JP2008100481A - Diaphragm-integrated lens and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm-integrated lens and its manufacturing method which allow miniaturization and height reduction and its manufacturing method. <P>SOLUTION: The method comprises injecting the first light-shielding resin material into a cavity for formation of a diaphragm portion formed by mold-closing the first mold corresponding to one side of the lens portion 11a and the second mold corresponding to the diaphragm portion 12b; solidifying the first resin for primarily molding the diaphragm portion 12b; removing the second mold; injecting the second light-transmissive resin material into a cavity for formation of a lens portion formed by mold-closing the first mold holding the diaphragm portion 12b and the third mold corresponding to the other side of the lens portion 11a; and solidifying the second resin and secondarily molding the lens portion 11a integrated with the diaphragm portion 12 in order to mold a diaphragm-integrated lens 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a diaphragm integrated lens and a method for manufacturing the same.

  Currently, lenses mounted on devices such as silver salt cameras, digital cameras, and video cameras are equipped with a stop at one or more places in order to block unnecessary portions of incident light flux.

  For example, Patent Document 1 discloses a technique for printing or pasting a lens diaphragm on one or both surfaces of a lens.

However, in the technique of Patent Document 1, it is necessary to secure a space corresponding to the thickness of the diaphragm when the diaphragm is attached to the lens. For this reason, there is a problem in that the optical system is reduced in height and size. In addition, when the lens is downsized, the allowable accuracy of the center deviation of the aperture hole with respect to the optical axis becomes stricter, so that the assembly process becomes complicated.
Japanese Utility Model Publication No. 62-164617

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a lens with an aperture that can be reduced in height and size and a manufacturing method thereof.

In order to achieve the above object, a manufacturing method of a diaphragm integrated lens according to the first aspect of the present invention includes:
A method for integrally manufacturing an optical lens having a lens portion and a diaphragm portion,
A first resin material having a light-shielding property is formed in a cavity for molding a diaphragm part formed by closing a first mold corresponding to one surface of the lens part and a second mold corresponding to the diaphragm part. A primary molding step of injecting, solidifying, and primary molding of the drawn portion;
After the primary molding step, the second mold is removed, and the first mold in a state where the diaphragm portion is held and the third mold corresponding to the other surface of the lens unit are closed. A second molding step of injecting and solidifying a second resin material having optical transparency into a lens part molding cavity that is formed, and secondarily molding the lens part integrated with the diaphragm part,
It is characterized by that.

For example, the first mold or the second mold has a first injection port,
In the primary molding step, a first resin material is injected from the first injection port into the drawing part molding cavity, and the drawing part is primary molded,
The first mold or the third mold has a second injection port,
In the secondary molding step, the second resin material is injected into the lens part molding cavity from the second injection port, and the lens part integrated with the diaphragm part is secondary molded.
This may be a feature.

For example, the second mold corresponds to a throttle portion having a knife-edge-shaped end,
In the primary forming step, a drawing portion including the knife-edge-shaped end portion is formed.
This may be a feature.

A diaphragm integrated lens according to a second aspect of the present invention is:
A diaphragm part primarily molded from a first resin material having a light shielding property;
A lens part that is secondarily molded with a second resin material having optical transparency and integrated with the diaphragm part by a two-color molding method,
It is characterized by that.

For example, the diaphragm unit and the lens unit are flush with each other.
This may be a feature.

For example, the throttle portion includes a knife-edge-shaped end portion,
This may be a feature.

For example, the diaphragm portion has been processed to prevent reflection,
This may be a feature.

For example, the diaphragm portion covers a peripheral surface of the lens portion.
This may be a feature.

  ADVANTAGE OF THE INVENTION According to this invention, the lens with an aperture | diaphragm which can be reduced in height and size, and its manufacturing method can be provided.

(First embodiment)
Hereinafter, with reference to FIGS. 1 to 11, a diaphragm integrated lens 10 according to a first embodiment of the present invention and a manufacturing method thereof will be described.

  First, the aperture integrated lens 10 will be described. The aperture-integrated lens 10 includes convex lens surfaces on both sides, and includes an aperture on one lens surface. Here, FIG. 1A is a view of one lens surface to which the aperture 12b of the aperture integrated lens 10 is attached as viewed from the front, and FIG. 1B is a diagram of FIG. It is arrow sectional drawing in the AA line. FIG.1 (c) is the figure which looked at the other lens surface from the front.

  As shown in FIGS. 1A and 1B, the aperture integrated lens 10 is composed of a lens portion 11a and an aperture portion 12b, and the lens portion 11a and the aperture portion 12b are integrated by a two-color molding method. It has become. A portion of the lens portion 11a shown in FIG. 1A is a light transmitting region, which is one lens surface. In addition, the aperture 12b is a light shielding area. The surface shown in FIG. 1C is the other lens surface without an aperture.

  The lens portion 11a is made of an acrylic resin such as polymethyl methacrylate resin, polycarbonate, or the like, has light transparency, and includes convex lenses on both sides.

  The diaphragm 12b is formed of a liquid crystal polymer containing carbon black, polyethylene terephthalate, polycarbonate, polybutylene terephthalate, or the like, and has a light shielding property. The diaphragm portion 12b is formed flush with the lens portion 11a. The diaphragm 12 b functions as an aperture diaphragm that blocks the peripheral edge of the light beam incident on the diaphragm integrated lens 10.

  Next, a method for manufacturing the aperture integrated lens 10 will be described with reference to FIGS.

  For the manufacture of the integrated lens 10, the mold 20 and the mold 30 shown in FIG. 2 and the mold 40 shown in FIG. 7 are used.

  As shown in FIG. 2, the mold 20 is configured by inserting a core mold 20a into a movable mold plate 20b. The core mold 20a includes a surface 21 for molding the inner surface of the diaphragm 12b of the diaphragm integrated lens 10.

  As shown in FIG. 2, the mold 30 includes a surface 33 for molding one lens surface of the lens portion 11 a and the outer surface of the aperture portion 12 b in the aperture integrated lens 10.

  The mold 20 and the mold 30 are closed as shown in FIG. When the mold 20 and the mold 30 are closed, a primary molding space 13 (cavity) for molding the narrowed portion 12b is defined. The primary molding space 13 is formed in a ring shape with the center line AA shown in FIG. 3 as the center of rotation.

  As shown in FIG. 3, the mold 20 includes a primary molding material injection port 22. By injecting the primary molding material into the primary molding material injection port 22, the primary molding material can be injected into the primary molding space 13 defined when the mold 20 and the mold 30 are closed.

  As shown in FIG. 2, the mold 30 includes a resin injection port 31 and a resin injection port 32. The primary molding material can be injected into the primary molding material injection port 22 through the resin injection port 31. The mold 30 also includes a surface 33 for forming a lens surface on the diaphragm portion 12b side of the diaphragm integrated lens 10.

  As shown in FIG. 7, the mold 40 is configured by inserting a core mold 40a into a movable mold plate 40b. The core mold 40a includes a surface 41 for molding the other lens surface of the lens portion 11a.

  The mold 40 also includes a primary molding material interference prevention escape 42 that is a relief for preventing interference with the primary molding material that has already been molded, and a secondary molding material injection port 43. The secondary molding material injection port 43 can inject the secondary molding material into the mold through the resin injection port 32.

  The mold 30 and the mold 40 are closed as shown in FIG. When the mold 30 and the mold 40 are closed, a space 14 for forming the lens portion 11a is defined. By injecting the secondary molding material into the secondary molding material injection port 43, it is possible to inject the secondary molding material into a space formed when the mold 30 and the mold 40 are closed.

  The mold 20 and the mold 40 are arranged side by side in the X-axis direction or the Y-axis direction, for example, when an XY plane perpendicular to the optical axis direction of the lens 10 is considered. When one of the two is closed with respect to the mold 30, the other is retracted from the mold 20.

  For example, when the mold 20 and the mold 40 are arranged side by side in the X-axis direction, when the mold 20 and the mold 30 are closed, the mold 40 is any of the X-axis direction. Retreat to position. Similarly, when the mold 30 and the mold 40 are closed, the mold 20 is retracted to any position in the X-axis direction.

  Next, a manufacturing method of the diaphragm integrated lens 10 using the molding apparatus will be described.

  First, the mold 20 and the mold 30 are closed as shown in FIGS.

  As shown in FIGS. 3 and 4, the primary molding material is injected into the resin injection port 31 of the mold 30 and injected into the primary molding space 13. Here, the primary molding material is the above-described liquid crystal polymer containing carbon, polyethylene terephthalate, polycarbonate, polybutylene terephthalate, or the like that forms the diaphragm 12.

  The primary molding material injected and filled in the primary molding space is cooled and solidified, and the aperture 12 (primary molded product) is primary molded. Next, as shown in FIG. 6, the mold 20 is separated while the diaphragm 12 is attached to the mold 30. Here, as shown in FIG. 6A, the formed throttle 12 includes a throttle portion 12b and a throttle portion runner 12a formed when the primary molding material is injected into the primary molding material injection port 22. It has a different shape. The throttle runner 12a is removed in a separate process.

  As shown in FIGS. 7 and 8, the mold 30 and the mold 40 in a state where the throttle portion 12 is held are closed. At this time, the throttle part runner 12a is also attached on the mold 30; however, the primary molding material interference prevention relief 42 formed on the mold 40 and the throttle part runner 12a are joined in a fitting manner. There is no problem in closing the mold 40 and the mold 30.

When the mold 30 and the mold 40 are closed, a secondary molding space 14 (cavity) for molding the lens portion 11a is defined.

  Note that the center of the mold 20 and the center of the mold 40 are arranged apart from each other by a predetermined amount in the X-axis direction shown in FIG. Next, in a state where the mold 20 and the mold 30 are in a closing relationship, that is, in a state where the mold centers of the mold 20 and the mold 30 are matched, the mold 30 and the mold 40 are next moved. In order to close the mold, the mold 20 is moved by a predetermined amount to position the mold 40 at a position where the mold 20 can be closed. The predetermined amount refers to a distance at which the mold 40 does not interfere with the mold 20 when the mold 20 and the mold 30 are closed.

  Therefore, when the mold 20 and the mold 30 are closed, the mold center of the mold 40 is retracted to a position away from the mold center of the mold 30 by a predetermined amount in the X-axis direction. When the mold 30 and the mold 40 are closed, the mold center of the mold 20 is retracted to a position away from the mold center of the mold 30 by a predetermined amount in the X-axis direction.

  Here, as shown in FIG. 9, the secondary molding material is injected into the secondary molding material injection port 32 of the mold 30 and injected into the secondary molding space 14. Here, the secondary molding material is acrylic resin such as polymethyl methacrylate resin or polycarbonate that forms the lens portion 11a described above.

  The secondary molding material injected and filled in the secondary molding space 14 is cooled and solidified, and the lens portion 11a (secondary molded product) is secondarily molded. In this manner, the diaphragm integrated lens 10 in which the diaphragm portion 12b formed from the primary molding material and the lens portion 11a formed from the secondary molding material are integrated is manufactured.

  After that, as shown in FIG. 10A, the mold 40 is separated and the aperture integrated lens 10 is taken out. Here, as shown in FIGS. 10 (b) and 10 (c), the formed stop-integrated lens 10 is formed by subjecting the stop portion 12b and the stop portion runner 12a, and the lens portion 11a and the secondary molding material to secondary molding. It has a shape constituted by a lens portion runner 11b formed when injected into the material injection port 43. The diaphragm portion runner 12a and the lens portion runner 11b are removed in separate steps.

  Thus, according to the diaphragm integrated lens 10 and the manufacturing method thereof according to the first embodiment of the present invention, the lens includes a diaphragm, so that the arrangement space for the thickness of the diaphragm is reduced. Since the lens barrel can be designed without consideration, it is possible to reduce the height and size of the optical system.

  In addition, since it is possible to position the optical axis of the lens and the center of the aperture hole with high accuracy by the mold, it is possible to easily cope with strict allowable accuracy in the past.

(Second Embodiment)
In the first embodiment, the diaphragm is attached only to one convex surface of the convex lens, but the peripheral surface of the convex lens is also covered with a part of the diaphragm unit 120 as in the integrated lens 100 shown in FIG. Also, light can be shielded from the peripheral surface of the convex lens.

  The aperture integrated lens 100 includes a lens 110 and an aperture 120, and the lens 110 and the aperture 120 are integrated by a two-color molding method.

  Hereinafter, with reference to FIG. 11A and FIG. 11B, a manufacturing method of the diaphragm integrated lens 100 according to the second embodiment will be described.

  In the first embodiment, the primary molding material and the secondary molding material are injected and filled from the portion that becomes the peripheral surface of the lens. However, in the diaphragm integrated lens 100 according to the second embodiment, the peripheral surface is the aperture 120. The same method as that of the aperture integrated lens 10 according to the first embodiment cannot be used.

  For manufacturing the aperture integrated lens 100, a mold 200 and a mold 300 shown in FIG. 11A and a mold 400 shown in FIG. 11B are used.

  As shown in FIG. 11A, the mold 300 includes a resin injection port 310 and a resin injection port 320. By injecting the primary molding material into the resin inlet 310, the primary molding material can be injected into the primary molding space defined when the mold 200 and the mold 300 are closed.

  The mold 400 includes a secondary molding material injection port 410. The mold 300 and the mold 400 are closed as shown in FIG. When the mold 300 holding the aperture 120 and the mold 400 are closed, a space (cavity) for secondary molding of the lens 110 is defined. By injecting the secondary molding material into the secondary molding material injection port 320, the secondary molding material can be injected into a space (cavity) formed when the mold 300 and the mold 400 are closed.

  Next, a manufacturing method of the diaphragm integrated lens 100 using the molding apparatus will be described.

  First, as shown in FIG. 11A, the mold 200 and the mold 300 are closed.

  A primary molding material similar to that of the first embodiment is injected into the resin injection port 310 of the mold 300, and injection filling is performed in the primary molding space.

  The primary molding material injected and filled in the primary molding space is cooled and solidified, and the aperture 120 (primary molded product) is primary molded. Next, the mold 200 is separated with the diaphragm 120 attached to the mold 300.

  As shown in FIG. 11 (b), when the mold 300 and the mold 400 with the diaphragm 120 attached are closed, a secondary molding space for molding the lens 110 (secondary molded product) ( Cavity) is defined. And the secondary molding material similar to 1st Embodiment is inject | poured from the resin injection port 320 of the metal mold | die 300, and it is injection-filled in the space for secondary molding.

  The lens 110 is molded by cooling and solidifying the secondary molding material injected and filled in the secondary molding space. In this way, the diaphragm integrated lens 100 in which the diaphragm 120 formed from the primary molding material and the lens 110 formed from the secondary molding material are integrated is manufactured. The runner of the diaphragm 120 and the runner of the lens 110 are removed in separate steps.

  Thereafter, the mold 400 is separated and the aperture integrated lens 100 is taken out.

  Thus, according to the diaphragm integrated lens 100 and the manufacturing method thereof according to the second embodiment of the present invention, light can be shielded even at the peripheral surface of the lens.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation and application are possible.

  In the first and second embodiments, the lens is a convex lens, but is not limited to a convex lens, and may be a concave lens as shown in FIGS. 12 (a) and 12 (b).

  Further, as shown in FIGS. 12C and 12D, a portion that separates the light shielding region and the light transmitting region of the diaphragm may be formed in a knife edge shape. In this way, the irregular reflection of light generated by the diaphragm wall surface 12c shown in FIG. 6B can be minimized. Thereby, since generation | occurrence | production of the element which degrades an image, such as a flare and a ghost, can be suppressed to the minimum, a sharper image can be obtained. For example, a stop-integrated lens 3000 shown in FIG. 12C includes a lens 3100 and a knife-edge stop 3200.

  In addition, as shown in FIG. 13, a mold 3300 for molding the inner surface of the diaphragm 3200 and a mold 3400 for molding the outer surface of the diaphragm 3200 are formed in the knife edge-shaped diaphragm 3200. And use. The mold 3300 and the mold 3400 are closed, and the primary molding space 3500 is injected and filled from the resin injection port 3410, and is cooled and solidified to perform primary molding of the aperture 3200 (primary molded product). The subsequent secondary molding process is the same as in the above embodiment.

  Furthermore, as shown in FIG. 12C and FIG. 12D, the area of the aperture (primary molded product) may be enlarged within a range that does not affect the optical path. In this case, it is not necessary to extremely reduce the thickness of the diaphragm, and the moldability is improved.

  Moreover, you may give the process which prevents reflection by roughening the surface of an aperture | diaphragm | squeeze part. Thereby, flare and ghost can be suppressed.

  In addition, when the surface of the aperture portion is roughened, the joint surface between the lens portion 11a and the aperture portion 12b is not limited to the surface on the light incident side or the surface of the aperture portion wall surface 12c shown in FIG. 6B. Also good.

  In the first embodiment, the primary molding material is injected from the resin injection port 31 of the mold 30, the throttle portion 12 b is molded, the secondary molding material is injected from the resin injection port 32, and the lens portion 11 a is molded. did.

  However, for example, the mold 20 may be provided with a primary molding material injection port, the throttle portion 12b may be molded, and the mold 40 may be provided with a secondary molding material injection port, and the lens portion 11a may be molded. As described above, as a result, if the aperture integrated lens is molded, the primary molding material injection port and the secondary molding material injection port may be arranged in any of the three molds.

  Also in the second embodiment, as a result, when the aperture integrated lens is molded, the primary molding material inlet and the secondary molding material inlet are arranged in any of the three molds. May be.

(A) It is a front view of the aperture stop integrated lens which concerns on 1st Embodiment. (B) It is arrow sectional drawing in the AA line of Fig.1 (a). (C) It is a rear view of the aperture integrated lens which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 1st Embodiment. (A) It is a front view of the aperture stop of the aperture integrated lens according to the first embodiment. (B) It is arrow sectional drawing in the BB line of Fig.6 (a). It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 1st Embodiment. It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 1st Embodiment. (A) It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 1st Embodiment. (B) It is sectional drawing in the direction of the arrow in CC line of FIG.10 (c). (C) It is a front view of the aperture stop integrated lens which concerns on 1st Embodiment. (A) It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 2nd Embodiment. (B) It is sectional drawing which shows the manufacturing method of the aperture stop integrated lens which concerns on 2nd Embodiment. (C) It is sectional drawing of the aperture stop integrated lens which concerns on 2nd Embodiment. (A) It is sectional drawing of the application example of a diaphragm integrated lens. (B) It is sectional drawing of the application example of a diaphragm integrated lens. (C) It is sectional drawing of the application example of a diaphragm integrated lens. (D) It is sectional drawing of the example of application of a diaphragm integrated lens. It is sectional drawing of the metal mold | die which manufactures the aperture integrated lens shown in FIG.12 (c).

Explanation of symbols

10 Aperture integrated lens 11 Lens (secondary molded product)
11a Lens part 11b Lens part runner 12 Aperture (primary molded product)
12a Restrictor runner 12b Restrictor 13 Space for primary molding (cavity)
14 Space for secondary molding (cavity)
20 mold 20a core mold 20b movable mold plate 21 surface 22 primary molding material injection port 30 mold 31 resin injection port 32 resin injection port 33 surface 40 mold 40a core mold 40b movable mold plate 41 surface 42 primary molding material interference prevention escape 43 Secondary molding material injection port 100 Aperture integrated lens 110 Lens (secondary molded product)
120 aperture (primary molded product)
200 Mold 200a Core mold 200b Movable mold plate 300 Mold 310 Resin injection port 320 Resin injection port 400 Mold 400a Core mold 400b Movable mold plate 1000 Integrated aperture lens 2000 Integrated aperture lens 3000 Integrated aperture lens 3100 Lens (two Next molded product)
3200 aperture (primary molded product)
3300 Mold 3300a Core mold 3300b Movable mold plate 3400 Mold 3410 Resin inlet 3420 Resin inlet 3500 Primary molding space (cavity)
4000 Aperture integrated lens

Claims (8)

A method for integrally manufacturing an optical lens having a lens portion and a diaphragm portion,
A first resin material having a light-shielding property is formed in a cavity for molding a diaphragm part formed by closing a first mold corresponding to one surface of the lens part and a second mold corresponding to the diaphragm part. A primary molding step of injecting, solidifying, and primary molding of the drawn portion;
After the primary molding step, the second mold is removed, and the first mold in a state where the diaphragm portion is held and the third mold corresponding to the other surface of the lens unit are closed. A second molding step of injecting and solidifying a second resin material having optical transparency into a lens part molding cavity that is formed, and secondarily molding the lens part integrated with the diaphragm part,
A method of manufacturing a lens with an integrated diaphragm. The first mold or the second mold has a first injection port,
In the primary molding step, a first resin material is injected from the first injection port into the drawing part molding cavity, and the drawing part is primary molded,
The first mold or the third mold has a second injection port,
In the secondary molding step, the second resin material is injected into the lens part molding cavity from the second injection port, and the lens part integrated with the diaphragm part is secondary molded.
The method of manufacturing a diaphragm integrated lens according to claim 1. The second mold corresponds to a throttle portion having a knife-edge-shaped end,
In the primary forming step, a drawing portion including the knife-edge-shaped end portion is formed.
The method of manufacturing a diaphragm integrated lens according to claim 1 or 2, wherein A diaphragm part primarily molded from a first resin material having a light shielding property;
A lens part that is secondarily molded with a second resin material having optical transparency and integrated with the aperture part by a two-color molding method,
An aperture-integrated lens characterized by that. The diaphragm portion and the lens portion are flush with each other.
The stop-integrated lens according to claim 4. The throttle part includes a knife-edge-shaped end part,
The stop-integrated lens according to claim 4. The diaphragm is subjected to processing to prevent reflection,
The diaphragm integrated lens according to claim 4 or 5, wherein: The diaphragm portion covers a peripheral surface of the lens portion;
The diaphragm integrated lens according to any one of claims 4 to 7, wherein the lens is integrated with an aperture.

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