JP2922709B2 - Optical element molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding an optical element for integrally forming a resin layer on the surface of a glass member.

[0002]

2. Description of the Related Art Conventionally, there has been known a method in which a thin film made of a resin material is formed on the surface of a glass member to form a lens having an aspherical shape which is difficult to process with a glass material. A lens formed by such a method is generally called a replica lens.

[0003] In forming the replica lens,
Conventionally, as shown in FIG.
A glass member 50 processed into a spherical shape having a curvature close to the aspherical shape is placed on the mold member 52 having a, a surface 50a of the glass member 50, and a molding surface 52a of the mold member 52. A method is adopted in which a liquid lens is filled in a space portion 54 defined between them and cured to form a replica lens 55 having a desired aspherical shape.

In such a molding method, the glass member 5
Before placing the “0” on the mold member 52, it is necessary to supply a resin material to the surface of the molding surface 52a of the mold member 52 in advance. As a method of supplying the resin material, conventionally, as shown in FIG. 2, the resin material is dropped onto the molding surface 52a with the tip 60a of the resin material supply device 60 separated from the molding surface 52a. Alternatively, as shown in FIG. 3, a method of supplying the resin material in a state in which the distal end portion 60a of the supply device 60 is close to the molding surface 52a is adopted.

[0005]

However, of these supply methods, the method of dropping the distal end portion 60a of the supply device 60 shown in FIG. There is a problem that bubbles are mixed into the resin material due to the shock. Further, the distal end portion 60a of the supply device 60 shown in FIG.
In the method of supplying the resin material in a state where the resin material is brought close to “a”, there is a problem that the resin material adheres to the tip of the supply device 60 and the supply amount of the resin material becomes inaccurate.

After the resin material is supplied onto the molding surface 52a, the glass member 50 is placed on the mold member 52. In this placing step, air bubbles are mixed in the resin material. There is a problem that there is a risk of doing so. In the case where the resin material is cured in a state in which bubbles are mixed in the resin material as described above, even if the bubbles can be visually confirmed even if the optical performance is not adversely affected, the product is shipped as a product. It becomes impossible to do. Therefore, there is a problem that the yield of the manufactured replica lens is deteriorated.

Therefore, the present invention has been made in view of the above-mentioned problems, and a first object of the present invention is to prevent air bubbles from being mixed in a resin material when supplying the resin material, and to reduce the resin material. An object of the present invention is to provide a method for forming an optical element that can supply a required amount of an optical element accurately. Further, a second object of the present invention is to reliably prevent air bubbles from being mixed into a resin material when placing a glass member on a mold member,
An object of the present invention is to provide a method for forming an optical element that can improve the yield of the optical element.

[0008]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, a molding method of an optical element according to the present invention is to integrate a glass material and a resin material by forming a resin layer having a predetermined surface shape on a surface of a glass member by molding. An optical element molding method for forming a formed optical element, wherein a tip of a supply unit for supplying the resin material to a molding surface for transferring the predetermined surface shape to a surface of the resin layer. A second step of discharging the resin material by a predetermined amount from the distal end of the supply unit in a state where the distal end of the supply unit is brought close to the predetermined distance.
And moving the distal end of the supply means in a direction away from the molding surface while maintaining a state in which the lower end of the resin material discharged from the distal end is in contact with the molding surface. And a third step of discharging the resin material at a predetermined discharge speed from the distal end portion until the total amount of the resin material reaches the required supply amount.

In the method of molding an optical element according to the present invention, in the second step, the predetermined amount may be such that at least a lower end of the resin material discharged from a leading end of the supply means is attached to the molding surface. It is characterized in that it is more than the amount necessary for contact.

In the method of molding an optical element according to the present invention, in the second step, the predetermined amount may be:
It is characterized by being managed by the elapsed time from the start of discharge of the resin material by the supply means. Also,
In the method for molding an optical element according to the present invention, the required supply amount is managed by an elapsed time from the start of the discharge of the resin material by the supply unit.

In the method for molding an optical element according to the present invention, the resin material is an active energy ray-curable resin.

[0012]

[0013]

[0014]

[0015]

As described above, since the method for molding an optical element according to the present invention is constituted, the resin material is discharged by discharging the resin material in a state where the tip of the resin material supply device is close to the molding surface. After the resin material is ejected while being retracted from the molding surface, the resin material can be supplied without dropping onto the molding surface, and the resin adheres to the distal end of the supply device. Since this can be prevented, air bubbles are not mixed into the resin material, and the required amount of the resin material can be supplied accurately.

[0016]

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 4 is a diagram showing a schematic structure of a molding apparatus used for molding an aspherical lens by an optical element molding method according to one embodiment.

First, before describing the configuration of the molding apparatus, the outline of a method for molding an optical element according to an embodiment will be described. The method for forming an optical element according to this embodiment is for forming a shape on a surface of a glass material such that the glass material is difficult to be processed. Then, a resin layer having a desired complicated surface shape made of a resin material is formed. As an example, there is a method in which an aspherical resin film is formed on a surface of a glass member processed into a spherical shape, and an aspherical lens is formed by combining a glass material and a resin material. That is, in order to provide a lens whose aberration is corrected by a single lens, it is necessary to make the surface shape of the lens an aspherical shape. However, it is not easy to process a glass material into an aspherical shape. A lens using a resin that is easy to mold into a spherical shape does not easily gain the power of the lens. Therefore, by combining the two, it is intended to take advantage of only the advantages of the two. The lens manufactured in this manner is called a replica lens.

More specifically, as shown in FIG. 4, a bonding surface 30a which is one surface of a glass member 30 whose surface is processed into a spherical shape.
Next, a resin layer 32 made of a thin film of an active energy ray-curable resin is formed. The glass member 30 has a flange-shaped body portion 30b on an outer peripheral portion thereof. The body portion 30b is held on the support member 14 in a state in which the body portion 30b is in contact with the upper end surface 14b of the support member 14. ing. The upper end surface 14b protrudes by a height h from the edge of the molding surface 12b of the mold member 12 for forming the surface shape of the resin material. The protrusion amount h defines a predetermined thickness even at a portion where the thickness of the resin layer 32 is the thinnest (the thickness of the resin layer varies depending on the location because the molding surface 12b has an aspheric shape). Then, the resin material in a liquid state filled in the space defined by the molding surface 12b of the mold member 12 and the bonding surface 30a is irradiated with active energy rays to cure the resin material, and the replica lens is cured. 33 is completed.

Hereinafter, the configuration of an apparatus for forming a replica lens will be described with reference to FIG. Reference numeral 10 denotes a mold member 12 for molding the resin layer 32.
And a substrate for holding a supporting member 14 for supporting the glass member 30 and the like, and is provided so as to extend horizontally. On the upper surface of the substrate 10, a mold member 12,
The support member 14 and the mold 16 are supported, and the substrate 1
An air cylinder 20 for moving the support member 14 relative to the mold member 12 is disposed on the lower surface of the cylinder 0.

More specifically, on the upper surface of the substrate 10, a mold 1 having a cylindrical concave portion 16a opened vertically upward in the center.
6 is fixed. Inside the cylindrical concave portion 16a,
Having an outer diameter slightly smaller than the inner diameter of the recess 16a,
A cylindrical support member 14 is inserted. That is, the support member 14 is slidable along the axial direction (that is, along the vertical direction in the drawing) with respect to the mold 16 in a state where the outer peripheral surface is fitted to the inner peripheral surface of the concave portion 16a. It is inserted. The support member 14 has a lower end surface 1.
4a is prevented from moving further downward by contacting the bottom surface 16b of the concave portion 16a.

Inside the support member 14, a cylindrical mold member 1 whose outer diameter is slightly smaller than the inner diameter of the support member 14 is provided.
2 are further inserted, and the support member 14 and the mold member 1
Reference numeral 2 indicates that the outer peripheral surface of the mold member 12 and the inner peripheral surface of the support member 14 are relatively slidable in a state where they are slidably fitted to each other. Here, since the bottom surface 12a of the mold member 12 is fixed to the bottom surface 16b of the concave portion 16a, the support member 14 defines the inner peripheral surface and the outer peripheral surface of the mold member 12 with the outer peripheral surface of the mold member 12, respectively. While being guided by the inner peripheral surface of the reference numeral 16, it is slidable in the vertical direction.

On the other hand, an air cylinder 20 for vertically moving the support member 14 with respect to the mold member 12 and the mold frame 16 is fixed to the lower surface of the substrate 10.
The air cylinder 20 has an air cylinder body 20
The cylinder rod 20b relatively moves with respect to a. A cylindrical connecting member 22 for connecting to the support member 14 is attached to the upper surface of the cylinder rod 20b. And these cylinder rods 20
b and the connecting member 22 are formed in the through holes 10 formed in the substrate 10.
Through a, it is connected to a mechanism member disposed above the substrate 10.

The connecting member 22 has a flange 2
2a are formed, and connection rods 24A, 24B, 24C are formed at three circumferential positions on the upper surface of the flange portion 22a.
(Only 24C is not shown) is fixed in an upright state. The upper ends of the connecting rods 24A, 24B, 24C are formed with three through holes 16c,
16d, 16e (only 16e is not shown), respectively, enters into the cylindrical recess 16a, and is connected to the lower end surface 14a of the support member 14. Therefore, when the air cylinder 20 operates and the connecting member 22 moves upward,
The support member 14 is pushed upward through the connection rods 24A, 24B, 24C.

FIG. 4 shows a state in which the support member 14 is pushed up most. In this state, the upper end surface 14b of the support member 14 is formed on the molding surface 12b of the resin material which is the upper surface of the mold member 12. It protrudes from the edge by the protruding amount h. Here, since the molding surface 12b of the mold member 12 is processed into the aspherical shape required for the completed shape of the replica lens 33, the glass member 30 is placed on the upper end surface 14b of the support member 14. Then, by curing the resin material filled in the space defined by the bonding surface 30a of the glass member 30 and the molding surface 12b, the aspherical shape of the molding surface 12b is transferred to the surface of the glass member 30. Resin layer 32 can be formed.

At this time, as can be seen from the figure, the protrusion amount h of the support member 14 defines the thickness of the resin layer 32 formed on the glass member 30, and this protrusion amount h is accurately determined. In order to define, the contact surface 2
2b is formed. When the contact surface 22b contacts the lower surface 16f of the mold 16, the support member 1
4 is defined. Here, the value of the protrusion amount h is
The thickness of the resin layer 32 is set to a value at which the thickness of the resin layer 32 does not become thinner than, for example, 30 μm at a position where the thickness of the resin layer 32 becomes thinnest, depending on the degree of the aspherical surface of the molding surface 12b.

An escape portion 14c is formed at the upper end of the support member 14 for accommodating the protruding portion of the resin material, thereby preventing the protruded resin material from adhering to the support member 14. Glass member 30 and support member 1
4 prevents the resin material from protruding from the contact portion with the upper end surface 14b to form burrs. Further, between the lower surface 16f of the mold 16 and the upper surface of the flange portion 22a of the connecting member 22, connecting rods 24A, 24B,
24C, the compression springs 26A,
26B and 26C (only 26C is not shown) are arranged, so that the connecting member 22 is
It is urged in a direction to be pushed down with respect to f. Therefore, when the operation of the air cylinder 20 is released, the cylinder rod 20b and the connecting member 22 are pushed down by their own weight and the urging force of the compression springs 26A, 26B, 26C, and the support member 14 It moves downward with respect to the member 12 and the mold 16. As a result, the upper end surface 14b of the support member 14 is lowered to the same height as the molding surface 12b of the mold member 12, and the support member 1
The support state of the glass member 30 by 4 is released.

An irradiation device 34 for irradiating an active energy ray is disposed above the glass member 30.
By irradiating the resin layer 2, the resin layer 32 can be cured. The irradiation device 34 is supported by a moving mechanism 36, and can be retracted from the optical axis of the glass member 30 as necessary.

On the other hand, above the glass member 30, in addition to the irradiation device 34, a resin material supported by a moving mechanism 38 that can move between a position on the optical axis of the glass member 30 and a retracted position. A supply device 40 is arranged. This supply device 4
0 is a vertical lifting mechanism 4 held by the moving mechanism 38
2, a syringe 44 supported by the lifting mechanism 42,
A drive device 46 for driving the piston of the syringe 44 is provided. Then, a predetermined amount of the resin material is supplied to the molding surface 12b of the mold member 12 by the supply device 40.

Further, although not shown in its entirety, a suction type hand 4 for supplying the glass member 30 onto the mold member 12 is provided.
The supply robot 47 (see FIG. 6) including 7 a is disposed at a predetermined position with respect to the mold member 12. Next, a procedure for molding a replica lens in the molding apparatus having the above-described configuration will be described.

In forming the replica lens 33,
First, it is necessary to supply a resin material to the molding surface 12b of the mold member 12. FIG. 5 is a diagram showing a procedure of the supply operation of the resin material. First, the moving mechanism 38 is operated to supply the supply device 40 to the mold member 12 with the syringe 4.
4 is positioned so that the front end portion is located at the center of the molding surface 12b. FIG. 5A shows this state. From this state, as shown in FIG. 5B, the elevating mechanism 42 is operated to lower the syringe 44 so as to approach the molding surface 12b, and stop immediately before the tip of the syringe 44 contacts the molding surface 12b. Let it. In this state, as shown in FIG. 5C, the resin material is discharged little by little from the distal end of the syringe 44, and at the same time as the start of the discharge or after a lapse of a predetermined time from the start of the discharge, the syringe 44 is discharged. It is slowly raised as shown in FIG. The discharging operation of the resin material is continued even when the syringe 44 is raised, and the discharging operation is terminated when the supply amount of the resin material reaches a predetermined value. However, the discharge speed of the resin material and the rising speed of the syringe 44 at this time are set to such a speed that the resin material is not interrupted between the molding surface 12b and the tip of the syringe 44 when the syringe 44 is raised. You. Thereafter, when the syringe 44 reaches a predetermined height, the operation of the elevating mechanism 42 is stopped.

As a specific example of the supply operation of this resin material, urethane-modified acrylate and an ultraviolet-curing resin containing acrylate as a monomer component are used as the resin material, and the center of the glass lens having a diameter of 18 mm is formed on the surface of the glass lens. A case in which an aspherical resin layer having a thickness of 30 μm and a maximum thickness of 60 μm is formed (the volume of the resin material supplied at this time is 14 × 10 ⁻³ cc) will be described.

First, referring to FIG.
The height H1 from the molding surface 12b of the distal end of the is 44 mm, and the syringe 44 is moved from this position to V1 = 100 mm.
/ S, and the tip of the syringe 44 is
As shown in (b), the height H2 = 1.1 from the molding surface 12b.
Stop at the position of mm. Next, in the state shown in FIG. 5B, the resin material is started to be discharged from the syringe 44 at a speed of 3.5 × 10 ⁻³ cc / s, and as shown in FIG. When a resin material of 3.5 × 10 ⁻³ cc is discharged from the tip of the mold, and the resin material comes into contact with the molding surface 12b, the syringe 44 starts to slowly rise. The rising speed at this time is 0.2 mm / s.
Even in a state where the syringe 44 is raised, the discharging operation of the resin material is continuously performed as shown in FIG. 5D. The discharge of the supply amount of 14 × 10 ⁻³ cc is ended. At this time, the tip of the syringe 44 is
At a height of 1.7 mm from
The ascending operation of No. 4 is continued, and stops at the position where the tip of the syringe 44 is 6 mm from the molding surface 12b. Thereafter, the syringe 44 is raised at a high speed, returns to the same position as shown in FIG. 5A as shown in FIG. 5E, and ends the step of supplying the resin material.

The following two effects can be obtained by performing the resin material supply step as described above. (1) Since the resin material is brought into contact with the molding surface 12b in a ball-like state due to its surface tension without dropping the resin material from a high position above the molding surface 12b. It is possible to prevent air bubbles from being mixed into the resin material due to the shock of falling. (2) When the ejection is continued at a position close to the molding surface 12b, a ball of the resin material is formed so as to wrap the tip of the syringe 44 by the surface tension of the resin material. The resin material adheres to the portion, and the supply amount becomes inaccurate. On the other hand, when the distal end of the syringe 44 is raised as the ink is discharged, the resin material does not adhere to the distal end of the syringe 44, and the supply amount of the resin material can be accurately controlled.

Regarding (1), in the step of placing the glass member 30 on the support member 14 after the step of supplying the resin material, it is conceivable that air bubbles may be mixed into the resin material. Therefore, in each step, it is extremely important to manage so that air bubbles are not mixed. Even if the air bubbles are of a degree that does not affect the optical performance, if air bubbles that can be visually confirmed are mixed in, it will not be possible to ship them as a product, thus improving the product yield. It is also important above.

Regarding (2), since the amount of the resin material filled between the bonding surface 30a and the molding surface 12b of the glass member 30 is extremely small, the amount of the resin material is precisely adjusted to a fixed amount. It is important to control In this regard, by adopting the above-described method, the volume of the supplied resin material can be accurately controlled to a constant amount. Here, for example, when the weight of the resin material is controlled at the time of supply, even if the weight is constant, the volume of the resin material greatly changes depending on the temperature and humidity. It is necessary to strictly control the temperature and the humidity in order to spread the resin material to all corners and prevent the amount of protrusion from becoming large between the space 12b. Therefore, it is most preferable to control the supply amount of the resin material by volume.

When the supply of the resin material is completed, the moving mechanism 3
By operating 8, the supply device 40 is retracted from the optical axis of the glass member 30. Then, as shown in FIG. 4, the support member 14 is raised by operating the air cylinder 20, and the upper end surface 14 b of the support member 14 protrudes from the edge of the molding surface 12 b of the mold member 12 by the protrusion amount h. To In this state, the upper end surface 14b of the support member 14 is coated with the coupling member 30a coated with a coupling agent for preventing the resin layer 32 from peeling off.
Is placed so that

The step of placing the glass member 30 on the support member 14 needs to be performed carefully so that air bubbles do not enter the resin material. FIG. 6 is a diagram showing a procedure for placing the glass member 30 to prevent air bubbles from being mixed into the resin material. First, in a state where the glass member 30 is sucked by the suction hand 47a, the supply robot 47 positions the glass member 30 above the mold member 12 so that the optical axis of the glass member 30 coincides with the center axis of the mold member 12. FIG. 6A shows this state. From this state, the supply robot 47 is operated as shown in FIG. 6B to lower the glass member 30 at a high speed in a direction approaching the forming surface 12b, so that the center of the bonding surface 30a of the glass member 30 is formed. It stops just before contacting the resin material already supplied on the surface 12b.

Next, from this state, the supply robot 47 is operated again to lower at a first low speed until the center of the joining surface 30a of the glass member 30 contacts the resin material on the molding surface 12b. Stop. This joining surface 30
FIG. 6 shows a state in which the center of a is in contact with the resin material.
(C), the glass member 30 is held at this position for a predetermined time. By holding the glass member 30 in contact with the resin material in this manner, the contact area between the resin material and the bonding surface 30a gradually increases as shown in FIG.

When the contact area between the resin material and the bonding surface 30a is sufficiently widened, the supply robot 47 is operated again, and the glass member 30 is lowered at a second speed slightly higher than the first speed. Then, when the body-attached portion 30b of the glass member 30 contacts the upper end surface 14b of the support member 14, the supply robot 47 is stopped. This glass member 3
As one specific example of the mounting operation on the support member 14 of the first embodiment, the urethane-modified acrylate and an ultraviolet ray containing acrylate as a monomer component are used as the resin material in the same manner as the conditions described in the above-described operation of supplying the resin material. Using a curable resin (viscosity about 2500 cps), the thickness of the central part is 30 μm and the maximum thickness is 60 μm on the surface of a glass lens having a diameter of 18 mm.
The case of forming an aspherical resin layer of m will be described.

First, in FIG. 6A, the resin material has already been supplied to the surface of the molding surface 12b of the mold member 12 by 14 × 10 ⁻³ cc as described above. In FIG. 6A, the height H1 'of the glass member 30 from the molding surface 12b is shown.
Is about 100 mm, and the glass member 30 is lowered from this position at a speed of V3 = 10 mm / s. As shown in FIG. 6B, the center of the bonding surface 30a of the glass member 30 is Stop just before touching. At this time, the glass member 3
Time T from when 0 starts to fall until it comes into contact with resin material
Is approximately T = (H1'-H2 ') / V, where H2' is the height of the droplet due to the surface tension of the resin material on the molding surface 12b.
It becomes 3. The height H2 'of the droplet of the resin material is determined by the properties such as the surface tension of the resin material and the wettability of the molding surface 12b, and the value of the height H2' also depends on these physical property values. It has already been confirmed by calculations and experiments. Therefore, the time T until the glass member 30 comes into contact with the resin material can be calculated, and the lowering of the glass member 30 is stopped immediately before the elapsed time from the start of the lowering operation of the glass member 30 becomes T. You.

Next, from the state shown in FIG.
Glass member 3 at a speed of V4 = 0.1 mm / s, which is a low speed of
0 is lowered, and as shown in FIG.
Is stopped when the center portion of the is in contact with the resin material. The stop timing at this time is also determined by measuring the time from the start of lowering the glass member 30. Glass member 3
The glass member 30 is held for about one second at a position where the No. 0 bonding surface 30a is in contact with the resin material. During this approximately one second, the contact area between the resin material and the bonding surface 30a gradually increases from the state shown in FIG. 6C, and reaches the state shown in FIG. 6D.

Next, after the state shown in FIG. 6D is reached, the glass member 30 is again set to the second low speed V5 = 0.
Lower at 5 mm / s. Here, the second low speed V
5 is made faster than the first low speed V4 at the moment when the glass member 30 collides with the resin material, bubbles are most likely to be mixed into the resin material. This is because the lowering speed in the latter half is increased to improve the productivity because it is difficult to mix. Then, the lowering operation of the glass member 30 is continued, and the lowering operation is stopped when the glass member 30 comes into contact with the support member 14 as shown in FIG. The placing operation on the is ended.

By performing the mounting step of the glass member 30 as described above, the following effects can be obtained. First, the time required for the mounting step can be reduced by performing the first descending step at high speed, which does not include an element that affects the performance of the replica lens. Then, at the moment when the glass member 30 comes into contact with the resin material, that is, at the moment when air bubbles are most likely to be mixed into the resin material, the descending speed of the glass member 30 is extremely slowed, thereby reliably preventing air bubbles from being mixed into the resin material. can do. Also, by leaving the glass member 30 in a state of being slightly in contact with the resin material for a predetermined period of time, the contact area between the resin material and the glass member 30 is increased, and air bubbles in the subsequent descending process of the glass member 30 are increased. Can be further reduced. further,
By slightly increasing the descending speed in the subsequent descending step, the time required for the placing step can be shortened.

When the glass member 30 is placed on the support member 14 under the conditions described in the above example, the probability that bubbles that can be visually confirmed are mixed in the resin material is about 1%.
%Met. That is, when the mounting process of the glass member 30 is performed under the above conditions, the non-defective rate of the replica lens is 99%.
%, And it was confirmed that the yield of the replica lens could be reliably improved.

In the resin material supply step and the glass member mounting step, the resin material spreads to all corners of the space between the bonding surface 30a and the molding surface 12b of the mold member 12, and the resin material protrudes. It is actually impossible to do nothing at all. Therefore, a small amount of resin material always protrudes from the edge of the molding surface 12b. Then, the protruding resin material is used as the body-attached portion 30b of the glass member 30.
When the replica lens 33 is attached to the lens barrel, the replica lens 33 is attached at an angle to the optical axis of the lens barrel when the completed replica lens 33 is assembled into the lens barrel, and the optical performance is degraded. Therefore, the glass member 3 is formed so that the protruding resin material does not adhere to the body-attached portion 30b.
At 0, an escape portion 30c of the resin material is provided between the outside of the effective ray diameter D and the body portion 30b (see FIG. 9).

The escape portion 30c is formed by cutting the glass member 30 so as to form a slope that is steeper upward than the extension surface of the joining surface 30a of the glass member 30. Since the protruding resin material tends to move downward in accordance with gravity, the escape portion 30c is formed to have a steeply upward slope so that the resin material is prevented from sneaking into the body-attached portion 30b. it can.

An escape portion 14c is also formed at the upper end of the support member 14 so as to prevent the protruding resin material from adhering to the support member 14. When the operation of placing the glass member 30 on the support member 14 is completed, the moving mechanism 36 is operated to move the irradiation device 34 on the optical axis of the glass member 30. The resin layer 32 is irradiated with ultraviolet rays as active energy rays through the glass member 30. By this irradiation, the resin layer 32 starts to harden.

Here, not only UV-curable resins, but also adhesives generally shrink in volume upon curing. Therefore, when the glass member 30 is held by the support member 14 until the resin layer 32 is completely cured, the contraction of the resin layer 32 causes the gap between the resin layer 32 and the bonding surface 30 a of the glass member 30. , Or peeling off from the molding surface 12b. To solve this,
In one embodiment, the support state of the support member 14 is released as shown in FIG. 7 in a state where the resin layer 32 has hardened to such a degree that the glass member 30 can be held.
By doing so, the glass member 30 can move as the resin layer 32 shrinks, so that the peeling phenomenon can be prevented.

To explain this in one specific example, when the above-mentioned urethane-modified acrylate and an ultraviolet-curable resin containing acrylate as a monomer component are used as the resin material, first, the irradiation device 34 The center wavelength of the resin layer 32 is 365 n by the fluorescent lamp.
m of ultraviolet rays at an irradiation intensity of 30 mW / cm ² for 30 seconds. The irradiation energy amount per 1 cm ² by this first irradiation is 30 mW × 30 sec = 900 mWs
= 900 mJ, and the polymerization rate of the resin material at this time is:
As shown by a white circle on the graph showing the relationship between the irradiation energy and the polymerization rate in FIG. 8, it is about 70%. About 70% polymerization rate
In this state, the resin layer is no longer in contact with the glass member 30 even if the support of the glass member 30 by the support member 14 is released.
The hardness of the molding surface 12b has reached a level that does not cause misalignment. However, even in this state, if force is applied from outside,
It is possible to move the glass member 30 with respect to the mold member 12.

When the irradiation of the first stage is completed, the operation of the air cylinder 20 is released as shown in FIG. 7, and the support state of the glass member 30 by the support member 14 is released. Thereafter, a high-pressure mercury-xenon lamp, which is another light source in the irradiation device 34,
Similarly, ultraviolet light having a center wavelength of 365 nm is irradiated at 100 mW / c.
Irradiate at an irradiation intensity of m ² for 60 seconds. The irradiation energy amount per 1 cm ² by this second stage irradiation is 100 mW
× 60 sec = 6000 mJ, and the total irradiation energy amount with the first stage irradiation energy amount is 69
00 mJ. The polymerization rate corresponding to this irradiation energy amount is about 96%, as shown by the black circles in FIG. 8, and is in a substantially completely cured state.

In the above example, the irradiation intensity and the irradiation time are set so that the polymerization rate of the resin material becomes 70% by the first irradiation, but the set value of the polymerization rate is 7%.
It is not limited to 0%, but is actually 50% to 90%.
The same effect can be obtained by setting in the range of%.
Then, the replica lens 33 in which the curing of the resin layer 32 is completed is released from the mold member 12, and a predetermined coating (for example, an anti-reflection coating) is applied to upper and lower surfaces to complete the replica lens 33. FIG. 9 shows a completed shape of the replica lens 33.

Next, a second embodiment of the first embodiment will be described below. In the second embodiment, as the resin material, a urethane-modified polyester acrylate, 38% by weight, and ditrimethylolpropane tetraacrylate, 35% by weight, which is a resin material of a type having a higher curing speed than the resin material used in the first embodiment. Using a liquid composition containing 1% by weight, 25% by weight of isobornyl acrylate, and 2% by weight of 1-hydroxycyclohexyl phenyl ketone, molding is performed using exactly the same molding apparatus and mold member as in FIG.

First, the fluorescent lamp of the irradiation device 34
2 m of ultraviolet light having a center wavelength of 365 nm is applied to the resin layer 32.
Irradiate at an irradiation intensity of W / cm ² for 10 seconds. The irradiation energy amount per 1 cm ² by this first stage irradiation is 2 m
W × 10 sec = 20 mWs = 20 mJ, and the polymerization rate of the resin material at this time is about 90%. When the first-stage irradiation is completed, the resin layer 32 is hardened to some extent. However, if a force is applied from the outside, the glass member 30 can be moved with respect to the mold member 12. It is in a state.

When the irradiation of the first stage is completed, the operation of the air cylinder 20 is released as shown in FIG. 7, and the support state of the glass member 30 by the support member 14 is released. Thereafter, a high-pressure mercury-xenon lamp, which is another light source in the irradiation device 34,
Similarly, ultraviolet light having a center wavelength of 365 nm is irradiated at 100 mW / c.
Irradiate at an irradiation intensity of m ² for 20 seconds. The irradiation energy amount per 1 cm ² by this second stage irradiation is 100 mW
× 20 sec = 2000 mJ, and the total irradiation energy amount with the first stage irradiation energy amount is 20
20 mJ. The polymerization rate corresponding to this irradiation energy amount is about 96%, which is a substantially complete cured state.

According to the second embodiment, the irradiation time is 10 seconds for the first stage and 20 seconds for the second stage, for a total of 30 seconds.
sec, so that the molding time is shortened, which is advantageous for improving the production efficiency. Further, since the initial viscosity of the resin material used in the second embodiment is relatively low at 500 cps, bubbles are less likely to be mixed when the resin material comes into contact with the mold member.

Next, FIG. 10 shows an example of a lens barrel in which the replica lens 33 is mounted. FIG.
In the lens barrel 48, a positioning portion 48a is provided for abutting on the body portion 30b of the replica lens 33 described above and for defining the center position of the replica lens 33 and the position in the direction along the optical axis. Have been. A relief portion 48b for accommodating the protruding resin material is formed in the resin relief portion 30c of the replica lens 33.
The incident side of the lens barrel 48, that is, in front of the replica lens 33, has an inner diameter slightly larger than the effective diameter of the incident light, and prevents light from entering the escape portion 30c of the resin. Light-shielding portion 48c is provided.

As described above, the escape portion 48b for accommodating the protrusion of the resin material is provided in the lens barrel 48, and the light shielding portion 48c is provided in front of the light incident side, so that the replica lens 33 can be connected to the lens mirror. In addition to being able to be accurately positioned with respect to the cylinder 48, undesired irregular reflection of light rays and irregular refraction of light rays caused by light rays entering a protruding portion of a resin material having an irregular surface shape. Can be prevented, and the deterioration of the image quality can be prevented.

In the above embodiment, the case of forming a replica lens having a convex surface has been described. However, the method of forming an optical element according to one embodiment is exactly the same as the case of forming a replica lens having a concave surface. Applicable to FIG. 11 shows a replica lens 3 having a concave surface.
FIG. 4 shows a molding device for molding No. 3, which is different from the molding device shown in FIG.
The other configuration and the molding operation thereof are exactly the same as those of the molding apparatus shown in FIG. 4 except that the mold member is replaced with a mold member corresponding to the concave surface.

FIG. 12 shows a completed shape of the replica lens 33 having a concave surface, which has a body-attached portion and a relief portion of a resin material like the convex lens having a convex surface. FIG. 13 shows a replica lens 3 having a concave surface.
FIG. 11 is a diagram showing a lens barrel to which the replica lens 3 is attached, and is identical to the lens barrel 48 shown in FIG.
3 has a positioning portion 48a, an escape portion 48b for accommodating the protruding resin, and a light shielding portion 48c for preventing light rays from entering the protruding portion of the resin.

As described above, according to the optical element molding method of one embodiment, the glass member is moved from a position where the surface is away from the molding surface to a position immediately before coming into contact with the resin material on the molding surface. By moving the glass member at a high speed and moving it at a low speed from a position immediately before the surface of the glass member comes into contact with the resin material to a position where the glass member comes into contact with the support portion, it is possible to prevent bubbles from being mixed into the resin material, and to prevent the optical element The yield can be reliably improved.

It should be noted that the present invention can be applied to a modification or modification of the above embodiment without departing from the gist thereof. For example, in the above-described embodiment, the case where an ultraviolet curable resin is used as the active energy ray-curable resin has been described. However, the present invention is not limited thereto, and an X-ray curable resin or an infrared curable resin may be used. May be used.

Further, conditions such as a discharge speed, a moving speed of a syringe, a descending speed of a glass member, etc., and a condition such as an irradiation intensity, an irradiation time, etc., when irradiating an ultraviolet ray when the resin material is supplied to the mold member. With respect to those shown in the above examples,
This is one preferable example, and the present invention is not limited to the conditions described in the above embodiment. Further, it has been described that the glass member is temporarily stopped when the glass member comes into contact with the resin material. However, the glass member may be continuously lowered without stopping, or without changing the speed at the time of lowering at a low speed. You may make it descend at a fixed low speed. Even in this case, if the instantaneous speed of the contact between the glass member and the resin material is sufficiently low, it is possible to prevent air bubbles from being mixed into the resin material.

Although the case where a replica lens is formed has been described, the present invention can be similarly applied to other types of optical elements as long as a resin layer is formed on the surface of a glass material. Also, to raise and lower the support member,
Although the case where the air cylinder and the spring are used has been described, it goes without saying that these may be replaced with an elevating mechanism such as a combination of a ball screw, a stepping motor, or a DC servomotor.

In the above description, the mold member is fixed and the support member is moved up and down with respect to the mold member. Alternatively, the support member may be fixed and the mold member is moved up and down.

[0066]

As described above, according to the optical element molding method of the present invention, the resin material is discharged to the molding surface by discharging the resin material in a state where the tip of the resin material supply device is close to the molding surface. After contacting, by ejecting the resin material while retracting the tip of the supply device from the molding surface, the resin material can be supplied without falling onto the molding surface, and the resin adheres to the tip of the supply device. Therefore, no bubbles are mixed into the resin material, and the required amount of the resin material can be supplied accurately.

[0067]

[Brief description of the drawings]

FIG. 1 is a diagram showing a conventional example.

FIG. 2 is a diagram showing an example of a conventional method of supplying a resin material.

FIG. 3 is a view showing another example of a conventional method of supplying a resin material.

FIG. 4 is a diagram showing a configuration of a molding apparatus to which a molding method of an optical element according to an embodiment is applied.

FIG. 5 is a view showing a procedure of a supply operation of a resin material.

FIG. 6 is a diagram showing a procedure of a mounting operation of a glass member.

FIG. 7 is a view showing a state where a support member of the molding apparatus shown in FIG. 4 is released.

FIG. 8 is a diagram showing a relationship between an irradiation energy amount and a degree of polymerization.

FIG. 9 is a diagram showing a completed shape of a replica lens having a convex surface.

FIG. 10 is a diagram showing an example of a lens barrel to which the replica lens shown in FIG. 9 is attached.

FIG. 11 is a diagram showing a configuration of a molding apparatus for a pre-lens having a concave surface.

FIG. 12 is a view showing a completed shape of a replica lens having a concave surface.

13 is a diagram illustrating an example of a lens barrel in which the replica lens illustrated in FIG. 12 is mounted.

[Explanation of symbols]

 Reference Signs List 10 substrate 12 mold member 14 support member 16 mold frame 20 air cylinder 22 connecting member 24 connecting rod 26 compression spring 30 glass member 32 resin layer 33 replica lens 34 irradiation device 36 moving mechanism 38 moving mechanism 40 supply device 42 elevating mechanism 44 syringe 46 Drive

Continuation of the front page (51) Int.Cl. ⁶ identification code FI B29K 105: 32 B29L 9:00 11:00 (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 39/00-39/44 B29C 31/06 B29C 35/08

Claims (5)

(57) [Claims] 1. A resin layer having a predetermined surface shape is formed on a surface of a glass member by molding.
In a method for molding an optical element for forming an optical element in which a glass material and a resin material are integrated, the resin material is formed on a molding surface for transferring the predetermined surface shape onto a surface of the resin layer. A first step of bringing a tip end of a supply unit for supplying the resin to a predetermined distance, and a step of bringing the resin from the tip end of the supply unit in a state where the tip end of the supply unit is brought close to the predetermined distance. A second step of discharging a predetermined amount of the material, from the molding surface, while maintaining a state in which the lower end of the resin material discharged from the distal end is in contact with the molding surface; A third step of discharging the resin material from the distal end portion at a predetermined discharge speed until the total amount with the predetermined amount becomes a necessary supply amount while moving the resin material away from the resin material. Optical element molding method 2. In the second step, the predetermined amount is that at least the lower end of the resin material discharged from the tip of the supply unit is equal to or more than an amount necessary for contacting the molding surface. The method for forming an optical element according to claim 1, wherein: 3. The method according to claim 1, wherein in the second step, the predetermined amount is controlled by an elapsed time from a start of the discharge of the resin material by the supply unit.
3. The method for molding an optical element according to 1. 4. The optical element molding method according to claim 1, wherein the required supply amount is controlled by an elapsed time from a start of the discharge of the resin material by the supply unit. 5. The method according to claim 1, wherein the resin material is an active energy ray-curable resin.