JP7004587B2 - Mold equipment, injection molding equipment, injection molding method, resin lens, resin lens manufacturing method, lens unit and camera - Google Patents

Description

The present invention relates to a mold device, an injection molding device, an injection molding method, a resin lens, a method for manufacturing a resin lens, a lens unit, and a camera.

In recent years, resin lenses have been used in various fields. For example, pickup lenses for optical discs such as Blu-ray discs, DVDs, and CDs, lenses for handheld video cameras, parking assistance, lane deviation warning, inter-vehicle distance control, collision prevention, driver monitoring, night vision, and pedestrian detection. , A resin lens is used as a lens or the like of an in-vehicle camera used for blind spot monitoring or the like. In particular, recently, resin lenses are often used to realize an aspherical lens having a high aberration correction ability due to an increase in the number of pixels of a sensor.
The resin lens is resin-molded by an injection molding apparatus including at least two molds, a fixed mold and a movable mold. These two molds have, for example, nests in the portion that forms the lens. Further, in a large number of moldings capable of molding a plurality of resin lenses by one molding, an injection molding apparatus having a plurality of nests in each mold is used. Since an injection molding machine is constructed by assembling a relatively large number of parts including nests, the positions of the two molds when assembled (set up) and the pair of molds that face each other are provided in each mold. There is a shift in the nesting position of.

In the design stage of an aspherical lens, for example, the optical axis of the aspherical surface of the first surface of the lens and the optical axis of the aspherical surface of the second surface of the lens are set to coincide with each other. However, in an injection molding apparatus, in a resin lens having a small diameter as used in the above-mentioned various fields, the positions of a pair of nests provided in each mold and facing each other are displaced at the time of mold setup. In many cases, the optical axis of the aspherical surface on one surface and the optical axis of the aspherical surface on the second surface of the lens do not match, and each optical axis does not pass through the center of the outer diameter of the lens and is displaced. In the aspherical lens, the optical axis of each lens surface is uniquely determined from the shape of each lens surface on the first surface and the second surface. In the case of a spherical lens, the optical axis of each lens surface is not uniquely determined from the shape of the lens surface on the first surface and the second surface, and here, the lens surface has a spherical shape (optical functional surface). The normal line passing through the center of the outer circumference of the spherical surface portion is called an optical axis. Further, the center of the outer diameter of the lens is the center of the diameter of the lens having the outer diameter, and is, for example, the center of the circle when the outer circumference of the substantially circular lens is assumed to be a circle.

Here, in the fixed mold and the movable mold, the inserts can be rotated, and the lens molding surface is provided so as to be offset from the rotation axis of the insert rotation for each insert. It is conceivable that the optical axis of the lens surface (the virtual optical axis on the lens forming surface) is eccentric. If there is an overlapping point on the locus of each optical axis when each nest is rotated, the virtual optical axis of the lens molding surface of the nest that forms the first surface and the second one at the position of this overlapping point. Lens of the nest that molds the surface The rotation positions of the two nests are adjusted so that the virtual optical axes of the molded surface match. In this case, the optical axes of the two lens surfaces are aligned with each other, and the resolution of the resin lens can be improved.
However, in this case, although the optical axis of the first surface and the optical axis of the second surface are theoretically the same, the optical axis is not aligned with the center of the outer diameter of the molded resin lens and is displaced. Further, as described above, in the molding of the first surface and the second surface, since the optical axis of the lens forming surface is eccentric with respect to the rotation axis of the nest, it is the center of the outer diameter of the molded resin lens. The deviation of the optical axis of each surface becomes large, and the optical axes of the first surface and the second surface of the resin lens deviate from the center of the outer diameter by 5 μm to 10 μm.
If a resin lens is installed on a holder or lens barrel based on the outer diameter, the central axis of the holder or lens barrel and the optical axis will deviate from each other.

In such a case, in various cameras using resin lenses, a plurality of resin lenses are installed, for example, in a lens barrel and used as a lens group (a series of lens systems). In this case, if the optical axis of each lens is deviated from the center of the outer diameter of the resin lens having a polygonal or circular outer shape (outer peripheral surface), the position of the optical axis will be different for each lens. The lens group as a whole causes a decrease in resolution (deterioration of MTF), resulting in poor product yield. In this case, each resin lens whose outer peripheral surface of the lens is positioned by the inner peripheral surface of the lens barrel is eccentric because the optical axis of each resin lens is deviated from the center of the outer peripheral surface (center of the outer diameter). By rotating each of the multiple resin lenses in the cylinder, the optical axes of each resin lens can be gathered (aligned in phase) as close to one axis as possible, which can improve the resolution of the lens system. can. However, in each lens barrel, it is difficult to rotate each resin lens to align the optical axis, and even if it can be done, it takes time and cost. Further, even if the phases of the lenses are aligned as much as possible, the optical axes of the lenses are still deviated from each other in the lens barrel, and there is a limit to the improvement of the optical characteristics.

In addition, when the center of the incident surface and the center of the exit surface of each plastic lens in the lens barrel are displaced, a composite lens in which two lenses, a base lens and a resin lens, are bonded together is used, and a base lens or another lens is used. By adjusting the position of the center of the emission surface of the resin lens with respect to the center of the emission surface of the base lens in the composite lens, the amount of transmission eccentricity due to the deviation of the center of the incident surface and the emission surface of the plastic lens can be canceled out in the entire lens system. It has been proposed (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-268876

By the way, according to Patent Document 1, it is not necessary to rotate each plastic lens in the lens barrel, and only the position of the resin lens with respect to the base lens is adjusted in the composite lens, so that the labor can be reduced, but the actual number of lenses is plural. The centers of the incident surface and the exit surface of the plastic lens are not aligned near one axis, and there is a limit to the improvement of resolution. Position adjustment is required and it takes time and effort.

The present invention has been made in view of the above circumstances, and in a resin lens, an injection molding device capable of aligning the optical axes of the first surface and the second surface with the center of the outer diameter, an injection molding method, a resin lens, and a resin. It is an object of the present invention to provide a method for manufacturing a lens, a lens unit, and a camera.

In order to solve the above problems, the mold apparatus of the present invention has a pair of molds for molding a resin lens having two optical functional surfaces, and one of the molds is the mold. The first optical functional surface forming portion for molding one of the two optical functional surfaces inside the outermost periphery of the resin lens is provided, and the other mold is the other of the resin lens. Equipped with a second optical functional surface forming part for forming the optical functional surface,
One of the molds is provided with an outer peripheral molding portion that forms the outermost outer peripheral portion of the optical functional surface of the resin lens to determine the outer diameter of the resin lens.
The center of the outer diameter of the resin lens determined by the first optical axis intersection portion of the first optical functional surface forming portion for forming the optical axis intersection of one of the resin lenses and the outer peripheral molding portion. Is arranged so as to overlap with the outer diameter center portion of the first optical functional surface forming portion for forming the lens.
On the other hand, the mold has a substantially columnar eccentric insert provided with the second optical functional surface forming portion on the tip surface, and the eccentric insert is rotatably supported around the central axis of the eccentric insert. Equipped with a support tube to
In the eccentric insert, the second optical axis intersection portion of the second optical functional surface forming portion that forms the optical axis intersection of the other optical functional surface of the resin lens is relative to the central axis of the eccentric insert. Eccentric and provided
The support cylinder is rotatably supported by one of the molds around the central axis of the support cylinder.
It is characterized in that the central axis of the eccentric nest is eccentric with respect to the central axis of the support cylinder.

According to such a configuration, one mold forms a surface having one optical functional surface of the resin lens. At this time, the first optical axis intersection portion that forms the optical axis intersection of one optical functional surface of the resin lens and the outer diameter center portion that forms the outer diameter center of one optical functional surface are arranged so as to overlap at substantially the same position. Therefore, since the optical axis intersection is basically at the center of the outer diameter of the resin lens on one surface of the resin lens molded by this injection molding device, the outermost circumference (outer diameter) of the resin lens is used as a reference. The position of the optical axis intersection can be adjusted. On the other hand, in the other mold for forming the other surface of the resin lens, a second optical functional surface forming portion for forming the other optical functional surface of the resin lens is formed on the tip surface of the eccentric insert, and the eccentric insertion is performed. The second optical axis intersection of the second optical functional surface forming portion, which can rotate integrally with the child and forms the other optical functional surface with respect to the central axis which is the rotation center of the eccentric insert, is eccentric. In addition, it supports the eccentric insert rotatably and is equipped with a support cylinder that rotates by itself. Since the central axis that is the center of rotation of the support cylinder is eccentric with respect to the central axis that is the center of rotation of the eccentric insert. By combining the rotation of the eccentric insert and the rotation of the support cylinder, the position of the second optical axis intersection of the second optical functional surface forming portion can be arranged at any position as long as it is within a predetermined range. ..

Therefore, when the mold device is assembled, the first optical axis intersection of the first optical functional surface forming portion of one mold is set to overlap with the center portion of the outer diameter, and the second optical of the other mold is set. It is possible to align the second optical axis intersection portion of the functional surface forming portion with the position where it overlaps with the first optical axis intersection portion, or to make it as close as possible. As a result, in the molded resin lens, the intersection of the optical axes of the two optical functional surfaces can be aligned with the center of the outer diameter, and the two optics can be aligned on one axis of the resin lens (the actual optical axis of the lens). It is possible to arrange the optical axis intersections on the functional surface and to bring the optical axis intersections closer to the one axis. To adjust the angle of the eccentric insert and the support cylinder, for example, the angle is repeatedly adjusted and injection molding is repeated. For example, the angle of the support cylinder and the eccentric insert is adjusted so as to improve the optical characteristics. These angles can be narrowed down. The position of the optical axis intersection may be directly measured and adjusted so that the position of the optical axis intersection of the molded resin lens is on the center of the outer diameter of the resin lens. Further, when a lens unit such as a camera is formed by combining a plurality of types of resin lenses of the present invention with a series of resin lens groups, when the outermost periphery of each resin lens is positioned on the inner peripheral surface of the lens barrel, each of them is used. It is possible to arrange all the optical axis intersections of the resin lens on one axis or in the vicinity of this axis. At this time, in each resin lens, the optical axis intersections are arranged at the center of the outer diameter or close to each other, so that the optical axis intersections of the resin lenses can be aligned by simply setting the resin lens in the lens barrel. When installing a resin lens in the lens barrel, it is not necessary to rotate the resin lens to align the optical axis intersection of each resin lens, improve the optical characteristics of the resin lens group, and save labor in assembly work. It is possible to reduce the cost based on the conversion.

In a single lens (one resin lens), the intersection of the optical axis on each optical functional surface and the optical functional surface is defined as the optical axis intersection. Here, as described above, in the resin lens, due to the displacement between the first optical functional surface molding portion and the second optical functional surface molding portion in the pair of molds during injection molding, each of them is relative to the center of the outer diameter of the resin lens. As described above, the optical axes of the two optical functional surfaces are aligned with each other on the center of the outer diameter so that the optical axes of the optical functional surfaces are displaced. It is not necessary that the center of the outer diameter and the intersection of the optical axes of each optical functional surface completely coincide with each other, and it may be set to be within the set allowable range.

In the configuration of the present invention, one of the molds is provided with a substantially cylindrical insert provided with the first optical functional surface forming portion on the tip surface so as to be rotatable around the central axis of the insert. It is preferable that the first optical axis intersection portion of the first optical functional surface forming portion is provided on the central axis of the nest.

According to such a configuration, by rotating the insert with one of the molds, it is possible to make fine adjustments for various errors such as manufacturing errors. That is, when the shape of the molded surface deviates from the design due to various errors, it is possible to make fine adjustments by rotating the nest, and it is possible to improve the optical characteristics of the resin lens.

Further, in the configuration of the present invention, the molding surface for molding the resin lens of the other mold has an opening for exposing the tip surface of the eccentric insert.
The eccentric insertion based on the rotation around the central axis of the support cylinder eccentric with respect to the central axis of the eccentric insert between the inner peripheral edge of the opening and the outer peripheral edge of the distal end surface of the eccentric insert. It is preferable that a gap is provided to allow the runout of the child.

According to such a configuration, the eccentric insert rotates with the support cylinder about the central axis of the support cylinder eccentric with respect to the central axis of the eccentric insert, so that the eccentric insert becomes the eccentric insert. The opening of the molding surface of the other mold, which moves a wider range than the tip surface and exposes the tip surface of the eccentric insert of the other mold, becomes wider than the tip surface of the eccentric insert, and the eccentric insert By providing a gap between the outer peripheral edge of the tip surface and the inner peripheral edge of the opening to allow the eccentric insert to swing based on the eccentricity with respect to the central axis of the eccentric insert at the center of rotation of the support cylinder. It is possible to rotate the eccentric nest by rotating. At this time, if the gap between the inner peripheral edge of the opening of the molding surface and the outer peripheral edge of the tip surface of the eccentric insert becomes too large, the resin flows into this gap during molding and burrs are generated. It is preferable that the above-mentioned gap is narrow so that the above-mentioned gap does not flow in. In this case, it is preferable that the diameter of the optical functional surface of the resin lens is small, and if the diameter of the second optical functional surface molded portion is small based on the size of the resin lens, the above-mentioned gap becomes narrow and the resin becomes burrs. Indeed, it can be prevented from flowing into the gap. Further, the appropriate gap functions as an air vent (gas vent) when the mold is filled with the resin, and the gas in the mold can be discharged to facilitate the filling of the resin.

Further, in the configuration of the present invention, the distance between the central axis of the eccentric insert and the central axis of the support cylinder is the central axis of the eccentric insert and the second optical axis of the eccentric insert. It is preferably less than or equal to the distance from the intersection.

According to such a configuration, the distance between the central axis of the eccentric insert and the central axis of the support cylinder is R1, and the central axis of the eccentric insert and the second optical axis of the eccentric insert are used. When the distance between the axis intersection and the axis intersection is R2, by setting R1 ≤ R2, the radius R1 + of the second optical axis intersection of the second optical functional surface forming portion with the central axis of the support cylinder as the center. It can be arranged within the circle of R2. Even if the combination of the angle of the support cylinder and the angle of the eccentric nesting is different, the position of the second optical axis intersection is not duplicated and the same, so that the second optical axis intersection can be efficiently set. In order to make it movable, it is preferable that R1 = R2, and one second optical axis is used for one combination of the angle of the support cylinder and the angle of the eccentric intersection except for the position which is the central axis of the support cylinder. Since the position of the intersection is determined, the angle adjustment between the support cylinder and the eccentric insert can be made more efficient.

The injection molding apparatus of the present invention includes the mold apparatus of the present invention, a mold opening / closing portion for opening / closing one mold and the other mold, a first optical functional surface molding portion, and the second optical. It is provided with a molten resin supply unit that supplies the molten resin to the cavity partitioned by the functional surface forming portion and the outer peripheral forming portion. According to this injection molding apparatus, as described above, the resin lens can be manufactured so as to align the positions of the optical axis intersections of the two optical functional surfaces with the center of the outer diameter.

The injection molding method of the present invention is an injection molding method for molding a resin lens using the mold device of the present invention.
After assembling the injection molding apparatus including the pair of the molds, the second optical axis intersection portion of the second optical functional surface forming portion is located at the first optical axis intersection portion of the first optical functional surface forming portion. It is characterized in that the support cylinder is rotated about the central axis with respect to the other mold and the eccentric insert is rotated about the central axis with respect to the support cylinder so as to overlap with each other.

According to such a configuration, when molding the resin lens, it is possible to arrange the optical axis intersections of the two optical functional surfaces on the center of the outer diameter of the resin lens. It is preferable that the optical axis intersections of the two optical functional surfaces of the resin lens are arranged so as to overlap each other on the center of the outer diameter. And the optical axis intersection may be separated from each other within a set allowable range.

The resin lens of the present invention is a resin lens having a first surface and a second surface, and each of these surfaces has an optical functional surface.
The intersection of the optical axes of each of the two optical functional surfaces is located at a position 2 μm or less from the center of the outer diameter, and
On one of the first surface and the second surface, a substantially annular and parting line-shaped ridge is provided inside the outer peripheral surface.
The ridges are characterized in that the total value of the widths of the ridges facing each other across the optical axis intersection is constant at an arbitrary position.

According to such a configuration, by molding the resin lens by the above-mentioned mold device or injection molding method, the above-mentioned gap between the outer peripheral edge of the tip surface of the eccentric insert and the inner peripheral edge of the opening around it. As a result, a parting line-shaped ridge is formed so as to substantially surround the portion formed on the tip surface of the eccentric nest of the resin lens. This makes it possible to reduce the distance between two optical axis intersections when the optical axis intersections of each optical functional surface are projected onto a plane orthogonal to the optical axis direction. As a result, one of the two surfaces has an annular parting line-shaped ridge that is not on the other surface, and as described above, the optical axis intersection of the two optical functional surfaces is set on the resin lens. It can be used to distinguish that the lens is a resin lens close to the center of the outer diameter.
Further, the inner circumference of the ridge corresponds to the outer peripheral edge of the tip surface of the eccentric insert, and the outer circumference of the ridge is provided on the molding surface for molding the resin lens of the other mold, and the tip surface of the eccentric insert is provided. Corresponds to the inner perimeter of the opening that exposes. In this case, if the tip surface of the eccentric insert in the opening is placed in the center of the opening, the width of each part of the ridge will be the same, but in reality, the outer peripheral edge of the tip surface is inside the opening. It will be in a state of being substantially in contact with one of the peripheral edges, and the width of the ridge will differ depending on the location of the ridge. However, the sum of the widths of the two ridges along the radial direction passing through the intersection of the optical axes of the ridges is the diameter of the outer peripheral edge of the tip surface of the eccentric insert and the diameter of the opening that exposes this tip surface. It is the absolute value of the difference, and the sum of the widths of the two ridges mentioned above is constant regardless of the diameter in any direction. That is, in the ridges, the total value of the widths of the ridges facing each other across the optical axis intersection is constant at an arbitrary position.

The parting line refers to a line (face) at which two molds are separated, and also refers to a linear convex portion (protrusion) formed on the separation line of the mold of a molded product. Here, the parting line is referred to as a ridge formed on the molded product, and the line from which the mold is separated is referred to as a separating surface.

Further, in the resin lens having the above-mentioned configuration of the present invention,
It is preferable that the optical functional surfaces of the first surface and the second surface are aspherical surfaces.
According to such a configuration, a resin lens having a high aberration correction ability can be obtained.

The method for manufacturing a resin lens of the present invention is:
It is characterized in that the resin lens is manufactured by using the mold device of the present invention.
According to such a configuration, the resin lens can be manufactured so as to align the positions of the optical axis intersections of the two optical functional surfaces with the center of the outer diameter as described above.

The lens unit of the present invention has a first surface and a second surface, each of which has an optical functional surface having an optical axis intersection, and the optical axis intersection of each of the two optical functional surfaces is the center of the outer diameter. One of the first surface and the second surface is formed into a substantially annular shape and a parting line shape on the outer side of the optical functional surface and on the inner side of the outer peripheral surface so as to be arranged at a position of 2 μm or less. , Equipped with a plurality of resin lenses having ridges in which the total value of the widths of two facing points across the optical axis intersection is constant at an arbitrary position.
Since each of the plurality of resin lenses is press-fitted into the lens barrel and positioned, all the optical axis intersections of the plurality of resin lenses are arranged at positions of 2 μm or less from the center line of the lens barrel. It is a feature.
According to such a configuration, by molding the resin lens by the above-mentioned injection molding apparatus or injection molding method, the above-mentioned gap between the outer peripheral edge of the tip surface of the eccentric insert and the inner peripheral edge of the opening around it. As a result, a parting line-shaped ridge is formed so as to substantially surround the portion formed on the tip surface of the eccentric insert of the resin lens. Can be brought closer. By press-fitting each resin lens into the lens barrel, the optical axis intersection of each optical functional surface is adjusted to 2 μm or less with respect to the center of the outer diameter even if each resin lens has a different surface shape and diameter. The optical axis intersection of each resin lens can be aligned with the center line (center of the inner diameter) of the lens barrel, and each optical axis intersection can be arranged at 2 μm or less from the center line. As a result, the resolution of the lens unit can be "increased" at low cost.

The camera of the present invention is provided with the lens unit of the present invention, and an image sensor is provided on a side forming an image of the lens unit.

According to such a configuration, the resolution of the lens unit can be increased at low cost, and a high-performance camera can be manufactured at low cost.

According to the present invention, it is possible to improve the optical characteristics of the resin lens by bringing the optical axis intersection of the incident surface and the optical axis intersection of the exit surface close to the center of the outer diameter of the resin lens.

It is a front view which shows the 1st surface of the resin lens of embodiment of this invention. It is the back view which shows the 2nd surface of the resin lens. It is the cross-sectional view along the optical axis which shows the resin lens. The same is a schematic cross-sectional view showing a main part of a mold device for molding a resin lens. It is the figure which shows the 2nd molding surface of the eccentric nesting. It is the figure which shows the 1st forming surface of the nest. It is the front view which shows the eccentric nesting part of the separation surface of the fixed mold. It is a cross-sectional view of a main part showing the eccentric nesting of the mold device and the support cylinder. The relationship between the center of rotation of the support cylinder, the center of rotation of the eccentric insert, the second optical axis intersection of the second optical functional surface forming portion of the eccentric insert, and the range of movement of the second optical axis intersection are explained. It is a figure to do. It is a figure which shows a part of the locus of the intersection of the 2nd optical axis. It is a figure which shows the outline of the lens unit and the camera provided with the resin lens. It is a cross-sectional view of a main part along the optical axis of the resin lens. It is a figure which shows the outline of the injection molding apparatus.

Hereinafter, the mold device, the injection molding device, the injection molding method, the resin lens, the method for manufacturing the resin lens, the lens unit, and the camera according to the embodiment of the present invention will be described with reference to the drawings.
First, the resin lens according to the present embodiment will be described. 1 to 3 show the resin lens 10 of this example, FIG. 1 shows the first surface 11 of the resin lens 10, FIG. 2 shows the second surface 12 of the resin lens 10, and FIG. 3 shows the resin lens. 10 shows a cross section along the optical axis 24.

The resin lens 10 is formed by injection molding, and a plurality of resin lenses 10 are taken (for example, four or eight) from one molded product.
In an injection molding apparatus, a molded product containing the resin lens 10 is directed from a sprue on which the resin is injected, a sprue, to a plurality of cavities in order to guide the resin (for example, a thermoplastic resin) to the cavity in which the resin lens 10 is molded. It is formed corresponding to a runner for branching and guiding the resin in each cavity, and a gate between the runner and the cavity. Therefore, each resin lens 10 formed in the cavity portion is connected to a runner portion formed by a runner via a gate portion formed by a gate, a sprue portion formed by a sprue, and another resin lens 10. In the resin lens 10, the gate portion protruding from the outer periphery of the resin lens 10 is cut inside the outer periphery to obtain a finished product. Therefore, the molded product immediately after injection molding includes a plurality of resin lenses 10 to be taken in large numbers, a gate portion, a runner portion, and a sprue portion.

Further, the mold device has two molds as shown in FIG. 4, includes a movable mold (one mold) 32 and a fixed mold (the other mold) 31, and is fixed at the time of molding. With the mold 31 and the movable mold 32 butted against each other, the portion (cavity) filled with the resin to be the resin lens 10 is placed in a substantially sealed state, and after the resin is filled, it is cooled and fixed when the molded product is solidified to some extent. By moving the movable mold 32 away from the mold 31 and opening the mold, the portion filled with the resin is opened and the resin lens 10 is taken out. At this time, the resin lens 10 is generally released from the fixed mold 31 of the opened fixed mold 31 and the movable mold 32, and is held in the movable mold 32.

In the present embodiment, the outer peripheral surface 19 of the resin lens 10 is formed by the movable mold 32 of the fixed mold 31 and the movable mold 32. The outer peripheral surface 19 is formed on the outer peripheral molded portion 150 (shown in FIG. 4) of the movable side plate 37 of the movable mold 32. Thereby, the outer diameter of the resin lens 10 to be molded is determined by the outer peripheral molding portion 150 of the movable mold 32.

Further, the resin lens 10 has a first surface 11 and a second surface 12, and when the first surface 11 is the front surface, the second surface is located on the back surface side of the first surface. A first optical functional surface 13 is provided on the first surface, and a first flange surface 15 is provided on the outside of the first optical functional surface 13. A second optical functional surface 14 is provided on the second surface 12, and a second flange surface 16 is provided on the outside of the second optical functional surface 14. It should be noted that the optical functional unit having the first optical functional surface 13 and the second optical functional surface 14 has optical functions such as parallel light, light collection, and diffusion with respect to light. Is. In the present embodiment, the first optical functional surface 13 and the second optical functional surface 14 have an aspherical shape, and the resin lens 10 is an aspherical lens. The flange portion having the first flange surface 15 and the second flange surface 16 is used for mounting the resin lens 10, positioning, and the like.

Further, the first optical functional surface 13 has a first optical axis intersection 17 through which the optical axis of the first optical functional surface 13 passes, and the second optical functional surface 14 has an optical axis of the second optical functional surface 14. There is a second optical axis intersection 18 that passes through. That is, the intersection of the first optical functional surface 13 and the optical axis 24 of the first optical functional surface 13 is the first optical axis intersection 17, and the second optical functional surface 14 and the optical axis 24 of the second optical functional surface 14 The intersection of is the second optical axis intersection 18. Here, in the design stage of the resin lens 10 of the present embodiment, the outer peripheral surface 25 of the first optical functional surface 13 and the outer peripheral surface 19 of the resin lens 10 are concentric, and are concentric with the outer peripheral surface 26 of the second optical functional surface 14. The outer peripheral surface 19 of the resin lens 10 is also concentric. The center of the first optical axis intersection 13 having a circular outer circumference 25 is the first optical axis intersection 17, and the center of the second optical function surface 14 having a circular outer circumference 26 is the second optical axis intersection 18. The first optical axis intersection 17 and the second optical axis intersection 18 are arranged at the center of the outer peripheral surface 19 of the resin lens 10. In other words, the positions of the optical axis 24 in FIGS. 1 to 3 and the center of the outer diameter of the resin lens 10 substantially coincide with each other. The optical axis 24 is shown by aligning the optical axis of the first optical functional surface 13 and the optical axis of the second optical functional surface 14, but these optical axes are deviated within an allowable range.

However, in terms of design, the optical axis of each surface and the center of the outer diameter match as described above, but in reality, there is a manufacturing error, especially in the mold after setup of the fixed mold 31 and the movable mold 32. Due to the deviation, the positions of the first optical axis intersection 17 and the second optical axis intersection 18 (position of the optical axis 24) and the center of the outer diameter are displaced. The deviation is suppressed to make it small. Further, the center of the first optical functional surface 13 having a circular outer circumference 25 is the first optical axis intersection 17, and the center of the second optical functional surface 14 having a circular outer circumference 26 is the second optical axis intersection 18. Therefore, even if the first optical function surface 13 and the second optical function surface 14 are spherical surfaces, the respective optical axes 24 pass through the first optical axis intersection 17 and the second optical axis intersection 18.

Further, the resin lens 10 is provided with, for example, a gate mark 23 in which the gate portion is linearly removed inside the outer peripheral surface 19 in the portion where the gate portion is removed. In the resin lens 10, the portion where the gate mark 23 remains is formed in a linear shape in advance inside the circle which is the outer circumference.
Further, the second flange surface 16 of the second surface 12 formed by the fixed mold 31 of the resin lens 10 protrudes toward the second surface 12 of the resin lens 10 and has a parting line-shaped substantially circular protrusion. 21 is provided. The ridge 21 is derived from a gap provided in the molding surface for molding the resin lens 10 of the fixed mold 31 for enabling the movement of the eccentric insert 101 as described later.

In the present embodiment, the first surface 11 is formed by a movable mold 32 together with the outer peripheral surface of the resin lens 10. At least the first optical functional surface 13 of the first surface 11 is formed by the nest 103 of the movable mold 32. The first optical axis intersection 17 of the resin lens 10 is formed by the central portion of the circular tip surface of the insert 103 of the movable mold 32, and the outer peripheral surface 19 of the resin lens 10 is formed by the movable side plate 37 surrounding the insert 103. Will be done. There is almost no gap between the outer peripheral edge of the tip surface of the insert 103 and the inner peripheral edge of the opening where the tip surface of the insert 103 of the movable side plate 37 is exposed. As a result, on the first surface 11 which is the aspherical surface of the resin lens 10, the optical axis of the first surface 11 substantially coincides with the center (outer diameter center) of the outer peripheral surface 19 and passes through the first optical axis intersection 17. The positional deviation of the first optical axis intersection 17 with respect to the center of the outer diameter can be extremely small, for example, can be smaller than 1 μm, and can be further set to 100 nm or less.
That is, since the movable mold 32 is formed by rotating the concave surface at the tip of the insert 103 with an aspherical processing machine, it is easy to match the center of the insert 103 with the first optical axis intersection 17. Since the insert 103 is inserted into the hole of the movable side plate 37 without any gap, the insert 103 and the movable side plate 37 do not deviate from each other.

On the other hand, on the second optical functional surface 14, the position of the second optical axis intersection 18 can be moved to match the outer diameter center axis or the first optical axis intersection 17, as will be described later. The distance from the central axis and the first optical axis intersection 17 can be set to 2 μm or less, and the direction perpendicular to the optical axis from the first optical axis intersection 17 to the second optical axis intersection 18 when viewed from the front. The distance can be 2 μm or less. Further, the second optical axis intersection 18 can be brought closer to the outer diameter central axis or the first optical axis intersection 17, and the above-mentioned distance can be set to 1 μm or less. The outer diameter of the resin lens in this case is, for example, 20 mm or less, preferably 2 mm to 15 mm.

As shown in FIG. 4, the mold device used for molding the resin lens 10 includes a fixed mold 31 and a movable mold 32 that can be opened and closed with respect to the fixed mold 31. FIG. 4 shows a state in which the movable mold 32 is abutted against the fixed mold 31 and the movable mold 32 is closed, the right side in the figure is the fixed mold 31 and the left side is the movable mold with the separation surface 33 as a boundary. It is a mold 32. Here, in the fixed mold 31 and the movable mold 32, the separation surface 33 side is the tip end (front end) side, and the opposite side is the rear end (base end) side. Further, the tip surfaces of the fixed mold 31 and the movable mold 32 are referred to as separation surfaces 33, respectively.
The fixed mold 31 has a mounting plate (not shown) on the opposite side of the separation surface 33, a mold plate 34 is provided on the separation surface 33 side, and a fixed side plate 36 is provided on the separation surface 33 side of the mold plate 34. Is provided. The template 34 is a portion to which various members are attached, and determines the positions of the above-mentioned fixed side plate 36, a guide pin (not shown) for guiding the opening / closing movement of the movable mold 32, and the closed movable mold 32. A positioning pin (not shown) and the like are provided.
Further, the mold plate 34 of the fixed mold 31 is provided with a support cylinder (sleeve insert) 102 that is rotatable with respect to the mold plate 34 and an eccentric inserter 101 that is rotatable with respect to the support cylinder 102. There is.

The support cylinder 102 is a cylindrical member by providing a cylindrical hollow portion arranged in a state in which the eccentric insert 101 penetrates the cylindrical member, but the central axis of the cylindrical support cylinder 102 On the other hand, the central axis of the cylindrical hollow portion is eccentric. That is, these central axes are parallel to each other but out of position. The support cylinder 102 is rotatably arranged in a columnar space provided in the template 34 via a ball slider 41. The ball slider 41 is a cylindrical ball cage in which a large number of balls are arranged side by side at intervals in the axial and circumferential directions. The balls are rotatably held and substantially all of the balls are held in the ball slider 41. The columnar member arranged so as to come into contact with the sphere can be smoothly rotated around the central axis with a small resistance. Therefore, the support cylinder 102 is rotatable with respect to the template 34. The central axis of the support cylinder 102, which is the rotation axis at this time, is along the direction orthogonal to the separation surface 33 described above. The outer peripheral side of the ball slider 41 is in a state where substantially all the spheres are in contact with the inner peripheral surface of the columnar space of the template 34.

A ball slider 46 is provided inside the support cylinder 102, and the eccentric insert 101 is rotatably supported by the support cylinder 102 via the ball slider 46. The ball slider 46 has the same configuration except that the diameter of the ball slider 46 is smaller than that of the ball slider 41. In the ball slider 46, an eccentric insert rotating portion 45, which will be described later, of the eccentric insert 101 is inserted. In this state, the ball slider 41 that rotatably supports the support cylinder 102 and the central axis (rotational axis) of the support cylinder 102 substantially coincide with each other, and the eccentric insert 101 rotatably supports the support cylinder 102 with respect to these central axes. The central axis (rotational axis) of the ball slider 46 and the central axis (rotating axis) of the eccentric insert 101 are eccentric. The central axis of the ball slider 46 and the central axis of the eccentric nesting 101 coincide with each other. All of these central axes are orthogonal to the separation surface 33.

The tip surface of the eccentric insert 101 is a second molded surface 43 that forms the second surface 12 of the resin lens 10. Further, the eccentric inserter 101 is rotatably supported from the tip end surface side by a columnar eccentric inserter main body 44 having the same diameter as the tip end surface and a mold plate 34 of the fixed mold 31 via a ball slider 46. It is provided with a columnar eccentric nesting rotating portion 45.

The central portion of the second molded surface 43 of the eccentric insert 101 is a second optical functional surface forming portion 131 (shown in FIG. 5) that forms the second optical functional surface 14 of the resin lens 10, and the outside thereof is It is a second flange forming portion 132 (shown in FIG. 5) that forms a part of the inner peripheral side of the second flange surface 16. The fixed mold 31 does not have a portion for molding the outer peripheral surface 19 of the resin lens 10. In the present embodiment, the second molded surface 43 of the tip surface of the eccentric insert 101 is the second surface of the resin lens 10. The inner peripheral side portions of the second optical functional surface 14 and the second flange surface 16 of the 12 are molded. The outer peripheral side portion of the second flange surface 16 is formed by a fixed side plate 36 around the eccentric insert 101.

Further, as outlined in FIG. 7, between the inner peripheral surface of the opening portion of the through hole into which the eccentric insert main body 44 of the fixed side plate 36 is inserted and the outer peripheral surface of the eccentric insert main body 44. Is provided with a gap that allows the amount of deflection of the eccentric insert 101 and allows the eccentric insert 101 to rotate smoothly due to the eccentricity between the central axis of the support cylinder 102 and the central axis of the eccentric insert 101. There is. This gap is such that the resin does not enter and burrs do not occur during injection molding, but the resin lens 10 is formed with a parting line-shaped ridge 21 based on this gap. Further, this gap has an effect of causing a function of venting gas during injection molding and facilitating injection molding of the resin.
However, as outlined in FIG. 12, the diameter of the eccentric nesting main body 44 may be formed to be larger than the diameter of the molded resin lens 10 (outer diameter of the cavity portion). In this case, the boundary (gap) between the inner peripheral surface of the opening portion of the through hole in the fixed side plate 36 and the outer peripheral surface of the eccentric nesting main body 44 is located on the radial outer side of the resin lens 10 to be molded. It becomes. Therefore, the ridge 21 is not formed on the resin lens 10.

Further, the fixed side plate 36 of the fixed mold 31 is provided with a groove 38 which is abutted against the movable side plate 37 and becomes a runner, and a groove 39 which becomes a narrower gate. Further, the movable side plate 37 of the movable mold 32 is provided with a groove 54 that serves as a runner together with the groove 38 and a groove 53 that serves as a gate together with the groove 39. The fixed side plate 36 may be provided only on the movable side plate 37 without providing the groove 38 serving as a runner and the groove 39 serving as a gate.

The movable mold 32 is movable between a state in which it is abutted against the fixed mold 31 and closed, and a state in which the movable mold 32 is opened away from the fixed mold 31 in a direction orthogonal to the separation surface 33. The movable mold 32 is provided with a movable side mounting plate (not shown) on a portion opposite to the separation surface 33, and a movable side mold plate 35 is provided on the separation surface 33 side of the mounting plate. A movable side plate 37 up to the separation surface 33 is provided on the separation surface 33 side.
The mold plate 35 on the movable side is provided with a bush (not shown) into which the above-mentioned guide pin and positioning pin extending orthogonal to the separation surface 33 from the fixed mold 31 are inserted. Further, a device (not shown) for extruding a molded product including a plurality of resin lenses 10 held by the movable mold 32 when the mold is opened after resin molding is provided.
Further, the template 35 is provided with a through hole for rotatably holding the insert 103, and the insert 103 in a state of being inserted into the cylindrical ball slider 64 is arranged in the through hole, and the insert 103 is arranged. It is rotatably supported by the template 35 via the ball slider 64. Further, the movable side plate 37 on the separation surface 33 side of the template 35 is provided with a through hole into which the insert main body 58 on the tip end side of the insert 103 is inserted, and the insert 103 is provided through the opening of the through hole. The tip surface is exposed on the separation surface 33 side.

The nesting 103 is provided with a movable first molded surface 57 for molding the first surface 11 of the resin lens 10 on the front end surface, and is a columnar column having the same diameter as the front end surface in order from the front end surface to the rear end side. It includes a nesting main body 58, a columnar nesting rotating portion 59 having a diameter larger than that of the nesting main body 58, and a disc-shaped nesting base end portion 60 having a diameter larger than that of the nesting rotating portion 59. Each part of these nests 103 is arranged coaxially.
The central portion of the first molded surface 57 forms the first optical functional surface 13 of the resin lens 10 with the first optical functional surface molded portion 142 (shown in FIG. 6) and the first outer surface of the first optical functional surface 13. It has a first flange forming portion 143 (shown in FIG. 6) for forming a part of the inner peripheral side of the flange surface 15. Further, a part of the outer peripheral side of the first flange surface 15 is molded with a part of the movable side plate 37 outside the first molding surface 57.

The first optical axis intersection 140 (shown in FIG. 6), which will be described later, for forming the first optical axis intersection 17 of the first optical functional surface 13 of the resin lens 10 of the first molding surface 57 is on the central axis of the nest 103. It is arranged on the rotation axis corresponding to the central axis, and is arranged at the center of the first forming surface 57 and at the center of the first optical functional surface forming portion. Such an arrangement basically aligns the center of the insert 103, the hole for accommodating the insert 103, and the molding surface of the insert 103, and can be easily performed.
Further, the outer diameter of the resin lens 10 is formed by the outer peripheral molding portion 150 formed by the inner peripheral surface of the opening that exposes the tip surface of the insert 103 of the movable side plate 37. That is, the outer diameter of the resin lens 10 is defined by the movable mold 32 that forms the first surface 11 having the first optical functional surface 13 of the resin lens 10.
Here, since the nesting 103 has the above-mentioned first optical axis intersection portion 140 on its rotation axis, basically, the first optical axis intersection portion 140 does not move even if the nesting 103 rotates. However, there is a possibility of movement within an error range such as manufacturing error. Further, since the insert 103 only rotates on its axis and does not swing during rotation unlike the eccentric insert 101, the inner peripheral surface of the through hole of the movable side plate 37 and the insert main body portion 58 of the insert 103. There is no gap between the outer peripheral surface and the outer peripheral surface to allow runout, and the gap is sufficient to allow smooth rotation.

The nesting body portion 58 is a portion having a first forming surface 57 at the tip as described above. The nesting rotation portion 59 is a portion that is inserted into the ball slider 64 and is supported by the ball slider 64 for rotation self-determination. The ball slider 64 has the same configuration as the ball slider 41 except that the diameter is different. In the ball slider 64, substantially all the balls of the ball slider 64 come into contact with the nested rotating portion 59, and the movable side plate. Almost all the balls of the ball slider 64 are in contact with the inner peripheral surface of the through hole into which the nest 103 of 37 is inserted.

Here, in the movable mold 32, the insert 103 is basically rotated for error adjustment of the first molding surface 57, and even if the insert 103 is rotated, the first surface of the resin lens 10 is rotated. The position of the first optical axis intersection portion 140 for forming the first optical axis intersection 17 of the first optical functional surface 13 of 11 remains almost unchanged, and is at the position for forming the center of the outer diameter of the resin lens 10.
On the other hand, in the fixed mold 31, the support cylinder 102 that rotatably supports the eccentric insert 101 via the ball slider 46 is rotatably supported by the mold plate 34 of the fixed mold 31 via the ball slider 41. Further, the rotation axis (central axis) of the support cylinder 102 is eccentric with respect to the rotation axis (central axis) of the eccentric insert 101, and the second optical axis intersection portion 113 of the second forming surface 43 of the eccentric insert 101 (FIG. Since the rotation axis (central axis) of the eccentric insert 101 is eccentric with respect to (shown in 8), by rotating the eccentric insert 101 and the support cylinder 102, respectively, the second optical axis intersection portion is within a predetermined range. 113 can be moved arbitrarily.

FIG. 5 shows the second forming surface 43 of the fixed mold 31, in which the second optical axis intersection portion 113 is eccentric from the rotation axis 112 of the eccentric insert 101. Further, the central portion of the second molded surface 43 is the second optical functional surface molded portion 131 as described above, and the outer side thereof is the second flange molded portion 132. FIG. 6 shows the first forming surface 57 of the movable mold 32, and forms the outer diameter center which is the intersection of the first optical axis intersection portion 140 and the outer diameter center of the first surface 11 of the resin lens 10. It is in a state of being in agreement with the outer diameter center portion 141. Further, the central portion of the first molded surface 57 is the first optical functional surface molded portion 142, and the outer side thereof is the first flange molded portion 143. Further, the rotation shaft 112 (shown in FIG. 8) of the nest 103 coincides with the outer diameter center portion 141.

In the present embodiment, since R1 = R2 as described above, the second optical axis intersection portion 113 can be moved anywhere within the circular range of the radius R1 + R2, and the injection molding apparatus can move the second optical axis intersection 113 at the time of setting up the mold. Even if an error occurs, it is possible to align the second optical axis intersection portion 113 of the fixed mold 31 with the first optical axis intersection portion 140 of the movable mold 32 after setup.

Next, an injection molding method for the resin lens 10 using the mold device of the present embodiment will be described. First, the movable mold 32 and the fixed mold 31 of the mold device are set up so that the resin lens 10 can be molded.
Next, the resin lens 10 is prototyped. At this time, the angle of the eccentric insert 101 and the support cylinder 102 is appropriately adjusted based on the deviation between the insert 103 and the eccentric insert 101. A prototype may be produced without adjustment.

Next, the outer diameter of the prototype resin lens 10 and the center of the second optical functional surface 14 of the second surface 12 formed by the movable mold 32 are measured by a three-dimensional shape measuring instrument. Next, the center of the first optical functional surface 13 and the center of the second optical functional surface 14 are measured by a three-dimensional shape measuring instrument. Next, as a measurement result, the angles of the eccentric insert 101 and the support cylinder 102 are adjusted based on the deviation between the positions of the center of the first optical functional surface 13 and the center of the second optical functional surface 14.
Next, the resin lens 10 is prototyped again. By repeating this trial production, measurement, and angle adjustment of the eccentric insert 101 and the support cylinder 102, the amount of deviation between the center of the first optical functional surface 13 and the center of the second optical functional surface 14 is within a predetermined common range. When this happens, the trial production of the resin lens 10 is completed.
As a result, the deviation between the positions of the center of the outer diameter, the first optical axis intersection 17, and the second optical axis intersection 18 can be set to 2 μm or less. After adjusting the angles of the eccentric insert 101 and the support cylinder 102 in this way, mass production of the resin lens 10 is started, and injection molding is sequentially repeated.

The injection-molded resin lens 10 has the above-mentioned eccentric insert 101 between the outer peripheral edge of the tip surface of the above-mentioned eccentric insert 101 and the inner peripheral edge of the opening where the eccentric insert 101 of the fixed side plate 36 is exposed. A parting line-shaped substantially annular ridge 21 is formed by a gap for allowing runout. Due to the ridges 21 formed only on one side (second side) of the resin lens 10, the resin lens 10 has the first optical axis intersection 17 and the second optical axis intersection with respect to the outer diameter central axis as described above. It becomes possible to distinguish that the lens is formed so as to match the 18, and it becomes easy to distinguish the lens from the resin lens whose optical axis intersection is greatly deviated from the outer diameter central axis.
It is preferable that the ridge 21 is outside the first optical functional surface 13 and the second optical functional surface 14.

FIG. 7 is a schematic front view of a main part showing the side of the separation surface 33 abutted against the movable mold 32 of the fixed mold 31, and is an eccentric insertion of the eccentric insert 101 from the opening of the hole provided in the fixed side plate 36. The second molded surface 43 of the child main body 44 is in a visible state. Note that FIG. 7 is a schematic view, and the illustration of the unevenness corresponding to the shape of the resin lens 10 on the front surface (separation surface 33) of the second molding surface 43 and the fixed side plate 36 is omitted.

In FIG. 7, there is the above-mentioned gap between the eccentric insert 101 and the fixed side plate 36 so that the eccentric insert 101 can move. For example, it is assumed that the difference between the inner diameter of the opening of the hole into which the eccentric insert 101 is inserted and the outer diameter of the eccentric insert main body 44 of the eccentric insert 101, which is shorter than that, is, for example, 10 μm. When the eccentric insert 101 is unevenly arranged on one side of the hole, a gap of up to 10 μm is created. This gap amount is set so that the resin does not flow into the gap in consideration of the viscosity of the resin. Burrs on the ridge 21 portion of a slight height (which does not affect the lens fitting) may occur.
From this, the total value of the widths of the ridges 21 (the sum of the widths of the two places) of the ridges 21 that are opposed to each other with the second optical axis intersection 18 aligned with the center of the outer diameter of the ridges 21 generated in the resin lens 10 is arbitrary. It becomes constant at the position of (at any position).

FIG. 8 is a sectional view taken along the line AA of FIG. 4 of the eccentric insert rotating portion 45 of the eccentric insert 101 of the fixed mold 31 of the mold apparatus, and is a cross-sectional view orthogonal to the rotation axis, from the center side. The eccentric insert rotating portion 45 of the eccentric insert 101, the ball slider 46 for the eccentric insert 101, the support cylinder 102, the ball slider 41 for the support cylinder 102, and the mold plate 34. Although the ball sliders 41 and 46 are shown as an annular space, they actually have a ball cage and a ball. The rotation center axis (central axis) 111 of the support cylinder 102 is indicated by +, the rotation center axis (central axis) 112 of the eccentric insert 101 is indicated by X, and the eccentric insert 101 (second forming surface 43) is indicated by X. The bi-optical axis intersection portion 113 is indicated by O. Since the positions of the rotation axis 111 of the support cylinder 102, the rotation axis 112 of the eccentric nesting 101, and the second optical axis intersection portion 113 are eccentric, in the present embodiment, the second optical axis intersection portion 113 is formed. It can be moved to any position within a predetermined range. For example, as shown in FIG. 9, when the support cylinder is fixed so that the central axis × of the eccentric insert is fixed at the position shown in the figure, the eccentric insert 101 is centered on the central axis 112 of the eccentric insert 101. It is rotatable, and the second optical axis intersection portion 113 of the second forming surface 43 formed on the eccentric insert 101 can move along the circular locus 122.

Further, the second optical axis intersection portion 113 can be moved to an arbitrary position within the circular predetermined range 123.
FIG. 10 shows the locus 122 of the second optical axis intersection portion 113 when the central axis 112 of the eccentric insert 101 is moved stepwise by 45 degrees by rotating the support cylinder 102 fixed in FIG. Is. In reality, since the angle of the support cylinder 102 can be continuously changed steplessly, the second optical axis intersection portion 113 can be moved to any of all the points within the predetermined range 123 described above. That is, the second optical axis intersection portion 113 of the molded surface formed on the eccentric insert 101 on the fixed side of the present embodiment can be arranged in any of the predetermined ranges 123 by the rotation of the support cylinder 102 and the eccentric insert 101. Therefore, as long as the first optical axis intersection portion 140 (outer diameter center portion 141) of the molded surface on the movable side is within the predetermined range 123, the first optical axis intersection portion 140 (outer diameter center portion 141) and the second It is possible to match the optical axis intersection portion 113.
The distance between the central axis 112 of the eccentric insert 101 and the central axis 111 of the support cylinder 102 is R1 , and the distance between the central axis 112 of the eccentric insert 101 and the second optical axis intersection 113 is R2 . In this embodiment, R1 = R2, and the center position in FIG. 10 coincides with 111. If R1 <R2, a region that cannot be covered in the central portion of FIG. 10, that is, a region in which the second optical axis intersection portion 113 cannot be arranged occurs in the central portion, which is not preferable. Therefore, it is preferable that R1 ≧ R2. When R1> R2, a range that is overlapped and covered is generated in the central portion of FIG. 10, the diameter of the circle of the predetermined range 123 becomes small, and the area where the second optical axis intersection portion 113 can be arranged is small as a whole. Become. Within the circular movement range where the second optical axis intersection point, that is, the radius is R2-R1, the combination of the angle of the eccentric nesting 101 and the angle of the support cylinder 102 at which the position of the second optical axis intersection portion 113 is the same is 2 They exist one by one, resulting in inefficient settings.

FIG. 11 is a schematic view of a camera 205 for sale having a lens unit 202 in which a plurality of resin lenses 10a to d are supported in a lens barrel 201, and an image sensor 203 arranged on a side connecting an image of the lens unit 202. Is. Although the shapes of the resin lenses 10a to 10d are different from those of the resin lens 10, the positions of the first optical axis intersection 17 and the second optical axis intersection 18 are aligned with the center of the outer diameter as described above. It is a mold device that is molded by the injection molding method of the present embodiment using a mold having a different molding surface. These resin lenses 10a to d are press-fitted into the lens barrel 201. Since the deviation of the first optical axis intersection 17 and the second optical axis intersection 18 from the center of the outer diameter of the resin lenses 10a to d is small like the above-mentioned resin lens 10, each resin lens 10a to d is used as a lens. Even if the lens unit 201 is press-fitted without worrying about the directionality, the deviation of each optical axis of each resin lens 10a to d can satisfy the required accuracy of 2μ or less, and the resolution of the lens unit 202 can be improved. It becomes possible to increase the resolution, and the resolution can be increased in the shooting with the camera 205 using the lens unit 202. Therefore, when it is desired to use the high pixel image sensor 203, it can be effectively used. It is also possible to further improve the accuracy by rotating each lens in advance and press-fitting the lenses so that the deviation directions of the optical axes of the resin lenses 10a to d coincide with each other.
The lens unit of the form shown in FIG. 11 is all made of a resin lens, but a part of the lens unit may be a glass lens.

FIG. 13 is a schematic view of an injection molding apparatus. The injection molding apparatus includes a mold apparatus, a mold opening / closing unit 301, a molten resin supply unit 302, and the like. As described above, the mold device includes a fixed mold 31 and a movable mold 32. The mold opening / closing portion 301 is a portion for opening / closing the fixed mold 31 and the movable mold 32, and includes a movable plate, a fixed plate, a tie bar, and the like. The molten resin supply unit 302 is a portion for supplying the molten resin to the cavity partitioned by the first optical functional surface forming unit 142, the second optical functional surface forming unit 131, and the outer peripheral forming unit 150, and is a nozzle and a hand heater. , Cylinder, etc. are provided.

10 Resin lenses 10a to d Resin lenses 11 1st surface 12 2nd surface 13 1st optical functional surface 14 2nd optical functional surface 17 1st optical axis intersection 18 2nd optical axis intersection 19 Outer peripheral surface 21 Protrusion 31 Fixed mold (The other mold)
32 Movable mold (one mold)
43 Second forming surface 57 First forming surface 101 Eccentric nesting 102 Support cylinder 103 Nesting 111 Central axis (rotating shaft) of the support cylinder
112 Center axis of eccentric nesting (rotation axis)
113 Second optical axis intersection 131 Second optical functional surface forming part 140 First optical axis intersection 141 Outer diameter center part (center axis of nest, rotation axis)
142 First optical functional surface forming part 150 Outer peripheral forming part 202 Lens unit 205 Camera 301 Mold opening / closing part 302 Molten resin supply part R1 Distance between the central axis of the eccentric insert and the central axis of the support cylinder R2 Distance between the central axis and the intersection of the second optical axis of the eccentric nest

Claims (11)

It has a pair of molds for molding a resin lens having two optical functional surfaces, and the mold of one of the molds is one of the two optical functional surfaces inside the outermost periphery of the resin lens. The first optical functional surface forming portion for forming one of the optical functional surfaces is provided, and the other mold includes a second optical functional surface forming portion for forming the other optical functional surface of the resin lens.
Only one of the molds, not the other mold, is provided with an outer peripheral molding portion that forms the outermost outer peripheral side surface of the optical functional surface of the resin lens to determine the outer diameter of the resin lens.
In one of the molds, the resin determined by the first optical axis intersection portion of the first optical functional surface molding portion for molding the optical axis intersection of one of the optical functional surfaces of the resin lens and the outer peripheral molding portion. It is arranged so as to overlap with the outer diameter center portion of the first optical functional surface forming portion that forms the center of the outer diameter of the lens.
On the other hand, the mold has a columnar eccentric insert provided with the second optical functional surface forming portion on the tip surface.
A support cylinder that rotatably supports the eccentric insert around the central axis of the eccentric insert is provided.
In the eccentric insert, the second optical axis intersection portion of the second optical functional surface forming portion that forms the optical axis intersection of the other optical functional surface of the resin lens is relative to the central axis of the eccentric insert. Eccentric and provided
The support cylinder is rotatably supported by the other mold around the central axis of the support cylinder.
A mold device characterized in that the central axis of the eccentric nest is eccentric with respect to the central axis of the support cylinder. On the other hand , in the mold, a cylindrical insert provided with the first optical functional surface forming portion on the tip surface is rotatably provided around the central axis of the insert, and the central axis of the insert is provided. The mold apparatus according to claim 1, wherein the first optical axis intersection portion of the first optical functional surface forming portion is provided above. On the other side, the molding surface for molding the resin lens of the mold is provided with an opening for exposing the tip surface of the eccentric insert.
The eccentric insertion based on the rotation around the central axis of the support cylinder eccentric with respect to the central axis of the eccentric insert between the inner peripheral edge of the opening and the outer peripheral edge of the distal end surface of the eccentric insert. The mold device according to claim 1 or 2, wherein a gap is provided to allow runout of the child. The distance between the central axis of the eccentric insert and the central axis of the support cylinder is equal to or less than the distance between the central axis of the eccentric insert and the second optical axis intersection of the eccentric insert. The mold device according to any one of claims 1 to 3, wherein the mold device is characterized by the above. With the mold apparatus according to any one of claims 1 to 4.
A mold opening / closing portion for opening / closing the mold on one side and the mold on the other side ,
A molten resin supply unit that supplies the molten resin to the cavity partitioned by the first optical functional surface forming portion, the second optical functional surface forming portion, and the outer peripheral forming portion .
Injection molding equipment. An injection molding method for molding a resin lens using the mold apparatus according to any one of claims 1 to 4.
After assembling the injection molding apparatus including the pair of the molds, the second optical axis intersection portion of the second optical functional surface molding portion is located at the first optical axis intersection portion of the first optical functional surface molding portion. Injection characterized by rotating the support cylinder around the central axis with respect to the other mold and rotating the eccentric insert with respect to the support cylinder around the central axis so as to overlap each other. Molding method. A resin lens having a first surface and a second surface, each of which has an optical functional surface.
The intersection of the optical axes of each of the two optical functional surfaces is arranged at a position of 2 μm or less from the center of the outer diameter of the resin lens , and
An annular and parting line-shaped ridge is provided on one of the first surface and the second surface inside the outer peripheral surface.
The ridge is a resin lens characterized in that the total value of the widths of the ridges facing each other across the intersection of the optical axes is constant at an arbitrary position. The resin lens according to claim 7, wherein the optical functional surfaces of the first surface and the second surface are aspherical surfaces. The method for manufacturing a resin lens according to claim 7 or 8.
A method for manufacturing a resin lens, which comprises manufacturing the resin lens using the mold apparatus according to claim 3 . It has a first surface and a second surface, each of which has an optical functional surface having an optical axis intersection, and the optical axis intersection of each of the two optical functional surfaces is 2 μm or less from the center of the outermost outer diameter. One of the first surface and the second surface is formed into an annular shape and a parting line shape on the outer side of the optical functional surface and on the inner side of the outer peripheral surface so as to be arranged at the position, and the optical axis intersection. It is equipped with a plurality of resin lenses having ridges in which the total value of the widths of the two facing portions is constant at an arbitrary position.
Since each of the plurality of resin lenses is press-fitted into the lens barrel and positioned, all the optical axis intersections of the plurality of resin lenses are arranged at positions of 2 μm or less from the center line of the lens barrel. A featured lens unit. A camera comprising the lens unit according to claim 10, wherein an image sensor is provided on a side connecting an image of the lens unit.

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