JPS6294311A - Positioning of mold for molding plastic lens - Google Patents

Abstract

PURPOSE:To make it possible to position molds for various types of lenses, by inserting a gauge having thickness to the light axis direction preset in the central position between a pair of molds being held by a pair of holding devices and by making the gauge memorize the positions of the molds with respect to the light axis direction for various types of the lenses. CONSTITUTION:A pair of molds 1, 2 facing each other is held by a pair of cups 9, 10 from both sides of the light axis direction under a condition where the central position and the degree of parallelism are aligned with each other. A gauge 19 or 20 is inserted into the central position between the molds 1, 2 and held thereat. As the thicknesses, of the gauge 19 and 20 with respect to the light axis direction are set at a specified dimension in advance, the distance at the central position dimension and the positions of the molds are memorized in a memory device 18. After memorizing, the top force 2 is moved upward by the action of a pulse motor 17 and the gauge 19 or 20 is removed. The top force 2 is thereafter restored to the position where it was by the action the motor 17 based on the signal from the memory device 18 and the distance at the central position between the top and bottom forces 1, 2 is determined at the objective value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for positioning a pair of molds used when molding a PlusDeck lens.

[Prior Art] Conventionally, a cast molding method has been known in which a plastic lens is molded by filling a plastic lens material into a cavity formed between a pair of molds facing each other at a predetermined interval. In mold molding, in order to mold plastic lenses with high precision, the precision with which a pair of molds can be placed in the predetermined position is critical.
ru.

Mold 1? As a method, a ring-shaped space is sandwiched between the peripheral edges of two 1-pieces. ”'('-i1
The -E-ruled 1'/7'J method for making a purchase decision is known -C-iro (Special Publication No. 6 (1) -293333''; Publication). Remove the spacer between the upper and lower molds, return the rear mold to its original position, and apply adhesive tape that spans between the two molds. At 1↓, the key and bifi for lens molding are formed.

If this method is used, a spacer is sandwiched between two molds. positioning becomes possible.

[Problems to be solved by the invention] However, the above method has the following problems.

That is, a ring-shaped space of 1J is held between the peripheral edges of the two seven-roots! Since this is a method in which the distance between the two halves is determined by the method, it is necessary to have a large number of spaces (I) with different heights depending on the thickness of the peripheral part of the lens to be molded. Therefore, there is a problem in that the production and management of spacers (requires a lot of cost and manpower).

However, when it comes to lenses for myopia, the [
The peripheral thickness varies depending on σ, but the center thickness varies☆
It has the characteristic that it is almost constant. I wanted to,
◇As long as the positioning is done, the above J
, it is necessary to have a large number of spaces 1j, but if the center thickness can be regulated, it is not necessary to have as many positioning tools.

The present invention focuses on the above-mentioned points, and aims to provide a method that enables positioning of molds for producing lenses with various specifications using only the minimum necessary positioning tools. .

[Means for Solving the Problems] This method of positioning molding molds for plastic lenses according to the present invention along a pair of molding molds is a method for positioning molding molds for molding plastic lenses along a pair of molding molds. In the method of positioning the molds, a pair of molds is held from both sides in the optical axis direction by a pair of opposing holders with the center position and parallel distance aligned, and then the center position between the pair of -L and At position 1N, from the 7-rd side,
Insert the gauge with the preset thickness in the optical axis direction to the right (), and move the optical axis surface of the holding shell. At the time of pinching, memorize the position of one of the [-] leads in the optical axis direction, then separate the [7-] leads, remove the [-] gauge, and set the -] leads at the previously memorized L (1'/position). How to get back to it.

The above-mentioned gauge is made of, for example, a sphere or a tongue-shaped body, and is set to have a predetermined thickness in the direction of the optical axis Ip.

[Effect] Like this! In the Klj method, first, the center positions of the first lead in the first position are aligned, and the parallel stones are aligned in a facing state, and in this state, they are held from both sides in the direction of the optical axis Jj by a pair of holders. Ru. Next, the thickness of the IJ lens, that is, the distance between the molds is determined. This positioning is performed by inserting a gauge into the center between the molds and sandwiching them between the molds. Since the thickness of the gauge in the optical axis direction is set in advance to a predetermined value, at least one of the gauges is moved in the optical axis direction while the center axis is aligned with the center axis. Just by placing both molds in close contact with the gauge, the distance between the molds can be set to the desired value. Thus, the determined mold spacing is stored by storing the positions of both molds or by storing the position of one mold and keeping the position of the other mold fixed. After storing, the gauge is removed from between the molds, and the mold is returned to the stored position, completing the positioning of the mold.

In this way, even without using the conventional ring-shaped space,
The mold spacing can now be determined at the center of the mold using a gauge, and it is sufficient to have the minimum number of gauges necessary for a lens whose center thickness hardly changes.

In addition, for lenses for myopia, etc., the quality of the product is 19 mm at the periphery, and the thickness at the center is 19 mm at the periphery. The lens quality is directly regulated by the designated customer, so 1 month - 1 drop of filter lees is weighed on the lens's power, etc. ! 1 will also be improved.

[Embodiment 1] A preferred practical example of the present invention will be described below with reference to the drawings.

1 and 4 show an apparatus for carrying out a method for positioning a plastic lens mold according to a first embodiment of the present invention. In the figure, 1 and 2 indicate a pair of molds for molding plastic lenses. The lens is molded by filling the mold.

3.4 - and 1.2 from the periphery (i'/
By restraining F7 1Y, align the center position of the -E lead concave and 2, and align the center position of the -E lead 1.2 with the χ・1 direction 1
! The figure shows the lower and the lower centripetal centripetal devices, which take parallel [q] and the I-7-led centripetal arrangement. The lower mold centripetal device 3 consists of a chuck 5 that can slide horizontally on the reference plane A'- in the radial direction of the mold 1, and a cylinder 6 that moves the chuck 5 in the radial direction of the mold 1. The mold centripetal device 4 is a chuck 7 that can be slid in the horizontal direction on a reference plane B formed on the − side of the chuck 5.
It consists of a cylinder 8 that moves the chuck 7 in the radial direction of the mold 2.

On both upper and lower sides of the upper and lower molds 1.2, -shields 1.2
A cup 9.10 is provided as a mold holder whose holding surfaces are opposed in parallel.

In this embodiment, the cups 9 and 10 are suction cups, and are configured to be rotatable. The pair of molds 1.2 whose centers and parallelisms are matched by the lower mold centripetal device 3 and the mold centripetal device 4 are held by cups 9.10 from both sides in the direction of the optical axis 11, respectively. Ru.

In addition, the center position and parallelism of the mold 1.2 are adjusted using the device shown in FIGS. 2 and 3.
good. FIG. 2 shows a state in which the mold 1, 2 is held by a ring-shaped holder 12, and the parallelism is adjusted by the holding, and the mold 2 is placed in the V positioning device 1?
be tested. The positioning device has an i11 as shown in Figure 3.
? An centering [l-ra 13 is provided, and the center position of the seventh lead 1.2 is aligned. This retainer 12 is for holding a pair of 4-fields on the instep, and is not for determining the spacing between the molds, so there is no need to have many types.

Now, returning to FIG. 1, the ten cup 10 is supported so as to be able to move up and down via a rad 14, and is moved by a cylinder 15 when making a large up-and-down movement, and when making a small up-and-down movement. Pulse motor all 17 through threaded part 1 fS
(r/fi control in the optical axis 11 direction is possible and <-1
ing.

All pulse motors 17 are connected to a storage device 18,
It is operated based on a signal from the storage device 18, so that the mold 2 can be returned to the storage position with high precision.

FIG. 4 shows a state in which the gauge 19 is inserted at the center position between the pair of molds 1.2, which have the same center position and parallelism as described above. In this embodiment, the gauge 19 is inserted.
is made up of spheres. This gauge includes a gauge 20 consisting of a tongue piece body, as shown in a second embodiment in FIG.
Any suitable shape may be used as long as it has a predetermined thickness in the optical axis direction and can be inserted into and taken out from the center between the molds. However, it is desirable to use a material that is less hard than the mold so as not to damage the mold.

The method of the present invention is carried out as follows using the apparatus configured as described above.

First, a pair of opposing molds 1.2 are aligned in center position and parallelism, and in this state are held from both sides in the optical axis direction by a pair of opposing cups 9.10.

In order to match the center position and parallelism, in the apparatus shown in FIG. 1, first place the lower mold 1 on the cup 9! Then, the chuck 5 for the lower mold is closed, and then the upper mold 2 is placed on the Js□tsuku 5 that constitutes the horizontal reference white B. When the -L upper mold grip 7 is closed and the center positions of the lower molds 1 and 2, that is, the optical axes are aligned, the parallel eclipses are aligned.Second
1) In the device shown in FIG. 3, the mold 1.
2 holds in a ring shape! ':! 124 to be held (positioned by aligning the parallel tortoise with the center position of 1.2). After being rotated, the center is accurately aligned with the centering roller 13, and the cup 9.10 is held in a parallel state.

Next, unless the gap between the molds is as wide as -F, open the chuck 7 or open the centering roller 13 and hold the lower mold 2 in the cup 10 for a while (
I can get crushed. And gauge 19 between mold 1.2
or 20 is inserted. Gauge 19 or 20 is -
The heart of Ludo 1.2! (The bobble C ~ is inserted, and in that state, the upper mold 2 is lowered, and the gauge 19 or 20 is held between the molds 1.2 by the opposing surfaces of the molds 1.2. This holding is done as shown in the figure. In the case of a mold for forming lenses for myopia, the spacing is the narrowest at the center of the seventh lens, so it is ensured that the molding is performed at the center of the seventh lens.

Since the thicknesses of the gauges 19 and 20 in the optical axis direction are set in advance to one predetermined thickness, the spacing between the molds 1 and 2 and their centers is naturally determined to one predetermined thickness by the above-mentioned clamping. It will be done. At this time, if a spherical gauge 19 as shown in Fig. 4 is used, the gauge 19 can be simply inserted between the upper and lower molds 1 and 2, and the gauge 19 will naturally roll on the concave surface of the upper surface of the lower mold 1, which is fixed horizontally. Then press the button gently in the center position.

Further, by using a tongue-like gauge 20 as shown in FIG. 5, it is possible to quickly and easily insert and remove the material from the center of the mold.

In this way, the distance between the centers of the molds 1 and 2 is determined at a predetermined value (A1). 1 is fixed in position, and the position of the upper mold 2 in the optical axis direction is memorized. After memorization, the upper mold 2 is moved upward by the operation of the pulse motor 17, and the movement W is memorized as the number of pulses of the pulse motor 17. The gauge 19 or 20 is then removed from the gap between the molds.

Shikaru Shun, memory)! The operation of the pulse motor 17 based on the signal from ii & 1B is lowered through the threaded portion 16. returned to position. Since the movement is controlled by a pulse motor 17 of 6-element 1η, the 10-mold mold 2 is easily returned to its original position 1.
] - the center of the upper and lower 1.2 is determined by the target.

In this way, exactly (?/positioned mold 1.2
For example, a tape 21 is wrapped around it as shown in FIG. 6, and the unnecessary part of the chi 121 is cut off as shown in FIG. It is formed.

Although the pulse motor 17 is used in this embodiment, any other suitable high-precision movement control means may be used, and regarding the storage device 18, any device capable of restoring the b-mold to its original position with high precision may be used. For example, any device such as an electronic type, an electric type, a mechanical type, etc. can be used.

[Effects of the Invention] As explained above, according to the present invention, since the inter-mold spacing is determined at the center of the mold, the distance between the molds is determined at the lens periphery using a conventional ring-shaped spacer. The number of preparatory size gauges for lenses with multiple specifications can be greatly reduced, and the production and management thereof can be greatly facilitated.

In addition, since the center of the lens, which corresponds to the most important center thickness for lens products, is directly positioned, it is possible to form the targeted high-precision lens molding cavity, which improves the quality of plastic lenses. The effect of contributing to -1- can also be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a positioning device for implementing a positioning method for a plastic lens mold according to an embodiment of the present invention, and FIG. 2 shows the mold center position and Parallel bite! Fig. 3 is a cross-sectional view of the Hannya in which the center of the mold is used. FIG. 5 is a vertical sectional view around the mold showing the positioning method according to the second embodiment of the present invention; FIG. 6 is a vertical sectional view around the mold showing the positioning method according to the first embodiment; FIG. FIG. 7 is a perspective view showing the state in which the tape in FIG. 6 is cut. 1.2... Mold 5. 7...B (knock 9.10...Cup 11 as a pair of holders)
...Optical axis 12...Ring-shaped holder 13...t? Interning roller 16...
・Threaded portion 17...Pulse motor 1B...Storage device 19...Spherical gauge 20...Language gauge Fig. 3 Fig. 4 Fig. 5 Mold ＼＼ ＼ 20 gauge,,
,, /// 鐐、1゜Figure 6Figure 7-~l

Claims (3)

[Claims] (1) In the method of positioning the pair of molds for molding a plastic lens between the pair of opposing molds, the pair of opposing molds are held in a state where the center positions and parallelisms are aligned. A gauge having a predetermined thickness in the optical axis direction is inserted into the center between the pair of molds from the side of the mold, and a gauge having a predetermined thickness in the optical axis direction is By moving, the inserted gauge is sandwiched between a pair of molds, the position of at least one of the molds in the optical axis direction at the time of the gauge sandwiching is memorized, and then the molds are separated and the gauge is removed, and the mold is stored in the memorized position. A method for positioning a plastic lens mold, characterized in that the mold is returned to the original position. (2) The method for positioning a plastic lens mold according to claim 1, wherein the gauge is a sphere. (3) The method for positioning a plastic lens mold according to claim 1, wherein the gauge is a tongue piece.