JP2785683B2 - Optical lens molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, a polishing method has been generally used for mass production processing of optical lenses, especially spherical lenses, but recently, with the miniaturization and high magnification of a camera-integrated video or the like, lens accuracy and tolerance have been severe. Sufficient processing accuracy of the lens cannot be obtained only by the polishing processing technology.

In order to mass-produce optical lenses irrespective of spherical lenses and aspherical lenses, many molding methods using molds have been tried and are in a practical stage. In such a molding method, a glass material is filled in a molding die corresponding to a lens to be obtained, and molding is performed by heat transfer.

[0004] In general, the molding dies of a spherical lens and an aspherical lens are composed of an upper mold and a lower mold, and axes of spherical and aspheric optical functional surfaces machined on opposite end faces of the upper mold and the lower mold. A first body mold that holds the upper mold slidably in the up-down direction by aligning the hearts, and a height when pressed to house and hold the first body mold and to set the center thickness of the lens The upper and lower molds are formed by heating and pressing a glass material filled in a space formed by the upper mold, the lower mold, and the first mold, which is composed of a second mold that restricts the upper mold and the lower mold. The surface is transferred to a glass material to form a lens surface.

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

FIG. 6 is a structural view showing a cross section of a conventional lens mold, and FIG.
1A is a plan view and FIG. 1B is a cross-sectional view illustrating a schematic configuration of a conventional optical lens molding machine that transfers between cooling steps. In FIG. 6, reference numeral 1 denotes an upper die, and 2 denotes a lower die. One end face of each is a flat bottom face 1b, 2b, and the other end face is an optical functional face 1a, 2b.
2a are formed and arranged so as to face each other, and each has a spherical or aspherical shape to form a predetermined lens functional surface. Reference numeral 3 denotes a first body mold, which holds the upper mold 1 and the lower mold 2 in a state where the axes thereof are aligned with each other, whereby, for example, the upper mold 1 can be slid up and down. 4 is
The second body mold accommodates the first body mold 3. The entire lens molding die 5 includes an upper die 1, a lower die 2, a first trunk die 3, and a second trunk 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 are transferred.
In FIG. 7, reference numeral 7 denotes a stage of each process, on which a lens mold 5 filled with a glass material 6a is sequentially placed, and various process processes are performed. That is, 7a is a preheating stage for heating the lens mold 5 to the plastic deformation temperature (several hundred degrees) of glass, and 7b is a pressing stage for the lens mold 5
The upper die 1 is pressed (pressed) by the press head 10 while heating is performed. Reference numeral 7c denotes a cooling stage for cooling the glass to an elastic deformation temperature or lower. Reference numeral 18 denotes a transfer arm, which repeatedly moves and stops in parallel to the direction of arrow A shown in FIG. 7 so that the lens mold 5 is sequentially arranged on each of the stages 7a, 7b, 7c. The mold 5 is pressed and transferred sequentially.

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

[0008] The lens 6 thus molded is molded for a molding time commensurate with the lens performance, so that desired performance can be stably realized. Further, the fact that the glass material 6a to be filled is in an accurate amount is one condition for ensuring transfer.

[0009]

However, in the above-mentioned conventional configuration, since one lens molding die is formed, and only one lens molding die is used for transferring between each process, production is difficult. Inefficiency in terms of performance has the following problems. (1) There is a limit in improving the production tact (time required for one production) in order to improve productivity, and an inexpensive lens cannot be obtained. (2) Although the production tact can be improved by molding at an excessively high temperature, the desired properties cannot be obtained because the lens performance and the lens appearance are deteriorated. In addition, excessive oxidation at high temperatures accelerates the oxidation and fatigue of the metal, which damages the molding machine and the mold and shortens its life. (3) In order to improve production capacity (increase production), it is necessary to increase the number of molding machines, robots, etc., resulting in large capital investment.

The present invention solves the above-mentioned conventional problems. A plurality of lens molds are collectively transferred simultaneously between heating, pressing, and cooling steps, and the respective steps can be processed. It is an object of the present invention to simultaneously and stably obtain lenses having desired performance.

[0011]

In order to achieve this object, an optical lens molding machine according to the present invention comprises an upper mold having a spherical or aspherical optical function surface on one end face, and an upper mold having an optical function surface on one end face. At least one of the upper and lower dies can be slid in the vertical direction with the lower and upper dies having a spherical or aspherical optical function surface and the upper and lower dies having the same optical center. A plurality of lens molds having a first body mold held in the first body mold, a second body mold accommodating the first body mold, a plurality of stages for mounting the plurality of lens molds, and a plurality of stages. Is provided with transfer means for simultaneously moving a plurality of lens molds in a position-regulated state.

[0012]

[0013]

According to this structure, the upper mold for molding the lens is provided.
A plurality of sets of a lower mold and a first body mold can be simultaneously transferred and heated / pressed / cooled sequentially, and a large number of lenses having desired performance can be efficiently obtained at the same time. Can be.

Further, since a plurality of components are held in one lens mold, a plurality of molded lenses can be simultaneously obtained by one heating, pressing and cooling.

[0015]

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

FIGS. 1A and 1B are views showing a configuration of an optical lens molding machine according to a first embodiment of the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a sectional view. In FIG. 1, reference numeral 5 denotes a lens mold, and upper and lower molds 1 and 2 have optical functional surfaces 1a and 2a formed on opposing surfaces, respectively.
The configuration in which the upper die 1 is slidably held coaxially by the body die 3 and the second body die 4 accommodates the first body die 3 is the same as the above-described conventional example. Reference numeral 7 denotes a stage of each process, which shows any two of the three stages shown in the conventional example, and has the same configuration 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 molds 5 having the above-described configuration, and a positioning recess 8a having inclined surfaces 8b at both corners on a surface facing each lens mold 5.
Is provided, and repeatedly moves and stops parallel to the direction of arrow B,
The plurality of lens molds 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 molds 5 are disposed thereon, a concave portion 8a for moving the plurality of lens molds 5 is provided on the transfer arm 8, and the lens mold 5 comes into contact with a slope 8b of the concave portion 8a so that these lenses are formed. 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 forming dies 5 including an upper mold 1, a lower mold 2, a first body mold 3, and a second body mold 4 containing a glass material serving as a base of a molded lens are mounted on a stage. 7
Placed on top. After performing a process on one stage as in the conventional example, the two lens molds 5 are transferred to the next stage by the transfer arm 8 operating in the direction of arrow B in FIG. Since the transfer arm 8 has a concave portion 8a whose surface facing the lens forming die 5 regulates the position of the two lens forming dies 5 by the inclined surface 8b, the lens forming die 5 is displaced by the movement of the transfer arm 8. Each stage 7 without causing
It does not deviate significantly from the center of the.

Thus, in the first embodiment of the present invention,
The concave portion 8a of the transfer arm 8 regulates the position of the two lens molds 5, and during the transfer, the lens mold 5
, A substantially uniform temperature distribution can be obtained even when these are heated at the same time, and a lens having desired performance can be stably obtained even when a plurality of press moldings are performed at the same time.

Next, a second embodiment of the present invention will be described. FIG. 2 is a configuration diagram of a second embodiment of the present invention,
3A is a plan view, and FIG. 3B is a cross-sectional view taken along line C of the plan view. In FIG. 2, a point different from the first embodiment shown in FIG. 1 is that a second body 14 has a plurality of through holes 14a into which the outer shape of the first body 3 fits. 14a, a structure composed of an upper mold 1, a lower mold 2, and a first body mold 3 is fitted. In this embodiment, the height of the second body mold 14 in the axial direction is made higher than the height of the first body mold 3 as in the first embodiment to limit the height at the time of pressing to form a molded lens. 6 is determined.

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

As described above, in the second embodiment of the present invention, a plurality of through-holes 14a are provided in the second barrel mold 14, and the upper mold 1, the lower mold 2, and the first By assembling them and heating them all at the same time and pressing them at the same time,
A plurality of lenses having desired performance can be obtained simultaneously and stably. In particular, in this embodiment, the second body mold 14 not only holds and keeps a plurality of components, but also forms the molded lens 6.
Is determined by the height H of the second barrel 14, so that there is no variation in the center thickness of the molded lens due to the height tolerance of the plurality of second barrels as in the first embodiment. In addition, more uniform molded lenses can be mass-produced.

Next, a third embodiment of the present invention will be described. FIG. 3 is a configuration diagram of a third embodiment of the present invention,
(A) is a plan view, and (b) is a cross-sectional view taken along line D of the plan view (a). In FIG. 3, reference numeral 24 denotes a second body die, which has a plurality of through-holes 24a into which a plurality of members composed of an upper die 1, a lower die 2, and a first body die 3 are fitted as in the second embodiment. Have. A recess 24 is provided at the center of each side of the second body mold 24.
b is formed and a small through hole 24c is formed in the center. By providing each of the recesses 24b and the small through holes 24c in the second body mold 24 in this manner, the upper area (volume) of the second body mold 24 surrounding each first body mold becomes substantially the same.

In such a configuration, similarly to the second embodiment shown in FIG.
By heating the whole, and then pressing and cooling the upper mold 2, a plurality of molded lenses 6 are simultaneously molded. At this time, each recess 24b of the second body mold 24 and the small through hole 24c
Because the portion of the second body mold 24 surrounding each first body mold 3 is substantially constant, the temperature change during heating and cooling is performed more uniformly and in a shorter time over the entire lens mold 25. Will be

As described above, in the third embodiment of the present invention, the temperature distribution of each part of the lens mold 25 during the heating and cooling is different from that of the second embodiment between the end and the center of the second body mold 24. Since the temperature difference changes in a relatively short time because the difference between the two is small and heat storage is difficult, more stable molding can be performed even in a short production cycle.

Next, a fourth embodiment of the present invention will be described. FIG. 4 is a configuration diagram of a fourth embodiment of the present invention,
(A) is a plan view, and (b) is a cross-sectional view taken along line E of the plan view (a). In FIG. 4, reference numeral 34 denotes a second body, which has a plurality of through-holes 34a having different internal shapes, b, c, and d, and molded lenses having different specifications (curvature, outer shape) (here, 6 c,
6 are shown at the same time).
a first body type 3a, b, c, adapted to a, b, c, d
D, an upper mold 1a, 2b, 3c, and 2d having optical functional surfaces according to the specifications of each molded lens, and a lower mold (only 2c and 2d are shown here). That is, due to the specifications of the molded lenses having different external shapes, the through holes 34a and 34a have different internal shapes from the through holes 34a and 34a. Further, since the outer shapes of the molded lenses 6 and 6 are the same, the specifications of the molded lenses 6 and 6 are different even if the internal shapes of the through holes 34a and 34a are the same (here,
Molded lens 6c is a convex lens, and 6d is a concave lens)
The shapes such as the curvatures of the optical functional surfaces of the upper mold 1 and 1 and the lower mold 2 and 2 are different.

In such a configuration, on the stage 7, a plurality of through-holes 34a of the second body mold 34 is provided with a structure composed of the first body mold 3, the upper mold 1 and the lower mold 2 of each specification. As in the second embodiment shown in FIG. 2, the entire lens molding die 35 is subjected to heating, pressing, and cooling steps to simultaneously mold a plurality of different shaped lenses 6 corresponding to different specifications.

As described above, in the fourth embodiment, different shaped lenses can be formed at a time by one pressing, and in particular, a group lens (a group of lenses made up of a plurality of lenses; chromatic aberration, etc.) (Excellent optical properties). In addition, it is possible to simultaneously mold a plurality of lenses for a single movie, which brings about an advantage that the number of lenses manufactured 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 increased stepwise. Further, in the first embodiment, a plurality of sets of the same upper mold 1, lower mold 2, and first body mold 3 are formed so as to simultaneously mold lenses having the same specifications. However, the same as in the fourth embodiment. In order to enable such heterogeneous lens molding, the optical function surfaces of the upper mold and the lower mold may be variously designed with the same outer diameter of the first barrel mold. Similarly, since the transfer arm may move the plurality of lens molds while regulating the position of the plurality of lens molds, the transfer arm has a plurality of arc-shaped concave portions for regulating the position of one lens mold as shown in FIG. However, a similar effect can be obtained. FIG. 5 shows an example of an upper mold, a lower mold, and a first body mold for a non-circular molded lens as shown in the fourth embodiment (FIG. 4).

In the second, third and fourth embodiments, the second
Has four through-holes, but is not limited to this number. Similarly, in the second, third, and fourth embodiments, it is needless to say that the same effect can be obtained even if the transfer is performed by the transfer means over a plurality of stages of each process as in the first embodiment. Absent.

Further, in all the embodiments, the structure in which the height of the upper die for determining the center thickness of the molded lens at the time of pressing the upper die is set by the height of the second barrel die which is the highest is exemplified. 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 of the first body dies when the upper mold is pressed can be determined.

[0032]

As described above, according to the present invention, there are provided a plurality of spherical or aspherical lens molds, a transfer arm provided with a concave portion for regulating the position thereof, and a second barrel having a plurality of through holes. An excellent optical lens molding machine that can simultaneously obtain a plurality of lenses of desired performance by simultaneous heating and simultaneous press molding depending on the mold, and can improve productivity more than twice (2 to 4 times). A lens mold is provided.

[Brief description of the drawings]

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

FIG. 2A is a plan view showing a configuration of a lens mold according to a second embodiment of the present invention, and FIG.

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

FIG. 4A is a plan view showing a configuration of a lens mold according to a fourth embodiment of the present invention, and FIG.

FIG. 5 is a plan view of a transfer unit 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 a configuration of a conventional optical lens molding machine, and FIG.

[Explanation of symbols]

 Reference Signs List 1 upper die 1a optical function surface 1b bottom surface 2 lower die 2a optical function surface 3 first body die 4 second body die 5 lens molding die 6 molding lens 6a glass material 7 stage 8 transfer arm 8a recess 8b slope 14th 2 body mold 14a through hole 15 lens mold 24 second body mold 24a through hole 24b depression 24c small through hole 25 lens mold 34 second body mold 34a through hole 35 lens mold H of the second body mold height

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-16435 (JP, A) JP-A-1-100030 (JP, A) JP-A-61-227929 (JP, A) (58) Field (Int. Cl. ⁶ , DB name) C03B 11/00 C03B 11/08

Claims (1)

(57) [Claims] 1. An upper mold having a spherical or aspheric optical function surface on one end surface, a lower mold having a spherical or aspheric optical function surface on one end surface, the upper mold and the upper mold A first body mold that holds at least one of the upper mold and the lower mold slidably in a vertical direction in a state where the axes of the optical functional surfaces of the lower mold are aligned, and the first body mold. A plurality of lens molds having a second body mold to be housed, a plurality of stages on which the plurality of lens molds are mounted, and the plurality of lens molds simultaneously moved between the plurality of stages in a position-regulated state. A molding machine for an optical lens, comprising: a transfer means for causing the optical lens to move.