JP2011101978A - Method of molding plastic optical lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of molding a plastic lens which is adjustable to even a lens having a complicated lens characteristics without necessitating many frames. <P>SOLUTION: A plurality of actuators 17 are arranged in the lower position of a first lens frame 2 of a gasket 4 of a mother form 1 comprising the first lens and a second lens fames 2, 3 and the gasket 4, and a drive shaft 18 is controlled so as to be set in a predetermined advance position. Thereby the first lens frame 2 is deformed into a desired lens surface shape. A monomer for lens molding is injected from an injection port 7 while the drive shaft 18 is kept in the advance position and thermally cured to obtain the lens. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for molding an optical lens using plastic as a raw material.

2. Description of the Related Art Conventionally, there is known a molding method in which a thermosetting plastic material (monomer) as a liquid molding material for lens molding is filled in a cavity of a molding mother mold, and this is heated to mold a lens. Patent Document 1 and Patent Document 2 are shown as examples of such a molding method. In Patent Document 1, as shown in FIGS. 1 and 2, first and second molds 12 and 13 are attached to a gasket 14 as a holding member to form a mother mold, and a filling port formed in the gasket 14. A liquid thermosetting plastic material is injected into the inside from 16 and cured to obtain a plastic lens. Alternatively, a tape may be used as a mold holding member in a state where two molds are opposed to each other with a predetermined interval between the surfaces on which the lens is molded instead of such a gasket. It is also possible to use a thermoplastic material as the material. Similarly in Patent Document 2, the first and second molds 3 and 4 are mounted on the gasket 2 to form a mold (matrix).
In this way, when a plastic material is introduced into a molding die and a plastic lens is molded, the mold already has the shape of the lens surface. Since there is no part to be discarded by cutting, the cost is reduced as compared with the case of manufacturing a lens by cutting.

JP 2006-341538 A JP 2005-132043 A

However, when the lens is used as, for example, a spectacle lens, a large number of molds must be prepared according to the frequency in order to cope with various prescriptions of the user. Further, when considering not only the S frequency but also the C frequency (astigmatism frequency) and progressive characteristics, more types of molds are required. In that case, the production cost of the formwork will be increased.
In addition, when a lens having complicated lens characteristics is manufactured, it is difficult to manufacture the mold itself. In fact, there are many cases in which special lens characteristics are handled by cutting. Therefore, there has been a demand for a plastic lens molding method that can deal with lenses having complicated lens characteristics without preparing many types of molds.
The present invention has been made paying attention to such problems existing in the prior art. The object is to provide a plastic lens molding method that does not require many molds and is compatible with even lenses having complicated lens characteristics.

In order to solve the above-mentioned problems, in the invention described in claim 1, a lens mold having a surface (hereinafter referred to as a lens forming surface) for forming a lens surface on either the front or back side of the lens, and an outer edge of the lens are formed. In addition, a molding material for lens molding is introduced into a container including a holding member that holds the lens mold frame so that the lens molding surface faces upward, and the molding material is allowed to flow according to the shape of the container. Thereafter, the molding material is cured, and then the lens mold and the holding member are released to obtain a lens.
A plurality of actuators that linearly advance and retract the moving body are arranged adjacent to each other in a two-dimensional direction at a predetermined interval, and the lens mold is composed of a flexible and elastic film body having a uniform thickness. The movable body tip is disposed opposite to the outer position of the lens mold, and each actuator is driven and controlled so that each movable body is at a predetermined advance position, and the lens mold is moved by the movable body. The lens molding surface is deformed so as to be a surface having a predetermined lens characteristic by pressing, and a lens molding material is introduced into the container while holding the lens mold in the deformed state to cure the lens. The gist is that it is designed.
According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, each actuator is disposed below the lens mold frame, and the tip of the movable body is perpendicular to the actuator installation surface. The gist of this is to make progress.
Further, in the invention of claim 3, in addition to the structure of the invention of claim 1 or 2, the molding material for lens molding is a liquid thermosetting plastic, and heat, light or microwave energy is passively passed. The gist is that it is cured by polymerization.
Further, in the invention of claim 4, in addition to the structure of the invention of claim 1 or 2, the molding material for molding the lens is a thermoplastic, and the thermoplastic is melted by passively applying heat or microwave energy. The gist is that the liquid is injected into the container.

In such a configuration, a moving body of a plurality of actuators is advanced from a position facing the lens mold formed of a flexible and elastic film having a uniform thickness, and the lens mold is pressed at the tip. Then, the surface is deformed to have a predetermined lens characteristic. Then, the molding material for lens molding is introduced into the container while maintaining the deformed state, the molding material is flowed according to the shape in the container, the molding material is cured, and the lens mold frame is cured. Then, the lens is obtained by releasing the holding member.
Here, the actuator of the present invention is a driving device that linearly moves the moving body by input energy. As an electric actuator, an electromagnetic solenoid is used as a driving source, a motor is used as a driving source, and air pressure is reduced. Although what is utilized is common, if it is a drive source which can control the advance / retreat amount of a moving body, it will not specifically limit. In the actuator of the present invention, the advance position of the moving body is controlled. The control method varies depending on the type of input energy. Further, the moving body is assumed to be a shaft body itself built in the actuator, or a pushing member that is linked directly or indirectly from the built-in shaft body.
It is necessary that a plurality of actuators be arranged adjacent to each other in the two-dimensional direction. This is because the deformation according to the lens surface shape cannot be performed in a wide range unless there is such a two-dimensional expansion. The tip of the moving body is preferably on the same plane, but the tip of the moving body does not necessarily have to be on the same plane as long as the mutual positional relationship is known.
The number of actuators is not particularly limited, but as the number increases, the film thickness of the lens mold can be reduced, and more precise deformation can be ensured. Moreover, it is preferable to arrange the whole in a well-balanced manner.
As a material of the lens mold frame made of a flexible and elastic film having a uniform thickness, for example, a heat-resistant material such as silicon rubber and nylon is preferable. Moreover, it is preferable to provide sufficient elasticity so that wrinkles do not occur due to the pushing of the actuator by the moving body.

Moreover, it is preferable that each actuator is arrange | positioned under the lens formwork, and the front-end | tip of a moving body advances / retreats to a perpendicular direction. That is, it is preferable to press with a moving body from the back side of the lens formwork used as the bottom of a container.
Further, the upper surface of the container may be closed with another formwork or may be opened. Moreover, it is assumed that a liquid thermosetting plastic is used as a molding material for lens molding. In order to cure the liquid thermosetting plastic, heat, light, or microwave energy is passively polymerized and cured.
As a material of the plastic lens, it is assumed that a thermoplastic plastic is used. In this case, since the thermoplastic plastic is solidified at room temperature, it is necessary to heat and melt the thermoplastic plastic according to the shape in the container.

In the invention of claim 5, the first lens mold having a lens molding surface for molding the surface to be the back surface of the lens and the first lens molding surface for molding the surface to be the surface of the lens. Two lens molds are arranged at a predetermined distance with the lens molding surfaces facing each other, and a holding member for molding the outer edge of the lens is arranged between the first and second lens molds. Forming a mother mold having an outer space surrounded by the lens mold frame and the holding member and a partitioned inner space while maintaining a distance between the lens mold frames. A plastic molding material in which a liquid molding material for molding a lens is injected into the matrix from the formed injection port to cure the liquid molding material, and then both lens molds are released to obtain a lens. A method for molding an optical lens, the moving body A plurality of actuators that advance and retract linearly are arranged adjacent to each other in a two-dimensional direction with a predetermined interval therebetween, and either the first or the second lens mold frame is flexible and elastic and has a uniform thickness. The moving body tip of each actuator is disposed opposite to the outer position of the lens mold formed of the film body, and each moving body has a predetermined advance position. In this way, the lens mold frame composed of a film body is pressed by the movable body to deform the lens molding surface to a surface having a predetermined lens characteristic, and the film body is configured in the deformed state. The gist of the invention is to introduce a molding material for molding a lens into the container while holding the lens mold to be cured to cure the lens.
According to a sixth aspect of the present invention, in addition to the configuration of the fifth aspect of the invention, the actuators are arranged in a state of facing the lens mold made of a film body, and the movable body tip is provided with an actuator. The gist of this is to advance and retract in the direction perpendicular to the surface.
According to a seventh aspect of the invention, in addition to the constitution of the fifth or sixth aspect of the invention, the first or second lens mold is made of a flexible and elastic film having a uniform thickness. The other lens mold is composed of a lens precursor molded from the same molding material as the lens molding liquid, and the lens molding liquid molding material injected into the matrix is polymerized. The gist is that it is integrated with the lens precursor when it is cured.
Further, in the invention of claim 8, in addition to the structure of the invention of claim 5 or 6, the molding material for molding the lens is a thermoplastic, and the thermoplastic is melted by passively applying heat or microwave energy. The gist is that the liquid is injected into the container.
In addition, in the invention of claim 9, in addition to the structure of the invention of any one of claims 5 to 7, the liquid molding material for molding the lens is thermosetting which is polymerized and cured by passively applying heat, light or microwave energy. The main point is that it is a functional plastic.

In the configuration as in the above fifth to ninth aspects, the liquid molding material for molding the lens is injected into the inner space of the mother die composed of the first and second lens mold frames and the holding member to cure the liquid molding material. A method for molding a plastic optical lens in which both lens molds are separated from each other to obtain a lens, and either or both of the first and second lens molds are flexible and elastic. It is composed of a film body with a uniform thickness, and a movable body of a plurality of actuators is opposed to a lens mold frame composed of the film body, and the movable body is advanced to press the lens mold frame to obtain a surface having predetermined lens characteristics. Deform so that Then, the liquid molding material is introduced into the mother mold while maintaining the deformed state, the molding material is flowed according to the shape in the mother mold, the molding material is cured, and after being cured, the lens mold frame and The lens is obtained by releasing the holding member.
Here, the lens mold frame that is not composed of a film body is composed of a lens precursor that is molded from a molding material that is the same quality as the liquid molding material for lens molding, and the liquid molding for lens molding that is injected into the matrix. It is possible to adopt a configuration in which the material is integrated with the lens precursor when the material is polymerized and cured. That is, the lens mold frame for molding is used as a part of the lens to be molded. By configuring in this way, it is only necessary to prepare the lens formwork only below, and the upper lens formwork is virtually unnecessary. In addition, since the part to be molded by actually curing the liquid molding material in the matrix can be made to be a very small part, it is used for correcting the aberration when the lens surface is already molded, etc. Wide range of applications. The lens mold and the liquid molding material are preferably the same material, but may not be the same as long as there is no problem in the refractive index and compatibility.
Further, it is assumed that a thermosetting plastic is used as the liquid molding material for lens molding. In order to cure the liquid thermosetting plastic, heat, light, or microwave energy is passively polymerized and cured. Further, it is also possible to use a thermoplastic as a molding material for lens molding, in which case heat or microwave energy is passively melted after introduction into the container, and depending on the shape in the container It is preferable to make it flow.
In addition, it is preferable that each actuator is disposed so as to face a lens mold formed of a film body, and the distal end of the moving body advances and retreats in the vertical direction. That is, it is preferable that the moving body is pressed from the back side of the mother lens formwork.

In addition to the configuration of any one of the first to ninth aspects, the invention of claim 10 presses the lens mold frame by a moving body to deform the lens molding surface to a surface having a predetermined lens characteristic. Then, after the lens curing step of curing the lens by introducing a molding material for lens molding into the container while holding the lens mold in the deformed state, the movable body is held at the advanced position. The lens is taken out in a state, and the lens mold for the next molding is held at the advanced position where the movable body is held, and the next lens curing step is performed, so that the lens has the same lens characteristics. The gist is that the optical lens is continuously manufactured.
With such a configuration, by placing the lens mold frame on a moving body that has once advanced to a fixed position, the mold frame is deformed in the same manner as the previous shape. An optical lens can be produced efficiently.
Further, in the invention of claim 11, in addition to the structure of any one of claims 1 to 10, a sag for calculating how much sag is given to the lens surface of the lens to be molded with respect to the reference surface of the reference lens. The reference lens is placed on the lens mold composed of a flexible and elastic film having a uniform thickness, the reference surface is in contact with the lens, and the actuator is driven and controlled. A moving body initial position determining step of bringing the moving body into contact with the lens mold deformed in response to the reference surface shape to determine an initial position of the moving body for each actuator; The reference position on the lens surface of the lens to be molded corresponding to the arrangement position is determined, and the sag amount given to each reference position in the sag amount calculation step is determined with respect to the moving body at the reference advance position. With A moving body unique advance step for newly moving each moving body to a unique advance position, and after moving each moving body to an initial position in the moving body initial position determining step, the reference The lens is removed, and each moving body is advanced to a new unique advancing position in the moving body unique advancing step so that the lens molding surface of the lens mold is deformed so as to have a predetermined lens characteristic. This is the gist.
The gist of the invention of claim 12 is that, in addition to the configuration of the invention of claim 11, the actuators are arranged concentrically along a straight line passing through the center.

In the configuration as in the tenth and eleventh aspects, the reference lens is used to give the initial position to the moving body of the actuator. The reference lens is placed on a lens mold made up of a flexible, elastic and uniform film body so that the reference surface comes into contact, and the actuator is driven and deformed in response to the reference surface shape. The moving body is brought into contact with the lens mold thus formed, and the initial position of the moving body for each actuator is determined. On the other hand, the amount of sag given to the lens surface of the lens to be molded with respect to the reference lens is calculated. Then, the moving body of the actuator is arranged at the position where the moving body of the actuator is arranged, for example, the horizontal position a1. The lens mold is composed of a flexible and elastic film having a uniform thickness so that the deformation is equivalent to the sag amount. It is assumed that the sag amount (inherent advance amount) given to the reference positions p1 to pn on the lens surface of the lens to be molded corresponding to.
As a result, even if the position of the moving body of the actuator varies, the accurate initial position can be determined by following the curve of the reference lens through the lens mold, and the lens surface of the lens to be molded becomes the reference lens. On the other hand, since the lens mold can be deformed from the viewpoint of how much sag is given, it is possible to manufacture a very accurate lens.
In the present invention, the reference surface of the reference lens includes not only a lens having a predetermined curve but also an infinite curvature, that is, a flat surface. The actuators are preferably arranged densely along a straight line passing through the center.

  In the inventions of the above claims, many molds are not required for molding a plastic lens, and even a lens having complicated lens characteristics can be dealt with freely.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the structure of the mother die of Example 1 of this invention, (a) is an exploded sectional view from a front direction, (b) is a front sectional view. The front sectional view of explanatory drawing containing the peripheral device of the state which has arrange | positioned the mother die of Example 1 of this invention in oven. The top view which illustrates typically the arrangement | positioning state of the actuator used for Example 1 of this invention. The block diagram explaining the electrical constitution of Example 1 of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the shaping | molding process of the lens of Example 1 of this invention, (a) is explanatory drawing which mounts a reference lens on a 1st mold, (b) drives an actuator after mounting a reference lens. Explanatory drawing of the state which was made to move and the drive shaft was moved to the initial position. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the shaping | molding process of the lens of Example 1 of this invention, Comprising: (a) is explanatory drawing explaining the state which took out the reference | standard lens from the 1st formwork, (b) is according to the amount of sag. Explanatory drawing explaining the state in the middle of making the drive shaft advance by the amount of advance. Explanatory drawing explaining the method of determining the advance amount of the drive shaft of the actuator of Example 1 of this invention. It is a figure explaining the shaping | molding process of the lens of Example 1 of this invention, Comprising: (a) is explanatory drawing explaining the state which attached the 2nd formwork from the state of FIG.6 (b), (b) is mother. Explanatory drawing of the state which filled the thermosetting plastic material inside the type | mold. Explanatory drawing explaining the method of determining the advance amount of the drive shaft of the actuator of Example 2 of this invention. FIG. 6 is an explanatory diagram for explaining that the second mold is made of the same material as the liquid thermosetting plastic material M in the lens molding step of Example 3 of the present invention to integrate the two. (A) is a front cross-sectional view of a mother mold whose upper side is opened, (b) is an explanatory diagram for explaining a process in the middle of injecting a thermoplastic plastic, ) Is a cross-sectional view of a plastic lens manufactured using this matrix. The front sectional view of explanatory drawing containing the peripheral device of the state which has arrange | positioned the mother die of the other Example of this invention in oven.

Hereinafter, a specific molding method in which the plastic optical lens of the present invention is applied to a spectacle lens will be described with reference to the drawings.
Example 1
In the first embodiment, a mother die 1 as shown in FIGS. 1A and 1B is used. As a molding material, a thermosetting plastic having a refractive index of 1.500 was used. The mother mold 1 includes a first mold 2, a second mold 3, and a gasket 4 as a holding member. In the first embodiment, the first mold 2 is composed of a flexible flat plate made of silicon rubber having a uniform thickness of 2.0 mm and engages with the gasket 4 at the periphery thereof. An engaging portion 5 is formed for fixing the same. The second mold 3 is a meniscus glass plate made of spherical surfaces having the same curvature on both the front and back sides. As shown in FIG. 1 (b), the first mold 2 is bent in its own weight while drawing a curve having a gentle sectional quadratic curve in a horizontally installed state.
The inner surface of the first mold 2 is a lens molding surface for molding the back surface (eyeball side) of the plastic lens to be molded, and the inner surface of the second mold 3 is the surface (object side) of the plastic lens to be molded. ) Is used as a lens molding surface. The gasket 4 is a light-transmitting ring made of silicon rubber, and a support portion 8 having a shape protruding inward in a radial cross section is formed on the inner periphery thereof. The gasket 4 is provided with a filling port 7 for communicating the inside and outside. The first mold 2 and the second mold 3 are respectively fitted into the gasket 4 and abutted against the support portion 8 so as to maintain a space therebetween, so that a cavity is formed inside the mother die 1. In the first embodiment, since the lens diameter is 75 mm as will be described later, the first mold 2, the second mold 3, and the gasket 4 used here have inner diameters corresponding to the lens diameter. To do.

As shown in FIG. 2, the mother die 1 is supported on a support frame 11 through a gasket 4 so that the first mold 2 is located in the oven 10. The support frame 11 and the gasket 4 are engaged by a concave and convex engaging portion (not shown) for accurately aligning the both. The oven 10 is provided with a heat circulation unit 12 including a heater and a fan. A UV irradiation device 13 is disposed inside the oven 10. The UV irradiation device 13 irradiates ultraviolet rays from a total of eight directions, that is, four directions shifted by 90 degrees obliquely from the upper position and four directions shifted by 90 degrees obliquely from the lower position (only two directions in the figure) from the total eight directions. Are arranged to be.
An actuator unit 15 is disposed inside the support frame 11 in the oven 10. In the first embodiment, the actuator unit 15 is constituted by an aggregate of a total of 65 actuators 17 embedded in the base plate 16. The actuator 17 of the first embodiment is a motor-controlled linear actuator that determines the advance / retreat position by controlling the servo motor, and the drive shaft 18 as a built-in moving body is perpendicular to the bottom surface 10 a of the oven 10. It is designed to move forward and backward. The tip of the drive shaft 18 is configured in a cannonball shape. As shown in FIG. 3, in the first embodiment, the actuators 17 are arranged concentrically in 16 directions at equal angles from the center. In FIG. 3, four diametrical directions (that is, eight radial directions) in the AA direction, CC direction, EE direction, and GG direction have five actuators 17 in each direction shifted by 45 degrees. The main radiation direction is arranged at a predetermined interval. Further, in order to prevent the distance between the actuators 17 adjacent to each other in the circumferential direction near the periphery, the BB direction, DD direction, FF direction, and HH direction, which are intermediate positions in the main radial direction, are prevented. Three actuators 17 are arranged at predetermined intervals as sub-radial directions in the four radial directions (that is, eight radial directions). The actuators 17 in each direction are arranged on the same circumference having a predetermined radius from the center, and the actuators 17 are arranged in a balanced manner in all directions from the center.
As described above, since the first mold 2, the second mold 3 and the gasket 4 having an inner diameter corresponding to the lens diameter of 75 mm are used in the first embodiment, the actuator unit 15 has a size corresponding to these. Use things.

As shown in FIGS. 2 and 4, an actuator control computer 25 for controlling the actuator 17 is installed outside the oven 10. The computer 25 includes a CPU (central processing unit) 26, a memory 27 including a ROM and a RAM, an input device 28 (mouse, keyboard, etc.), a monitor 29, and a peripheral device such as a printer 30. The CPU 26 is connected to the actuator 17 (servo motor 17a, rotation speed detector 17b, encoder 17c), the heat circulation unit 12 (heater 12a and fan 12b), and the UV irradiation device 13, respectively.
The CPU 26 controls driving of a servo motor 17a as a driving source of the actuator 17. Further, the advance position of the drive shaft 18 is determined based on the voltage value from the rotational speed detector 17a provided in the actuator 17, and the drive shaft 18 is driven based on the pulse signal of the encoder 17c built in the servo motor 17a. Determine the amount of advance. Further, the servomotor 17a is controlled based on the predetermined advance amount data for each actuator 17 from the input device 27, that is, the sag amount data of the lens to be molded with respect to the reference lens, and the drive shaft 18 is held at the predetermined advance position.

Next, the molding process of the plastic spectacle lens using the mother die 1 and the oven 10 having such a configuration will be described in detail together with the control operation of the CPU 26.
First, as a premise, the sag amount on the back surface side of the lens to be molded with respect to the reference surface Bs of the reference lens 21 is calculated. In the first embodiment, it is assumed that a lens having a spherical lens of S-4.00 and a lens diameter of 75 mm is manufactured. The amount of sag is calculated by calculating the relative position of every part of the lens surface by three-dimensionally simulating the back surface shape of the lens to be molded, and the difference from the reference surface Bs of the reference lens 21 whose three-dimensional shape is known. Is the value obtained as The side in contact with the first mold 2 is used as the reference plane Bs. However, in the first embodiment, the front and back surfaces of the reference lens 21 are configured in parallel planes, so that either front or back surface may be used as the reference surface Bs. The sag amount with respect to this reference plane Bs is the sag amount to be obtained. Table 1 shows the main sag amounts from the geometric center of Example 1.
Here, the concave lens back surface is molded, but the first mold 2 is supported at the periphery, and when pushed by the drive shaft 18 of the actuator 17 from below, it is like this. It is preferable in terms of structure to be deformed into a concave shape on the lower side.
Since the lens to be molded in Example 1 is a single vision (SV) with an astigmatism power of 0, the sag amount increases or decreases by the same amount in all directions from the geometric center O.

As shown in FIGS. 5 (a) and 5 (b), before the second mold 3 is attached to the gasket 4 in the oven 10, the diameter matches the inner diameter of the gasket 4 (actually a very small diameter). The reference lens 21 is inserted from above and placed on the first mold 2.
In this state, the CPU 26 drives the actuator 17 in the direction in which the drive shaft 18 is advanced. Then, as shown in FIG. 5B, the tip of the drive shaft 18 first comes into contact with the first mold 2 as it is driven, and pushes back the slightly bent first mold 2 upward. The first mold 2 that has been extended by its own weight returns to its original shape. Since the rotational speed of the drive shaft 18 that is in contact with the reference surface Bs of the reference lens 21 via the first mold 2 is reduced by the reaction force due to the contact, the controller 18 detects the voltage value at this time. It is determined that the drive shaft 18 has advanced to the initial position. The CPU 26 temporarily stops driving the actuator 17 and holds the drive shaft 18 at the determined initial position. This initial position is stored.

Next, as shown in FIGS. 6A and 6B, with the reference lens 21 taken out, the CPU 26 performs control so as to advance the part corresponding to the sag amount corresponding to the drive shaft 18 of each actuator 17. . For example, let us now assume the amount of advancement of the actuator 17 in the A direction. As shown in FIG. 3, since a total of 11 actuators 17 are arranged in series in the A direction, they are numbered as Aa1 to Aa11.
As shown in FIG. 7, the position of the central actuator 17 corresponding to the geometric center p1 of the lens to be molded is Aa6. In the first embodiment, Aa1 and Aa11, Aa2 and Aa10, Aa3 and Aa9, Aa4 and Aa8, and Aa5 and Aa7 that are equidistant from Aa6 have the same advance amount. Now, Aa5 and Aa7 are 8 mm outward (p2 position) from the Aa6 position, Aa4 and Aa8 are 16 mm outward (p3 position) from the Aa6 position, and Aa3 and Aa9 are 24 mm outward from the Aa6 position (p4 position). It is assumed that Aa2 and Aa10 are 32 mm outward (p5 position) from the Aa6 position, and Aa1 and Aa11 are 37 mm outward (p6 position) from the Aa6 position.
Then, from Table 1, the actuator 17 at the Aa6 position has a sag amount of +7.2975 mm, the actuator 17 at the positions Aa5 and Aa7 has a sag amount of +6.9770 mm, the actuator 17 at the positions Aa4 and Aa8 has a sag amount of 6.0092 mm, and Aa3 and Aa9 The actuator 17 at the position is sag amount +4.3748 mm, the actuator 17 at the positions Aa2 and Aa10 is sag amount +2.0393 mm, the actuator 17 at the positions Aa1 and Aa11 is sag amount +0.2007 mm, and each sag amount is in the A direction. It is a unique advance amount of the column. Although the A direction has been described here, the lens to be molded in Example 1 has the same amount of sag in any direction from the center as long as it is the same distance. It is easy to decide. These values are input to the computer 25 and stored as unique values of each actuator 17.
The first mold 2 is pushed by the drive shaft 18 advanced by a specific advance amount in accordance with the sag amount of these actuators 17 and is deformed into a downward concave shape. Even if the first mold 2 is supported in the form of dots in such a manner as to be spaced apart from each other, since it has elasticity, the section line draws a smooth curve without sagging between the supported drive shafts 18, and a1 The trajectory of the cross-sectional line in the diameter direction passing through the position coincides with the curve obtained based on the trajectory of the cross-sectional line in the diameter direction passing through the geometric center O on the back surface of the lens to be molded, that is, the sag amount in Table 1.

Next, as shown in FIG. 8 (a), the second mold 3 is mounted on the gasket 4 with the first mold 2 deformed and held by the drive shaft 18 as described above, and adjusted from the filling port 7. The liquid thermosetting plastic material M thus filled is filled into the cavity as shown in FIG. Thereafter, the UV irradiation device 13 is operated for a predetermined time under the control of the CPU 26 in accordance with a regular method. First, after the surface of the filled curable plastic material is cured, the thermal circulation unit 12 is operated with a predetermined temperature history over a predetermined time. Operate and cure to the inside. As a result, a lens in which a predetermined characteristic is given to the shape on the back side of the lens to be molded is molded. The mother die 1 (the first and second molds 2, 3 and the gasket 4) is removed from the actuator 17, and the produced lens is released. At this time, the advance position of the drive shaft 18 of the actuator 17 is maintained as it is.
For the second and subsequent lens fabrications, in FIG. 8A, with the amount of advance of the drive shaft 18 of the actuator 17 held, the master 1 after taking out the lens or a separately prepared master of the same size 1 is set, and the lens is manufactured by filling the thermosetting plastic material M in the same manner as described above.

With the configuration as described above, the molding method of this embodiment has the following effects.
(1) Since the first mold 2 is formed of a deformable film body and can be deformed by a drive shaft 18 of the actuator 17 into a lens molding surface having a shape corresponding to a lens to be molded, the lens characteristics are improved. There is no need to prepare various types of molds.
(2) Since the actuators 17 are distributed in a well-balanced manner and are densely arranged, distortion is unlikely to occur when the first mold 2 is deformed.
(3) Since the initial position of the drive shaft 18 of the actuator 17 is first determined by the reference lens, the inherent error of the advance amount of the drive shaft 18 can be eliminated, and the first mold 2 can be deformed more accurately. .
(4) If the advance position of the drive shaft 18 of the actuator 17 is determined for the first time, it is not necessary to set the advance position of the drive shaft 18 from the next step. It is easy to continuously produce an optical lens having a specific surface.

(Example 2)
In the second embodiment, the same mother die 31 that is different in size from the first embodiment (inner diameter: 70 mm) is used. The oven 10 used for the curing process and its peripheral devices are also the same as those in the first embodiment. In the second embodiment, a case where the lens characteristic of the lens to be molded has C power (astigmatism power) will be described, and description of the same configuration as that of the first embodiment will be omitted. In Example 2, spherical lenses S-4.00, C-2.00. A lens having a lens diameter of 70 mm is manufactured by AX180. In the second embodiment, as in the first embodiment, the rear surface shape of the lens to be molded is simulated three-dimensionally to calculate the relative position of every part of the lens surface, and is obtained as a difference from the surface of the reference lens 21. To do.
Table 2 shows the main sag amounts from the geometric center of Example 2. Since the astigmatism power of the lens to be molded of Example 2 is set at an astigmatism axis of 180 degrees, the maximum sag amount and the minimum sag amount are obtained in the vertical and horizontal directions.

In this embodiment, unlike the first embodiment, the sag amount is different in all directions from the center. For this reason, all the actuators 17 have different unique advance amounts. Therefore, it is necessary to clarify the relative positions of all the actuators 17 with respect to the back surface shape of the lens to be molded. For this reason, in this embodiment, the calculation is simplified by making it coincide with one arrangement of the actuators 17 in the direction coincident with the astigmatic axis. For example, the Y-axis direction, which is the direction orthogonal to the astigmatism axis, is aligned with the array A.
For example, the array A actuator 17 is assumed as in the first embodiment. As shown in FIG. 9, the position of the central actuator 17 corresponding to the geometric center p1 of the lens to be molded is Aa6. In the first embodiment, Aa1 and Aa11, Aa2 and Aa10, Aa3 and Aa9, Aa4 and Aa8, and Aa5 and Aa7 that are equidistant from Aa6 have the same advance amount. Now, Aa5 and Aa7 are 8 mm outward (p2 position) from the Aa6 position, Aa4 and Aa8 are 16 mm outward (p3 position) from the Aa6 position, and Aa3 and Aa9 are 24 mm outward from the Aa6 position (p4 position). It is assumed that Aa2 and Aa10 are 30 mm outward (p5 position) from the Aa6 position, and Aa1 and Aa11 are 34 mm outward (p6 position) from the Aa6 position. Then, from Table 1, the actuator 17 at the position Aa6 is sag amount +9.1627 mm, the actuator 17 at the positions Aa5 and Aa7 is sag amount +8.7133 mm, the actuator 17 at the positions Aa4 and Aa8 is sag amount +7.3476 mm, Aa3 and Aa9 The actuator 17 at the position has a sag amount of +5.0010 mm, the actuator 17 at the positions Aa2 and Aa10 has a sag amount of +2.5573 mm, and the actuator 17 at positions Aa1 and Aa11 has a sag amount of +0.5516 mm. It is a unique advance amount of the column.
This is the advance amount in the array A direction, and is a value calculated according to the phase of the actuator 17 in each array in the 16 directions. For example, in the E direction orthogonal to the A direction, the Y axis direction is orthogonal to the astigmatic axis. These values are input to the computer 25 and stored as unique values of each actuator 17.
Also in the second embodiment, a lens that gives a predetermined characteristic to the shape of the rear surface side of the lens to be molded is molded in the same molding process as that of the first embodiment only in the amount of advancement of the drive shaft 18 of the actuator 17. Become.

(Example 3)
In Example 3, the second mold 3 in the matrix 1 of Example 1 was made of the same material as the liquid thermosetting plastic material M. The oven 10 used for the curing process and its peripheral devices are also the same as those in the first embodiment. In Example 3, as shown in FIG. 10, when the mold is released, the second mold 3 can produce a plastic lens PL integrated with the cured thermosetting plastic material M.

Example 4
In Example 4, a mother die 31 as shown in FIG. 11A is used. The mother die 31 includes a first mold 32 and a gasket 33 as a holding member. Similar to the first embodiment, the first mold 32 is formed of a flexible flat plate made of silicon rubber having a uniform thickness of 2.0 mm. Further, unlike the above embodiments, since there is no second mold, the mother die 31 is always in an open state and not in a sealed state. As shown in FIG. 11 (b), as in Example 1 or Example 2, the actuator 17 is controlled to mold a lens that gives a predetermined characteristic to the shape on the back side of the lens to be molded. Then, as shown in FIG. 11 (b), a thermoplastic plastic, for example, polycarbonate PC, is melted by controlling the thermal circulation unit 12 in the oven 10 and injected into the mother die 31 from the filling port 7, along the internal shape. When the polycarbonate PC is made to flow, and then cooled and released, a plastic lens PL in which only the back surface is molded with the first mold 32 as shown in FIG. 11C is obtained. In the fourth embodiment, the surface side is not molded, so the surface side is molded by cutting and polishing as appropriate.

It should be noted that the present invention can be modified and embodied as follows.
In the above embodiment, the case where the first molds 2 and 32 made of a film body are disposed on the lower side with respect to the gaskets 4 and 33 has been described, but the second mold 3 disposed on the upper side is the same. It is also possible to arrange the actuator 17 so that the drive shaft 18 advances downwardly.
In the above description, the first and second lens molds 2 and 3 are arranged in the vertical direction so that the actuator 17 is arranged below. However, the first and second lens molds 2 and 3 are placed vertically. The actuator 17 may be arranged so as to advance and retract from the lateral direction.
In the above embodiment, the actuator 17 is used for molding on the back surface side of the lens, but the surface side may be molded using the actuator 17.
In the above embodiment, the ovens 10 and 35 are heated with hot air by the heat circulation units 12 and 36. However, as shown in FIG. The liquid thermosetting plastic material (or thermoplastic) in the mother die 1 may be cured.
-Besides, it is free to implement in a mode that does not depart from the gist of the present invention.

  DESCRIPTION OF SYMBOLS 1,31 ... Mother type | mold, 2,32 ... 1st lens formwork, 3 ... 2nd lens formwork, 4,33 ... Gasket as a holding member, 17 ... Actuator, 18 ... Drive shaft as a moving body, M: Thermosetting plastic material, PC: Polycarbonate as thermoplastic.

Claims (12)

A lens mold frame having a surface (hereinafter referred to as a lens molding surface) that molds the lens surface on either the front or back side of the lens; and molding the outer edge of the lens so that the lens molding surface faces upward. A molding material for lens molding is introduced into a container composed of a holding member to be held, and the molding material is allowed to flow according to the shape in the container, and then the molding material is cured, and then the lens mold and the holding A plastic optical lens molding method in which a lens is obtained by releasing a member,
A plurality of actuators that linearly advance and retract the moving body are arranged adjacent to each other in a two-dimensional direction at a predetermined interval, and the lens mold is composed of a flexible and elastic film body having a uniform thickness. The movable body tip is disposed opposite to the outer position of the lens mold, and each actuator is driven and controlled so that each movable body is at a predetermined advance position, and the lens mold is moved by the movable body. The lens molding surface is deformed so as to be a surface having a predetermined lens characteristic by pressing, and a lens molding material is introduced into the container while holding the lens mold in the deformed state to cure the lens. A method for molding a plastic optical lens, characterized in that it is designed.   2. The molding of a plastic optical lens according to claim 1, wherein each of the actuators is disposed on a lower side of the lens mold frame, and the distal end of the moving body advances and retreats in a direction perpendicular to an actuator installation surface. Method.   3. The plastic optical lens according to claim 1, wherein the molding material for molding the lens is a liquid thermosetting plastic, and is polymerized and cured by passively applying heat, light or microwave energy. Molding method.   The molding material for molding the lens is a thermoplastic, and heat or microwave energy is passively melted, and the thermoplastic is melted and injected into the container. Molding method for plastic optical lenses. A first lens mold having a lens molding surface for molding a surface to be the back surface of the lens and a second lens mold having a lens molding surface for molding the surface to be the surface of the lens. The lens surfaces are arranged by arranging the holding surfaces for forming the outer edge of the lens between the first and second lens mold frames, with the molding surfaces facing each other with a predetermined distance therebetween. Forming a mother mold having an outer space surrounded by both the lens mold frame and the holding member and a partitioned inner space while maintaining the distance between the frames, and forming a lens from an injection port formed in a part of the holding member A plastic optical lens molding method in which a liquid molding material is injected into the mother mold to cure the liquid molding material, and then both lens molds are released to obtain a lens. ,
A plurality of actuators for linearly moving the moving body are arranged adjacent to each other in a two-dimensional direction at a predetermined interval, and either the first or the second lens mold frame or both are flexible and elastic. It is composed of a film body having a uniform thickness, and the distal end of each moving body of each actuator is disposed opposite to the outer position of the lens frame composed of the film body, and each of the moving bodies has a predetermined advance. The lens molding frame composed of the film body is pressed by the movable body so as to be in position, and the lens molding surface is deformed so as to become a surface having a predetermined lens characteristic. A plastic optical lens characterized in that a lens molding material is introduced into a container while holding the lens mold formed of a body so as to cure the lens. Molding method.   6. The actuator according to claim 5, wherein each actuator is disposed in a state of being directly opposed to the lens mold formed of a film body, and the distal end of the movable body advances and retreats in a direction perpendicular to the actuator installation surface. 2. A method for molding a plastic optical lens according to 1.   The first or second lens mold is composed of a flexible and elastic film having a uniform thickness, and the other lens mold is the same as the liquid molding material for molding the lens. It is composed of a lens precursor molded from the molding material, and is integrated with the lens precursor when polymerizing and curing the lens molding liquid molding material injected into the matrix. A method for molding a plastic optical lens according to claim 5 or 6.   The molding material for molding the lens is a thermoplastic, and heat or microwave energy is passively melted to melt the thermoplastic and injected into the container. Molding method for plastic optical lenses.   8. The plastic optical lens molding according to claim 5, wherein the liquid molding material for molding the lens is a thermosetting plastic that is polymerized and cured by passively applying heat, light or microwave energy. Method.   After the lens mold is pressed by a moving body and the lens molding surface is deformed so as to have a predetermined lens characteristic, a molding material for molding the lens is held while holding the lens mold in the deformed state. After the lens curing step for introducing the lens into the container to cure the lens, the lens is taken out with the movable body held at the advanced position, and the next molding is performed at the advanced position where the movable body is held. 10. The optical lens having a surface having equivalent lens characteristics is continuously produced by holding the lens mold and performing the next lens curing step. A method for molding a plastic optical lens according to the description. A sag amount calculating step for calculating how much sag amount is given to the lens surface of the lens to be molded with respect to the reference surface of the reference lens;
The reference lens is placed on the lens mold composed of a flexible and elastic film having a uniform thickness so that the reference surface comes into contact with the actuator, and the actuator is driven to control the reference surface shape. A moving body initial position determining step of bringing the moving body into contact with the lens mold deformed in response to determining an initial position of the moving body for each actuator;
The movable body which specifies the reference position on the lens surface of the lens to be molded corresponding to the arrangement position of each actuator, and the sag amount given to each reference position in the sag amount calculation step is at the reference advance position And a moving body unique advance step for newly moving each moving body to a unique advance position,
After moving each moving body to the initial position in the moving body initial position determining step, the reference lens is removed, and in the moving body unique advancing step, each moving body is advanced to a new unique advance position. The method for molding a plastic optical lens according to claim 1, wherein the lens molding surface of the lens mold is deformed so as to become a surface having a predetermined lens characteristic.   12. The method for molding a plastic optical lens according to claim 11, wherein the actuators are arranged concentrically along a straight line passing through the center.

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