JP2014100826A - Long plastic lens, production method of the same, and molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding die of a long plastic lens, which prevents a fitting reference boss from being deformed when it is released from the molding die, and which enables a molded product to be attached to another member with high precision when the molded product is attached to the other member.SOLUTION: A molding die of a long plastic lens is a mold in which a melted resin is injected, and a long plastic lens having a fitting reference boss at a lens side face is molded, includes: a pair of optical surface pieces facing each other; a slide flank piece; and a mirror plane piece, includes a concave face for forming the lens side face in which a level difference is disposed to be lowered on an inner flank of the slide flank piece, and includes at least one hole for forming the fitting reference boss on the lens side face on the concave face, and in the molding die, relation between a depth (a) of a level difference between an inner flank of the slide flank piece and the concave face, and a depth (b) of the deepest hole among the holes indicates (a)>(b).

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long plastic lens, a manufacturing method thereof, and a molding die, and in particular, a long plastic lens such as an fθ lens used in a scanning optical system of a laser beam printer or a copying machine, a manufacturing method thereof, and a molding die. It relates to types.

  In recent years, optical elements such as fθ lenses used in laser scanning optical systems such as printers and copiers have been required to be improved in mounting accuracy as the performance of printers and copiers increases. In a long plastic lens manufactured using a mold, a boss-shaped mounting reference boss may be provided on the outer shape of the lens as a mounting reference. However, since the long plastic lens expands and deforms in the longitudinal direction of the molded product when it is released from the mold in the manufacturing process, the mounting reference boss moves in the longitudinal direction when the mounting reference boss comes out of the mold. It comes out of the state. For this reason, there is a problem in that interference between the mounting reference boss and the mold occurs, and the mounting reference boss is deformed.

  Also in the prior art, a technique for preventing the deformation of the shape of the mounting reference boss is disclosed. For example, Patent Document 1 discloses a method of preventing deformation of the mounting reference boss by providing a dummy boss shape larger than the mounting reference boss on the opposite gate side of the molded product.

Japanese Patent No. 3814591

  According to the method of Patent Document 1, by providing a dummy boss shape larger than the mounting reference boss on the opposite gate side of the molded product, the dummy boss can be prevented from expanding in the longitudinal direction when released, and the mounting reference boss can be accurately It can be removed from the mold well. However, in Patent Document 1, in order to give a dummy boss that is not necessary to the molded product, when the molded product is attached to another member, secondary processing is performed to remove the dummy boss or to the member on the side to be attached. Design considerations were necessary to prevent the dummy boss from interfering.

  The present invention has been made in view of such a background art, and prevents the deformation of the mounting reference boss at the time of mold release, and can be attached with high accuracy when the lens molded product is attached to another member. A plastic lens, a manufacturing method thereof, and a molding die are provided.

  A mold for molding a long plastic lens that solves the above problems is a mold for injecting molten resin to mold a long plastic lens having a mounting reference boss on the side of the lens, facing each other. A pair of optical surface pieces, a slide side piece and a mirror piece, and an inner surface of the slide side piece has a concave surface for forming the lens side surface which is lowered by providing a step, and the concave surface Has at least one hole for forming a mounting reference boss on the lens side surface, and has a depth a between the inner surface and the concave surface of the slide side piece, and the deepest hole among the holes. The relationship with the depth b is a> b.

  A manufacturing method of a long plastic lens that solves the above-described problem has a pair of optical surface pieces, a slide side piece, and a mirror piece, and the lens side face that is lowered by providing a step on the inner side surface of the slide side piece. A concave surface for forming, the concave surface has at least one hole for forming a mounting reference boss on the lens side surface, and a step between the inner surface of the slide side piece and the concave surface Method of manufacturing a long plastic lens having a mounting reference boss on the side surface of a lens using a molding die in which the relationship between the depth a and the depth b of the deepest hole among the holes is a> b And a step of injecting a molten resin into the molding die, and a step of releasing the mold after cooling and solidifying the injected resin. Isometric plastic lens lens Until the mounting reference boss formed on the surface comes out of the hole on the concave surface of the slide side piece, the molded long plastic lens is held in contact with the step between the inner surface and the concave surface of the slide side piece. It is characterized by.

  A long plastic lens that solves the above-mentioned problem is a long plastic lens having an optical surface through which light passes and a lens side surface that is positioned in the same direction as the longitudinal direction of the optical surface and has at least one mounting reference boss. The optical surface has at least one optical function surface on the light incident surface side and the light exit surface side, and a distance c between the score line and the end of the optical surface in the short direction, and the attachment The relationship of the height d of the highest mounting reference boss among the reference bosses is that c> d.

  According to the present invention, there is provided a long plastic lens that prevents deformation of the mounting reference boss at the time of mold release and can be attached with high accuracy when a lens molded product is attached to another member, a manufacturing method thereof, and a molding die. Can be provided.

It is a schematic perspective view which shows one embodiment of the elongate plastic lens of this invention. It is a schematic sectional drawing which shows one embodiment of the metal mold | die for shaping | molding of this invention. It is explanatory drawing showing the positional relationship of a cavity and a slide side piece. It is a figure showing the positional relationship of the long plastic lens in the middle of mold opening, and a slide side piece. It is a figure showing the positional relationship of the attachment reference | standard boss | hub of a long plastic lens, and a secant. It is a schematic perspective view which shows the other embodiment of the elongate plastic lens of this invention. It is a schematic sectional drawing which shows the other embodiment of the metal mold | die of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

  The long plastic lens according to the present invention is a long plastic lens having an optical surface through which light is transmitted and a lens side surface which is located in the same direction as the longitudinal direction of the optical surface and has at least one mounting reference boss. There is a secant on the outside of at least one optical function surface on the light incident surface side and the light exit surface side of the optical surface, a distance c between the secant and the end of the optical surface in the short direction, and the mounting reference boss Among them, the relationship of the height d of the highest mounting reference boss is c> d.

  FIG. 1 is a schematic perspective view showing an embodiment of the long plastic lens of the present invention. In FIG. 1, a long plastic lens 1 is an opposing optical surface 2 through which light passes, and an opposing lens side surface that is located in the same direction as the longitudinal direction E of the optical surface 2 and has at least one mounting reference boss 5. 3 and an opposing lens end side surface 4 located at the end in the longitudinal direction E of the optical surface 2. One or a plurality of attachment reference bosses 5 are provided on the opposite lens side surfaces 3. F indicates the short direction of the optical surface 2.

  In the xyz coordinates shown in FIG. 1, the x-axis direction is referred to as an optical axis direction, the y-axis direction is referred to as a longitudinal direction, and the z-axis direction is referred to as a short direction. In order to attach the long plastic lens to other parts with high accuracy, it is necessary for the long plastic lens to have a high-accuracy attachment reference surface in each of xyz. For example, in the mounting reference boss shown in FIG. 1, one at the center of the lens is used for positioning in the longitudinal direction, and two at both ends are used for positioning in the optical axis direction.

  In addition, the optical surface 2 of the long plastic lens 1 of the present invention has a secant outside at least one optical function surface on the light incident surface side and the light exit surface side. In FIG. 1, the optical surface 2 includes an optical functional surface 2 a that functions as a lens, a dividing line 7 that is generated outside the optical functional surface 2 a due to a molding die in the manufacturing process, and an outer side of the dividing line 7. And an optical surface short side end 2b of the portion. The generation of the dividing line 7 in the manufacturing process will be described later. A gate 6 which is a resin inflow port is provided on one end face of the opposite lens end side faces 4.

  The mold for molding a long plastic lens of the present invention is a mold for injecting molten resin to mold a long plastic lens having an attachment reference boss on the side of the lens, and a pair of opposed plastic molds. An optical surface piece, a slide side piece, and a mirror face piece, and an inner surface of the slide side piece has a concave surface for forming the lens side surface that is lowered by providing a step, and the concave surface has the lens A depth a of a step between an inner surface and a concave surface of the slide side piece, and a depth b of the deepest hole among the holes, having at least one hole for forming a mounting reference boss on a side surface; The relationship is that a> b.

  FIG. 2 is a schematic cross-sectional view showing an embodiment of the molding die of the present invention. 2A is a molding die for molding the long plastic lens 1, and is a cross-sectional view including a cross section A shown in FIG. FIG. 2B is a cross-sectional view taken along line BB in FIG. The molding die is composed of a fixed side die 8 and a movable side die 9. Each die is provided with a temperature control water pipe 10, and is connected to a die temperature controller (not shown) and adjusted to a constant temperature. . The fixed side mold 8 and the movable side mold 9 are each provided with a pair of optical face pieces 11 and 12 facing each other, and the movable side mold 9 is provided with a pair of slide side pieces 13 and 14 facing each other. Further, a pair of facing mirror pieces 21 and 22 are provided, and these pieces mainly form a cavity 15.

  The method for producing a long plastic lens of the present invention is a method for producing a long plastic lens having an attachment reference boss on the lens side surface using the molding die described above. A step of injecting, cooling and solidifying the injected resin, and then releasing the mold; in the step of releasing, the mounting reference boss formed on the lens side surface of the molded long plastic lens slides The molded long plastic lens is held in contact with the step between the inner surface and the concave surface of the slide side piece until it is removed from the hole on the concave surface of the side piece.

  Here, the secant 7 of the long plastic lens of the present invention shown in FIG. 1 will be described. The dividing line 7 shown in FIG. 1 is a line generated in the manufacturing process and formed at the boundary between the optical face pieces 11 and 12, the slide side face pieces 13 and 14 and the mirror face pieces 21 and 22 in FIG. In the mold design, a clearance is required between the optical surface piece and the slide side piece, and a secant is formed by a slight amount of resin entering the clearance. The resin is injected into the cavity at a high temperature and a high pressure, and is filled by the injection pressure and the holding pressure. The slide side pieces 13 and 14 are pushed in the vertical direction in FIG. 2 by the resin pressure and holding pressure at this time, and the slide side pieces come into contact with a locking block (not shown) located behind the slide side pieces 13 and 14 so that the position is determined. Sometimes there is always a clearance between the optical face piece and the slide side piece. As shown in FIG. 2, the optical surface short direction end 2b of the long plastic lens in the embodiment of the present invention is formed by a slide side piece, so that the optical surface has an optical surface as shown in FIG. There is a secant generated at the boundary between the optical face piece and the slide side face piece. Similarly, the lens end side surface 4 has a secant line generated at the boundary between the slide side surface piece and the mirror surface piece.

  It is not limited to the long plastic lens that is the subject of the present invention, but a lens using plastic as a material has a larger birefringence and refractive index distribution than a lens made of glass, and it is found that the optical performance is adversely affected. ing. In general, the influence of birefringence and refractive index distribution increases as the shape becomes closer to the outer shape of the molded product. Therefore, in many cases, the lens is actually used only near the center of the lens where the influence of birefringence and refractive index distribution is small. Specifically, in FIG. 1, the optical function surface 2a functions as a lens. For this reason, in the embodiment of the present invention, the light beam passes only near the center in the lens lateral direction, so the portion of the optical surface lateral direction end 2b formed by the slide side piece is defined as an optical functional surface. Even if you can't do it, there will be no major problems.

  The material of the long plastic optical element may be a resin, but is manufactured using, for example, a thermoplastic resin. For example, it is manufactured by injection molding using ZEONEX (registered trademark) manufactured by Zeon Corporation or TOPAS (registered trademark) manufactured by TOPAS ADVANCED POLYMERS.

  Next, the mounting reference boss provided on the side surface of the long plastic lens of the present invention will be described. The dimensions of the mounting reference boss, the slide side piece, the positional relationship between the secant lines, and the dimensions will be described with reference to FIGS. FIG. 3 is an explanatory diagram showing the positional relationship between the cavity and the slide side piece. FIG. 3A is a view of the long plastic lens 1 as viewed from the side. FIG. 3B is a view showing the cavity 15 and the two slide side pieces 13 and 14 in the cross section taken along the dotted line B shown in FIG. As shown in FIG. 3 (b), the side of the slide side piece of the cavity 15 is in a position where a step 19 is formed on the surface 18 of the concave surface formed by dug down the inner side 20 of the slide side piece. When viewed from the slide side piece, the inner side surface 20 of the slide side piece has a concave surface 18 for forming the lower lens side surface by providing a step 19, and the concave surface 18 has an attachment reference boss on the lens side surface. It has a hole 23 for forming. Further, in FIG. 3B, there is a gate 6 on the right side, and when the mold is released, a force is exerted so that the molded product expands to the left side (counter gate side) due to expansion by the overpack of the molded product or runner.

  FIG. 3C is an enlarged view of a portion C shown in FIG. In FIG. 3 (c), the depth a of the step 19 between the inner surface 20 and the concave surface 18 of the slide side pieces 13, 14 of the molding die, and the depth b of the deepest hole among the holes 23. When a> b, the relationship between the two is a> b. Here, the depth b of the hole indicates the depth of the hole for forming the boss having the highest boss height when there are a plurality of attachment reference bosses on the side surface of the long plastic lens.

  In addition, the length of the concave surface 18 having the hole 23 for forming the attachment reference boss in the slide side pieces 13 and 14 shown in FIG. 3B is opposite to that shown in FIG. The step 19 of the concave surface 18 of the slide side piece is provided at the position of both ends of the optical face pieces 11 and 12. FIG. 7 is a schematic cross-sectional view showing another embodiment of the molding die of the present invention. In the molding die shown in FIG. 7, the step 19 of the concave surface 18 of the slide side piece is provided at the end of one optical surface piece 12, and no step is provided at the end of the other optical face piece 11. An aspect is shown. One slide side piece shown in FIG. 3 (b) is provided with three holes 23, and one slide side piece shown in FIG. 7 is provided with one hole 23. Depending on the number of holes, the number, position and the like of the step 19 on the concave surface of the slide side piece can be selected.

  Next, the mold opening process of the slide side piece of the molding die in the manufacturing method of the present invention will be described. FIG. 4 is a diagram showing the positional relationship between the long plastic lens and the slide side piece in the middle of mold opening. FIG. 4 shows a state in which the slide side piece starts to separate from the optical surface piece when the mold is opened. The production method of the present invention includes a step of releasing the mold after cooling and solidifying the resin injected into the molding die. In the step of releasing, the molded reference length boss 5 formed on the lens side surface of the molded long plastic lens 1 is removed from the concave surface hole 23 of the slide side pieces 13 and 14 until the molded length is increased. The shaku plastic lens 1 (hereinafter also referred to as “lens molded product”) is held in contact with a step 19 between the inner surface and the concave surface of the slide side pieces 13 and 14.

  Since the relationship between the step depth a of the slide side piece and the hole depth b is as shown in FIG. 3C where a> b, the attachment of the lens molded product 1 is shown in FIG. Although the reference boss 5 has been removed from the hole 23 of the slide side piece, the outer shape of the lens molded product, that is, the optical surface short side end 2b and the lens end side surface 4 of the lens longitudinal side is still missing from the step 19 of the slide side piece. You can see that it is not complete. As a result, the force that the lens molded product described above extends in the anti-gate direction is suppressed by the slide side piece, that is, when the mounting reference boss comes out of the slide side piece, it is separated accurately without being affected by the force extending in the anti-gate direction. It becomes possible to mold.

  FIG. 5 is a diagram illustrating the positional relationship between the attachment reference boss and the secant of the long plastic lens 1. FIG. 5 shows an enlarged view of the opposite side of the molded lens product after being taken out. In FIG. 5, the distance c between the dividing line 7 outside the optical functional surface of the optical surface of the long plastic lens and the end of the optical surface in the short direction, and the highest mounting reference boss among the mounting reference bosses 5. The relationship between the height d and the height d is c> d. In this case, any boss height may be the same. Here, the depth b of the hole dug in order to form the mounting reference boss on the slide side piece and the mounting reference boss height d of the actual lens molded product have the same dimensions because molding shrinkage occurs after mold release. Must not. Similarly, the depth a of the step dug into the inner surface and concave surface of the slide side piece and the distance c from the lateral side surface of the actual lens molded product to the secant do not have the same dimensions.

  As described above, according to the manufacturing method of the present invention, when the mounting reference boss is removed from the slide side piece, the short side end of the optical surface and the short side of the lens long side are still the slide side. It is mated with a piece. Therefore, it is possible to remove the attachment reference boss from the slide side piece without being affected by expansion occurring in the longitudinal direction without giving a special shape.

  Further, according to the molding die of the present invention, the depth a of the step between the inner surface of the slide side piece and the concave surface, and the depth b of the deepest hole among the holes for forming the mounting reference boss, Is a> b. Therefore, when the mounting reference boss is removed from the slide side piece, the short end of the optical surface and the short side of the lens side in the longitudinal direction are still fitted to the slide side piece, and a special shape is not required. The mounting reference boss can be removed from the slide side piece without being affected by the expansion occurring in the longitudinal direction.

  Further, according to the long plastic lens of the present invention, there is a relationship between the dividing line and the distance c between the optical surface and the end in the short direction of the optical surface, and the height d of the highest mounting reference boss among the mounting reference bosses. c> d. Therefore, when the mounting reference boss is removed from the slide side piece, the short end of the optical surface and the short side of the lens side in the longitudinal direction are still fitted to the slide side piece, and a special shape is not required. The mounting reference boss can be removed from the slide side piece without being affected by the expansion occurring in the longitudinal direction.

  Examples of the present invention will be described below.

Example 1
The depth (b) of the hole dug into the slide side piece to form each mounting reference boss and the depth of the step (a) between the inner side surface and the concave surface of the slide side piece were set as shown in Table 1. A long plastic lens was molded using the molding die shown in FIG. The mounting reference bosses of the long plastic lens are called boss 1, boss 2 and boss 3 from the gate 6 side, and are equivalent to the lens side surfaces on both sides in consideration of the balance when the lens molded product comes off from the slide side piece. The boss was placed on. The molding material was a thermoplastic resin (ZEONEX (registered trademark) E48R, manufactured by Nippon Zeon Co., Ltd.), the mold temperature was adjusted to 130 ° C., and molding was performed by an injection molding apparatus (not shown).

  Table 1 shows the dimensions (unit: mm) of the slide side piece in Example 1.

(Example 2)
In the same resin material and mold temperature as in Example 1, each dimension of the slide side piece was set as shown in Table 2, and a long plastic lens was molded.
Table 2 shows the dimensions (unit: mm) of the slide side piece in Example 2.

(Comparative Example 1)
In the same resin material and mold temperature as in Example 1, the dimensions of the slide side piece were set as shown in Table 3, and a long plastic lens was molded.
Table 3 shows the dimensions (unit: mm) of the slide side piece in Comparative Example 1.

(Comparative Example 2)
In the same resin material and mold temperature as in Example 1, each dimension of the slide side piece was set as shown in Table 4, and a long plastic lens was molded.
Table 4 shows the dimensions (unit: mm) of the slide side piece in Comparative Example 2.

(Comparative Example 3)
In the same resin material and mold temperature as in Example 1, each dimension of the slide side piece was set as shown in Table 5 and a long plastic lens was molded. That is, conventionally, the inner side surface of the slide side piece of the molding die is a flat surface, and no step is formed between the inner side surface and the concave surface of the slide side piece as in the present invention. a) is 0 mm.
Table 5 shows each dimension (unit: mm) of the slide side piece in Comparative Example 3.

(Evaluation 1 of Example and Comparative Example 1)
The height (d) of each mounting reference boss of the long plastic lens manufactured by Examples 1 and 2 and Comparative Examples 1 to 3 and the distance (c) between the dividing line and the end (side surface) in the short direction of the optical surface ) Is shown in Table 6.
Table 6 shows dimensions (unit: mm) of the mounting reference bosses in Examples 1 and 2 and Comparative Examples 1 to 3.

  As shown in Table 6, the lens molded product shrinks by about 0.01 mm from the mold size, but the boss 3 is close to the gate and has good pressure transmission, compared with the thick part near the boss 2. Since it is thin and overpacked, it is almost the same size as the mold.

Next, Table 7 shows whether or not the long plastic lenses molded in Examples 1 and 2 and Comparative Examples 1 to 3 are deformed at the respective attachment reference bosses and the longitudinal ends on the side opposite to the gate.
Table 7 shows the presence or absence of deformation of the mounting reference bosses in Examples 1 and 2 and Comparative Examples 1 to 3.

  As shown in Table 7, in Example 1 and Example 2, it is slower for the outer shape of the lens molded product to be removed from the slide side piece than each mounting reference boss is removed from the hole of the slide side piece. Accordingly, it can be seen that each mounting reference boss forms a highly accurate boss without being affected by the force that expands in the anti-gate direction when the lens molded product is opened. On the other hand, when the lens molded product outer shape is removed from the slide side piece, the longitudinal end on the opposite gate side is deformed because it is removed from the slide side piece while being affected by the expansion force in the anti-gate direction.

  In Comparative Example 1, since the outer shape of the lens molded product is removed from the slide side piece faster than each attachment reference boss is removed from the hole of the slide side piece, each attachment reference boss is affected by the expansion force in the anti-gate direction. It will come off the slide side piece while receiving, and the mounting reference boss will be deformed. On the other hand, when the non-gate side end portion comes out of the slide side piece, each attachment reference boss is still restrained by the slide side piece, so that the anti-gate side end portion is released without being deformed.

  Further, in Comparative Example 2, since the timing at which the boss 2 is removed from the hole of the slide side piece and the timing at which the outer shape of the lens molded product is removed from the slide side piece are simultaneous, the boss 2 and the opposite gate side end are deformed. On the other hand, when the bosses 1 and 3 come out of the holes on the slide side piece, the boss 2 and the lens molded product outer shape are constrained by the slide side piece. ing.

  Further, in Comparative Example 3, all the bosses are deformed because each mounting reference boss comes out of the hole of the slide side piece while being affected by the expansion force in the anti-gate direction. In particular, the boss 3 is positioned on the side opposite to the gate and is greatly affected by the largest expansion force, so that the deformation is increased.

(Example 3)
A perspective view of a long plastic lens in Example 3 is shown in FIG. FIG. 7 shows a schematic cross-sectional view of a molding die for molding a long plastic lens in Example 3. FIG. 7 is a cross-sectional view including the cross section D illustrated in FIG. 6. As shown in FIG. 6, the mounting reference boss 5 provided on the lens side surface 3 is one on each surface, and the dividing line of the optical surface is also the light emitting surface side (not shown) and the lens end side surface 4. The dividing surface does not exist in the optical surface 2 on the incident surface side. That is, as shown in FIG. 7, the optical surface piece 11 provided in the fixed side mold 8 is a piece having the same width as the full width in the lens lateral direction.

With the same resin material and mold temperature as in Example 1, the dimensions of the slide side piece were set as shown in Table 8, and a long plastic lens was molded.
Table 8 shows the dimensions (unit: mm) of the slide side piece in Example 3.

(Comparative Example 4)
With the same configuration of the long plastic lens and molding die as in Example 3, and with the same resin material and mold temperature, the dimensions of the slide side piece were set as shown in Table 9, and a long plastic lens was molded.
Table 9 shows the dimensions (unit: mm) of the slide side piece in Comparative Example 4.

(Evaluation 2 of Example and Comparative Example 2)
Table 10 shows the height dimension (d) of the attachment reference boss of the long plastic lens manufactured in Example 3 and Comparative Example 4 and the distance (c) between the secant and the end (side surface) in the short side direction of the optical surface. Shown in
Table 10 shows dimensions (unit: mm) of the attachment reference boss and the like in Example 3 and Comparative Example 4.

  As shown in Table 10, the lens molded product contracted by about 0.01 mm from the mold size.

Next, Table 11 shows whether the long plastic lens molded in Example 3 and Comparative Example 4 is deformed at the attachment reference boss and the longitudinal end portion on the side opposite to the gate.
Table 11 shows the presence or absence of deformation of the attachment reference boss and the like in Example 3 and Comparative Example 4.

  As shown in Table 11, in Example 3, it is slower for the outer shape of the lens molded product to be removed from the slide side piece than the attachment reference boss is removed from the hole of the slide side piece. Accordingly, it can be seen that each mounting reference boss forms a highly accurate boss without being affected by the force that expands in the anti-gate direction when the lens molded product is opened. On the other hand, when the outer shape of the lens molded product is removed from the slide side piece, the longitudinal end on the opposite gate side is deformed because it is removed from the slide side piece while being affected by the expansion force in the anti-gate direction.

  In Comparative Example 4, since the outer shape of the lens molded product is removed from the slide side piece faster than each attachment reference boss is removed from the hole of the slide side piece, each attachment reference boss is affected by the expansion force in the anti-gate direction. As a result, the mounting side boss is deformed as it comes out of the slide side piece. On the other hand, when the non-gate side end portion comes out of the slide side piece, each attachment reference boss is still restrained by the slide side piece, so that the anti-gate side end portion is released without being deformed.

  The long plastic optical element of the present invention prevents the deformation of the mounting reference boss at the time of mold release, and can be mounted with high precision when the molded product is mounted on another member. It can be used for conversion.

1 Long plastic lens (lens molded product)
2 Optical surface 2a Optical functional surface 2b Optical surface short side end 3 Lens side surface 4 Lens end side surface 5 Mounting reference boss 6 Gate 7 Split line 8 Fixed side mold 9 Movable side mold 10 Temperature control pipe 11 12 Optical surface piece 13, 14 Slide side piece 15 Cavity 18 Concave surface 19 Step 20 Inner side face 21, 22 Mirror face piece 23 Hole

Claims (3)

  A mold for injecting molten resin to form a long plastic lens having a mounting reference boss on the lens side surface, and having a pair of optical surface pieces, slide side pieces and mirror face pieces facing each other The inner surface of the slide side piece has a concave surface for forming the lower lens side surface by providing a step, and the concave surface has at least one hole for forming a mounting reference boss on the lens side surface. And the relationship between the depth a of the step between the inner surface and the concave surface of the slide side piece and the depth b of the deepest hole among the holes is a> b. Mold for molding long plastic lenses.   A pair of optical surface pieces, a slide side piece, and a mirror piece; and an inner surface of the slide side piece has a concave surface for forming the lens side surface by providing a step, and the concave surface has A depth a of a step between an inner surface and a concave surface of the slide side piece, and a depth of the deepest hole among the holes; A method of manufacturing a long plastic lens having a mounting reference boss on the side surface of a lens using a molding die having a relationship of b> a> b, wherein a molten resin is contained in the molding die. A step of injecting, cooling and solidifying the injected resin, and then releasing the mold; in the step of releasing, the mounting reference boss formed on the lens side surface of the molded long plastic lens slides Hole on the concave surface of the side piece Until exit al, the molded elongate plastic lens manufacturing method of the long plastic lens characterized by being held in contact with the step between the inner surface and the concave surface of the sliding side piece.   In a long plastic lens having an optical surface through which light is transmitted and a lens side surface having at least one mounting reference boss located in the same direction as the longitudinal direction of the optical surface, the light incident surface side of the optical surface; There is a secant on the outside of at least one optical function surface on the exit surface side, a distance c between the secant and the end of the optical surface in the short direction, and the height of the highest mounting reference boss among the mounting reference bosses A long plastic lens, wherein the relationship of d is c> d.

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