KR101655335B1

KR101655335B1 - Injection molded lens

Info

Publication number: KR101655335B1
Application number: KR1020150048393A
Authority: KR
Inventors: 박근; 윤승탁
Original assignee: 서울과학기술대학교 산학협력단
Priority date: 2015-04-06
Filing date: 2015-04-06
Publication date: 2016-09-07

Abstract

The present invention relates to an injection-molded product for lens, comprising: a sprue; a runner of which one end is connected to the sprue; a gate connected to the other end of the runner; and a cavity connected to the gate. The runner has a thin plate type and is uniformly maintained to the other end after being reduced in a predetermined position while the width is radially increased from the one end.

Description

[0001] INJECTION MOLDED LENS [0002]

The present invention relates to an injection molded article for a lens.

Recently, the performance of mobile phone cameras has rapidly advanced (up to 16 million pixels in 2014), replacing the existing digital camera market. As the performance of the camera module becomes more advanced, a technique for improving the performance of an optical system is required. Currently, aspheric lenses of 5 sheets for 13 million pixels and 6 sheets for 16 million pixels are assembled and used.

Since the thickness of the smart phone is gradually decreasing, it is necessary to place a large number of lenses in a small space. Thus, although the thickness of the lens gradually became thinner, such a thin lens was difficult to mold.

As shown in FIG. 1, an injection mold is generally manufactured for the purpose of producing a large number of open water (8 to 16 cavities) and applied to a production process.

Referring to FIG. 1, a conventional injection molded article for a lens generally uses a cylindrical runner, and a runner having a diameter of 2 to 5 mm is usually used. Therefore, even when the lens is solidified to a thickness of 1 mm or less, the runner is not sufficiently solidified even after the solidification of the lens is finished, and additional cooling time is required.

Korean Patent Laid-Open Publication No. 10-2009-0075042 discloses a lens made of an injection mold, in which a lower core is unnecessarily moved in a clearance in a lower mold and a center of the upper surface is displaced from a center of the lower surface, And a part of the resin material flows into the gap between the lower mold and the lower core to generate burrs. When such a burr is seated on the module to be used, the burr It is possible to prevent the eccentricity caused by the gap between the lower core and the lower mold while preventing the lens from being reliably landed on the seating point and causing a slight inclination, Although the injection molded article using the mold is described, the shape of the runner is not described It does not control did not solve the above problems.

Korean Patent Publication No. 10-2009-0075042 (2009.07.08)

It is an object of the present invention to provide an injection molded article for a lens which can reduce the cross sectional area by changing the shape of the runner during lens injection molding.

It is another object of the present invention to provide an injection molded article for a lens which can shorten the cooling time without deteriorating the fluidity.

The injection molded article for a lens according to the embodiment is an injection molded article for a lens including a sprue, a runner connected at one end to the sprue, a gate connected to the other end of the runner, and a cavity connected to the gate, , The width increases radially from the one end, decreases again at a predetermined position, and is maintained to the other end.

Further, the injection molded article for a lens according to the embodiment is an injection molded article for a lens including a sprue, a runner connected to one end of the sprue, a gate connected to the other end of the runner, and a cavity connected to the gate, And a plurality of through holes passing through the upper surface and the lower surface are formed in a part thereof.

Here, the number of the through-holes may be the same as the number of the cavities or n times.

The upper and lower surfaces of the runner may be flat.

Here, the thickness of the runner may decrease from one end to the other end.

Here, the upper surface of the runner may be a flat portion, and the lower surface may be a tapered inclined portion.

Here, the upper surface of the runner may be a flat portion, and the lower surface thereof may be a step portion.

Here, the upper surface of the runner may be a flat portion, and the lower surface thereof may be a curved portion.

Here, the width of the runner increases radially from the one end, decreases again at a predetermined position, and can be maintained to the other end.

Here, the gate may decrease in cross sectional area toward the lens side.

Here, protrusions may be formed on the lower surface of the other end of the runner.

According to the injection molded article for a lens according to the embodiment, since the runner is of a thin plate type, the raw material can be saved as compared with the conventional cylindrical runner, the time for solidifying the runner can be shortened, The productivity can be improved as compared with the case of the conventional cylindrical runner.

According to the injection molded article for a lens according to the embodiment, since the runner is formed in a thin plate shape, and a through hole is formed in a part of the runner to penetrate the upper surface and the lower surface, the volume of the runner can be further reduced, And the cooling time can be further reduced.

According to the injection molded article for a lens according to the embodiment, since the number of through holes is equal to or n times the number of cavities, the same injection pressure can be applied to all the cavities.

According to the injection molded article for a lens according to the embodiment, since the thickness of the runner decreases from one end to the other end, the pressure drop of the resin for forming the lens can be reduced.

According to the injection molded article for a lens according to the embodiment, since the upper surface of the runner is a flat portion and the lower surface is one of a flat portion, a tapered inclined portion, a step portion and a curved portion, various runners can be used have.

According to the injection molded article for a lens according to the embodiment, since the width of the runner increases radially from one end, the pressure drop can be reduced, and the flow velocity can be increased since it decreases again at a predetermined position.

According to the injection molded article for a lens according to the embodiment, since the sectional area of the gate decreases toward the cavity side, the flow resistance can be reduced and the pressure drop upon injection can further be reduced.

According to the injection molded article for a lens according to the embodiment, since the projecting portion is formed on the lower surface of the other end of the runner, it is easy to take out the thin plate runner from the mold after injection molding.

1 is a perspective view of an injection molded article having a conventional cylindrical runner.
2 is a perspective view of an injection molded article for a lens according to the first embodiment.
3 is a plan view of the injection molded article for a lens according to the first embodiment.
4 is a longitudinal sectional view of the sprue, runner and gate shown in Fig.
Figs. 5-8 illustrate variations of Fig.
9 is a perspective view of an injection molded article for a lens according to the second embodiment.
10 is a diagram for comparing the cooling characteristics of the conventional cylindrical runner and the runner according to the embodiment.

The following detailed description refers to the accompanying drawings which illustrate, by way of example, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention may be different but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with one embodiment. It is also to be understood that the location or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

&Lt; First Embodiment >

Fig. 2 is a perspective view of the injection molded article for a lens according to the first embodiment, Fig. 3 is a plan view of the injection molded article for a lens according to the first embodiment, Fig. 4 is a cross- .

2 to 4, the injection molded article for a lens according to the first embodiment includes a sprue 100, a runner 200 to which one end 210 is connected to the sprue 100, A gate 300 coupled to the gate 300, and a gate 300 coupled to the gate 300.

The sprue 100, the runner 200, the gate 300, and the cavity 400 are members that serve as water channels for forming the lens 1000. Specifically, the resin for injection molding is injected into the sprue 100, and the resin injected into the sprue 100 moves through the runner 200 and the gate 300, and the lens 400 1000 are formed.

The runner 200 is of a thin plate shape as shown in Fig. 2 and has a structure that extends radially from the center of the sprue 100. As shown in Fig. Therefore, the thin plate-like runner 200 can save the raw material compared to the conventional cylindrical runner, shorten the time for solidifying the runner, and further reduce the cooling time after solidification of the lens is completed. Therefore, when using the conventional cylindrical runner Productivity can be improved.

Here, the thickness of the runner 200 may be 2 mm or less. Therefore, the injection molded article for a lens according to the first embodiment can save the raw material as compared with a conventional cylindrical runner having a diameter of 2 to 5 mm.

3, the width of the runner 200 increases radially from one end 210 and then decreases again at a predetermined position 230 to be maintained at the other end 220. [ Here, the end of the other end 220 of the runner 200 can be rounded. Therefore, the injection molded article for a lens according to the first embodiment can increase the width of the runner 200 radially from one end 210 to decrease the pressure drop and decrease again at the predetermined position 230 to increase the flow velocity .

Although not shown in the drawings, the gate 300 may have its cross-sectional area reduced toward the cavity 400 side. Therefore, the injection molded article for a lens according to the first embodiment can reduce the flow resistance and further reduce the pressure drop upon injection.

As shown in FIG. 4, the upper and lower surfaces of the runner 200 may be flat portions 240 and 250.

A protrusion 260 may be formed on the lower surface of the other end 220 of the runner 200. Therefore, the injection molded article for a lens according to the first embodiment can easily take out the thin plate type runner due to the projecting portion 260.

2, eight lenses 1000 are formed using eight runners 200, but the present invention is not limited thereto. It is possible to use eight or less runners 200 or eight or more runners 200, Or eight or more lenses 1000 can be formed.

Figs. 5-8 illustrate variations of Fig.

Referring to FIGS. 5 to 8, the thickness of the runner 200 of the injection molded article for a lens according to the first embodiment may decrease from one end 210 to the other end 220. Therefore, there is an advantage that the pressure drop of the resin for forming the lens 1000 can be reduced.

The lower surface of the runner 200 of the injection molded product for a lens according to the first embodiment may be one of a tapered inclined portion 241, a stepped portion 242, and curved portions 243 and 244. Therefore, the injection molded article for a lens according to the first embodiment can use runners 200 of various shapes depending on the manufacturing environment.

&Lt; Second Embodiment >

9 is a perspective view of an injection molded article for a lens according to the second embodiment.

9, the injection molded article for a lens according to the second embodiment includes a sprue 100, a runner 500 having one end 210 connected to the sprue 100, a second end 220 of the runner 500, A gate 300 coupled to the gate 300, and a cavity 400 coupled to the gate 300. The runner 500 is formed with a plurality of through holes 570 passing through the top and bottom surfaces thereof. Here, the number of the through holes 570 may be equal to or n times the number of the cavities 400.

Therefore, the injection molded article for a lens according to the second embodiment can further reduce the volume of the runner 500, further reduce the pressure drop at the time of injection, and further reduce the cooling time. Since the number of the through holes 570 of the runner 500 is equal to or n times the number of the cavities 400, the same injection pressure can be applied to all the cavities 400.

10 is a diagram for comparing cooling characteristics of a conventional cylindrical runner and a runner according to the first embodiment. Specifically, Fig. 10 shows the temperature distribution obtained from the results of the injection molding cooling analysis performed on the conventional cylindrical runner, the runner according to the first embodiment, and the runner according to the second embodiment.

10, the temperature of the inside of the runner is higher than the temperature of the lens of the conventional injection molded product. On the other hand, referring to the middle view and the right side view of FIG. 10, the lens for the lens according to the first and second embodiments It can be seen that the temperature of the runner 200 is significantly lowered compared to the temperature of the lens 1000.

As described above, the injection molded articles for lenses according to the first and second embodiments can reduce the overall cooling time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It can be understood that The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

100: Spruce
200: Runner
300: gate
400: cavity

Claims

A runner connected to one end of the sprue, a gate connected to the other end of the runner, and a cavity connected to the gate,
Wherein the runner is of a thin plate type, its width increasing radially from the one end, decreasing again at a predetermined position, and being held to the other end.

A runner connected to one end of the sprue, a gate connected to the other end of the runner, and a cavity connected to the gate,
Wherein the runner is of a thin plate type and has a plurality of through holes penetrating a top surface and a bottom surface of the runner.

3. The method of claim 2,
Wherein the number of the through-holes is equal to or n times the number of the cavities.

3. The method according to claim 1 or 2,
Wherein an upper surface and a lower surface of the runner are flat portions.

3. The method according to claim 1 or 2,
Wherein the runner decreases in thickness from the one end to the other end.

6. The method of claim 5,
Wherein the upper surface of the runner is a flat portion and the lower surface is a tapered inclined portion.

6. The method of claim 5,
Wherein the upper surface of the runner is a flat portion and the lower surface is a stepped portion.

6. The method of claim 5,
Wherein the upper surface of the runner is a flat portion and the lower surface is a curved portion.

3. The method of claim 2,
Wherein the runner has a width that increases radially from the one end, decreases again at a predetermined position, and is held constant to the other end.

3. The method according to claim 1 or 2,
Wherein the gate decreases in cross-sectional area toward the cavity side.

3. The method according to claim 1 or 2,
And the projecting portion is formed on the lower surface of the other end of the runner.