a cured resin layer formed on one side of the base material (same as in Example 2). And an antireflection film (having a spectral characteristic shown in FIG. 3) having a reflectance of more than 1% for light having a wavelength of 365 nm is provided on the other surface of the substrate.

The composite optical component (lens) 1 of this comparative example
When the aspherical shape of each of the 0 sheets was measured, it was found that the variation of the aspherical shape was about 2 μm, which was extremely large as compared with the above examples. Since the optical surface shape of the composite optical component (lens) of this comparative example largely deviates from the desired shape (aspherical shape), the required optical performance cannot be sufficiently achieved.

It was found that the reflectance of the antireflection film on each lens surface with respect to light having a wavelength of 365 nm was very large, from 6% to 16%, for the ten lenses.

[0045]

As described above, the present invention (Claim 1)
In the resin-bonded optical elements of (8) to (9), the optical surface shape only slightly deviates from a desired shape (for example, an aspherical shape), so that the required optical performance can be sufficiently achieved. For example, according to the present invention, at the time of forming the cured resin layer, the amount of ultraviolet light transmitted through the lens substrate surface can be stabilized more than before, so that the aspherical shape of the cured resin layer surface can be stably created.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a configuration of a composite optical component (a resin-joined optical element and a lens) according to a first embodiment.

FIG. 2 is a manufacturing process diagram of the composite optical component (resin-joined optical element, lens) of Example 1.

FIG. 3 is a reflection characteristic diagram of a conventional (for example, a comparative example) antireflection film.

FIG. 4 shows ultraviolet rays 5 radiated to form a cured resin layer through a portion D of an antireflection film applied to a lens surface B and an arazuri portion (without an antireflection film) C on the outer periphery of the lens. FIG. 4 is an explanatory diagram showing a state of being divided into ultraviolet rays 6 that pass through.

FIG. 5 is a spectral reflection characteristic diagram of an antireflection film (one example) according to the present invention.

FIG. 6 is a configuration explanatory view showing a composite optical component (resin-joined optical element, lens) of Example 2.

FIG. 7 is a composite optical component (lens) 10 according to the first embodiment.
It is the data figure which measured the aspherical shape of one sheet.

FIG. 8 is a data diagram showing variations in the spectral reflection characteristics of the antireflection film on each lens surface of the ten lenses of Example 1.

FIG. 9 is a data diagram obtained by measuring the aspherical shapes of ten conventional composite optical components (lenses) (comparative examples).

FIG. 10 is a data diagram showing variations in spectral reflection characteristics of antireflection films on each lens surface of ten lenses of a comparative example.

FIG. 11 is a process chart showing a method of forming a cured resin layer on a base material.

[Explanation of symbols]

Reference numerals 1, 11, 51: substrate of optical element 2: cured resin layer 3: anti-reflection film (on substrate surface), 4: anti-reflection film (on cured resin layer) 5.・ Ultraviolet rays (ultraviolet rays transmitted through the antireflection film portion D), 6 ... ultraviolet rays (ultraviolet rays transmitted through the arazuri portion C) 52 ... cured resin layer 52a ... photocurable resin liquid 53 ... mold 54: Light (ultraviolet light) A: Surface on which the cured resin layer of the substrate is formed B: Surface of the substrate opposite to the surface A of the substrate C: Deflected portion of the substrate surface B ..Anti-reflection film forming portion on substrate surface B

Claims (8)

[Claims] 1. A resin-bonded optical element having a cured resin layer provided on a substrate, wherein the cured resin layer is provided on one surface of the substrate, and a wavelength of 365 nm is provided on the other surface of the substrate. A resin-bonded optical element, provided with an antireflection film having a reflectance of 1% or less with respect to the light. 2. The antireflection film has a wavelength shift of ± 10 nm from a set spectral characteristic due to a manufacturing error such as a deposition angle condition.
2. The resin-bonded optical element according to claim 1, wherein the resin-bonded optical element has a spectral characteristic such that the measured reflectance for light having a wavelength of 365 nm stably becomes 1% or less even if it occurs. 3. The anti-reflection film includes an alternating multilayer film of a high-refractive index material and a medium-refractive index material located on the substrate side, and an outermost layer of a low-refractive index material formed on the alternating multilayer film. By
The resin-bonded optical element according to claim 1, wherein the optical element is formed by laminating a plurality of layers. 4. The anti-reflection film has a visible region (400 to 7).
The resin-bonded optical element according to any one of claims 1 to 3, wherein the reflectance for light having a wavelength of (00 nm) is 1% or less. 5. A visible region (400 to 400) on the cured resin layer.
The resin-bonded optical element according to any one of claims 1 to 4, further comprising an antireflection film having a reflectance of 1% or less for light having a wavelength of 700 nm). 6. The surface of a substrate provided with the cured resin layer (first surface).
The optical effective diameter of the surface (second surface) is larger than the optical effective diameter of the substrate surface (second surface) on which the antireflection film is provided. An arazuri part without a film, characterized by the above-mentioned.
6. The resin-bonded optical element according to any one of 5. 7. The resin-bonded optical element according to claim 1, wherein the base material is an optical glass or a crystalline optical material. 8. The resin bonded optical element according to claim 1, which has at least one aspherical optical surface.