JP2024060687A - Optical component, mold of optical component, and manufacturing method of optical component - Google Patents

Abstract

To provide an optical component with a reflective surface formed inside capable of suppressing degradation of optical properties.SOLUTION: An optical component 100 includes a lens part 1, and an edge part 2. The lens part 1 includes: an incidence surface 11 that receives light from a light source; reflective surfaces 12, 13 for reflecting light incident the incidence surface 11; and an output surface 14 that outputs the light reflected by the reflective surfaces 12, 13. A third direction is perpendicular to a first direction as the direction in which light is incident on the reflective surface 12 and a second direction as the direction in which the light reflects on the reflective surface 12. The edge part 2 is arranged on at least one side of the third direction of the lens part 1.SELECTED DRAWING: Figure 1

Description

This disclosure relates to optical components, molds for optical components, and methods for manufacturing optical components.

In recent years, as imaging devices in cameras and scanners have become smaller, there is a demand for smaller optical components such as lenses.

For example, the imaging optical system of Patent Document 1 has multiple reflecting surfaces inside a prism member (optical component). These multiple reflecting surfaces fold the optical path inside the prism member. This makes the imaging optical system smaller and thinner.

JP 2000-231060 A

However, when a reflective surface is formed inside an optical component as in Patent Document 1, the thickness of the optical component becomes thicker than that of a normal lens. This makes the optical component more susceptible to sink marks, deteriorating the optical characteristics. Therefore, one option to prevent sink marks is to mold the optical component under high pressure.

However, when optical components are molded under high pressure, excessive internal stress occurs near the gate. This causes birefringence in the area near the gate of the optical component, deteriorating its optical properties.

The present disclosure therefore aims to provide an optical component and a mold for the optical component that can prevent deterioration of optical characteristics in an optical component having a reflective surface formed therein.

In order to achieve the above object, an optical component according to one embodiment of the present disclosure includes a lens portion and a first edge portion, the lens portion includes an entrance surface that receives light from a light source, a reflecting surface that reflects the light that is incident on the entrance surface, and an exit surface that exits the light reflected by the reflecting surface, the third direction is perpendicular to the first direction in which the light is incident on the reflecting surface and the second direction in which the light is reflected on the reflecting surface, and the first edge portion is disposed on at least one side of the third direction in the lens portion.

According to the present disclosure, it is possible to prevent deterioration of optical properties in optical components having internal reflective surfaces.

FIG. 2 is a perspective view of the optical component according to the first embodiment, viewed obliquely from above. FIG. 2 is a perspective view of the optical component according to the first embodiment when viewed obliquely from below. FIG. 2 is a bottom view of the optical component according to the first embodiment. FIG. 2 is a side view of the optical component according to the first embodiment. FIG. 2 is a cross-sectional view of the optical component according to the first embodiment. FIG. 2 is a cross-sectional view of a mold for the optical component according to the first embodiment. FIG. 11 is a perspective view of an optical component according to a second embodiment, as viewed obliquely from above. FIG. 11 is a perspective view of an optical component according to a second embodiment, as viewed obliquely from below. FIG. 11 is a side view of an optical component according to a second embodiment. FIG. 13 is a bottom view of the optical component according to the third embodiment. FIG. 11 is a cross-sectional view of a mold for an optical component according to a third embodiment. FIG. 13 is a bottom view of the optical component according to the fourth embodiment. FIG. 13 is a cross-sectional view of a mold for an optical component according to a fourth embodiment.

The following describes in detail the embodiments of the present disclosure with reference to the drawings. The following description of the preferred embodiments is essentially merely illustrative and is in no way intended to limit the present invention, its applications, or its uses. In the following description, the same parts are given the same reference numerals, and detailed descriptions will be omitted as appropriate.

First Embodiment
(Configuration of optical components)
FIG. 1 is a perspective view of the optical component according to the first embodiment when viewed obliquely from above. FIG. 2 is a perspective view of the optical component according to the first embodiment when viewed obliquely from below. FIG. 3 is a bottom view of the optical component according to the first embodiment. FIG. 4 is a side view of the optical component according to the first embodiment. FIG. 5 is a cross-sectional view of the optical component according to the first embodiment. Specifically, FIG. 4 is a cross-section taken along the line X-X in FIG. 3. Note that the left-right direction in FIG. 3 may be simply referred to as the left-right direction (corresponding to the third direction), the up-down direction in FIG. 3 as the front-rear direction, and the up-down direction in FIG. 4 as simply the up-down direction (corresponding to the fourth direction). In addition, in FIG. 5, the optical path in the optical component 1 is illustrated by a dashed arrow.

As shown in Figures 1 to 5, the optical component 100 includes a lens portion 1, an edge portion 2 (first edge portion), and a gate portion 3. The optical component 100 is formed of a material such as a transparent resin that transmits light. The optical component 100 is injection molded using a mold 200, which will be described later.

The lens unit 1 receives light from a light source (not shown) and emits the light. The lens unit 1 has an entrance surface 11, reflecting surfaces 12 and 13, an exit surface 14, side surfaces 15 and 16, and a product fixing surface 17.

The incident surface 11 is an incident surface that receives (enters) light from a light source (not shown). The incident surface 11 is formed on the lower rear side of the lens portion 1 (see FIG. 5).

The reflecting surface 12 is a reflecting surface that reflects light incident on the incident surface 11. The reflecting surface 12 is formed on the upper rear side of the lens portion 1 (see FIG. 5). As shown in FIG. 5, the reflecting surface 12 receives light from an incident direction S1 (corresponding to a first direction) and reflects the light in a reflection direction S2 (corresponding to a second direction).

Reflective surface 13 is a reflective surface that further reflects the light reflected by reflective surface 12. Reflective surface 13 is formed on the lower front side of lens portion 1 (see FIG. 5). The rear end of reflective surface 13 is connected to the front end of incident surface 11.

The exit surface 14 is an exit surface that emits the light reflected by the reflecting surface 13. The exit surface 14 is formed on the front side above the lens portion 1 (see FIG. 5). The rear end of the exit surface 14 is connected to the front end of the reflecting surface 12.

The side surface 15 is a surface formed in front of the optical component 100 and extends upward from the front end of the reflecting surface 13 (see Figure 5).

The side surface 16 is a surface formed at the rear of the optical component 100 and extends downward from the rear end of the reflecting surface 12 (see Figure 4).

The product fixing surface 17 is a flat surface extending in the left-right and front-rear directions, and is formed on both the left and right sides of the incident surface 11. The product fixing surface 17 is, for example, a surface that comes into contact with a component of a product such as a camera when the optical component 100 is attached to the product.

As described above, the lens unit 1 has reflecting surfaces 12 and 13 that reflect the light incident on the incident surface 11 into the lens unit 1. This allows the optical path to be folded within the optical component 100 (lens unit 1), making it possible to reduce the size and thickness of the optical system including the optical component 100.

The edge portion 2 is formed on the right side (one side) of the lens portion 1 (see Figures 1 to 4). Specifically, the edge portion 2 is connected to the right end portions of the reflecting surfaces 12, 13, the exit surface 14, the side surfaces 15, 16, and the product fixing surface 17. For example, the edge portion 2 has a length of about 1 mm in the left-right direction.

The edge portion 2 is formed so that the cross-sectional area decreases from the left end (the other side) to the right end (the one side) (see FIG. 3). Specifically, the edge portion 2 is formed so that the distance L1 from the front end to the rear end at the center in the left-right direction is 1/3 or more and 2/3 or less of the distance L2 from the front end to the rear end at the center in the left-right direction of the lens portion 1. In this embodiment, the distance L2 corresponds to the distance between the rear end of the reflecting surface 12 and the front end of the reflecting surface 13 at the lens portion 1 (see FIG. 4).

The edge portion 2 is formed so that the distance L3 (corresponding to the first distance) from the top to the bottom at the center in the left-right direction is 1/3 or more and 2/3 or less of the distance L4 (corresponding to the second distance) from the top to the bottom at the center in the left-right direction of the lens portion 1 (see FIG. 4). In this embodiment, the distance L4 corresponds to the distance between the top of the exit surface 14 and the bottom of the entrance surface 11 in the lens portion 1 (see FIG. 5).

The gate portion 3 corresponds to the gate mark of the gate through which the material of the optical component 100 flows when the optical component 100 is produced by injection. The gate portion 3 is formed on the right side of the edge portion 2 (see Figures 1 to 4). The length of the gate portion 3 in the left-right direction is, for example, 0.1 mm or more.

(About the composition of molds for optical components)
FIG. 6 is a cross-sectional view of a mold for the optical component according to the first embodiment.

The mold 200 is a mold used when creating (manufacturing) the optical component 100. As shown in FIG. 6, the mold 200 includes a fixed side mold 21 and a movable side mold 22. The fixed side mold 21 is a mold that is fixed to an injection molding machine (not shown) used to create the optical component 100. The movable side mold 22 is a mold that moves when opening and closing the mold 200 after the optical component 100 is created. In addition, a gate 23 is formed on the right side of the mold 200. When the optical component 100 is injection molded, the material of the optical component 100 flows in from the gate 23.

When the optical component 100 is injection molded using the mold 200, a parting line P1 is formed in the optical component 100 at the portion (parting surface) where the fixed mold 21 and the movable mold 22 come into contact. The parting line P1 is formed on the lower parts of the side surfaces 15 and 16 (see Figures 5 and 6). Specifically, the parting line P1 is formed so that it is lower than the gate portion 3 and higher than the lower surface of the edge portion 2 in the vertical direction.

Here, the side surface 16 is formed so as to incline slightly diagonally backward from the upper end to the parting line P1, and the side surface 15 (and the side surface of the edge portion 2) is formed so as to incline slightly diagonally forward (and inward) from the upper end to the parting line P1.
Specifically, the side surfaces 15, 16 and the side surface of the edge portion 2 are formed so that the angle with respect to the vertical direction is 3° or more in the range from the upper end to the parting line P1.

In addition, side surface 15 is formed so as to slope slightly diagonally forward from the bottom end to parting line P1. In addition, side surface 16 (and the side surface of edge portion 2) is formed so as to slope slightly diagonally backward (and inward) from the bottom end to parting line P1. Specifically, side surfaces 15, 16 and the side surface of edge portion 2 are formed so that the angle with respect to the vertical direction in the range from the bottom end to parting line P1 is 5° or more. In other words, the angle with respect to the vertical direction in the range from the bottom end to parting line P1 of side surfaces 15, 16 and the side surface of edge portion 2 is larger than the angle with respect to the vertical direction in the range from the top end to parting line P1.

As described above, by forming the side surfaces 15 and 16 so that they are slightly inclined in the vertical direction, the optical component 100 can be easily removed from the mold after injection molding.

Incidentally, optical components having a reflective surface that reflects light inside, such as the optical component 100 according to this embodiment, have a thicker lens thickness (length of the lens portion 1 in the vertical direction in this embodiment) than general lenses (for example, 5 mm or more). As a result, sink marks are generated in the optical component, and the shape accuracy of each optical surface (incident surface, reflective surface, etc.) deteriorates. In order to prevent the generation of sink marks and to make the shape accuracy of each optical surface 1 μm or less, molding with a pressure of 120 MPa or more is required in the pressure holding process, which is high-pressure molding. However, under high-pressure molding, excessive internal stress is generated in the range of 1 mm from the gate and the range of 1 mm from the filling end, and birefringence increases within these ranges. As described above, in optical components having a reflective surface that reflects light inside, light passes through the optical component multiple times, so the optical path inside the optical component is more than twice as long as that of a normal lens. Therefore, the effect of birefringence is greater in optical components having a reflective surface that reflects light inside.

When the optical component 100 is injection molded, the material of the optical component 100 flows in through the gate 23. If there is a large difference between the cross-sectional area of the lens portion 1 and the cross-sectional area of the gate portion 3, the inflow speed of the material of the optical component 100 changes significantly when the material flows from the left end of the gate portion 3 to the right end of the lens portion 1, and the birefringence increases.

In contrast, the optical component 100 according to this embodiment has an edge portion 2 formed between the lens portion 1 and the gate portion 3. As a result, the main birefringence occurs in the edge portion 2 formed between the lens portion 1 and the gate portion 3, and the effect of birefringence on the lens portion 1 (incident surface 11, reflecting surfaces 12, 13, and exit surface 14) that constitutes the optical system of the optical component 100 can be suppressed. Therefore, in an optical component that has a reflecting surface that reflects light inside, it is possible to suppress deterioration of the optical characteristics.

Second Embodiment
Fig. 7 is a perspective view of the optical component according to the second embodiment when viewed obliquely from above. Fig. 8 is a perspective view of the optical component according to the second embodiment when viewed obliquely from below. Fig. 9 is a side view of the optical component according to the second embodiment. Compared to the optical component according to the first embodiment, the optical component according to the second embodiment has edge portions (edge portions 2a, 2b) formed on both the left and right sides of the lens portion 1.

As shown in Figures 7 to 9, the edge portion 2a (first edge portion) is formed on the right side of the lens portion 1. The edge portion 2b (second edge portion) is formed on the left side of the lens portion 1. The edge portions 2a and 2b are formed so as to face each other in the left-right direction.

The edge 2a also has a gate portion 3 formed at the right end. That is, when the optical component 100 is injection molded, the material of the optical component 100 is filled from the right side of the edge 2a.

The edge portions 2a and 2b each have a substantially constant cross section in the up-down direction and the front-rear direction. That is, the edge portions 2a and 2b are each formed in a substantially rectangular parallelepiped shape. As shown in FIG. 9, the edge portion 2a is formed so that the distance L5 from the top to the bottom at the center in the left-right direction is 1/3 or more and 2/3 or less of the distance L4 from the top to the bottom at the center in the left-right direction of the lens portion 1. The edge portion 2b is formed so that the distance L6 from the top to the bottom at the center in the left-right direction is 1/3 or more and 2/3 or less of the distance L4 from the top to the bottom at the center in the left-right direction of the lens portion 1.

By making the distances L5 and L6 at least 1/3 of the distance L4, the pressure retention during high pressure forming (injection molding) can be ensured, and the precision of each optical surface (such as the entrance surface 11 and the exit surface 14) of the lens portion 1 can be improved. In addition, by making the distances L5 and L6 at least 2/3 of the distance L4, the inflow speed of the material of the optical component 100 can be prevented from changing significantly when the material flows from the gate portion 3 into the lens portion 1 during injection molding. As a result, for example, in the optical component 100, the difference between the highest and lowest points of the shape precision of each optical surface can be suppressed to 1 μm or less, and the amount of birefringence present in the optical path can be suppressed to 40% or less of the amount of birefringence present in the edge portion 2.

When an optical component is produced by injection molding, the inflow speed of the material of the optical component 100 decreases at the point farthest from the gate 23 through which the material flows, causing birefringence. In this embodiment, the edge portion 2b is formed at the point farthest from the gate 23 (gate portion 3) through which the material of the optical component 100 flows, so that the effect of birefringence on the lens portion 1 can be suppressed.

Third Embodiment
Fig. 10 is a bottom view of the optical component according to the third embodiment. Fig. 11 is a cross-sectional view of a mold for the optical component according to the third embodiment. Compared to the optical component according to the second embodiment, the optical component according to the third embodiment has a sensor 24 formed in the fixed mold 21.

The sensor 24 measures the pressure and temperature of the material of the optical component 100 during injection molding of the optical component 100. The sensor 24 is placed at a position corresponding to the underside of the edge portion 2b. For this reason, a sensor hole for attaching the sensor 24 is formed in the fixed side mold 21 at a position corresponding to the underside of the edge portion 2b. Then, a sensor portion 18 corresponding to the sensor mark (sensor surface) of the sensor 24 is formed on the underside of the edge portion 2b.

As shown in Figures 10 and 11, by placing a sensor 24 on the fixed mold 21, it is possible to measure the pressure and temperature of the material of the optical component 100 during injection molding of the optical component 100. This makes it possible to control the quality of the optical component during injection molding.

The sensor 24 may be disposed at a position on the fixed die 21 that corresponds to the lower side of the edge portion 2a.

Fourth Embodiment
Fig. 12 is a bottom view of the optical component according to the fourth embodiment. Fig. 13 is a cross-sectional view of the mold for the optical component according to the fourth embodiment. In the optical component according to the fourth embodiment, compared to the optical component according to the fourth embodiment, an overflow portion 19 is formed on the left side of the edge portion 2b. In addition, a sensor 25 is disposed in the fixed mold 21.

The sensor 25 measures the pressure and temperature of the material of the optical component 100 during injection molding of the optical component 100. The sensor 25 is placed at a position corresponding to the lower side of the overflow portion 19. For this reason, a sensor hole for attaching the sensor 25 is formed in the fixed side mold 21 at a position corresponding to the lower surface of the edge portion 2b. Then, a sensor portion 20 corresponding to the sensor mark (sensor surface) of the sensor 25 is formed on the lower surface of the overflow portion 19.

The overflow portion 19 is formed on the left side of the edge portion 2b. The overflow portion 19 is formed so that the distance L7 from the front end to the rear end at the center in the left-right direction is 1/3 or more and 2/3 or less of the distance L2 from the front end to the rear end at the center in the left-right direction of the lens portion 1 (see FIG. 12).

As described above, when an optical component is produced by injection molding, the inflow speed of the material of the optical component 100 decreases at the point farthest from the gate 23 through which the material flows, causing birefringence. In this embodiment, the overflow portion 19 is formed at the point farthest from the gate 23 (gate portion 3) through which the material of the optical component 100 flows, so that the effect of birefringence on the lens portion 1 can be suppressed. In addition, by cutting the overflow portion 19 in the process of producing the optical component 100, no sensor marks are left on the optical component 100.

In this embodiment, the edge portion 2b may be omitted and an overflow portion 19 may be formed on the left side of the lens portion 1.

In addition, in each of the above embodiments, the lens unit 1 has two reflective surfaces 12 and 13, but the lens unit 1 may have one or three or more reflective surfaces.

The optical components disclosed herein are useful because they can be used as lenses for imaging devices such as cameras and scanners.

100 Optical component 1 Lens portion 11 Emission surface 12, 13 Reflection surface 14 Incident surface 15, 16 Side surface 18, 20 Sensor portion 19 Overflow portion 2 (2a, 2b) Edge portion (first edge portion, second edge portion)
3 Gate section 200 Mold 21 Fixed side mold 22 Movable side mold 23 Gate 24, 25 Sensor P1 Parting line

Claims (14)

A lens portion;
A first edge portion,
The lens portion is
an incident surface for receiving light from a light source;
a reflecting surface that reflects light incident on the incident surface;
an exit surface that emits the light reflected by the reflecting surface,
the third direction is perpendicular to the first direction in which light is incident on the reflecting surface and the second direction in which light is reflected by the reflecting surface;
The first edge portion is disposed on at least one side of the lens portion in the third direction. Further comprising a second edge portion,
the first edge portion is disposed on one side of the lens portion in the third direction,
The optical component according to claim 1 , wherein the second edge portion is disposed on the other side of the lens portion in the third direction. The optical component according to claim 1, wherein the first edge portion is formed between the lens portion and a gate portion that is a gate mark. The optical component according to claim 3, further comprising a second edge portion disposed opposite the first edge portion in the third direction. The optical component according to claim 3, wherein the gate portion has a length in the third direction of 0.1 mm or more. The incident surface and the exit surface are disposed opposite to each other in a fourth direction,
2. The optical component according to claim 1, wherein a first distance, which is a distance between one side and the other side of the first edge portion in the fourth direction, is greater than or equal to 1/3 and less than or equal to 2/3 of a first distance, which is a distance between the incident surface and the exit surface in the fourth direction. The optical component according to claim 1, wherein the cross-sectional area of the first edge portion decreases from the other side to the one side in the third direction. A mold for optical components used to produce the optical component according to claim 1. a gate for filling a material of the optical component in a mold for the optical component;
The mold for an optical component according to claim 8 , wherein the gate is disposed so as to be connected to a position where the first edge portion is formed. The optical component mold according to claim 8, wherein a sensor hole for mounting a sensor for measuring the pressure and temperature of the filled optical component material is formed in the optical component mold. The optical component is
A second edge portion is disposed so as to face the first edge portion in the third direction,
The mold for an optical component according to claim 10 , wherein the sensor hole is disposed in the vicinity of a position where the second edge portion is formed. The optical component is
a second edge portion disposed to face the first edge portion in the third direction;
an overflow portion extending in the third direction from the second edge portion,
The mold for an optical component according to claim 10 , wherein the sensor hole is disposed in the vicinity of a position where the overflow portion is formed. A method for manufacturing an optical component according to claim 1 by using a mold for an optical component according to claim 8, comprising the steps of:
A method for manufacturing an optical component, wherein, when the optical component is injection molded, material of the optical component is filled into a position where the lens portion is formed through a position where the first edge portion is formed. The method for manufacturing an optical component according to claim 13, further comprising measuring the pressure and temperature of the material of the optical component filled in the mold for the optical component during injection molding of the optical component.