JP4454292B2 - Method and apparatus for manufacturing plastic lens - Google Patents

Description

  The present invention relates to a plastic lens used for an optical element such as a camera or an optical disk device, a manufacturing method thereof, a history management method of a plastic lens, and an optical pickup device equipped with the plastic lens.

  In recent years, optical disk apparatuses that record and reproduce various information on optical recording media such as digital cameras, CDs, and DVDs have become widespread. For example, the optical disc apparatus includes an optical pickup device that reads information recorded on an optical recording medium. The optical pickup device includes a pickup lens for condensing light from a light source onto an optical recording medium.

  The pickup lens is generally manufactured by molding a plastic such as polyolefin resin or acrylic resin, or glass. A plastic pickup lens is manufactured by injection molding or transfer molding using a molding die. For example, in injection molding, a pickup lens is manufactured by pouring a resin from a gate into a cavity in a mold and cooling the resin.

  On the other hand, this type of plastic lens is mass-produced in order to lower the product unit price. Therefore, a plurality of pickup lenses are manufactured simultaneously using a molding die having a plurality of cavities. For example, a molding die having eight cavities is used, and eight pickup lenses are manufactured at the same time. In this case, it is desirable to manufacture pickup lenses having the same quality in the respective cavities, but in reality, there may be variations in quality. In addition, there may be variations in manufacturing quality for each molding die and each molding machine.

  The technique for marking plastic lenses is disclosed in, for example, Patent Document 1, but in this example, a coating film that becomes a marking by printing, coating or vapor deposition is provided on one side of the ribs to distinguish the lens surface. It is provided. Therefore, since the lens and the marking are not the same material, in this method, when the lens is formed by injection molding, it is necessary to provide a marking forming step separately from the molding.

On the other hand, the technique disclosed in Patent Document 2 is provided with a convex or concave portion on the flange surface to indicate the injection position of the resin. However, there is no description about the manufacturing method and the molding die. Since it is on the upper surface of the surface, the marking is likely to be scraped or soiled when placed on a desk or due to handling, etc., and the marking information may not be transmitted well. The marking disclosed in Patent Document 2 is for gate alignment, and is not for identifying a lens or managing history in the production process. This is obvious from the fact that the markings disclosed in the document are provided only in one place and individual lenses cannot be identified among a plurality of lenses. Further, the convex marking in the configuration example shown in FIG. 5 of Patent Document 2 protrudes by 0.1 to 0.5 mm from the upper end of the flange surface. Therefore, the stability when the side with the convex portion is placed is inferior, and the convex marking may be scraped in contact with other members and the marking may disappear. Since foreign matter accumulates in the concave shape of such a size provided at the upper end of the flange and the visibility becomes poor, a structure in which the marking itself can be visually recognized separately from the flange surface and is not in contact with other members is desired.
JP 2002-122711 A JP 2000-111709 A

  As described above, in the method of manufacturing a lens using a molding die, there may be variations in quality for each molding die or cavity. Therefore, for quality control, manufacturing control, and management of the history of the lens after being incorporated into an optical device, marking for easily identifying a manufacturing jig such as a molding die or a cavity or a manufacturing line on the lens itself. It is desirable to apply. However, the lens is an optical component, and the marking cannot be formed in such a manner as to reduce the performance required for the optical component. For example, an optical function part is formed at the center of the lens. However, it is not preferable to apply this optical function part to the optical function because it impedes the optical function.

Further, when the marking is damaged by sliding with other members, it is difficult to visually recognize the marking itself, and the damaged portion adheres to the optical function portion, resulting in deterioration of optical performance.
Furthermore, if the lens surface corresponding to the optical function part and the marking are manufactured at the same time with one mold, the lens optical function part will be scratched or soiled when the marking is processed into the mold. Have problems such as being unusable.

  The present invention has been made to solve such problems, and provides a manufacturing method, a mold, and a history management method suitable for manufacturing a plastic lens in which marking is applied in an optimal manner. For the purpose. It is another object of the present invention to provide a plastic lens with easy history management.

  The method for producing a plastic lens according to the present invention is a method for producing a plastic lens, which is produced by injection-molding a resin material using a molding die, and has a marking in addition to the optical function part, on the side on which the marking is formed. The molds are at least a first mold for forming the optical function part (for example, the nestings 51 and 52 in the embodiment of the present invention) and a second part for forming a part other than the optical function part. In this embodiment, the second mold is used to form a marking using a second mold (for example, the molds 53 and 54 in the embodiment of the present invention). By such a method, when the marking is processed into a mold, a lens with stable quality and productivity can be formed without damaging the mold portion corresponding to the lens surface or attaching dirt.

  Here, the part other than the optical function part includes a flange part on the outer periphery of the lens surface, and the boundary between the first mold and the second mold is located in the vicinity of the innermost periphery of the flange part. Is preferred. When the resin is cured at the boundary between the first mold and the second mold, even if a burr that is an acute protrusion is generated, there is a problem if the burr does not exceed the step portion provided separately. Because there is no. In addition, if the boundary between the first mold and the second mold is positioned at a thin portion at the boundary between the flange surface and the lens surface, mirror processing of the flange surface becomes difficult.

  Here, it is preferable that the flange surface of the flange portion of the lens has a step portion at least partially, and has a marking that is integrally injection-molded on the step portion.

The flange surface of at least one surface side of the flange portion of the lens has a portion formed higher than the lens surface, the flange surface has a step portion at least partially, and is integrated with the marking surface of the step portion. Preferably, the highest portion of the marking that is injection molded is lower than the highest surface of the flange surface.
Furthermore, it is desirable that a portion for forming a notch is provided on the outer periphery of the flange surface of the lens. With such a configuration, the notched portion functions as a puddle of adhesive, and the adhesive can be prevented from flowing into the area where the marking is provided and erasing the marking, thereby improving the visibility of the marking.
Further, it is preferable that at least the vicinity of the region where the marking is formed on the flange surface of the flange portion of the lens is a mirror surface. With such a configuration, the marking visibility can be improved.

  A history management method according to the present invention is a method of history management of a plastic lens obtained by injection molding a resin material, wherein the plastic lens includes a flange portion on an outer periphery of a lens surface, and at least of the flange portion. The flange surface on one side has a portion formed higher than the lens surface, and has a marking that is integrally injection-molded on the flange surface, and the history management is performed by the marking formed on the lens. It is characterized by. Thereby, the history of a lens can be managed easily.

Another history management method according to the present invention is a method of history management of a plastic lens obtained by injection molding a resin material, wherein the plastic lens includes a flange portion on an outer periphery of the lens, and at least of the flange The flange surface on one side has a portion formed higher than the lens surface, and has a marking that is integrally molded with the flange surface. The highest portion of the marking is higher than the highest surface of the flange surface. Low, the history management is performed by a marking formed on the lens. This also makes it possible to easily manage the history of the lens.

  Here, the marking is preferably different in the circumferential direction on the flange surface in order to show a difference in history. Alternatively, the marking may be applied to at least one place, and the shape of the marking may be different in order to show a difference in history.

  The lens according to the present invention is a plastic lens obtained by injection molding a resin material, and includes a flange portion on the outer periphery of the lens surface, and the flange surface on at least one surface side of the flange portion is formed higher than the lens surface. Characterized in that it has a marking that is integrally injection-molded on the flange surface, and this marking is a marking that identifies a manufacturing jig used to manufacture the lens It is.

  Here, it is desirable that the highest part of the marking is lower than the highest part of the flange surface. Moreover, it is preferable that the said marking is shape | molded by the level | step-difference part of a flange surface. Furthermore, it is desirable to have a notch on the outer peripheral side surface of the flange portion. Furthermore, it is desirable that at least the vicinity of the area where the marking is formed on the flange surface is a mirror surface. An optical pickup device can be configured by mounting these lenses.

  A mold according to the present invention is a mold that is manufactured by injection molding a resin material using a molding mold, and is used for manufacturing a plastic lens having a marking in addition to an optical function part. The mold on the side to be formed is at least a first mold for forming an optical function part and a first mold for forming a part other than the optical function part, which is separable from the first mold. The second mold is provided with a part for forming a marking on the second mold.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method suitable for manufacturing the lens in which the marking was performed in the optimal aspect, a metal mold | die, and a history management method can be provided. Furthermore, it is possible to provide a lens with easy history management.

Embodiment 1 of the Invention
The lens according to the first embodiment of the invention will be described with reference to FIGS. 1 and 2, taking a pickup lens as an example.

  FIG. 1A is a top view of the lens. FIG.1 (b) is a side view of a lens, and the left half has shown the cross section. As shown in the figure, a flange portion 2 is formed on the outer periphery of the lens 1. The flange portion 2 is provided with a flange surface 21 on the optical recording medium side when the lens 1 is attached to the optical disc apparatus and information is read from the optical recording medium. Hereinafter, for the sake of explanation, the optical recording medium side will be described as the upper side 21 and the opposite side will be described as the lower side 23. The flange part 2 is located in the outer periphery of the optical function part of the lens 1, and is formed in the strip | belt shape over the perimeter. In addition, the flange part 2 does not need to be continuous on the outer periphery, and may have a shape having a notch portion on a part of the outer periphery.

  As shown in FIG. 1B, the flange surface 21 is formed with a portion that is higher than the upper surface of the optical function portion as viewed from the optical axis direction. Therefore, even when the lens 1 is placed on a desk or the like with the flange surface 21 side down during work, the flange surface 21 contacts the desk and the optical function unit does not contact the desk. Therefore, damage due to contact of the optical function unit with a desk or the like can be avoided. Further, it is possible to avoid damage caused by the optical recording medium coming into direct contact with the optical function unit after the lens 1 is attached to the optical disc apparatus.

  The lens according to this example (including the flange portion 2) has a diameter of 5.8 mm. And the width | variety of the up-down direction of the flange part 2 is 0.9 mm. The diameter of the lens according to another example is 3.8 mm.

  As shown in FIG. 1A, a stepped portion 20 is provided on the upper surface of the flange surface 21, and for example, a molding die, a cavity, and a manufacturing jig such as an injection molding apparatus are identified in that portion. The markings 3a and 3b are provided at two locations. The markings 3 a and 3 b are provided so as not to protrude from the uppermost surface of the flange surface 21. The markings 3a and 3b are formed integrally by providing shapes corresponding to the markings 3a and 3b in the mold portion facing the upper surface of the flange surface 21 during molding. The reason why the markings 3a and 3b are provided at two locations is to make it possible to identify different lenses such as a manufacturing jig by making their relative positions different. For example, when a cavity is identified by marking, the marking is provided at a different relative position for each cavity. For example, in the case of the first cavity, the marking is arranged at a position where the angle formed by the line connecting the center of the lens and the position of each marking is 180 degrees. In the case of the second cavity, the markings are arranged at different positions in the circumferential direction so as to be 120 degrees.

  The markings 3a and 3b are convex bodies having a shape such that a hemisphere protrudes. The concave body also functions as a marking, but the convex body is preferable because the mold can be easily manufactured. The height of the markings 3a and 3b according to this example is 0.02 to 0.03 mm. Thus, if marking 3a, 3b is made hemispherical shape, there exists an advantage that manufacture using a metal mold | die is easy. The shape of the marking 3 itself may not be hemispherical, but may be other shapes such as a square shape or a cross shape, or may be a letter such as an alphabet or a number. In this example, the marking 3a and the marking 3b have the same shape, but may have different shapes. Three or more markings 3 may be provided. Further, if the markings have different shapes in units to be identified such as each cavity, the number may be one. Further, when a marking indicating the gate position is present on the lens, it can be identified by the relative position between the marking indicating the gate position and the marking 3. Furthermore, a marking that can identify each of the mold and the cavity may be provided on one lens. For example, the marking for identifying the mold is two parallel convex portions, and the marking for identifying the cavity is one convex portion, so that the two can be distinguished.

  FIG. 2 shows an enlarged cross-sectional view of the vicinity of the flange portion 2 of the lens 1. Here, when the marking 3 is attached to the surface of the horizontal flange surface 21 that is the highest in the optical axis direction, sliding contact with the installation location at the time of operation and contact with the optical recording medium when the lens 1 is mounted on the optical pickup device. Therefore, there is a possibility that the minute marking 3 is damaged and cannot be confirmed. In addition, the marking 3 may be scraped, which may cause a disadvantage that plastic dust is generated. Therefore, in order to eliminate such inconvenience, the flange surface has a stepped portion at least partially, and the marking 3 is configured such that its upper end is lower than the highest portion of the flange surface 21. In the embodiment of the present invention, the flange surface has a step portion in the circumferential direction, and the marking 3 on the step portion is configured such that its upper end is lower than the highest portion of the flange surface 21. . With such a configuration, the marking 3 does not protrude from the flange surface 21, and the possibility of damage due to sliding contact or the like can be reduced.

  Of the flange surface 21, particularly regarding the stepped portion provided with the marking 3 b, a surface 211 that is lower in the optical axis direction than the flange surface is referred to as a marking surface. The marking surface 211 is preferably less than 100 μm from the highest surface of the flange surface 21 and more preferably lower within a range of 50 μm in order to easily release the molded product from the mold. Further, the height of the marking surface may be higher or lower than the height of the lens surface.

The flange surface 21 including the marking surface 211 is mirror-finished by a corresponding mold polishing process. Since the region subjected to the mirror finish has a higher light reflectance than the region not subjected to the mirror finish, the difference in brightness between the marking 3 portion and the other portions is increased. Therefore, there is an advantage that the visibility of the marking 3 is improved. In addition, although the whole area | region of the flange surface 21 is good also as a mirror surface, the vicinity of the area | region in which marking was formed should just be a mirror surface. When marking is provided on the marking surface, the ratio M / W of the marking bottom width (M) to the marking surface width (W) is preferably 2 or more and 10 or less, more preferably 2.5 or more and 5 or less. .
It is preferable that the marking surface 211 is provided with the highest portion of the flange surface on the outer periphery of the marking surface 211 and does not extend to the outer periphery of the lens so that an adhesive or the like flows into the marking surface 211.

  From the viewpoint of preventing damage due to sliding contact, it is also conceivable to arrange the marking 3 not on the flange surface 21 but on a region other than the optical function part, for example, the outermost peripheral surface of the lens surface. However, in the case of such a configuration, there arises a problem that the marking 3 is difficult to see behind the flange portion 2. In order to obtain a large effective diameter, that is, a wider optical function portion, it is not preferable to provide the marking 3 on the lens surface. Therefore, in the embodiment of the present invention, the marking 3 is provided on the flange portion 2. In the embodiment of the present invention, since the marking 3 is provided on the flange surface 21, the marking 3 can be visually observed even when the lens 1 is mounted on the optical disc apparatus.

  In the embodiment of the present invention, as shown in FIG. 2, the upper and lower portions of the lens have a shape that does not match the minimum thickness. That is, the boundary Q between the flange surface 23 and the lens surface is located outside the boundary P between the flange surface 21 and the lens surface. By adopting such a shape, the marking surface having a sufficient width can be secured even when the thickness of the entire lens is reduced and thereby the thickness of the flange portion is also reduced.

Embodiment 2 of the Invention
The lens according to the second embodiment of the invention is different from the lens according to the first embodiment of the invention in the shape of the flange portion. Since the other points are the same as those of the first embodiment, the description thereof is omitted.

  FIG. 3 is an enlarged cross-sectional view of the flange portion of the lens according to the second embodiment of the invention. As shown in the figure, a concave portion is provided on the flange surface, and the bottom surface of the concave portion is used as a marking surface. The bottom surface of the recess is also a step portion that is lower than the high surface of the flange surface 21. The marking surface 211 extends to the inner peripheral portion of the flange portion, but a high surface of the flange surface 21 is formed on the inner peripheral side as in the outer peripheral side as shown in FIG. 3, and the marking surface 211 is sandwiched between the flange surfaces 21. In this case, the two flange surfaces 21 do not have to have the same height.

  The flange surface 21 is preferably perpendicular to the optical axis direction, but may be an inclined surface.

  Here, a method for manufacturing a lens having the above-described structure by injection molding will be briefly described.

  First, a mold is created. The mold has a shape corresponding to the shape of the molded product. In particular, the mold used in the embodiment of the present invention has such a shape that a marking is formed on the flange surface 21.

  Next, a mold is mounted on the injection molding machine. Thereafter, in an injection molding machine, resin is poured from the gate into the cavity in the mold. Then, the lens is manufactured by cooling the resin poured into the cavity.

  As described above, the lens according to the embodiment of the present invention is provided with markings for identifying a manufacturing jig such as a cavity number and a mold number in an optimal manner. The same effect as the form can be obtained.

Embodiment 3 of the Invention
The lens according to the third embodiment of the invention differs from the lens according to the first embodiment in the marking position. Since the other points are the same as those of the first embodiment, the description thereof is omitted.

  FIG. 4 is an enlarged cross-sectional view of the flange portion of the lens according to the third embodiment of the invention. As shown in the figure, the marking 3 b is a convex portion protruding in a hemispherical shape and provided on the flange surface 21. The marking 3b is formed such that its upper end is lower than the highest surface of the flange surface 21. In the lens according to the third embodiment of the present invention, the step portion 20 is provided in the outer region of the flange surface 21.

  As described above, the lens according to the third embodiment of the present invention is provided with markings for identifying manufacturing jigs such as cavities and molding dies in an optimal manner. The same effect can be obtained.

Embodiment 4 of the Invention
The lens according to the fourth embodiment of the invention differs from the lens according to the first embodiment of the invention in the shape of the outer peripheral side surface of the flange portion. Since the other points are the same as those of the first embodiment, the description thereof is omitted.

  FIG. 5 is an enlarged cross-sectional view of the flange portion of the lens according to the fourth embodiment of the invention, and particularly shows a state in which the lens is fixed to the pickup holder of the optical pickup device. As shown in the figure, a notch 221 is formed on the outer peripheral side surface of the flange portion 2 of the lens. The notch portion 221 is formed so as to cut out a part of the upper end of the outer peripheral side surface of the flange portion 2. The notch portion 221 is provided over the entire circumference of the flange portion 2, but does not necessarily have to be the entire circumference.

  The pickup holder 4 has a shape that comes into contact with the flange lower portion 23 and the flange side portion 22. Specifically, it has a mounting portion 41 on which the flange lower portion 23 is mounted, and a convex portion 42 protruding upward on the outside of the mounting portion 41.

  The bottom of the notch 221 is formed so as to be substantially the same height as the top of the convex portion 42 of the pickup holder 4. That is, the height H of the convex portion 42 is formed to be substantially the same as the distance from the flange lower portion 23 at the bottom of the notch 221.

  When the lens 1 is fixed to the pickup holder 4, it is common to use an adhesive. However, by providing the notch 221 as described above, the notch 221 becomes a pool of adhesive. Function as. Therefore, it is possible to prevent the adhesive from flowing into the area where the marking 3b is provided and erasing the marking 3b.

Embodiment 5 of the Invention
The lens according to the fifth embodiment of the invention is different from the lens according to the first embodiment in the position and shape of the marking. Since the other points are the same as those of the first embodiment, the description thereof is omitted.

  FIG. 6 is a top view and a side view of a lens according to a fifth embodiment of the invention. As shown in FIG. 6A, the marking 3b is provided on the flange surface 21 and has a semi-cylindrical convex shape protruding toward the center of the lens. Further, as shown in FIG. 6B, the upper end of the marking 3 b is provided on the same plane as the flange surface 21.

  As described above, the lens according to the fifth embodiment of the present invention is provided with markings for identifying manufacturing jigs such as cavities and molding dies in an optimal manner. Similar effects can be obtained.

  The convex shape protruding toward the center of the lens may be a triangle or a quadrangle other than a semi-cylindrical shape.

Embodiment 6 of the Invention
The lens according to the sixth embodiment of the invention has the same shape as the lens according to the first embodiment of the invention, and a part of the mold is nested in the manufacturing process. Since the other points are the same as those of the first embodiment, the description thereof is omitted.

FIG. 7 is a side view of a lens according to a sixth embodiment of the invention, and also shows nestings 51 and 52. As shown in the figure, dies 51 and 52 are used as molds for forming a portion including the optical function portion of the lens 1. The molds for the other flange portions 2 are formed by molds 53 and 54 that are separate from the inserts 51 and 52. It should be noted that the surface on which no marking is provided may be an integrated type in which the mold 54 and the insert 52 are integrated without using the insert 52.
As can be seen from the description, the optical function unit means the diameter of the light beam that actually passes through the lens, and the diameter varies depending on the application. For example, NA is 0.45 for CD, NA is 0.60 for DVD, and NA is 0.85 for Blu-ray, which is located on the inner peripheral side from the lens surface diameter.

  The division | segmentation location of the nestings 51 and 52 and other parts should just exist between the outermost periphery of the optical function part of a lens, and the innermost periphery of a marking surface. More preferably, it is desirable that the nest portions 51 and 52 and other portions are divided at the innermost peripheral portion of the flange portion 2. The first reason is that even if burrs that are sharp protrusions occur when the resin hardens at the boundary between the nestings 51 and 52 and other parts, the burrs exceed the stepped portion provided separately. This is because there is no problem if it does not. Secondly, if the nesting portions 51 and 52 and other portions are divided at the thin portion at the boundary between the flange surface 21 and the lens surface, it is difficult to mirror the flange surface 21.

A portion that functions as a marking is provided in a portion of the separate mold 53 that faces the upper surface 21 of the flange portion, and this portion is formed into the marking 3b on the flange surface by injection molding.
Here, the marking functions as a concave body, but it is preferable to use a convex body.

  In this way, the reason why the portion corresponding to the optical function portion is mainly set as the nest 51 is that the marking provided on the upper surface of the flange is also integrally formed. This is because it is desirable to appropriately rotate the nesting part of the optical function part only around the optical axis without moving the nesting part of the flange part for marking the cavity number as a marking. As in the case where the optical function part is molded with a single mold, it is not necessary to provide a part functioning as a marking on the flange part each time in another integral mold.

For example, if the lens manufactured once with the nesting portion installed at a predetermined position is not good, the lens is rotated and manufactured again, and the nesting position is adjusted until the performance is improved.
In the present embodiment, the mold member that forms other than the optical function unit may be two or more members.

  In the present invention, the marking is provided not on the optical function part but on the other part, but this is particularly suitable for the manufacturing method in the case where the part corresponding to the optical function part is the nest 51. That is, when processing into a shape in which the marking is formed at a position corresponding to the marking of the mold, the mold 53 to be processed is a separate body from the nest 51 forming the optical function part, This is because the possibility of damaging the nest 51 can be reduced.

Embodiment 7 of the Invention
The lens according to the seventh embodiment of the invention differs from the lens according to the first embodiment in the marking shape. Since the other points are the same as those of the first embodiment, the description thereof is omitted.

  FIG. 8 is an enlarged cross-sectional view (FIG. 8A) of the flange portion of the lens according to the fourth embodiment of the invention and a cross-sectional view showing a state in which the lens is incorporated in a mold including the inserts 51 and 52 (FIG. 8B). )). As shown in the drawing, the marking 3 b is a concave portion recessed in a hemispherical shape, and is provided on the flange surface 21. Since the marking 3b is recessed from the flange surface 21, it does not slide in contact with the installation location during work. Further, even when the lens 1 is mounted on the optical pickup device, it does not come into contact with the optical recording medium. Therefore, it is possible to reduce the possibility of damage due to sliding contact with the installation location or the optical recording medium.

  As shown in the figure, the molds 51 and 52 are used for forming the optical function portion of the lens 1. The molds for the other flange portions 2 are formed by molds 53 and 54 that are separate from the inserts 51 and 52.

Embodiment 8 of the Invention
The eighth embodiment of the present invention relates to an optical pickup device equipped with the lens according to the first to seventh embodiments of the present invention.

  FIG. 9 shows a configuration of an optical pickup device 100 in which the lens 1 is mounted. The lens 1 is fixed at four points by a pickup holder 4. In particular, the flange portion 2 of the lens 1 and the pickup holder 4 are fixed with an adhesive.

  Thus, in a state where the lens 1 is mounted on the optical pickup device 100, the marking provided on the flange portion 2 can be observed visually or with a magnifying glass. For a lens having a predetermined defect, it is possible to manage the history of manufacturing jigs, molds, manufacturing lines, manufacturing locations, producers, etc. using the marking as a clue.

Other embodiments.
As the shape of the lens of the present invention, for example, it can be used for a meniscus-shaped lens in which one surface is convex and the other surface side is concave.
Note that the marking of the lens manufactured by the above-described manufacturing method does not necessarily need to be lower than the highest surface of the flange surface.

It is a figure which shows the upper side figure and side view of the lens concerning this invention. It is an expanded sectional view of the flange part of the lens concerning the present invention. It is an expanded sectional view of the flange part of the lens concerning the present invention. It is an expanded sectional view of the flange part of the lens concerning the present invention. It is an expanded sectional view of the flange part of the lens concerning the present invention. It is a figure which shows the upper side figure and side view of the lens concerning this invention. It is sectional drawing which shows the mode of manufacture of the lens concerning this invention. It is sectional drawing which shows the mode of manufacture of the lens concerning this invention. It is a figure which shows the optical pick-up apparatus concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens 2 Flange part 3 Marking 4 Pickup holder 100 Optical pick-up apparatus

Claims (7)

An optical function part, and a flange part provided around the optical function part , wherein an outer peripheral part provided with a marking on the recess part of the flange part and positioned on the outer peripheral side from the recess part A method of manufacturing a plastic lens provided for the flange portion ,
A step of vertically arranging a set of nestings for forming the optical function part; and
Laminating a set of molds for molding the flange portion and the marking;
Filling a plastic material into a space between a set of the nestings arranged vertically opposite to each other and a space between the set of molds stacked vertically;
Rotating at least one of the set of the nesting with the optical axis of the plastic lens as a rotation axis in a state where the set of molds is fixed;
Equipped with a,
In at least one of the pair of molds, the plastic lens manufacturing method is such that a depth of a portion for forming the marking is shallower than a depth of a portion for forming the outer peripheral portion . The mold is integrally formed with a plurality of the markings on the flange portion,
The method for manufacturing a plastic lens according to claim 1, wherein relative positions between the plurality of markings are set in association with manufacturing jigs to be identified.   The method for manufacturing a plastic lens according to claim 1, wherein the mold for forming the marking forms the marking into a convex shape. The method for manufacturing a plastic lens according to any one of claims 1 to 3 , wherein the mold for forming the marking forms the marking so that the marking has a curved surface . A plurality of convex markings having an optical function part and a flange part provided around the optical function part, and having a relative position set in correspondence with a manufacturing jig to be identified, are recessed in the flange part. A plastic lens manufacturing method in which an outer peripheral portion that is provided to a portion and located on an outer peripheral side with respect to the hollow portion is provided to the flange portion,
A step of vertically arranging a set of nestings for forming the optical function part; and
Laminating a set of molds for molding the flange and the convex markings; and
Filling a plastic material into a space between a set of the nestings disposed opposite to each other in a vertical direction and a space between the set of molds stacked in a vertical direction;
With
The set of molds is provided on the outer periphery of the set of the inserts,
In at least one of the set of molds, the plastic lens manufacturing method is such that the depth of the portion for forming the convex marking is shallower than the depth of the portion for forming the outer peripheral portion. 6. The plastic according to claim 5, further comprising a step of rotating at least one of the set of nestings with an optical axis of the plastic lens as a rotation axis in a state where the set of molds is fixed. Lens manufacturing method. A plurality of convex markings having an optical function part and a flange part provided around the optical function part, and having a relative position set in correspondence with a manufacturing jig to be identified, are recessed in the flange part. A plastic lens manufacturing apparatus in which an outer peripheral portion provided on a portion and located on an outer peripheral side of the hollow portion is provided on the flange portion,
A set of inserts for molding the optical function part;
A set of molds for molding the flange portion and the convex marking;
Means for filling a plastic material into a space between a set of the nestings arranged vertically opposite to each other and a space between the set of molds stacked vertically;
Have
The set of molds is provided on the outer periphery of the set of the inserts,
In at least one of the pair of molds, a plastic lens manufacturing apparatus in which a depth of a portion for forming the convex marking is shallower than a depth of a portion for forming the outer peripheral portion.

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