JP6357904B2 - Mold apparatus and optical element - Google Patents

Description

  The present invention relates to a mold apparatus for molding a lens and other optical elements, and an optical element formed by the mold apparatus.

  An optical element incorporated in an electronic product generally has a main body and a frame. However, both the optical surface formed on the former main body and the reference surface for mounting formed on the latter frame are precisely manufactured. It is not easy to do. For example, in an optical pickup lens, since the lens is relatively thick, the reference surface has a strong tendency to tilt in a specific direction with respect to the optical axis of the optical surface. Is relatively easy. On the other hand, in recent years, the thinning of the imaging lens has been remarkably progressed, and the inclination and deformation direction of the reference surface tend to be different, and mold correction is relatively easy. Further, even if the inclination of the reference plane can be corrected, the flatness cannot be completely reduced to zero. Therefore, it is not easy to adjust the lens interval and the inclination depending on how the reference planes are brought into contact with each other. Further, in the case of a thin lens, the entire lens is easily formed by being curved, but the curvature is corrected or corrected when a plurality of such lenses are incorporated in a holder. As a result, even if the reference surface and the like can be made highly accurate with a single lens, the optical performance may be deteriorated due to the interaction between the lenses. Such performance degradation may be improved, for example, by rotating a specific lens, but it is a multi-factor adjustment, and there may be a case where a sufficient effect cannot be obtained for the adjustment requiring cost and time. Many.

  As a technique for preventing a positional shift or inclination of the lens in the optical axis direction due to environmental changes, a technique using multi-point support is known (Patent Document 1). In this method, three or more protrusions are provided on one surface of the flange portion of any one of the plurality of lenses, and these protrusions are brought into contact with the surface of the flange portion of the adjacent lens, thereby providing a flange. A plurality of lenses are fixed by pressing the lenses in the optical axis direction with a gap provided between the portions.

  Further, as a method for fixing optical components while aligning them, a method using semi-curing of a resin is known (Patent Document 2). In this method, a resin material in a liquid state is applied to the mounting surface of the optical component, and light is irradiated on the mounting surface to make it a semi-cured state having elasticity. Is positioned at a predetermined position. By irradiating the resin material with light in this state, it is possible to fix the optical component to the optical device with the resin material in a cured state.

  In the method of Patent Document 1, since three or more protrusions are used, it is relatively easy to adjust the surface interval and tilt. However, in the method of Patent Document 1, since the protrusion is formed by transferring a recess formed on the mold surface, it is not easy to adjust the height of the protrusion. In addition, there is no wrinkle formed on the protrusion and its opposite surface, and there is a possibility that the light incident on the protrusion is guided in an unintended direction by refraction or reflection and becomes stray light.

  In the method of Patent Document 2, it is necessary to form or process a resin material into a protrusion, and the height adjustment is not easy. In addition, the addition of a process for semi-curing or curing the resin material leads to an increase in cost. Furthermore, since the optical component material and the resin material are different, there is a possibility that the optical performance and the like may be adversely affected depending on the use environment.

JP 2010-224208 A JP 2010-139722 A

  The present invention has been made in view of the above-described background art, and can easily form an adjustment protrusion while suppressing cost, can prevent stray light, and hardly deteriorates optical performance depending on the use environment. And it aims at providing an optical element.

In order to achieve the above object, a mold apparatus according to the present invention is a mold apparatus for molding an optical element having a main body portion and a frame portion, and has projections at three positions in the frame portion toward the optical axis direction. In order to form, there are three recesses as a part of the transfer surface, and the three recesses can be adjusted in depth by a pin embedded in the recess, and the tip surface of the pin corresponding to the bottom of the recess Processing is performed, and the bottom of the recess is formed in a curved surface having a deep center and a shallow periphery .

Since the mold apparatus has three concave portions as a part of the transfer surface, projections can be formed at three locations in the frame portion in the optical axis direction when the optical element is molded. These three protrusions enable positioning with respect to the optical axis direction and inclination when the optical element is fixed to another optical element or a holder. In particular, when the main body or the like is thin, the optical element tends to be bent slightly, but the support is easily stabilized by the three-point support using the protrusions. Here, since the depth of the three recesses formed in the mold apparatus can be adjusted by pins embedded in the recess, the height of the protrusion can be adjusted as compared with the case of engraving the mold. As a result, the assembly accuracy of the optical element can be easily increased. In addition, the tip end surface of the pin corresponding to the bottom portion of the concave portion is subjected to a graining process, so that it is possible to prevent the light incident on the protrusion from being guided in an unintended direction by refraction or reflection and becoming stray light. The bottom of the recess is formed in a curved surface with a deep center and a shallow periphery, and the upper end of the protrusion formed by the recess can be formed in a dome shape, so there is a variability between the pin and the insertion hole into which the pin is inserted. Even if formed, it is possible to prevent the burr from interfering with the support by the protrusion.

In another aspect of the present invention, the frame portion has a flat portion that extends flatly surrounding the main body portion, and the protruding portion protrudes from a flat surface extending perpendicularly to the optical axis direction.

  In still another aspect of the present invention, it is used for molding an optical element used alone.

  In yet another aspect of the present invention, the optical element is released by a pin protrusion or a core protrusion. In this case, it is possible to facilitate the release of the molded product.

  In still another aspect of the present invention, the pin protruding is performed by a protruding pin provided separately from the pin. In this case, it becomes easy to increase the accuracy of assembling the projection pin.

In order to achieve the above object, an optical element according to the present invention includes a main body portion and a frame portion, and has protrusions at three positions in the frame portion toward the optical axis direction. The top of each projection is formed in a curved surface with a high center .

In the optical element, when the optical element is fixed to a holder or another optical element, the three protrusions can be positioned with respect to the optical axis direction and inclination. In particular, when the main body or the like is thin, the optical element tends to be bent slightly, but the support is easily stabilized by the three-point support using the protrusions. Here, since the embossing is performed on the tip surface of the protrusion, it is possible to prevent the light incident on the protrusion from being guided in an unintended direction by refraction or reflection and becoming stray light. In addition, since the top of each projection is formed in a curved surface with a high center, even when a burr is formed between the pin and the insertion hole for inserting the pin during molding, the burr is supported by the projection. You can prevent it from getting in the way.

(A) And (B) is sectional drawing and the back view of an imaging lens incorporating the optical element of embodiment. (A) And (B) is the top view and back view of one optical element. It is the elements on larger scale explaining the contact state between a pair of optical elements. It is a figure which shows an example of the type | mold apparatus for shaping | molding an optical element. (A) And (B) is the side sectional view and end view of a type | mold apparatus. It is a partial expanded sectional view explaining the front-end | tip part of the height adjustment pin which forms a projection part. It is a figure explaining the modification of the lens number which comprises an imaging lens. It is a partial expanded sectional view explaining the example of a change of arrangement | positioning of a projection part. It is a figure explaining the example of a change of the shape of a projection part. It is a figure explaining the example of a change of the shape of a projection part. It is a figure explaining the example of a change of the mold release method of an optical element.

  Hereinafter, embodiments of a mold apparatus and an optical element according to the present invention will be described with reference to the drawings.

  1A and 1B are a cross-sectional view and a back view of an imaging lens incorporating an optical element formed by the mold apparatus of the embodiment, and FIG. 1A is a diagram of FIG. It is AA sectional drawing. 2A and 2B illustrate the front and back surfaces of one optical element (specifically, the second lens) constituting the imaging lens. The illustrated imaging lens 100 is incorporated into, for example, a mobile phone or a smartphone.

  The imaging lens 100 includes five lenses, that is, first to fifth lenses 11 to 15 as a plurality of optical elements. These first to fifth lenses (optical elements) 11 to 15 are stacked and fixed or held in the holder 21 while being positioned as a combined lens. Each of the lenses (optical elements) 11 to 15 is an integral product made of resin, and includes a main body portion 10a and a frame portion 10b. The main body portion 10a has optical surfaces 10i and 10j by optical design, but is formed relatively thin by combining five pieces. Each frame portion 10b is an annular member, and has an annular flat portion 10y inside. Each flat portion 10y is formed with a pair of opposed flat surfaces 10d and 10e extending in a direction perpendicular to the optical axis OA. The 1st-5th lenses 11-15 have the projection part 10g in three places of the flat surface 10d on the object side among the flat surfaces 10d and 10e. Each protrusion 10g protrudes in the direction of the optical axis OA and has a hemispherical or dome-shaped outer shape. As shown in FIG. 2A, in the second lens 12, the three projections 10g are formed at angular positions that equally divide the circumference of the frame 10b into three. Similarly, also in the 1st, 3rd-5th lens 11, 13-15, the three projection parts 10g are formed in the angular position which divides the periphery of the frame part 10b into 3 equal parts. In the case of the present embodiment, in the first to fifth lenses 11 to 15, the orientations in which the protrusions 10 g are formed on the respective frame portions 10 b are matched. In other words, referring to FIG. 1B, in the fifth lens 15, the three protrusions 10g are formed in the azimuth or position corresponding to 1 o'clock, 5 o'clock and 9 o'clock on the paper as viewed from the image side. Although not shown in the first to fourth lenses 11 to 14, the three protrusions 10g are formed at azimuths or positions corresponding to 1 o'clock, 5 o'clock, and 9 o'clock of the watch as viewed from the image side. Has been.

  With reference to FIG. 2A, the arrangement of the protrusions 10g in the second lens 12 will be described. In the case of the second lens 12, a gate mark G1 is formed on the right side of the drawing (the direction corresponding to 9 o'clock in the timepiece) and removed by finishing. In the second lens 12, one location on the opposite side of the gate mark G1 (the orientation corresponding to 3 o'clock) of the frame portion 10b is a location G2 where a weld is easily formed. For this reason, the three projections 10g are formed avoiding this location G2. In other words, the three protrusions 10g are provided in the azimuth or position corresponding to 1 o'clock, 5 o'clock, and 9 o'clock on the paper. With such an arrangement, the protrusion 10g can be formed avoiding the weld, and the shape of the protrusion 10g can be made more precise. The location G2 where the weld is likely to be formed is not limited to the opposite side of the gate trace G1, but changes depending on the shape and thickness of the lens. Therefore, the arrangement of the three protrusions 10g can be set individually for each of the second to fifth lenses 12 to 15 when considered in relation to the gate mark G1. Weld formation can be predicted in advance by flow simulation, but can also be confirmed by trial manufacture.

  In the second lens 12, the arrangement of the three protrusions 10g is an arrangement that avoids the pin mark 10h that is the mark of the protruding pin formed at the time of molding. The second lens 12 is formed by injection molding. When the second lens 12 is separated from the mold apparatus, the second lens 12 is extruded by a protruding pin. This protruding pin is a sliding member, and at its tip, there is a gap around it and there is a slight difference in height that becomes convex or concave with respect to the periphery, so there are burrs and steps on the molding surface. Is formed and remains as a pin mark 10h. Here, if the protruding pin is appropriately processed, it is not impossible to form the protruding portion 10g by the protruding pin itself. However, it is not easy to precisely adjust the position of the protruding pin. As described later, the protruding portion 10g is formed by using a dedicated height adjusting pin (that is, a protruding portion pin) provided separately from the protruding pin.

FIG. 3 is a partially enlarged cross-sectional view for explaining relative support between the first lens 11 and the second lens 12. The top portion or the tip portion 10t of the protruding portion 10g protruding from the frame portion 10b of the second lens 12 is in contact with the frame portion 10b of the adjacent first lens 11, and the frame portion 10b of the second lens 12 has an optical axis. The position in the direction of OA is supported by the frame portion 10b of the first lens 11. At this time, the surface 10m of the protrusion 10g is a convex curved surface, is in contact with the flat surface 10e of the frame 10b of the first lens 11, and the flat surface 10e of the frame 10b of the first lens 11 Between the flat surface 10d of the frame portion 10b of the two lenses 12, a gap GA that is separated in the direction of the optical axis OA is formed. This gap GA corresponds to the height h of the protrusion 10g in the optical axis OA direction. A burr 10r is formed around the protrusion 10g due to the joint of the mold, but is sufficiently lower than the height h of the protrusion 10g.
Although only one protrusion 10g is described in FIG. 3, three protrusions 10g having the same shape are formed on the frame 10b of the second lens 12 shown in FIG. The amount of protrusion from the flat surface 10d, that is, the height h is the same, but there may be a slight difference. Further, as described above, the three protrusions 10g are formed at angular positions that divide the circumference of the frame part 10b into three equal parts (see FIG. 2), and the second lens 12 is formed by the three protrusions 10g. Three points are evenly supported on the frame portion 10b of one lens 11. That is, the distance between the first lens 11 and the second lens 12 is appropriately adjusted, and the first lens 11 and the second lens 12 are aligned with no relative inclination.

  The flat surface 10e on the first lens 11 side that is in contact with the surface 10m of the protrusion 10g is selected as a place where no burr is formed. That is, depending on the mold and molding method of the first lens 11, burrs may be formed on the flat surface 10e, but the locations where the protrusions 10g are brought into contact avoid the locations where burrs are formed. It is desirable to make the area free from burrs.

  Steps 11 d and 12 d are formed at corresponding positions on the frame 10 b of the first lens 11 and the frame 10 b of the second lens 12. The steps 11d and 12d have shapes that fit each other, but the step surfaces 11e and 12e are close to each other but not in contact with each other. The steps 11d and 12d enable the first lens 11 and the second lens 12 to be positioned with a certain degree of accuracy in the lateral direction perpendicular to the optical axis OA. In the case of the present embodiment, the first lens 11 and the second lens 12 are precisely aligned in the lateral direction by another method such as using a mark (not shown) separately formed on the lens surface. By adjusting the shape of the steps 11d and 12d and the proximity of the step surfaces 11e and 12e, the positioning accuracy in the lateral direction perpendicular to the optical axis OA of the first and second lenses 11 and 12 by the step surfaces 11e and 12e. Can also be increased.

  In the above description, the distance setting and axis alignment between the first lens 11 and the second lens 12 have been mainly described. However, the distance setting and axis alignment between the second to fifth lenses 12 to 15 shown in FIG. The same is done. That is, the three projections 10 g are also formed on the frame portion 10 b of the third lens 13, and these projections 10 g come into contact with the frame portion 10 b of the second lens 12, so that both the lenses 12 and 13 are in contact with each other. The distance is maintained at a specified value by stable three-point support, and the relative inclination of the optical axis is prevented. Three projections 10 g are also formed on the frame portion 10 b of the fourth lens 14, and these projections 10 g abut on the frame portion 10 b of the third lens 13 so that the distance between the lenses 13 and 14 is increased. The stable three-point support keeps the specified value and prevents relative inclination of the optical axis. Three projections 10g are also formed on the frame portion 10b of the fifth lens 15, and these projections 10g abut on the frame portion 10b of the fourth lens 14 so that the distance between the lenses 14 and 15 is increased. The stable three-point support keeps the specified value and prevents relative inclination of the optical axis.

  The surface on the image side or the object side of the frame portion 10b of the first to fifth lenses 11 to 15 is subjected to graining. Here, the depth or roughness of embossing is, for example, about several tens of μm. As with the flat surfaces 10d and 10e, the surface 10m of the three protrusions 10g is also subjected to a graining process that scatters light. For this reason, it can prevent that the light which passed through the projection part 10g is kept bright, and becomes stray light. That is, for example, even if stray light is incident on the protrusion 10g provided on the frame portion 10b of the second lens 12 from the inside, it is diffused when passing through the surface 10m of the protrusion 10g and is further opposed to the first lens 11 facing the first lens 11. Since it diffuses when it enters the flat surface 10e of the frame part 10b, the influence of stray light can be reduced.

  The above first to fifth lenses 11 to 15 are held in a state of being positioned in the holder 21. The holder 21 has a cylindrical outer peripheral portion 21a and an annular end portion 21b. The outer peripheral portion 21 a exposes the optical surface 10 j of the fifth lens 15, and the end portion 21 b has an opening 21 c that exposes the optical surface 10 i of the first lens 11. The first lens 11 is positioned with respect to the end 21 b of the holder 21. At this time, three protrusions 10 g are formed on the object side of the frame portion 10 b of the first lens 11, and these protrusions 10 g come into contact with the inner surface of the end 21 b of the holder 21 to thereby form the first lens. 11 is positioned with respect to the holder 21 in the direction of the optical axis OA, and the inclination with respect to the optical axis OA is corrected. The first and fifth lenses 11 and 15 are positioned with respect to the holder 21 with respect to a direction perpendicular to the optical axis OA by a step portion 21 g and an inner wall surface 21 h provided on the holder 21. At least the fifth lens 15 or the like among the first to fifth lenses 11 to 15 is fixed to the holder 21 with an adhesive.

  Although illustration is omitted, a diaphragm can be arranged between the first to fifth lenses 11 to 15 using a gap formed between any two adjacent lenses.

  According to the imaging lens 100 of the present embodiment, when a specific lens is fixed to another lens among the first to fifth lenses 11 to 15 that are optical elements constituting the imaging lens 100, the direction 3 toward the optical axis OA is set. The two protrusions 10g enable positioning of these lenses with respect to the interval and inclination in the optical axis OA direction. In particular, when the main body 10a or the like is thin, the lenses 11 to 15 tend to be slightly bent, but the support is easily stabilized by the three-point support using the protrusion 10g. Here, since the surface 10m of the protrusion 10g, in particular, the surface of the tip 10t of the protrusion 10g and the flat surface 10e opposite to the surface are processed, the light incident on the protrusion 10g is refracted and It is possible to prevent stray light from being guided in an unintended direction by reflection.

  Hereinafter, with reference to FIG. 4 etc., the molding method of the second lens 12 shown in FIG.

  A mold apparatus 40 shown in FIG. 4 includes a movable mold 41 and a fixed mold 42, and both molds 41 and 42 can be opened and closed in the axis AX direction with a parting line PL as a boundary. As shown in FIGS. 4 and 5A, the cavity CV, which is a space between the movable mold 41 and the fixed mold 42, is a second lens 12 (FIG. 1A) as an optical element that is a molded product. ))).

  The movable mold 41 includes a transfer portion 51, a mold plate 53, and a mounting plate 54. The movable mold 41 is movable along the axis AX and opens and closes with respect to the fixed mold 42. In the movable mold 41, the transfer portion 51 is disposed to face the transfer portion 61 of the fixed mold 42 in order to form a cavity CV. The mold plate 53 is a mold member that holds the transfer portion 51 from the periphery, and the mounting plate 54 is a mold member that integrally supports the mold plate 53 from behind.

  The fixed mold 42 includes a transfer portion 61, a mold plate 63, and a mounting plate 64. Among these, the transfer portion 61 is disposed to face the transfer portion 51 of the movable mold 41 in order to form the cavity CV. The mold plate 63 is a mold member that holds the transfer portion 61 from the periphery, and the mounting plate 64 is a mold member that integrally supports the mold plate 53 from behind.

  Returning to the movable mold 41, the transfer portion 51 is a plate-like core portion 51a, a cylindrical peripheral mold portion 51b surrounding the core portion 51a, and a plate-like shape disposed on the base side of the core portion 51a and the like. And a support member 51c. An optical surface transfer surface 56a and a flange transfer surface 56b are provided at the tip of the core portion 51a in order to define a cavity CV. The optical surface transfer surface 56a is a curved surface formed at the tip of the core portion 51a, and serves as a transfer surface for molding one optical surface 10i of the second lens 12. The flange transfer surface 56 b is an annular transfer surface that molds one flat surface 10 d of the second lens 12. The optical surface transfer surface 56a is a mirror surface, but the flange transfer surface 56b is subjected to a textured process and has minute irregularities. The peripheral mold part 51b has a through hole 57a for accommodating the core part 51a, and a recess for the gate G and the runner R is formed at an appropriate position on the front end surface. The support member 51c functions as a spacer for the peripheral mold part 51b and the core part 51a.

  A columnar through-hole 57b that is supported by inserting the transfer portion 51 is formed in the template 53 of the movable mold 41. The template 53 has an end face 53a that forms a parting line PL.

  In the movable mold 41, three sliding holes 58q are formed so as to penetrate the peripheral mold portion 51b, the support member 51c, and the mounting plate 54 (see FIGS. 5A and 5B). A projecting pin 58j is inserted into the sliding hole 58q, and can advance and retreat in the axis AX direction within the sliding hole 58q. The protruding pin 58j is driven by an ejector provided behind the movable mold 41 to move forward and backward. That is, a molded product including the second lens 12 on the movable mold 41 side in a state in which the movable mold 41 and the fixed mold 42 are separated by moving the movable mold 41 backward by a drive mechanism (not shown). Remain. The molded product including the second lens 12 can be completely released from the movable mold 41 by extruding the molded product with the protruding pins 58j.

  Three holding holes 58p are formed between the three sliding holes 58q of the peripheral mold portion 51b (see FIGS. 5A and 5B). A height adjusting pin 58i is inserted into the holding hole 58p so as to be embedded in the recess. The height adjustment pin 58i is supported by the mounting plate 54 via a spacer 59p on the base side, for example (see FIG. 4), and is fixed in the holding hole 58p. The spacer 59p can be replaced and the height position of the tip of the height adjustment pin 58i can be adjusted. However, the height of the tip of the height adjustment pin 58i can be adjusted by replacing the height adjustment pin 58i itself. The position can also be adjusted.

  As shown in an enlarged view in FIG. 6, the tip end portion 59a of the height adjusting pin 58i is embedded in the tip end portion 59s of the holding hole 58p. The tip portion 59a is formed in a concave curved surface (specifically, a concave hemispherical surface) having a deep center and a shallow periphery, and the tip surface 59b which is the surface thereof is subjected to embossing. The leading end surface 59b is a part of the flange transfer surface 56b. The shape of the front end surface 59b of the height adjustment pin 58i is a concave portion 59z obtained by inverting the projection 10g provided on the second lens 12 or the like, and the projection 10g is transferred by the transfer of the front end surface 59b of the height adjustment pin 58i. It is formed. Here, the gap G3 existing between the height adjustment pin 58i and the holding hole 58p is extremely small and is difficult for molten resin to enter. For this reason, in the second lens 12 or the like that is a molded product, it is difficult to form the burr 10r (see FIG. 3) around the protrusion 10g, and even if the burr 10r is formed, the height 10h of the protrusion 10g is larger than that. It will be low enough. That is, the concave front end surface 59b of the height adjustment pin 58i functions as a burr escape. The height adjustment pin 58i can be adjusted in height. Thereby, the front end surface 59b of the height adjustment pin 58i can also be arrange | positioned in the position as shown with a dotted line. In this case, in the second lens 12 or the like that is a molded product, the height h of the protrusion 10g is slightly increased. The depth adjustment amount of the recess 59z by the height adjustment pin 58i is finely adjusted in a range of about 10 μm and an interval of about 0.2 μm, assuming that the diameter of the protrusion 10g is 0.1 mm, for example. The height adjustment of the height adjustment pin 58i is achieved by changing the thickness of the spacer 59p that is replaceably disposed on the rear end portion 59n side. A large number of spacers 59p are prepared as having different thicknesses by subjecting a plate-like substrate to mechanical polishing or thin film deposition. Here, the height position of the tip surface 59b of one or two specific height adjustment pins 58i is not adjusted to increase or decrease uniformly all the height positions of the tip surfaces 59b of the three height adjustment pins 58i. In this case, tilt adjustment is possible.

  For adjusting the height h of each projection 10g, the height and inclination of each lens 11-15 are measured in a state where the first to fifth lenses 11-15, which are prototyped, are stacked to form a combined lens. This can be achieved by feeding back the result and shaping. In this case, it is possible to obtain the imaging lens 100 including a combined lens adapted for actual use.

  Returning to FIG. 4, in the fixed mold 42, the transfer portion 61 is disposed on the base side of the shaft-shaped core portion 61 a, the cylindrical peripheral mold portion 61 b surrounding the core portion 61 a, the core portion 61 a and the like. And a plate-like support member 61c. At the tip of the core portion 61a, an optical surface transfer surface 66a and a flange transfer surface 66b are provided to define a cavity CV. The optical surface transfer surface 66a is a curved surface formed at the tip of the core portion 61a, and serves as a transfer surface for molding the other optical surface 10j of the second lens 12. The flange transfer surface 66 b is an annular transfer surface that molds the other flat surface 10 e of the second lens 12. The optical surface transfer surface 66a is a mirror surface, but the flange transfer surface 66b is subjected to embossing and has minute irregularities. The peripheral mold part 61b has a through hole 67a for accommodating the core part 61a, and a concave part for the gate G and the runner R is formed at an appropriate position of the front end surface. The support member 61c functions as a spacer for the peripheral mold part 61b and the core part 61a.

  The mold plate 63 of the fixed mold 42 is formed with a cylindrical through hole 67b that is supported by inserting the transfer portion 61 therein. The template 63 has an end face 63a that forms a parting line PL.

  According to the mold apparatus 40 of the present embodiment, since the three concave portions 59z are formed as a part of the flange transfer surface 56b, projections are made at three locations in the frame portion 10b toward the optical axis OA when molding the second lens 12 and the like. Part 10g can be formed. These three protrusions 10g enable positioning with respect to the optical axis OA direction and inclination when the second lens 12 and the like are fixed to other lenses. In particular, when the main body 10a or the like is thin, the lenses 11 to 15 tend to be slightly bent, but the support is easily stabilized by the three-point support using the protrusion 10g. Here, since the depth of the three concave portions 59z formed in the mold apparatus 40 can be adjusted by the height adjusting pin 58i embedded in the concave portion 59z, projections are formed in comparison with the case of engraving in the mold. The height of the portion 10g can be easily adjusted, and the assembly accuracy of the second lens 12 and the like can be easily increased.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the optical element constituting the imaging lens 100 is not limited to five grouped lenses, but can be a grouped lens according to the purpose, or a single lens configuration (FIG. 7). reference).

  In the above description, in the frame portion 10b of each lens (optical element) 11-15, the protrusion 10g is provided on the object-side flat surface 10d, but the image-side flat surface 10e of the first lens (optical element) 11 or the like. It is also possible to provide a protrusion 10g (see FIG. 8). Further, the protrusions 10g can be provided on the object side and the image side of the specific lens.

  The shape of the protrusion 10g is not limited to a hemispherical shape as long as it enables contact support at a point or a short line segment. For example, as shown by a solid line or a dotted line in FIG. 9, the protruding portion 10 g may be elliptical. Furthermore, the surface of the protrusion 10g may have a flat surface as well as a spherical surface, and can have a surface shape that forms a trapezoidal cross section, for example (see FIG. 10). The size of the protruding portion 10g is not limited to that shown in the drawing, and can be changed or adjusted as appropriate according to the lens size and application.

  In the above, the second lens 12 and other optical elements are released by the protruding pins 58j. However, the optical elements can also be released by protruding the core portion 51a and the like (see FIG. 11).

  The tip end surface 59b of the height adjusting pin 58i is not limited to the embossing process, but can be provided with a light blocking effect due to scattering by other roughening methods.

  The azimuths or positions where the three protrusions 10g in the first to fifth lenses 11 to 15 are arranged do not necessarily coincide with each other, and the azimuths or positions of the protrusions 10g between adjacent or distant lenses are different. Also good. Furthermore, in the above-described embodiment, the radial position where the protruding portion 10g is arranged is different for each lens. However, the radial position where the protruding portion 10g is arranged in a plurality of adjacent or separated lenses can be matched.

  It is not necessary to adjust the interval and inclination by providing three projections 10g between all the lenses 11 to 15, and to adjust the interval and inclination by providing a protrusion between two or three specific lenses. Can do. That is, for a lens that is not so sensitive, height adjustment and tilt adjustment by the protrusion 10g are not necessary.

  Although the distance and inclination adjustment of the lenses 11 to 15 have been described above, the protrusion 10g as described above can be used to adjust the distance and inclination of other optical elements. The lens as the optical element is not limited to the imaging lens, and for example, the projection can be provided on an array lens or a communication lens.

  CV ... cavity, G ... gate, G1 ... gate mark, GA ... gap, OA ... optical axis, PL ... parting line, 11-15 ... lens, 10a ... main body, 10b ... frame, 10d, 10e ... flat surface 10g: Projection part, 10h: Pin mark, 10i, 10j ... Optical surface, 10r ... Burr, 10t ... Tip part, 10y ... Flat part, 21 ... Holder, 21a ... Outer peripheral part, 21b ... End part, 21c ... Opening, DESCRIPTION OF SYMBOLS 40 ... Mold apparatus, 41 ... Movable mold, 42 ... Fixed mold, 51 ... Transfer part, 53 ... Mold plate, 54 ... Mounting plate, 56a ... Optical surface transfer surface, 56b ... Flange transfer surface, 57a ... Through-hole, 58i ... Height adjusting pin, 58j ... Projecting pin, 58p ... Holding hole, 58q ... Sliding hole, 59a ... Tip part, 59b ... Tip surface, 59p ... Spacer, 59z ... Concave 61: transfer portion, 63: template, 64 ... mounting plate, 66a ... optical surface transfer surface, 66b ... flange transfer surface, 67a ... through hole, 100 ... imaging lens

Claims (6)

A mold apparatus for molding an optical element having a main body portion and a frame portion,
In order to form protrusions at three locations in the frame portion toward the optical axis direction, it has three recesses as a part of the transfer surface,
The three recesses can be adjusted in depth by pins embedded in the recesses ,
The tip end surface of the pin corresponding to the bottom of the concave portion is subjected to a texture processing,
The mold apparatus is characterized in that the bottom of the recess is formed in a curved surface having a deep center and a shallow periphery . The mold apparatus according to claim 1 , wherein the frame portion includes a flat portion that extends flatly around the main body portion, and the protrusion protrudes from a flat surface that extends perpendicularly to the optical axis direction. The mold apparatus according to claim 1, wherein the mold apparatus is used to mold an optical element used alone. The mold apparatus according to any one of claims 1 to 3 , wherein the optical element is released by a pin protrusion or a core protrusion. The mold apparatus according to claim 4 , wherein the pin protruding is performed by a protruding pin provided separately from the pin. A main body and a frame,
The frame portion has projections at three locations in the optical axis direction,
The tip surface of each protrusion is subjected to graining ,
The top part of each said protrusion part is formed in the curved surface with a high center, The optical element characterized by the above-mentioned.

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