JPH07291637A - Molding machine for optical lens and mold for optical lens - Google Patents

Abstract

PURPOSE:To obtain a molded lens for a video movie having desired function at a low cost by molding a number of lenses at the same time. CONSTITUTION:Plural groups of lens-forming molds 5, in which each group consists of an upper mold 1, a lower mold 2, the first body mold 3 and the second body mold 4, are transferred among stages 7 each of which is used for a separate process by the parallel, movement of transferring arm 8 provided with recesses 8a and inclined faces 8b for positioning. By this, the lens-forming molds 5 are kept nearly at the center of each stage 7 and subjected to a homogeneous temperature distribution. Further, plural molded lenses 6 can be produced at the same time by one pressing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical lens molding machine and a lens molding die for forming spherical lenses and aspherical lenses used in optical equipment by precision molding.

[0002]

2. Description of the Related Art Conventionally, a polishing method has been generally used for mass production of optical lenses, particularly spherical lenses, but in recent years, lens precision and tolerances have become strict with downsizing and high magnification of video cameras with a built-in camera. Sufficient lens processing accuracy cannot be obtained by polishing technology alone.

Therefore, in order to mass-produce optical lenses regardless of whether they are spherical lenses or aspherical lenses, many molding methods using dies have been tried and are in a practical stage. In such a molding method, molding is performed by filling a glass material into a molding die corresponding to the lens to be obtained and transferring by heating.

Generally, the constitution of the molding dies for spherical lenses and aspherical lenses is such that the upper die and the lower die, and the axes of the spherical and aspherical optical functional surfaces machined on the end faces of the upper die and the lower die facing each other. For example, a first body mold that holds the upper mold in a vertically slidable manner by aligning the hearts with each other, and a height at the time of pressing for accommodating the first body mold to keep heat and to set the center thickness of the lens. The upper and lower molds each have an optical function by heating and pressing the glass material filled in the space formed by the upper mold, the lower mold, and the first cylindrical mold. The surface is transferred to the glass material and the lens surface is formed.

A conventional optical lens molding machine and lens molding die will be described below with reference to the drawings.

FIG. 6 is a block diagram showing a cross section of a conventional lens forming die, and FIG. 7 is a view showing heating and pressing of the lens forming die of an optical lens.
It is a figure which shows the schematic structure of the molding machine of the conventional optical lens which transfers between each process which cools, (a) is a top view, (b) shows sectional drawing. In FIG. 6, 1 is an upper mold, 2 is a lower mold, and one end face of each of them is a flat bottom face 1b, 2b, and the other end face of each is an optical function surface 1a,
2a are formed and are arranged so as to face each other, and each has a predetermined lens function surface in a spherical or aspherical shape. Reference numeral 3 denotes a first barrel die, which holds the upper die 1 and the lower die 2 in a state in which the axes of the upper die 1 and the lower die 2 are aligned with each other, whereby the upper die 1 can be slid vertically. 4 is
The second body mold accommodates the first body mold 3. The entire lens molding die 5 is composed of an upper die 1, a lower die 2, a first barrel die 3 and a second barrel die 4. Reference numeral 6 denotes a molded lens to which the optical function surfaces 1a and 2a of the upper mold 1 and the lower mold 2 have been transferred.
In FIG. 7, 7 is a stage of each process, on which a lens molding die 5 filled with a glass material 6a is sequentially placed, and various process treatments are performed. That is, 7a is a preheating stage for heating the lens forming die 5 up to the plastic deformation temperature (several hundreds of degrees) of glass, and 7b is a pressing stage for forming the lens forming die 5.
The upper mold 1 is pressed (pressed) by the press head 10 while heating. A cooling stage 7c cools the glass to an elastic deformation temperature or lower. Reference numeral 18 denotes a transfer arm, which is repeatedly moved and stopped in parallel with the direction of arrow A shown in FIG. 7 so that the lens molding die 5 is sequentially arranged on each stage 7a, 7b, 7c, and the lens is mounted on each stage 7. The molding die 5 is pressed to transfer sequentially.

The operation of the conventional optical lens molding machine thus configured will be described with reference to FIGS. 6 and 7. The lower mold 2 is fitted to the first barrel mold 3 and the second barrel mold 4, and the glass material 6a is filled on the optical function surface 2a of the lower mold 2 so that the optical function surface 1a is on the glass material 6a side. The upper die 1 is fitted into the first barrel die 3. Next, the entire lens forming die 5 is heated to the plastic deformation temperature of the glass on the preheating stage 7a, and then transferred to the next step by the transfer arm 18. In the pressing stage 7b of the next step, the bottom surface 1b of the upper mold 1 is pressed to the height H of the second barrel mold 4 by the press head 10 while keeping the lens molding mold 5 at a high temperature. As a result, the glass material 6a is plastically deformed into the shapes of the optical function surfaces 1a and 2a of the upper mold 1 and the lower mold 2. After pressing, the lens molding die 5 is moved to the next step by the re-operation of the transfer arm 18. Finally, the entire lens molding die 5 transferred to the cooling stage 7c is cooled to the elastic deformation temperature of the glass or lower, so that the glass material 6
The optical function surfaces 1a and 2a of the upper mold 1 and the lower mold 2 are transferred to a, and the lens 6 having desired performance is molded.

By molding the lens 6 molded in this way in a molding time corresponding to the lens performance, desired performance can be stably realized. In addition, an accurate amount of the glass material 6a to be filled is one condition for ensuring the transfer.

[0009]

However, in the above-mentioned conventional configuration, the lens forming die is formed by one piece, and the transfer between each process is performed by moving only one lens forming die. In terms of sex, it was inefficient and had the following problems. (1) There is a limit in improving the production tact of molding (time required for one production) in order to improve productivity, and an inexpensive lens cannot be obtained. (2) The production tact can be improved by molding at an excessively high temperature, but the lens performance, the lens appearance, and the like are deteriorated, and desired characteristics cannot be obtained. Furthermore, excessive high-temperature forming accelerates metal oxidation and fatigue, which damages the forming machine and the forming die and shortens their life. (3) In order to improve production capacity (increase production), it is necessary to add molding machines, robots, etc., resulting in large capital investment.

The present invention solves the above-mentioned problems of the prior art. A plurality of lens forming dies can be collectively transferred at the same time between heating, pressing, and cooling steps, and each step can be processed. The objective is to stably obtain a plurality of desired lenses at the same time.

[0011]

In order to achieve this object, an optical lens molding machine of the present invention comprises an upper mold having a spherical or aspherical optical functional surface on one end surface, and an end surface on one end surface. At least one of the upper mold and lower mold can be slid up and down with the lower mold having a spherical or aspherical optical function surface and the axial centers of the upper and lower mold optical function surfaces aligned. A plurality of lens molding dies having a first barrel mold held by the first barrel mold, a second barrel mold containing the first barrel mold, a plurality of stages for mounting the plurality of lens molds, and a plurality of stages Is equipped with a transfer means for simultaneously moving a plurality of lens forming dies in a position-regulated state.

Further, a lens molding die having a structure formed of an upper mold, a lower mold and a first barrel mold, and a second barrel mold having a plurality of through holes for holding the plurality of components. In particular, the optical function surface of at least one of the upper mold and the lower mold of at least one of the plurality of constituent members is different from the optical function surface of the other constituent member.

[0013]

With this configuration, the upper mold for lens molding,
A plurality of sets of lower mold and first barrel mold can be configured to be transferred at the same time and heated, pressed, and cooled sequentially, and at the same time efficiently obtain a large number of desired lenses. You can

Further, since a plurality of constituents are held in one lens molding die, a plurality of molded lenses can be obtained at the same time by heating, pressing and cooling once.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the construction of an optical lens molding machine according to the first embodiment of the present invention, in which (a) is a plan view and (b) is a sectional view. In FIG. 1, reference numeral 5 denotes a lens molding die, and the upper mold 1 and the lower mold 2 have optical function surfaces 1a and 2a formed on the surfaces facing each other.
The configuration in which the upper die 1 is held by the body die 3 coaxially and slidably, and the second body die 4 houses the first body die 3 is similar to the above-described conventional example. Reference numeral 7 denotes a stage of each step, which shows any two stages of the three stages shown in the conventional example, and the configuration thereof is the same as that of the conventional example (the press head is not shown in the figure). Reference numeral 8 denotes a transfer means (transfer arm) for simultaneously moving the two lens forming dies 5 having the above-described configuration, and a positioning recess 8a having slopes 8b at both corners on the surface facing the respective lens forming dies 5.
Is provided, moves parallel to the direction of arrow B, and repeats stopping,
The plurality of lens forming dies 5 on each stage 7 are pushed to move to the next step. The difference from the conventional example is that each stage 7
A plurality of lens forming dies 5 are arranged on the upper side, a recess 8a for moving the plurality of lens forming dies 5 is provided in the transfer arm 8, and the lens forming dies 5 are brought into contact with the sloped surface 8b of the recess 8a. The position of the molding die 5 is regulated.

The operation of the optical lens molding machine thus configured will be described below with reference to FIG.

As in the conventional example, two lens molding dies 5 composed of an upper mold 1, a lower mold 2, a first barrel mold 3, and a second barrel mold 4 containing a glass material which is a base of a molded lens are stages. 7
Placed on top. After the process on a certain stage is performed as in the conventional example, the two lens forming dies 5 are transferred to the next stage by the transfer arm 8 which moves in the direction of arrow B in FIG. Since the surface of the transfer arm 8 facing the lens mold 5 has a concave portion 8a that restricts the positions of the two lens molds 5 by the slope 8b, the movement of the transfer arm 8 causes the lens mold 5 to be displaced. Each stage 7 without causing
It does not deviate significantly from the center of.

As described above, in the first embodiment of the present invention,
The recess 8a of the transfer arm 8 regulates the positions of the two lens forming dies 5, and the lens forming dies 5 are moved by each stage 7 during transfer.
Since it does not shift to the peripheral edge portion, even if all of them are heated at the same time, a substantially uniform temperature distribution can be obtained, and even if a plurality of press moldings are simultaneously performed, a lens having desired performance can be stably obtained.

Next, a second embodiment of the present invention will be described. FIG. 2 is a block diagram of the second embodiment of the present invention.
(A) is a top view, (b) is a C line sectional view of a top view (a). 2 is different from the first embodiment shown in FIG. 1 in that 14 is a second barrel mold, and has a plurality of through holes 14a into which the outer shape of the first barrel mold 3 fits. 14a is a structure in which an upper mold 1, a lower mold 2, and a first body mold 3 are fitted into each other. In this embodiment, the height of the second barrel die 14 in the axial direction is made higher than that of the first barrel die 3 as in the first embodiment to limit the height at the time of pressing to form the molded lens. The thickness of 6 is decided.

In the second embodiment of the present invention thus constructed, the entire lens forming die is heated until the bottom surface 1b of each upper die 1 reaches the height H of the second barrel die 14. A plurality of molded lenses 6 are simultaneously molded by pressing all the upper molds 1 with a common press head and finally cooling. Therefore, this embodiment does not require a transfer arm.

As described above, in the second embodiment of the present invention, the second body mold 14 is provided with the plurality of through holes 14a, and the upper die 1, the lower die 2, and the first body die 3 are provided with a plurality of components. By constructing a set, heating all of these at the same time, and pressing at the same time,
A plurality of lenses having desired performance can be stably obtained at the same time. In particular, in this embodiment, the second barrel mold 14 not only holds the plurality of components and keeps the temperature, but also the molded lens 6
Is determined by the height H of one of the second barrel dies 14, there is no variation in the center thickness of the molded lens due to the height tolerance of the plurality of second barrel dies as in the first embodiment. Mass production of more homogeneous molded lenses is possible.

Next, a third embodiment of the present invention will be described. FIG. 3 is a block diagram of the third embodiment of the present invention.
(A) is a plan view, (b) is a sectional view taken along the line D of the plan view (a). In FIG. 3, reference numeral 24 denotes a second barrel mold, which has a plurality of through-holes 24a into which a plurality of structural members including an upper mold 1, a lower mold 2, and a first barrel mold 3 are fitted, as in the second embodiment. Have A recess 24 is formed in the center of each side of the second body mold 24.
b is formed, and a small through hole 24c is formed in the central portion. In this way, by providing the recesses 24b and the small through holes 24c in the second body mold 24, the upper areas (volumes) of the second body molds 24 surrounding the first body molds are substantially the same.

In such a structure, as in the second embodiment shown in FIG. 2, the lens molding die 25 is mounted on the stage 7.
A plurality of molded lenses 6 are simultaneously molded by heating the whole, then pressing the upper mold 2 and cooling it. At this time, the recesses 24b and the small through holes 24c of the second body mold 24 are formed.
Since the portion of the second barrel mold 24 that surrounds each first barrel mold 3 is substantially constant, the temperature changes during heating and cooling are performed more evenly throughout the lens molding die 25 and in a shorter time. Be seen.

As described above, in the third embodiment of the present invention, the temperature distribution of each part of the lens forming die 25 during heating and cooling is different from that of the second embodiment between the end portion and the central portion of the second barrel die 24. The difference between the two is small and heat is hard to be stored, so that the temperature change in a relatively short time enables more stable molding processing even with a short production tact.

Next, a fourth embodiment of the present invention will be described. FIG. 4 is a block diagram of the fourth embodiment of the present invention.
(A) is a plan view and (b) is a sectional view taken along the line E of the plan view (a). In FIG. 4, reference numeral 34 denotes a second barrel type, which has a plurality of through holes 34a, b, c, and d having different internal shapes, and molded lenses of different specifications (curvature, outer shape) (here, 6 c,
6 d only) to make each through hole 34 at the same time.
1st body type 3a, b, c that fits a, b, c, d
D, upper molds 1A, 1B, 2C, and 2D having an optical function surface according to the specifications of each molded lens, and lower molds (only 2C and 2D are shown here). That is, the internal shapes of the through holes 34a and 34a differ from the through holes 34a and 34a due to the specifications of the molded lenses having different outer shapes. Since the molded lenses 6C and 6D have the same outer shape, the specifications of the molded lenses 6C and 6D are different even if the through holes 34a and 34A have the same internal shape (here,
Since the molded lens 6C is a convex lens and the molded lens 6C is a concave lens,
The upper mold 1 c, 1 d, the lower mold 2 c, and 2 d have different shapes such as curvatures of the optical function surfaces.

In such a structure, on the stage 7, a plurality of through holes 34a of the second barrel mold 34 are provided with a structure consisting of the first barrel mold 3, the upper mold 1, and the lower mold 2 of the respective specifications. As in the case of the second embodiment shown in FIG. 2, the fitting and the entire lens molding die 35 are heated, pressed and cooled to simultaneously mold the molded lenses 6 according to a plurality of different specifications.

As described above, in the fourth embodiment, different types of molded lenses can be manufactured at a time by pressing once, and in particular, a combined lens (a plurality of lenses are combined into one set. Chromatic aberration, etc.) It has excellent optical characteristics). In addition, multiple lenses for one movie can be molded at the same time, which is an advantage that the number of mass-produced lenses can be easily managed.

In the first embodiment, the number of stages is three.
Although the stage has been described, the present invention is not limited to this. For example, the same effect can be obtained even if the preheating stage is divided into a plurality of stages and the temperature is raised stepwise. Further, in the first embodiment, a plurality of sets of the same upper mold 1, lower mold 2, and first barrel mold 3 are configured so that lenses having the same specifications are molded at the same time, but the same as in the fourth embodiment. In order to enable such heterogeneous lens molding, it is only necessary to make the outer diameter of the first barrel mold the same and design various optical functional surfaces of the upper mold and the lower mold. Similarly, since the transfer arm may be moved by restricting the positions of a plurality of lens forming dies, the transfer arm having a plurality of arc-shaped recesses for restricting the position of one lens forming mold as shown in FIG. However, the same effect can be obtained. Further, FIG. 5 shows an example of the upper die, the lower die, and the first barrel die for the non-circular molded lens as shown in the fourth embodiment (FIG. 4).

In addition, in the second, third and fourth embodiments, the second
The barrel type has four through holes, but is not limited to this number. Similarly, in the second, third, and fourth embodiments, the same effect can be obtained even when the transfer means is used to transfer over a plurality of stages of each step as in the first embodiment. Absent.

Further, in all of the embodiments, the structure in which the height when pressing the upper mold for determining the center thickness of the molded lens is set by the height of the second cylinder mold, which is the highest, is not necessarily shown. Not limited to the configuration, for example, by making at least one of the plurality of first body dies higher than the second body dies, the height when the upper die is pressed can be determined by the first body dies.

[0032]

As described above, according to the present invention, a plurality of spherical or aspherical lens molding dies are constructed, and a transfer arm having a concave portion for regulating the positions of the molds and a second barrel having a plurality of through holes are provided. An excellent optical lens molding machine capable of simultaneously obtaining a plurality of lenses having desired performances by simultaneous heating and simultaneous press molding depending on the mold and improving productivity more than twice (2 to 4 times). A lens mold is provided.

[Brief description of drawings]

FIG. 1A is a plan view showing the configuration of an optical lens molding machine according to a first embodiment of the present invention, and FIG. 1B is a sectional view of the same.

2A is a plan view showing the configuration of a lens molding die according to a second embodiment of the present invention, and FIG. 2B is a sectional view of the same.

FIG. 3A is a plan view showing the configuration of a lens molding die according to a third embodiment of the present invention, and FIG. 3B is a sectional view of the same.

FIG. 4A is a plan view showing the configuration of a lens molding die according to a fourth embodiment of the present invention, and FIG. 4B is a sectional view of the same.

FIG. 5 is a plan view of a transfer device showing another example in the first embodiment of the present invention.

FIG. 6 is a configuration diagram showing a cross section of a lens molding die in a conventional example.

FIG. 7A is a plan view showing the configuration of a conventional optical lens molding machine, and FIG. 7B is a sectional view of the same.

[Explanation of symbols]

 1 Upper Mold 1a Optical Functional Surface 1b Bottom Surface 2 Lower Mold 2a Optical Functional Surface 3 First Body Mold 4 Second Body Mold 5 Lens Mold 6 Molded Lens 6a Glass Material 7 Stage 8 Transfer Arm 8a Recess 8b Slope 14 2 body 14a through hole 15 lens forming die 24 second body 24a through hole 24b recess 24c small through hole 25 lens forming die 34 second body 34a through hole 35 lens forming die H second body forming height

Claims (3)

[Claims] 1. An upper mold having a spherical or aspherical optical functional surface on one end surface, a lower mold having a spherical or aspherical optical functional surface on one end surface, the upper mold and the above A first barrel mold that holds at least one of the upper mold and the lower mold slidably in the vertical direction in a state where the axes of the optical function surfaces of the lower mold are aligned, and the first barrel mold. A plurality of lens molding dies having a second barrel mold to be housed, a plurality of stages on which the plurality of lens molding dies are placed, and a plurality of lens molding dies simultaneously moved between the plurality of stages in a position-regulated state. A molding machine for an optical lens, comprising: 2. An upper die having a spherical or aspherical optical functional surface on one end surface, a lower die having a spherical or aspherical optical functional surface on one end surface, the upper die and the above A structure constituted by a first barrel mold that holds at least one of the upper mold and the lower mold slidably in the vertical direction in a state where the axes of the optical function surfaces of the lower mold are aligned; A lens forming die comprising a second barrel die having a plurality of through holes for holding a plurality of constituent bodies. 3. An optical function surface of at least one of an upper die and a lower die of at least one of the plurality of constructions,
The lens molding die according to claim 2, wherein the lens molding die is different from the optical functional surface of the other component.