JPH10272701A - Method and apparatus for manufacturing resin-bonded lens - Google Patents

Abstract

(57) [Problem] To provide a uniform resin layer without an uncured portion even for a lens base material having a large angle from the geometric center of a curved surface to the resin-coated surface. When irradiating a light curable resin (2) sandwiched between a lens substrate (1) and a mold (3) with a light beam (4), an optical path of the light beam is changed so as not to be totally reflected at an interface (7). If the focusing lens 5 is used, the direction of the light beam 4b can be changed like the focused light 6, so that the light incident on the resin-coated surface becomes smaller than the critical angle, and the light reaches the resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a resin-bonded lens in which a resin layer having a predetermined surface shape is formed on the surface of a lens substrate.

[0002]

2. Description of the Related Art Conventionally, a resin-bonded lens having a predetermined cured resin layer formed on a glass lens substrate has been known. As a method of forming a cured resin layer on such a glass lens substrate, a photoreactive resin such as an ultraviolet curable resin is applied to the surface of the lens substrate, and the lens is cured by irradiating light such as ultraviolet light. There is a method of forming on a substrate. FIG.
(A) is an example of a method for manufacturing a resin-bonded lens;
To (d) show the order of the steps. First, in FIG. 4 (a), when a resin layer is formed on one surface (R2 surface) 27 of the glass lens base material 21, a mold 23 for resin bonding has a desired surface of the resin layer. It has a mold surface 29 for forming an optical surface shape. An amount of the ultraviolet curable resin 22 determined by the area and thickness of the resin layer is injected into the mold 23, and the center axis of the mold 23 and the optical axis of the glass lens base material 21 are made coincident with each other to form a mold surface 29. And the R2 surface 27 are arranged to face each other. Next, in FIG. 4B, the glass lens substrate 21 is moved toward the mold 23 along the above-described central axis, and ultraviolet curing is performed between the R2 surface 27 and the mold surface 29 of the glass lens substrate 21. The resin 22 is held. At this time, the R2 surface 27 of the glass lens substrate 21 and the mold surface 29 of the mold 23
The ultraviolet curable resin 22 between them spreads over the entire mold surface 29. In FIG. 4C, ultraviolet rays 24 are irradiated from the other surface (R1 surface) 28 side of the lens substrate 21 using a xenon lamp or the like. At this stage, R2 surface 2
UV-curable resin 2 spreading over the entire mold surface 29 on 7
Reaction 2 proceeds, and an ultraviolet curable resin layer 22 having a certain hardness is formed. Finally, in FIG.
After the reaction of the ultraviolet curable resin 22 is completed, the irradiation of the ultraviolet light 24 is stopped, the boundary surface between the mold surface 29 and the ultraviolet curable resin layer 22 is separated, and a resin bonding type in which the ultraviolet curable resin layer 22 is formed on the R2 surface 27. Remove the lens. in this way,
The method of manufacturing a lens, in which a resin layer is formed on the surface using a photoreactive resin, requires a highly precise surface-shaped lens for the glass lens substrate used, in addition to the relatively simple manufacturing process. Therefore, there is an advantage that the manufacturing cost can be suppressed. In particular, when a lens having a complicated shape such as an aspherical lens is manufactured, there is a problem that processing cost is increased to accurately make the optical surface of the lens substrate itself an aspherical shape. However, according to the above-described method, the lens substrate itself may be any shape that is substantially similar to the shape of the target optical surface, and the surface of the resin layer formed on the surface may be finished to the target aspherical shape. Therefore, the manufacturing cost of the lens can be kept low, and the method can be said to be excellent in mass productivity.

[0003]

However, resin-bonded lenses used in cameras, microscopes, and the like have various lens shapes depending on required optical performance. Some of these variously shaped lenses have a large angle from the geometric center of the resin-coated surface to the resin-coated surface, such as the lens substrate shown in FIG. FIG. 3 is a cross-sectional view of a resin-bonded lens having a large angle at which a resin-coated surface is seen. That is, the resin layer 12 is joined to most of the concave surface of the lens substrate 11. FIG.
And point O is the lens surface (spherical surface) on the side on which the resin is adhered.
Is a straight line connecting the center O and the outermost end of the resin, solid line B is the optical axis of the lens, and θ is the angle between the broken line A and the solid line B.

Conventionally, a resin-bonded lens having such a shape has been difficult for light rays to reach the outer periphery of the resin.
The curing of the resin was insufficient. The present invention has been made in view of the above problems, and has an object to provide a manufacturing method and an apparatus for obtaining a uniformly cured resin layer over the entire surface of a resin-coated surface even when a curved surface portion of a lens substrate is large. Aim.

[0005]

Means for Solving the Problems The invention according to claim 1 of the present invention is directed to a method in which a photocurable resin is sandwiched between a lens substrate and a mold, and a light beam is transmitted through the lens substrate. In a method of irradiating a resin, applying and curing the resin on the lens substrate, and manufacturing a resin-bonded lens including the lens substrate and a resin layer, the light incident upon the light incident on the resin The optical path of the light beam is adjusted so that the angle is smaller than the critical angle. "

According to a second aspect of the present invention, there is provided an electronic apparatus comprising:
In a manufacturing apparatus for a resin-bonded lens having a light irradiation device for irradiating the light-cured resin with a light beam, the light irradiation device is provided between a light source and the lens substrate, when the light enters the resin. An apparatus for manufacturing a resin-bonded lens having an optical element for making the incident angle smaller than the critical angle ”.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a method for forming a resin layer to be adhered to a lens substrate irrespective of the shape of the lens substrate.
The light beam direction of the light applied to the photocurable resin is adjusted. As an adjusting method, between the light source and the lens substrate that transmits the light from the light source, an optical axis that changes the light beam direction of the light so that the incident angle when the light enters the photocurable resin is smaller than the critical angle. Install the element. By using a concavo-convex lens, an aspherical lens, or the like as the optical element, a desired light beam direction such as diverging light or converging light that satisfies the above conditions is given to the irradiation light.
Examples of the optical element include not only a lens but also, for example, an angle-variable mirror that can arbitrarily change a reflection angle of a light beam from a light source, and a plurality of light sources for emitting light from a required direction. The optical characteristics of this optical element are determined by the optical characteristics (shape, refractive index, etc.) of the lens substrate and the photocurable resin and the characteristics of the light flux from the light source (parallel light, divergent light, convergent light, etc.). In consideration of the manufacturing cost of the apparatus, it is preferable to use an inexpensive optical element such as a condensing lens or a diverging lens with a simple configuration. As described above, in the present invention, by irradiating light having a desired light beam direction according to the shape of the lens substrate, the light reaches the entire optical surface, at least the entire area where the photocurable resin is applied, and Since the light reaching the interface between the lens substrate and the photocurable resin can enter the photoreactive resin from the lens substrate without being totally reflected, curing of the entire photocurable resin can be achieved.

Hereinafter, the present invention will be described specifically. First,
In a lens having a very large angle θ as described above,
The reason why the resin at the outer peripheral portion away from the optical axis is not sufficiently cured will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a state in which a resin layer is formed on the concave surface of the lens having a large angle θ.
The light beam 4 enters from the R1 surface 8 of the concave lens 1, the optical path is bent by the concave lens 1, and reaches the resin 2 sandwiched between the concave lens 1 and the mold 3.

When comparing the refractive indices of a photocurable resin and a lens substrate, the lens substrate generally tends to have a higher refractive index. Since light irradiation is performed almost parallel to the optical axis of the lens substrate, when the light travels from the lens substrate to the photocurable resin, the light at the outer peripheral portion from the optical axis at a certain distance from the optical axis. The incident angle may be larger than the critical angle at which total reflection occurs. In FIG. 2, the light ray 4a travels along the optical path indicated by the broken line X and reaches the resin 2, but cannot enter the resin 2 because it is incident at a critical angle that causes total reflection. That is, light rays on the optical axis side of the light ray 4a can enter the resin 2, but light rays outside the light ray 4a
Can not enter. Therefore, in resin 2, 2
The part a is hardened, but the part 2b is not hardened. Next, the reason why the entire resin is cured and a uniform resin layer is formed in the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing a state in which a resin layer is formed on a concave surface of a lens having a large angle θ. FIG. 1 differs from FIG.
Is the point where is arranged. The light beam 4 is collected by the condenser lens 5.
Can be changed before entering the R1 surface 8 of the concave lens 1. In this case, the change in the light beam direction increases as the distance from the optical axis increases. The light whose direction has been changed is the R of the concave lens 1.
The light enters from one surface 8 and reaches the resin 2 sandwiched between the concave lens 1 and the mold 3. That is, the light beam 4 parallel to the optical axis is converted into light having a predetermined light beam direction by the condenser lens 5 and then enters from the R1 surface 8 of the concave lens 1.

The light ray 4b away from the optical axis is light that enters at an interface 7 between the concave lens 1 and the resin 2 at a critical angle at which total reflection occurs. When the optical path of the light beam 4b is traced, the converged light 6 whose light beam direction has been changed by the condenser lens 5 becomes a broken line Y
And enters the outermost peripheral portion of the resin 2. As described above, if the incident angle of the light beam reaching the outermost peripheral portion of the resin 2 is adjusted to be equal to the critical angle, the resin can be cured at least over the entire surface of the resin application region.

Of course, for safety, it is realistic that the light incident on the interface 7 between the concave lens 1 and the resin 2 has a critical angle further outside the outermost peripheral portion of the resin 2.
As described above, by using an optical element according to the shape and the refractive index of the lens substrate, the resin can be cured at least over the entire surface of the resin-coated region. Therefore, the resin layer 2 on which the mold surface shape of the mold 3 is accurately transferred is formed, and a resin-bonded lens having desired optical characteristics can be obtained.

[0012]

According to the present invention, the light from the light source can be guided to the entire surface of the photocurable resin without being affected by the shape and refractive index of the lens substrate, and the resin layer uniformly cured on the lens surface. Can be formed. In particular, since a desired surface shape can be traced on a lens substrate through a mold, an optical surface such as an aspheric surface, which is difficult to process, can be formed by simple means and at low cost.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a state in which a resin layer is formed on a concave surface of a lens having a large angle θ according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a conventional state in which a resin layer is formed on a concave surface of a lens having a large angle θ.

FIG. 3 is a sectional view of a resin-bonded lens having a large angle θ.

FIG. 4 is a diagram showing a manufacturing procedure of a resin-joined lens.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concave lens (lens base material) 2 Resin (resin layer) 3 Mold 4 Light beam (irradiation light) 5 Condensing lens 6 Focused light 7 Interface between lens base material and resin 8 R1 surface

Claims (3)

[Claims] 1. A photo-curing resin is sandwiched between a lens substrate and a mold, a light beam is transmitted through the lens substrate and irradiated to the resin, and the resin is adhered and cured to the lens substrate. hand,
In the method of manufacturing a resin-bonded lens including the lens substrate and the resin layer, the optical path of the light beam is adjusted so that an incident angle of the light beam when entering the resin is smaller than a critical angle. A method for producing a resin-bonded lens. 2. A manufacturing apparatus for a resin-bonded lens having the mold and a light irradiation device for irradiating a light beam to the photocurable resin, wherein the light irradiation device includes a light source and a lens base. An apparatus for manufacturing a resin-bonded lens, comprising: an optical element for reducing an incident angle at the time of incidence on the resin to be smaller than a critical angle. 3. The apparatus according to claim 2, wherein the optical element is a lens or a mirror.