JP2008299148A - Junction type optical element and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that it is very difficult to adjust optimum pressing force and a pressing process in detail, since there are a large number of parameters such as viscosity due to a curing resin material, a curing compression force generated when UV-cured, wettability therein between a filled resin and a molding die, and a curved face shape of a lens blank for the purpose of obtaining a junction type optical element high in reliability and mold releasability from the die, in a conventional optical element and molding process. <P>SOLUTION: An end part cut-out face 3 is provided in an end part of a glass base material 1, and 20°<θ<45° is satisfied where θ represents an angle formed with respect to an optical element face 4 adjacent thereto, in this junction type optical element of the present invention joined with a resin layer 2 comprising a photocuring type resin on one optical acting face of the glass base material 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bonded optical element formed by bonding a glass substrate and an optical resin material, and a method for manufacturing the same.

  The optical material of the junction type optical element is roughly divided into a glass material and a resin material. Among these, an optical element made of a resin material is easy to create a fine shape such as an aspherical shape or a relief pattern. As a result, chromatic aberration and various aberrations can be reduced, so that the degree of freedom in optical design is increased and a high-performance optical system can be realized. Moreover, since it can produce by the method excellent in mass productivity, such as injection molding, it can supply cheaply. For this reason, it is widely used for a digital still camera, a pickup lens of an optical disk device, a lens for a mobile phone with a camera, and the like. However, there are some inferior to optical elements using glass materials in that there are few types of resin materials that can satisfy the characteristics as optical elements, and in terms of mechanical strength and environmental reliability. Therefore, in order to compensate for the drawbacks of these resin materials, an optical element in which different materials such as a glass material and a resin material are joined and a manufacturing method are disclosed. Conventionally, a replica forming method as described below has been proposed (see, for example, Patent Document 1).

In Patent Document 1, in order to improve the releasability of the optical element from the mold in the replica molding method, the photocurable resin is pressed and filled with a flat or curved lens blank, and the bonded optical element is irradiated with light. In the manufacturing method, the angle θ expressed by the filling and curing side formed by the filling and curing resin surface at the outer peripheral portion of the interface between the filling and curing resin and the mold that generates interface peeling at the time of mold release is 90 ° <θ. <180 °. Also, during photocuring, an internal stress that is always greater than the curing shrinkage force compared to the resin shrinkage that occurs continuously inside the resin is applied to the photocurable resin by a lens blank or a mold. Thus, it is added continuously.
JP 2006-110882 A

  However, in this method, by pressing the lens blank with an appropriate force, the angle θ expressed on the filling and curing side formed by the filling and curing resin surface at the outer peripheral portion of the interface between the cured resin and the mold is 90 °. The control is performed so that the angle <θ <180 ° is satisfied. This control includes the viscosity of the cured resin material, the curing shrinkage generated during UV curing, the wettability between the filling resin and the molding die, There are many parameters such as the curved shape of the lens blank, and it is extremely difficult to adjust the optimal pressing force and pressing process in detail. In addition, depending on the shape of the optical element to be produced, the above-described control is difficult, and it is difficult to realize a desired optical element. In view of such a problem, the present invention provides a bonded optical element that is excellent in releasability and that can obtain high reliability without using a complicated process.

  In order to solve the above-described problems, the bonded optical element of the present invention is made of a glass material, and includes a glass substrate having an optical element surface and a notch surface provided at an end connected to the optical element surface, and a photocurable type. A resin layer made of a resin material and bonded so as to cover the optical element surface and the notch surface of the glass substrate, the optical element surface to which the resin layer is bonded, and the notch continuous therewith The angle formed with the surface is between 20 ° and 45 °.

  Further, the surface roughness of the notched surface of the glass substrate is set to 10 nm or more in Ra.

  The method for manufacturing a bonded optical element of the present invention includes a step of exposing a photocurable resin material on a molding die coated with a release film, an optical element surface, and the optical element surface. The optical material surface of the glass substrate is pressed by pressing the resin material with a glass substrate having a notch surface provided at an end and coated with a silane coupling agent. And attaching the resin material to the glass substrate by irradiating the resin material with light and curing the resin material, and attaching the resin material to the glass substrate. And a step of releasing the bonded optical element bonded with the mold from the molding die.

  In addition, the method for manufacturing a bonded optical element according to the present invention includes an optical element surface and a notch surface provided at an end connected to the optical element surface, on a glass substrate coated with a silane coupling agent. A step of applying a photocurable resin material; and pressing the applied resin material with a molding die so that the resin material forms the optical element surface and the notch surface of the glass substrate. A step of bonding the resin material to the glass substrate by irradiating the resin material with light, and a bonding optical element in which the resin material is bonded to the glass substrate. From the mold for molding.

  As described above, according to the present invention, it is possible to provide a bonded optical element having excellent releasability and high reliability without using a complicated process.

  The best mode for carrying out the present invention will be described below in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its application.

(Embodiment 1)
FIG. 1 is a sectional view of a junction type optical element according to Embodiment 1 of the present invention. As shown in FIG. 1, the bonded optical element 5 is formed by bonding a resin layer 2 made of a photocurable resin material to one optical element surface 4 of a glass substrate 1. When the angle formed by the edge notch surface 3 of the glass substrate and the optical element surface 4 connected thereto is θ, the edge cut of the glass substrate is performed so that the angle θ is 20 ° <θ <45 °. The notch surface 3 is processed. Further, the end notch surface 3 is formed outside the optical element surface 4 which is an effective lens diameter, and is processed so that its surface roughness is 10 nm or more in Ra.

  Further, the resin layer 2 is configured not only on the optical element surface 4 but also on the end notch surface 3.

  FIG. 2 is a diagram showing an outline of a method for manufacturing a junction-type optical element according to Embodiment 1 of the present invention.

  First, as shown in FIG. 2A, a release film is applied to a molding die 6 that has been processed to have a desired optical surface shape, and then a photocurable resin material 21 (for example, a radical polymerization system). Resin) is dispensed in a predetermined amount using a dispenser or the like. Next, as shown in FIG. 2 (b), after the glass substrate 1 coated with the silane coupling agent and held by the chuck member 22 is set on the molding die 6, Then, a pressing operation is performed to stretch the photocurable resin material 21 and attach it so as to cover the optical element surface 4 and the end notch surface 3 connected thereto.

  Further, as shown in FIG. 2C, after the pressing operation is performed until the gap between the molding die 6 and the apex of the glass substrate 1 reaches a predetermined amount, the positioning operation is performed. After positioning the glass substrate 1, the UV irradiation device 23 is set, the irradiation power and the irradiation time are controlled to be a predetermined amount, the photocurable resin material 21 is photocured, and is bonded to the glass substrate 1. . Then, as shown in FIG. 2 (d), the chuck member 22 is pulled up and released from the molding die 6 to obtain the junction type optical element 5.

  Next, the effect of the end notch surface 3 of the junction type optical element of the present invention and the set angle will be described with reference to FIG.

  FIG. 3A shows a case where there is no end cut-out surface, and 31 is a glass substrate having no end cut-out surface. FIG. 3B shows a case where there is an end notch surface.

  When there is no end notch surface as shown in FIG. 3A, the point P1 where the surface of the photocurable resin material 21 is in contact with the glass substrate 31 and the point Q1 where it is in contact with the molding die 6 are close. The wetting action at P1 and the lyophobic action at Q1 cancel each other, and as a result, the angle θ1 formed by the molding die 6 and the surface of the photocurable resin material 21 at Q1 becomes large, so that the interface at Q1 at the time of release A large release force is required to cause peeling.

  On the other hand, as shown in FIG. 3B, when there is the end notch surface 3, the photocurable resin material 21 adheres to the glass substrate 1 along the end notch surface 3. Since the point P2 where the surface of the photocurable resin material 21 is in contact with the glass substrate 1 and the point Q2 where it is in contact with the molding die 6 are separated from each other, the wetting action at P2 and the liquid repellent action at Q2 may cancel each other. As a result, the angle θ2 formed between the molding die 6 and the surface of the photocurable resin material 21 in Q2 becomes small, so that the mold release force for causing interface peeling at Q1 at the time of mold release is small.

  The angle θ formed by the optical element surface 4 and the end notch surface 3 connected to the optical element surface 4 is from the viewpoint of releasability from the molding die, stability of the obtained optical element shape, and environmental reliability of the optical element. When the angle is 20 ° or less, the effect of providing the end notch surface is reduced. When the angle is 45 ° or more, the photocurable resin material 21 is less likely to adhere along the end notch surface 3, and therefore 20 ° <θ <. A range of 45 ° satisfies each characteristic most.

The reason why these characteristics are improved is that the photocurable resin material is filled along the notch of the end portion, and after being photocured, it is bonded to the glass substrate. The angle with the photocurable resin material 21 can be made small. For this reason, it is easy to trigger the mold release from the molding die 6. Therefore, even when a weak force is applied in the vertical direction, the mold can be easily released from the molding die 6 and the following effects can be obtained.
(1) A junction type optical element with good molding accuracy can be obtained.
(2) The life of the molding die is extended, leading to cost reduction.

  Next, the surface roughening effect of the end notch surface will be described. Adhesiveness with the photocurable resin 21 to be joined is improved by the anchor effect by making the end notch surface 3 of the glass substrate rough. As a result, a bonded optical element having excellent environmental reliability can be obtained. When the surface roughness was 10 nm or more, the effect of improving the adhesion was obtained from the results of the reliability test (high temperature and high humidity leaving test, heat shock test). Since the end notch surface 3 is outside the lens effective diameter, even a rough surface does not affect the final optical performance.

  Next, another method for manufacturing the junction type optical element according to the present embodiment will be described with reference to FIGS. The manufacturing method shown in FIG. 4 is obtained by reversing the positional relationship between the molding die 6 and the glass substrate 1 with respect to the manufacturing method shown in FIG.

  First, as shown in FIG. 4A, a silane coupling agent is applied, and a photocurable resin material 21 is exposed on the optical element surface 4 of the glass substrate 1 held by the chuck member 22. Next, as shown in FIG. 4B, after the molding die 6 is set on the glass substrate 1, a pressing operation is performed to extend the photocurable resin material 21, and the optical element surface 4 and the end connected thereto. It adheres so that the part notch surface 3 may be covered. At this time, the photocurable resin material 21 flows more easily and adheres to the end notch surface 3 than the case of FIG. 2 due to the action of gravity, and also adheres to the molding die 6. Therefore, even if no mold release film is applied to the molding die 6, the angle corresponding to θ2 shown in FIG. 3 (b) becomes small, so that it is photocured as shown in FIG. 4 (c). After that, as shown in FIG. 4 (d), the mold can be released with a small force.

  As described above, in the manufacturing method shown in FIG. 4, the mold can be released with a small force without applying the release film to the molding die 6, so that the quality problem associated with the use of the release film is eliminated.

  As described above, the present invention provides a junction type optical element that is excellent in releasability and can be obtained with high reliability without using a complicated process. The possibility is high.

Sectional drawing of the junction type optical element which concerns on Embodiment 1 of this invention The figure which shows the outline of the manufacturing method of the junction type optical element which concerns on Embodiment 1 of this invention. The figure which shows the effect of the notch surface of the junction type optical element which concerns on Embodiment 1 of this invention The figure which shows the outline of the other manufacturing method of the junction type optical element which concerns on Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass base material 2 Resin layer 3 End part notch surface 4 Optical element surface 5 Bonding type optical element 6 Molding die 21 Photocurable resin material 22 Chuck member 23 UV irradiation apparatus

Claims (4)

A glass substrate made of a glass material and having an optical element surface and a notch surface provided at an end connected to the optical element surface;
A resin layer made of a photocurable resin material, and having a resin layer bonded so as to cover the optical element surface and the notch surface of the glass substrate,
The junction type optical element characterized in that an angle formed by the optical element surface to which the resin layer is bonded and the notch surface connected thereto is between 20 ° and 45 °. The junction type optical element according to claim 1, wherein a surface roughness of the notched surface of the glass substrate is 10 nm or more in Ra. Granting a photo-curable resin material on a molding die coated with a release film; and
The resin material is pressed by a glass substrate having an optical element surface and a notch surface provided at an end connected to the optical element surface and coated with a silane coupling agent. Is attached so as to cover the optical element surface and the notch surface of the glass substrate,
Bonding the resin material to the glass substrate by irradiating and curing the resin material; and
And a step of releasing the bonded optical element in which the resin material is bonded to the glass substrate from the molding die. Providing a photocurable resin material on a glass substrate having an optical element surface and a notch surface provided at an end connected to the optical element surface and coated with a silane coupling agent;
A step of pressing the resin material provided with a molding die so that the resin material covers the optical element surface and the notch surface of the glass substrate;
Bonding the resin material to the glass substrate by irradiating and curing the resin material; and
And a step of releasing the bonded optical element in which the resin material is bonded to the glass substrate from the molding die.

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