JP7111569B2 - OPTICAL ELEMENT, OPTICAL ELEMENT MANUFACTURING METHOD AND OPTICAL ELEMENT MOLD - Google Patents

Description

The present invention relates to an optical element used, for example, in optical communication, a method for manufacturing the optical element, and a mold for molding the optical element.

2. Description of the Related Art As an example of a method for manufacturing an optical element and an optical element, a square lens is known as described in Patent Document 1.
This method of manufacturing an optical element is a method of manufacturing an optical element including a lens surface by cooperating a first mold and a second mold to pressure-mold a material. , the shape of the cross section of the internal space of the second mold in the mold clamping direction in the internal space is square, and the mold clamping of the first mold in the internal space of the second mold the shape of the cross section with respect to the direction is circular, and the first mold enters into the internal space of the second mold to pressure-mold the material to form the lens surface; 3, the material protrudes from the gap between the first mold and the second mold around the lens surface during pressure molding to form a protruding portion.

Further, the optical element is an optical element including a prismatic main body and lens sections formed on upper and lower surfaces of the main body, wherein the leg sections are formed on the side surfaces of the main body and and a protruding portion formed at each corner of the upper surface or the lower surface and protruding in the thickness direction of the lens portion.

Such an optical element is mounted on an optical connection device 50, for example, as shown in FIG. The optical connection device 50 includes an optical element 1, a flat bench 51 on which the optical element 1 is mounted and bonded via the side surface 1a, a laser diode 52 for making output light incident on the optical element 1, and a laser diode 52. and an optical fiber (not shown) into which the light emitted from the optical element 1 is incident. A block member 53 is installed adjacent to the optical element 1 and a laser diode 52 is attached to the block member 53 .

The output light from the laser diode 52 is refracted by the lens portions 2 and 3 of the optical element 1 and then enters the light incident surface of the optical fiber (not shown).
The optical element 1 also has four projections 4 to increase the areas of the side surfaces 1a and 1b. Therefore, when the optical element 1 is adhered to the flat bench 51 with an adhesive, the adhesion area increases, so that the adhesion can be performed more firmly.

Japanese Patent No. 5074017

By the way, in the conventional optical element, since the center of the substantially rectangular plate-like main body and the optical axis are aligned, a plurality of optical elements are mounted (surface mounted) on the mounting surface such as the flat bench described above, for example. In this case, the heights of the optical axes of the lens portions from the four side surfaces that serve as the mounting surfaces are all equal.
For this reason, if you want to mount multiple optical elements on the mounting surface of the flat bench and make the height of the optical axis of the lens part of each optical element different, among the optical elements, glue them to the mounting surface of the flat bench. It is necessary to lower the optical axis by cutting the side surface on the side where it is applied, and to raise the optical axis by inserting a spacer between the side surface and the mounting surface of the flat bench. Attaching the optical element to the surface, that is, mounting the optical element requires time and effort.

In addition, the conventional optical element has projections at the four corners of the upper and lower surfaces, respectively. In addition, when the optical element is mounted on the flat bench, the center of gravity tends to move away from the flat bench due to the upper protrusion, which tends to cause instability.

Furthermore, since the optical element is to be surface-mounted on the mounting surface of the flat bench, it is necessary to grasp the optical element with the grip of the mounting device, convey it to the flat bench, and place it on the flat bench.
However, the above-described conventional optical element has a lens portion in the center of a substantially rectangular plate-shaped main body, and projections at four corners of the upper and lower surfaces, respectively. Some parts cannot be easily grasped. In other words, when an attempt is made to grip a portion of the optical element on the side opposite to the surface to be placed on the flat bench with the gripping portion, the protruding portion on this portion interferes with the gripping portion, making it difficult to grip the optical element in some cases. becomes difficult to implement.

The present invention has been made in view of the above circumstances, and provides an optical element, a method for manufacturing an optical element, and a mold for molding an optical element, which can be easily mounted and can be downsized and stabilized in mounting. intended to provide

In order to solve the above-described problems, an optical element of the present invention is formed in a substantially rectangular plate shape and has a main body portion having four side surfaces, an upper surface and a lower surface, and a main body portion formed on the upper surface and the lower surface, respectively. An optical element having a lens portion,
the optical axis of the lens portion is eccentric to one of the four side surfaces with respect to a central axis passing through the upper and lower surfaces of the main body;
Two other side surfaces that are adjacent to the one side surface in a direction perpendicular to the one side surface are closer to the one side surface side.

In the present invention, the optical axis of the lens portion is eccentric to one of the four side surfaces of the main body with respect to the central axis passing through the upper and lower surfaces of the substantially rectangular plate-shaped main body. By adjusting the amount of eccentricity, the height of the optical axis of the lens section from the mounting surface of the flat bench or the like can be adjusted.
Therefore, when it is desired to mount a plurality of optical elements on the mounting surface of a flat bench or the like and to make the height of the optical axis of the lens part of each optical element different, the There is no need to lower the optical axis by cutting the side surface on the receiving side or inserting a spacer between the side surface and the mounting surface of the flat bench to raise the optical axis. The other side surface opposite to is attached to the attachment surface as it is. Therefore, the optical element can be easily mounted.

In addition, since there is no protruding portion on the non-surface-mounted side of the main body, it is possible to downsize the optical element and stabilize mounting. You can grab it and implement it.

Further, in the above configuration of the present invention, a protrusion projecting in the thickness direction of the main body is provided at the corner located on the one side surface of the corners of the upper surface and the lower surface of the main body. may have been

According to such a configuration, of the corners of the main body, the corner located on the side of one side is provided with a protruding portion that protrudes in the thickness direction of the main body. The area can be increased, and when the device is installed on a mounting surface such as a flat bench, the projection can stabilize the installation.

Further, in the above configuration of the present invention, among the corners of the upper surface and the lower surface of the main body, the corners located on the other side surface opposite to the one side surface are provided with the upper surface and the lower surface and the An R surface may be formed to smoothly connect the other side surfaces.

According to such a configuration, since the corner portion located on the other side surface side of the main body portion is formed with the rounded surface that smoothly connects the upper and lower surfaces of the main body portion and the other side surface, the optical element can be At the time of mounting, the upper and lower surfaces of the other side surface of the main body can be easily gripped by the gripping portion of the mounting device, so that the optical element can be easily mounted.

Further, in the method for manufacturing an optical element of the present invention, the first mold and the second mold work together to pressure-mold the material in the cavity of the second mold to form the lens part. An optical element manufacturing method for manufacturing an optical element,
The cross-sectional shape of the cavity is a quadrangle,
The first mold is formed in a substantially quadrilateral plate shape having a lens molding portion for molding the lens portion on a surface facing the cavity side, and four corner portions each having an arcuate cross-sectional shape centered on one axis. and configured so that four side surfaces are in contact with four inner wall surfaces forming the cavity,
The first mold is arranged in the cavity with the axis eccentric from the center of the cavity toward one inner wall surface,
In the cavity, the material is press-molded by the first mold to form a substantially rectangular plate-shaped main body and the lens provided in the main body. an axis eccentric to one of the four side surfaces with respect to a central axis passing through the upper and lower surfaces of the main body;
It is characterized by forming an optical element in which two other side surfaces that are adjacent to the one side surface in a direction perpendicular to the one side surface are closer to the one side surface.

INDUSTRIAL APPLICABILITY In the present invention, it is possible to easily manufacture an optical element that can be easily mounted, downsized, and stabilized in mounting.

Further, in the above configuration of the present invention, when pressure molding the material, a gap between two corners of the first mold located on the one inner wall surface side and the inner wall surface forming the cavity is A part of the material may protrude from the gap to form a protruding portion protruding in the thickness direction of the main body portion.

According to such a configuration, since a protrusion projecting in the thickness direction of the main body is formed at a corner located on one side of the main body, the one side can be used as a mounting surface of a flat bench or the like. When installing, the projection can stabilize the installation.

Further, in the optical element molding die of the present invention, the lens portion is formed by pressure-molding the material in the cavity of the second die in cooperation with the first die and the second die. An optical element molding die for manufacturing an optical element having
The cross-sectional shape of the cavity is a quadrangle,
The first mold is formed in a substantially rectangular plate shape having a lens molding portion for molding the lens portion on a surface facing the cavity side, and four corner portions each having an arcuate cross section centered on one axis. and configured such that four side surfaces are in contact with four inner wall surfaces forming the cavity,
The first mold is arranged in the cavity with the axis eccentric from the center of the cavity toward one inner wall surface side.

INDUSTRIAL APPLICABILITY In the present invention, it is possible to easily manufacture an optical element that can be easily mounted, downsized, and stabilized in mounting.

Further, in the above configuration of the present invention, when pressure molding the material between two corners of the first mold located on the one inner wall surface side and the inner wall surface forming the cavity, , a space into which a part of the material flows may be provided.

According to such a configuration, since a part of the material flows into the space, a projection projecting in the thickness direction of the main body is formed at the corner located on one side surface of the main body. Therefore, when one side surface is installed on a mounting surface such as a flat bench, the installation can be stabilized by the protruding portion.

According to the present invention, it is possible to provide an optical element, a method for manufacturing an optical element, and a mold for molding an optical element, which can be easily mounted and can be downsized and stabilized in mounting.

BRIEF DESCRIPTION OF THE DRAWINGS The optical element which concerns on embodiment of this invention is shown, (a) is a top view (top view), (b) is a bottom view (bottom view). Similarly, (a) is a view on arrow A in FIG. 1A (a), (b) is a view on arrow B in FIG. 1A (a), (c) is a view on arrow C in FIG. 1A (a), (d) is a D arrow directional view in FIG. 1A (a). BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows the mold for optical element molding which concerns on embodiment of this invention. The first die fixed to the punch portion is also shown, (a) is a perspective view, (b) is a plan view, and (c) is an enlarged plan view of the first die. Similarly, (a) is a view on arrow A in FIG. 3A (a), and (b) is a view on arrow B in FIG. 3A (a). It is a top view of a 2nd metal mold|die equally. It is a plane cross-sectional view of the mold for molding an optical element of the same. It is a longitudinal cross-sectional view showing a state in which a preform is inserted between an upper mold and a lower mold. It is a plane sectional view which shows the molded optical element with a 2nd metal mold|die similarly. 1 is a diagram showing a schematic configuration of an optical connection device using a conventional optical element; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The optical element of this embodiment is used in optical communication, and is surface-mounted on the mounting surface of a silicon bench (flat bench) of an optical connection device, for example.

As shown in FIGS. 1A and 1B, the optical element 10 of this embodiment is a square lens including a body portion 11 and lens portions 12, 12, and is made of glass. Although glass lenses are more expensive to manufacture than plastic lenses, they can be used for lenses that require high durability and precision.
The main body 11 is made of a glass material and has a substantially square plate shape, and has an upper surface 13 , a lower surface 14 , and four side surfaces 15 , 16 , 17 , 18 . An upwardly convex lens portion 12 is formed integrally with the main body portion 11 on the upper surface 13 , and a downwardly convex lens portion 12 is formed integrally with the main body portion 11 on the lower surface 14 . These lens portions 12, 12 have an aspherical shape that is rotationally symmetrical about the optical axis O1, and the respective optical axes O1 of the upper and lower lens portions 12, 12 are aligned.
When viewed from the direction of the optical axis O1, curved surfaces connecting the side surfaces 15 and 16, the side surfaces 16 and 17, the side surfaces 17 and 18, and the side surfaces 18 and 15 are on the same circle centered on the optical axis O1. That is, when viewed from the direction of the optical axis O1, the radii of curvature of the curved surfaces are the same, and the centers of the curved surfaces are the same.

Further, the optical axis O1 of the lens portions 12, 12 is biased toward one side surface 17 among the four side surfaces 15, 16, 17, 18 with respect to the central axis O2 passing through the upper surface 13 and the lower surface 14 of the body portion 11. I have a heart Also, the optical axis O1 is located in the central portion between the opposing side surfaces 16 and 18 of the body portion 11 . Therefore, the lens portions 12, 12 are arranged closer to the side surface 17 between the side surfaces 15, 17 facing one of the main body portions 11, and are arranged closer to the side surface 16 between the other side surfaces 16, 18 facing each other. , 18 equidistant from each other.

Here, the central axis O2 of the body portion 11 is defined by a line segment S1 passing through the center between the side surfaces 15 and 17 on one side of the body portion 11 and a line segment S2 passing through the center between the side surfaces 16 and 18 on the other side of the body portion 11 . and extending in the thickness direction of the body portion 11 (the direction perpendicular to the paper surface in FIG. 1A, the vertical direction in FIGS. 2B (b) and (d)), and is parallel to the optical axis O1 .

Further, the other two side surfaces 16 and 18 that are adjacent to the one side surface 17 of the body portion 11 in the direction perpendicular to the side surface 17 are closer to the one side surface 17 side.
That is, as shown in FIG. 1B(b), the side surface 16 includes a substantially rectangular side portion 16a and a substantially triangular triangular side portion 16b formed continuously from the rectangular side portion 16a. The area of the rectangular side portion 16a is larger than that of the triangular side portion 16b. Also, the shortest distance between the rectangular side portion 16 a and the side surface 17 is shorter than the shortest distance between the triangular side portion 16 b and the side surface 15 when viewed from the B direction. Therefore, the side surface 16 has a larger area on the side surface 17 side and is closer to the side surface 17 side. Also, the side surfaces 16 are positioned at equal distances from the top surface 13 and the bottom surface 14 .

Further, as shown in FIG. 1B(d), the side surface 18 includes a substantially rectangular rectangular side portion 18a and a substantially triangular triangular side portion 18b formed continuously from the rectangular side portion 18a. The rectangular side portion 18a has a larger area than the triangular side portion 18b. Also, the shortest distance between the rectangular side portion 18 a and the side surface 17 is shorter than the shortest distance between the triangular side portion 18 b and the side surface 15 when viewed from the D direction. Therefore, the side surface 18 has a larger area on the side surface 17 side and is closer to the side surface 17 side. Also, the side surfaces 18 are positioned at equal distances from the top surface 13 and the bottom surface 14 .

Further, as shown in FIGS. 1B(a) and 1B(c), the side surface 15 of the body portion 11 and the side surface 17 separated parallel to the side surface 15 are formed in an elliptical shape, and the side surface 17 is the side surface. It has a larger area than 15. Sides 15 and 17 are arranged at equal distances from upper surface 13 and lower surface 14 and are arranged at equal distances from side surfaces 16 and 18 when viewed from direction A or D.

Furthermore, the side surfaces 15 and 16 of the main body 11 that are adjacent to each other in the direction perpendicular to each other are connected by a smooth curved surface, and the side surfaces 16 and 17 that are adjacent in the direction perpendicular to each other are connected by a smooth curved surface and are adjacent to each other in the direction of the right angle. The side surfaces 17 and 18 are connected by a smooth curved surface, and the side surfaces 18 and 15 adjacent in the perpendicular direction are connected by a smooth curved surface.

Protrusions 20 , 20 protruding in the thickness direction of main body 11 are provided at the corners of upper surface 13 and lower surface 14 of main body 11 that are located on the side of one side surface 17 .
That is, as shown in FIGS. 1B(b) and 1B(d), the projecting portions 20, 20 rise from the upper surface 13 and the lower surface 14 outside the lowest position of the lens surface of the convex lens portions 12, 12. The upper end is formed in an arc shape when viewed from the side. The protrusions 20, 20 shown in FIGS. 1B (b) and (d) have a continuous shape, and the height corresponding to the distance from the lens optical axis O1 when viewed from the lens optical axis O1 direction. have. That is, the height of the projecting portion 20 increases as the distance from the lens optical axis O1 decreases. Further, in the present embodiment, the highest apex of the protruding portion 20 is formed at a position close to the side surface 17 on the line segment S2 in FIG. higher than the apex. Therefore, it becomes possible to protect the lens portion 12 by the projecting portion 20 . For example, it is possible to prevent the lens portion 12 from being scratched by accidentally rolling the optical element 10 during setting. In addition, it is possible to prevent the lens portion 12 from being damaged due to the contact of the lens portion 12 with other components during setting.
Further, as shown in FIG. 1A, the outer edges of the protruding portions 20, 20 are formed in an arc shape that smoothly connects the side surface 17 and the side surfaces 16, 18 in plan view and bottom view.

In addition, of the corners of the upper surface 13 and the lower surface 14 of the main body 11 , the upper surface 13 and the lower surface 14 and the other side surface 15 slide at the corners located on the other side surface 15 side opposite to the one side surface 17 side. An R surface is formed that connects to the empty. That is, as shown in FIGS. 1B(b) and 1B(d), the R surfaces 21 and 21 are formed between the upper surface 13 and the lower surface 14 and the other side surface 15 in an arcuate shape in a side view. As shown, in plan view and bottom view, the side surface 15 and side surfaces 16 and 18 are formed in an arc shape that smoothly connects.
Further, the upper surface 13 and the four side surfaces 15 to 18 of the main body 11 are connected by smooth curved surfaces, and the lower surface 14 and the four side surfaces 15 to 18 are also connected by smooth curved surfaces.

Next, an optical element molding die 30 for manufacturing (molding) the optical element 10 described above will be described.
FIG. 2 is a longitudinal sectional view of the optical element molding die 30. As shown in FIG. The mold 30 for molding an optical element includes a pair of upper and lower first molds 31 , 31 provided facing each other vertically, and a sleeve-shaped second mold 32 having a cavity 33 .
In such a mold 30 for molding an optical element, the first molds 31, 31 and the second mold 32 work together to pressure-mold the material M in the cavity 33 of the second mold 32. Thus, an optical element 10 having lens portions 12, 12 is manufactured.

As shown in FIGS. 3A, 3B, and 4, the first mold 31 is formed in a substantially rectangular plate shape, and four corners 31e, 31e, 31f, and 31f are centered on one axis O3. The cavity 33 is formed to have an arcuate cross section, and four side surfaces 31a, 31b, 31c and 31d are configured to contact four inner wall surfaces 33a, 33b, 33c and 33d forming the cavity 33. As shown in FIG. Further, the arc length of the cross section of the corner portion 31e is longer than the arc length of the cross section of the corner portion 31f.
The surface of the first mold 31 facing the cavity 33 side has a lens molding portion 34 for molding the lens portion 12 . The lens molding portion 34 is formed in a substantially circular shape in plan view and in a concave curved surface. The center of the lens molding portion 34 is positioned on the axis O3 in plan view. That is, in a plan view, the center of the lens molding portion 34 coincides with the centers of the arcs of the four arc-shaped corners 31e, 31e, 31f, and 31f.
In addition, the mold surface including the four side surfaces 31a, 31b, 31c, 31d and the corners 31e, 31e, 31f, 31f of the first mold 31 and the lens forming part 34 is smoothly continuous (not shown). A C plane is formed.

Such a first mold 31 is used by being fixed to the tip surface of the punch portion 35 . The punch portion 35 includes a columnar fixed portion 35a and a disk-shaped flange portion 35b integrally formed at the proximal end portion of the fixed portion 35a in the axial direction. is fixed.
In addition, as shown in FIG. 2, since the first mold 31 is arranged as a pair of upper and lower molds facing each other, the punch portions 35, 35 are arranged to face each other, and the fixing portions 35a, 35a and 35a of the punch portions 35, 35 are arranged to face each other. The first molds 31, 31 are fixed to face the tip surface of 35a.

As shown in FIG. 2, the second mold 32 is formed in a substantially cylindrical shape, and is provided with cylindrical inserted portions 32a on the inner hollow sides of the upper and lower ends thereof. A fixed portion 35a of a punch portion 35 to which the first die 31 is fixed is inserted into the 32a. Further, the insertion amount (insertion length) of the fixed portion 35a into the inserted portion 32a is determined by the contact of the tip surface of the fixed portion 35a with the bottom surface of the inserted portion 32a. That is, the thickness of the optical element 10 to be pressure-molded is determined.
Then, the fixed portions 35a, 35a of the upper and lower punch portions 35, 35 are inserted into the inserted portion 32a, the upper and lower first molds 31, 31 are arranged in the cavity 33 of the second mold 32, and the cavity 33 The optical element 10 is formed by pressure-molding the material M with the upper and lower first molds 31 , 31 .

Further, as shown in FIG. 5, in a state in which the first mold 31 is placed in the cavity 33 of the second mold 32, the four side surfaces 31a, 31b, 31c, 31d of the first mold 31 are , four inner wall surfaces 33a, 33b, 33c, and 33d forming the cavity 33. Further, the first mold 31 extends the axis O3 in the cavity 33 from the center O4 of the cavity 33 to one inner wall surface 33c side. It is arranged eccentrically. Here, as shown in FIG. 4, the center O4 of the cavity 33 is a line segment S3 passing through the center of one opposing side of the quadrangle forming the cavity 33 in plan view, and a line segment S3 passing through the center of the other opposing side. It is the intersection with the line segment S4.

Further, as shown in FIG. 5, the distance L1 between the center O3 of the lens molding portion 34 and the inner wall surface 33c is shorter than the distance L2 between the center O3 and the inner wall surface 33a. is equal to the distance L3 between the center O3 and the inner wall surface 31d. Furthermore, the distance L3 between the center O3 and the inner wall surface 31b is longer than the distance L1 between the center O3 and the inner wall surface 33c, and the distance L2 between the center O3 and the inner wall surface 33a is greater than the distance L2 between the center O3 and the inner wall surface. 31b is longer than the distance L3. That is, L2>L3>L1.
Also, the material M is pressed between the two corners 31f, 31f of the first mold 31 located on the one inner wall surface 33c side of the cavity 33 and the inner wall surfaces 33b, 33c, 33d forming the cavity 33. Spaces 38, 38 are provided into which part of the material M flows during molding.

Next, a method for manufacturing (molding) the optical element 10 using the optical element molding die 30 described above will be described.
First, as shown in FIG. 6, when the upper first mold 31 (hereinafter also referred to as the upper mold 31) moves upward to open the mold, a predetermined volume of material M is formed. A preform P is put into the cavity 33 of the second mold 32 .
That is, the spherical preform P is placed on the lens forming portion 34 of the lower first mold 31 (hereinafter also referred to as the lower mold 31). In this case, as shown in FIG. 5, the lower mold 31 is arranged in the cavity 33 with the axis O3 eccentric from the center O4 of the cavity 33 toward the inner wall surface 33c. The portion 34 is close to one inner wall surface 33c. That is, the distance from the inner wall surface 33c of the cavity 33 to the lens molding portion 34 is shorter than the distance from the inner wall surface 33a. Further, the distance from the inner wall surfaces 33b and 33d of the lens molding portion 34 is shorter than the distance from the inner wall surface 33c. Furthermore, the distances from the inner wall surfaces 33b and 33d of the cavity 33 of the lens molding portion 34 are equal.
Therefore, the distance from the inner wall surface 33c of the preform P placed on the lens molding portion 34 is shorter than the distance from the inner wall surface 33a, and the distance from the inner wall surfaces 33b and 33d is the distance from the inner wall surface 33c. It is longer, and the distance from the inner wall surface 33a is longer than the distances of the inner wall surfaces 33b and 33d.

Thereafter, by lowering the upper mold 31 , the preform P placed on the lens molding portion 34 of the lower mold 31 is pressed in the cavity 33 by the upper mold 31 and the lower mold 31 .
As the pressurization progresses, the preform P is deformed so as to be crushed from above and below by the upper mold 31 and the lower mold 31, and the outer peripheral surface of the preform P contacts the lens molding portion 34 of the upper mold 31. The upper surface and the lower surface of the optical element 10 are formed by the mold surface including these molding surfaces in close contact with the molding surface including the lens molding surface and the lens molding surface of the lower mold 31 .
Further, as the preform P is deformed so as to be crushed from above and below, it is also expanded in the horizontal direction, and the outer peripheral surface of the preform P forms four inner wall surfaces 33a, 33b, 33c forming a cavity 33. , 33d.

Then, as shown in FIG. 2, the tip surface of the fixed portion 35a of the punch portion 35 to which the upper die 31 is fixed comes into contact with the bottom surface of the inserted portion 32a of the second die 32, whereby pressure is applied. Finished, the optical element 10 is molded.
At this time, since the distance from the inner wall surface 33c of the cavity 33 is shorter than the distance from the inner wall surface 33a of the preform P, the optical element 10 formed by pressure-molding the preform P has a shape as shown in FIG. , the contact area with the inner wall surface 33c is wider than the contact area with the inner wall surface 33a. In addition, since the distance from the inner wall surface 33c of the preform P is shorter than the distance from the inner wall surfaces 33b and 33d, the optical element 10 formed by pressure-molding the preform P cannot contact the inner wall surface 33c. The area becomes wider than the contact area with the inner wall surfaces 33b and 33d. Furthermore, since the distance from the inner wall surfaces 33b and 33d of the preform P is shorter than the distance from the inner wall surface 33a, the optical element 10 formed by pressure-molding the preform P does not extend to the inner wall surfaces 33b and 33d. becomes wider than the contact area with the inner wall surface 33a.
Also, the preform P comes into contact with the inner wall surfaces 33b and 33d while leaning toward the inner wall surface 33c.

Therefore, in the molded optical element 10, as shown in FIG. 1B, the side surface 17 of the substantially rectangular plate-like main body 11 has a larger area than the side surface 15, and the side surfaces 16 and 18 have a smaller area than the side surface 17 and the side surface 15 has a larger area than the side surface 15. Larger area. Moreover, the side surfaces 16 and 18 are close to the side surface 17 side. Also, the side surfaces 15 and 17 are equidistant from the side surfaces 16 and 18 .
Further, as shown in FIG. 1A , lens portions 12 are provided on the upper surface 13 and the lower surface 14 of the main body portion 11, respectively, and the optical axis O1 of the lens portion 12 extends along the central axis O2 passing through the upper surface 13 and the lower surface 14 of the main body portion 11. As shown in FIG. 1B, the other two side surfaces 16 and 18 adjacent to the one side surface 17 in the direction perpendicular to the one side surface 17 lean toward the one side surface 17 side.

Furthermore, as shown in FIG. 5, between the two corners 31f, 31f of the first molds 31, 31 positioned on the one inner wall surface 33c side and the inner wall surfaces 33b, 33c, 33d forming the cavity 33 are provided with spaces 38, 38 into which a part of the material M forming the preform P flows. In addition, the mold surface including the four side surfaces 31a, 31b, 31c, 31d and the corners 31e, 31e, 31f, 31f of the first mold 31 and the lens forming part 34 is smoothly continuous (not shown). A C plane is formed.
Therefore, when the preform P is pressure-molded, the preform P first reaches the inner wall surface 33c closest to the axis O3 corresponding to the optical axis, and forms the side surface 17 of the main body 11 while forming the C surface. After that, part of the material M flows into the spaces 38, 38, and the protrusions 20 projecting in the thickness direction of the main body 11 are formed.
That is, the spaces 38, 38 are horizontally surrounded by the two corners 31f, 31f of the first molds 31, 31 and the inner wall surfaces 33b, 33c, 33d forming the cavity 33. Since the expansion in the direction is restricted, part of the material M that has flowed into the space 38 flows in the spaces 38, 38 in the vertical direction, and the protruding portions 20, 20 that protrude in the thickness direction of the body portion 11. is formed.
Further, the protrusion formed on the C plane and the protrusions formed in the spaces 38, 38 are formed continuously, and the protrusion formed on the C plane and the protrusions formed in the spaces 38, 38 are formed continuously. The shape of depends on the thickness of the lens, the distance between the spaces 38, 38 and O3, the size of the C plane, etc., and the highest vertex may be a protrusion formed on the C plane. It may also be a formed protrusion.

Also, between the two corners 31e, 31fe of the first molds 31, 31 located on the side of the other inner wall surface 33a facing the one inner wall surface 33c, and the inner wall surfaces 33b, 33a, 33d forming the cavity 33 Spaces 39, 39 are formed in .
However, as the preform P is loaded with a predetermined volume, the spaces 38 and 38 are closer to the preform P than the spaces 39 and 39. After flowing in and contacting the inner wall surface 33a by a predetermined area, it does not flow into the spaces 39, 39, or does not fill the spaces 39, 39 even if it flows. Conversely, the preform P flows into the spaces 38, 38 to fill the spaces 38, 38, but does not flow into the spaces 39, 39, or does not flow into the spaces 39, 39. is set to its capacity.
In addition, the capacity of the preform P may be set to a capacity that fills the spaces 39 , 39 . In this case, a portion of the material M that has flowed into the spaces 39, 39 flows vertically in the spaces 39, 39, forming protrusions that protrude in the thickness direction of the main body 11. As shown in FIG.

As described above, according to the present embodiment, the optical axis O1 of the lens portion 12 is located at four angles of the main body portion 11 with respect to the central axis O2 passing through the upper surface 13 and the lower surface 14 of the substantially square plate-shaped main body portion 11 . One of the three side surfaces 15, 16, 17, and 18 is eccentric toward the side surface 17, so by adjusting the amount of eccentricity, the height of the optical axis O1 of the lens unit 12 from the mounting surface such as a flat bench can be adjusted. can be adjusted. Therefore, when it is desired to mount a plurality of optical elements 10 on a mounting surface such as a flat bench and to make the heights of the optical axes O1 of the lens portions 12 of the respective optical elements 10 different, the flat bench is used unlike the conventional art. It is not necessary to lower the optical axis by removing the side surface that is adhered to the mounting surface, or to increase the optical axis by inserting a spacer between the side surface and the mounting surface of the flat bench. The side surface 17 or another side surface 15 opposite to the side surface 17 may be directly mounted (surface mounted) on the mounting surface. Therefore, the optical element 10 can be easily mounted.

In addition, by surface-mounting one side surface 17 of the main body 11, there is no projecting portion on the non-surface-mounted side of the main body 11, so that the optical element 10 can be downsized and the mounting can be stabilized. can be achieved, and the optical element 10 can be easily gripped by the grip portion and mounted.
Further, the corners of the upper surface 13 and the lower surface 14 of the main body 11, which are located on the side of the first side surface 17, are provided with projections 20, 20 projecting in the thickness direction of the main body 11. , the area of the one side surface 17 can be increased, and when the one side surface 17 is installed on a mounting surface such as a flat bench, the protrusions 20, 20 can stabilize the installation.
In addition, of the corners of the upper surface 13 and the lower surface 14 of the main body 11 , the upper surface 13 and the lower surface 14 and the other side surface 15 slide at the corners located on the other side surface 15 side opposite to the one side surface 17 side. Since the R surfaces 21 and 21 are formed so as to connect to the hollow, when mounting the optical element 10, the upper surface 13 and the lower surface 14 can be easily sandwiched by the holding portion of the mounting device on the side of the other side surface 15 of the main body portion 11. can be easily grasped, and thus the optical element 10 can be easily mounted.
In addition, as a modification of the first mold 31 of the present embodiment, only corners 31e having arcuate cross-sections are formed at two corners of the first mold 30, and corners having arcuate cross-sections are formed at two locations. The portion 31 f may not be formed at the corner of the first mold 30 . In this case, as shown in FIG. 1A, in the optical element 10 to be molded, curved surfaces connecting the side surfaces 15 and 16 and the side surfaces 15 and 18 are present at two corners of the optical element 10 when viewed from the direction of the optical axis O1. However, there is no curved surface connecting the side surfaces 16, 17 and the side surfaces 17, 18 respectively.

REFERENCE SIGNS LIST 10 optical element 11 body portion 12 lens portion 13 upper surface 14 lower surface 15, 16, 17, 18 side surface 20 projecting portion 21 R surface 30 mold for optical element molding 31 first mold 31a, 31b, 31c, 31d side surface 31e, 31f Corner portion 32 Second mold 33 Cavity 33a, 33b, 33c, 33d Inner wall surface 34 Lens molding portion 38 Gap O1 Optical axis O2 Main body central axis O3 Axis O4 Cavity center M Material

Claims (7)

An optical element having a main body formed in a substantially square plate shape and having four side surfaces, an upper surface and a lower surface, and a lens part formed on each of the upper surface and the lower surface of the main body,
the lens portion has an aspherical shape that is rotationally symmetrical about its optical axis;
the optical axis of the lens portion is eccentric to one of the four side surfaces with respect to a central axis passing through the upper and lower surfaces of the main body;
An optical element, wherein two other side surfaces that are adjacent to said one side surface in a direction perpendicular to said one side surface are closer to said one side surface side. A protrusion projecting in a thickness direction of the main body is provided at a corner located on the one side surface of the upper and lower surfaces of the main body. Item 1. The optical element according to item 1. Of the corners of the upper surface and the lower surface of the main body, the upper surface and the lower surface and the other side surface are smoothly connected to a corner portion located on the other side surface opposite to the one side surface. 3. The optical element according to claim 2, wherein an R surface is formed. The first mold and the second mold work together to pressure-mold the material in the cavity of the second mold, thereby forming an aspherical lens portion that is rotationally symmetrical about the optical axis. An optical element manufacturing method for manufacturing an optical element having
The cross-sectional shape of the cavity is a quadrangle,
The first mold is formed in a substantially square plate shape having a lens molding portion for molding the lens portion on a surface facing the cavity side, and four corner portions are each centered on one axis coaxial with the optical axis. It is formed to have an arcuate cross section, and is configured so that four side surfaces are in contact with the four inner wall surfaces forming the cavity,
The first mold is arranged in the cavity with the axis eccentric from the center of the cavity toward one inner wall surface,
In the cavity, the material is press-molded by the first mold to form a substantially rectangular plate-shaped main body and the lens provided in the main body. an axis eccentric to one of the four side surfaces with respect to a central axis passing through the upper and lower surfaces of the main body;
A method of manufacturing an optical element, comprising forming an optical element in which two other side surfaces that are adjacent to said one side surface in a direction perpendicular to said one side surface are closer to said one side surface. When pressure molding the material, part of the material protrudes from a gap between two corners of the first mold located on the one inner wall surface side and the inner wall surface forming the cavity. 5. The method of manufacturing an optical element according to claim 4, wherein the protruding portion protruding in the thickness direction of the main body portion is formed. The first mold and the second mold work together to pressure-mold the material in the cavity of the second mold, thereby forming an aspherical lens portion that is rotationally symmetrical about the optical axis. An optical element molding die for manufacturing an optical element having
The cross-sectional shape of the cavity is a quadrangle,
The first mold is formed in a substantially square plate shape having a lens molding portion for molding the lens portion on a surface facing the cavity side, and four corner portions are each centered on one axis coaxial with the optical axis. It is formed to have an arcuate cross section, and is configured so that four side surfaces are in contact with the four inner wall surfaces forming the cavity,
A mold for molding an optical element, wherein the first mold is arranged in the cavity such that the axis is eccentric from the center of the cavity toward one inner wall surface. During pressure molding of the material, part of the material flows between the two corners of the first mold located on the one inner wall surface side and the inner wall surface forming the cavity. 7. The mold for molding an optical element according to claim 6, wherein a space is provided.

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