JP4674129B2 - Plastic molded products and plastic lenses - Google Patents

Description

  The present invention relates to a molded article using injection molding of a plastic part or the like, and more particularly to a plastic molded part that requires high precision such as a plastic lens or a mirror.

In recent years, there has been a greater emphasis on shortening the tact time of parts production, and in plastic molding, the proportion of time required for cooling and solidifying high-temperature plastic is large, so it is necessary to shorten the cooling time. The parts are difficult to be cooled due to the thick and uneven shape, and it is necessary to provide a certain amount of cooling time in order to maintain dimensional accuracy (see, for example, Patent Documents 1 to 8).
Patent Document 1 discloses a technique for changing the shape of the intersection of the lens surface and the rib in the cross section in order to make each cross-sectional area of the lens equal. Patent Document 2 similarly discloses a cross-sectional area of each part. In order to suppress this variation, a technique for reducing the width dimension of the lens thick portion is disclosed. Patent documents 3 to 8 are merely listed as technologies related to the present invention.
In such a conventional technique, the lens portion is thick at the central portion, whereas the rib portion is thin. In this lens, the cross-sectional area obtained by adding the lens portion and the rib portion is substantially the same at the center and at the end.
In a high-precision plastic molded product that is manufactured by molten resin injection molding and requires high transferability at least on one or more functional parts, a functionally complicated shape is formed by injection molding. In such a plastic molded product, in order to achieve high accuracy of the complicated shape, defects such as deformation of the functional part and sink marks are reduced by means of molding conditions, temperature conditions, heating or slow cooling, and the desired shape is obtained. Forming.
As an example, in plastic lens molding to which the above-described conventional technology is applied, high precision molding of an elongated plastic lens is desired due to high accuracy of the optical functional surface.
The plastic lens has an optical functional surface, and in order to improve the shape rigidity of the optical functional surface, a box-type plastic lens having a rib adjacent to the optical functional surface is used. At this time, if the thickness of the optical functional surface is thicker than the rib portion adjacent to the optical functional surface, sink marks and deformation are likely to occur on the optical functional surface.
JP 09-220770 A Japanese Patent Laid-Open No. 02-157703 JP 2004-205875 A JP 2003-084103 A Patent No. 2784164 Japanese Patent Laid-Open No. 08-136706 JP 05-210062 A Japanese Patent Laid-Open No. 05-080208

The above prior art aims at equalizing the heat capacities in the cross-sectional shapes. In plastic molding, shrinkage and deformation are less likely to occur because the thin part of the molded product solidifies quickly compared to its desired shape, but sinking and deformation are likely to occur because it solidifies later in the thick part. There is a characteristic, and there is a limit in controlling the deformation and sink of the functional part only by the molding conditions and temperature conditions of the prior art.
Therefore, the object of the present invention is to focus on the shape of the plastic lens, without degrading the performance of the optical functional surface, and by changing the thickness of the rib or structure within the allowable range of the non-optical functional surface, By controlling the deformation and sinking mechanism of the functional surface by devising the shape of the desired plastic molded product, the problem of the deformation and sinking of the plastic lens that has become longer in terms of optical function can be solved with high accuracy. The object is to provide a plastic molded product that can embody plastic molding.

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a long-length lens part requiring high transferability of at least one surface, and at least one surface rib adjacent to the lens portion. A thickness ratio between the thickness of the lens portion in the optical axis direction and the thickness of the rib portion in a direction orthogonal to the optical axis direction is equal to the thickness of the lens portion. It is controlled by changing the inner shape of the rib portion corresponding to the change, and is set constant at each longitudinal position.
According to a second aspect of the present invention, in the first aspect , the inner shape of the rib portion is constituted by discontinuously connecting a plurality of small planes.
According to a third aspect of the present invention, there is provided a plastic lens having an elongated lens portion that is required to have high transferability of at least one surface, and at least one or more rib portions adjacent to the lens portion. The thickness ratio of the thickness of the rib portion in the direction orthogonal to the optical axis direction and the thickness ratio of the rib portion in the direction orthogonal to the optical axis direction is the thickness ratio of the lens portion and the rib portion. It is controlled by changing the outer shape of the rib portion to be formed , and is set to be constant at each longitudinal position.
According to a fourth aspect of the present invention, in the third aspect , the outer shape of the rib portion is configured by discontinuously connecting a plurality of small planes.
According to a fifth aspect of the present invention, there is provided a plastic lens having an elongated lens portion that is required to have a high transfer property on at least one surface, and at least one rib portion adjacent to the lens portion. The thickness ratio of the thickness of the rib portion in the direction orthogonal to the optical axis direction and the thickness ratio of the rib portion in the direction orthogonal to the optical axis direction is the thickness ratio of the lens portion and the rib portion. It is controlled by changing an inner shape and an outer shape of the rib portion to be formed, and is set to be constant at each longitudinal position.
The invention of claim 6 is characterized in that, in claim 5 , the inner shape and the outer shape of the rib portion are constituted by discontinuously connecting a plurality of small planes.

According to the present invention, in a plastic molded article having an optical function part that requires high transferability of at least one surface and at least one non-optical function part adjacent to the optical function part, the function is described above. Since the thickness ratio of the functional part and the non-functional part in an arbitrary cross section orthogonal to the part and the non-functional part is made constant, a molding resin heated above the melting temperature by injection molding is filled in the mold apparatus, and the resin The difference in solidification timing that occurs during the slow cooling period until the solidification temperature is reached can be made almost uniform, the density difference accompanying the change in resin pressure can be reduced, and high-precision plastic molded products free from deformation and sink can be obtained. it can.
In addition, according to the present invention, the elongated lens unit has an optical function that requires high transferability of at least one surface, and has at least one surface in contact with the lens unit having the optical function. In a plastic lens having a rib portion having no optical function, the lens portion having the optical function required to have high transferability and the thickness of the lens portion and the rib portion in an arbitrary cross section perpendicular to the rib portion having no optical function. Since the thickness ratio is constant, the plastic thickness of the optical function is long, and the lens thickness in each short cross section and the solidification timing in the orthogonal direction of the rib part that does not have the optical function adjacent to it are almost uniform and deformed. It is possible to obtain a high-precision plastic molded product free from dents and sink marks.

Hereinafter, embodiments of the present invention and reference embodiments that solve the above-described problems will be described in detail with reference to the drawings. FIG. 1 is a schematic front view illustrating respective configurations of an optical function part (hereinafter referred to as a function part) and a non-optical function part (hereinafter referred to as a non-function part) of a reference embodiment of a plastic molded product. FIG. 2 is a side view of the plastic molded product of FIG. 3A is a top view of the plastic molded product of FIG. 1, and FIG. 3B is a perspective view.
A plastic molded product (plastic lens) 1 according to the reference embodiment shown in FIGS. 1 to 3 is integrated with a functional part A (lens part) that requires at least one surface having high transferability and an outer periphery of the functional part A. And at least one non-functional part B (rib part) arranged continuously.
Plastic moldings 1, each thickness of the functional portion A and the non-functional portion B at an arbitrary cross section perpendicular to the functional unit A and the non-functional part B, is configured as the thickness ratio of each other becomes constant It is characterized by a point. That is, the thickness ratio between the functional part A and the non-functional part B is configured to be constant in any cross section at any position.

The functional part A constituting the plastic molded product 1 shown in FIG. 1 to FIG. 3 is a functional part A formed in an arc shape (curved surface) when viewed from a side sectional view (FIG. 1) and a front view (FIG. 2). A non-functional portion B having a flat plate shape (rectangular ring shape) is formed on the outer periphery of the plate.
As can be seen from the side view of FIG. 2, the thickness of the functional part A is such that the cross-sectional thicknesses of the end part D1 and the central part D2 in the longitudinal direction are the end part D1 thickness <the thickness of the central part D2, The thickness is different due to functional requirements. On the other hand, the thickness E of the non-functional part B is small in any part in the longitudinal direction.
This plastic molded product 1 is molded by filling a molded product forming portion in the mold apparatus with a molding resin heated at a melting temperature or higher in an injection mold apparatus (not shown), and then molding the resin. A slow cooling period is provided until the solidification temperature is reached, and the plastic molded product is taken out when the resin solidification temperature is reached.
However, in FIGS. 1 to 3, the functional part A of the plastic molded product has a constant thickness in the longitudinal direction as viewed from the side surface, and the thickness gradually decreases in a curved shape toward the both sides with the maximum thickness at the central part. Then, the molding resin heated at the melting temperature or higher is filled in the molded product forming portion in the mold apparatus, and the solidification timing of the molten resin (the time required for solidification) is over in the slow cooling period until the resin solidification temperature is reached. Since there is little difference between the thickness of the functional part A and the thickness of the non-functional part B at the end part of the non-functional part B corresponding to the part D1, there is little difference in the time required for curing both parts. In the central part of the non-functional part B corresponding to the central part D2, the difference in thickness between the cross-sections of the functional part and the non-functional part becomes large, so that a difference occurs in the solidification timing (solidification time) between them.
In fact, in the process of slow cooling of the molded product in the molded product forming part in the mold apparatus, the thickness difference between the central part of the non-functional part B and the central part of the functional part A in the central part of the non-functional part B Due to the above, the solidification rate does not proceed equally as compared with the solidification rate of the end portion of the non-functional part B, and the solidification rate of the central part of the non-functional part B becomes slower than the end part. In the vicinity of the center portion D2, the density becomes rough due to a decrease in the resin pressure, so that sink marks occur in the functional portion A.

Therefore, in the reference embodiment , paying attention to the difference in the solidification rate of the plastic molded product 1, in the front view of FIG. 1, the additional thick surfaces Ca1 to Ca2 and Cb1 to Cb2 of the additional thickened portions Ca and Cb are plastic molded products. 1 is applied to the non-functional part B, and the functional part thickness in the cross section in the direction perpendicular to the center line of the top view of FIG. 3 is constant depending on the relationship of the end part D1: Ca1-Ca2 and the central part D2: Cb1-Cb2. And The dimensional difference at the D1 position is smaller than that at the D2 position.
Thereby, when a plastic molded product having no difference in cross-sectional thickness in the cross section in the direction orthogonal to the center line L in the top view of FIG. 3 of the functional part A is formed, uniformity in the solidification timing of the molten resin is obtained. The occurrence of sink marks in the portion where the difference in thickness seen in the functional part A is reduced.
Further, as described above, the mechanism of deformation and sinking in the plastic molded product 1 is gradually cooled after filling the molded product forming portion in the mold apparatus (not shown) with a molten resin, and the molded product is taken out. This will be explained in the process up to.
The plastic molded article 1 shown in FIGS. 1 to 3 is formed of an arc-shaped functional part A and a rectangular annular (flat plate) non-functional part B. In order to obtain the plastic molded product 1, inserts corresponding to the functional part A and the non-functional part B are arranged in the forming space in the mold apparatus. In particular, since the molding surface for forming the functional part A is required to have high transferability, a nested part made with high accuracy is used, and the formation space is filled with a resin heated at a melting temperature or higher. Note that the optical functional part that can achieve high transferability is usually referred to as an optical mirror surface when the reference length is 0.08 mm and the surface roughness is Rz. It is a concept that includes a mirror surface.
In the formation space, the resin temperature begins to decrease due to the slow cooling of the molten resin, and the resin begins to solidify. In terms of time, solidification progresses in the order of the thin-walled portion to the thick-walled portion of the molded product, but the non-functional portion B corresponding to the end portion D1 has a small vertical and horizontal thickness difference in the orthogonal cross section (vertical cross section). Since the difference in solidification timing hardly occurs, the solidification is carried out under the same resin pressure state, so that the desired shape is formed.
However, D2 and the non-functional part B have a larger difference in thickness in the vertical and horizontal directions of the cross-sections orthogonal to each other than D1 and the non-functional part B, so that a difference in solidification timing occurs. For this reason, in the non-functional part where the thickness difference is large, the thin part solidifies quickly and the density becomes dense, but in the thick part that solidifies slowly, the density becomes coarse due to a decrease in the resin pressure, resulting in a corresponding function. In many cases, a desired shape cannot be obtained because the portion A is easily deformed or sinked.

Here, when attention is paid to the partial resin density difference generated due to the difference in the solidification speed of the plastic molded product, the occurrence of the resin density difference is remarkable in any cross section perpendicular to the functional part A and the non-functional part B adjacent thereto. The functional part A and the non-functional part B have a large thickness ratio. That is, the difference in the thickness of each cross section of the functional part A and the non-functional part B when the plastic molded product is cut along a line orthogonal to the center line L in FIG.
In FIG. 2, the vicinity of the central part D2 of the functional part A is the part having the largest thickness difference with respect to the central part of the non-functional part B, and is a part where a large difference occurs between the solidification speeds. In the reference embodiment , the density of both at the time of resin solidification is equalized by substantially eliminating the difference in solidification time between the central part D2 of the functional part A and the central part of the non-functional part B adjacent (continuously provided) to the functional part A. The deformation and sink marks that are likely to occur in the central part are reduced, and a highly accurate molded product is obtained.
In FIG. 1, the additional portions Ca and Cb indicated by broken lines are used to reduce the difference in the solidification rate of each part due to the difference between the cross-sectional thickness of the functional part A and the cross-sectional thickness of the non-functional part B adjacent thereto. This is a portion added to the plastic molded product 1. Assuming that Cn (n = a or b) is the non-functional part B ′ after addition, B ′ = B + Cn.
In order to make the solidification timing of the functional part A and the non-functional part B substantially uniform, as shown in the top view of FIG. 3, the widths Ca1 and Ca2 of the functional part A and the thicknesses of the additional parts Cb1 and Cb2 are set. Set.
Corresponding to the difference in the vertical cross-sectional thickness of the end part D1 and the center part D2 of the functional part A, the additional parts Ca and Cb are set to increase on both side surfaces of the functional part B, so that the functional part A and the non-functional part B The thickness ratio is constant, the solidification timing of the functional part A and the non-functional part B is almost uniform in each part of the plastic molded product, the difference in density due to resin pressure change during solidification is reduced, and sink marks and deformation are suppressed. A highly accurate molded product can be obtained.
In the reference embodiment , the ratio of the transmission direction thickness of the functional part A (lens part) and the thickness in the width direction of the non-functional part B (rib part) is kept constant so that the vertical contraction and contraction in the vertical and horizontal directions of the lens To make them equal. Rather than equalizing the vertical cross-sectional area and equalizing the time required for cooling and solidifying each part in the longitudinal direction, the aim is to improve the shape accuracy by making the partial contraction in the longitudinal and lateral directions of the lens equal in each part in the longitudinal direction.
On the other hand, in the reference embodiment , as described above, the lens portion is focused on “thickness of the longitudinal section”, and the rib portion is focused on “width” (width / thickness) viewed from the plane direction. By keeping it, we try to prevent partial shrinkage.

Figure 4 is a schematic perspective view illustrating a functional portion and a non-functional part of the implementation in the form of a plastic molded article according to the present invention. FIG. 5 is a sectional view taken along a section AA-AA ′ of the plastic molded product of FIG. FIG. 6 is an arrow view seen from the arrow AAA in FIG. FIG. 7 is a cross-sectional view taken along the section BB-BB ′ of the plastic molded product of FIG.
Implementation of forms that by the present invention, elongated by having a lens unit having an optical function of at least one surface or more high transfer resistance is required, the optical over at least one surface that is adjacent to the lens unit The present invention relates to a plastic lens 2 having a rib portion having no function.
A plastic molded product (plastic lens) 2 shown in FIGS. 4 to 7 includes a lens portion F having an optical function and a rectangular annular rib portion G having no optical function. Further, as shown in FIGS. 5 and 7, the entire outer peripheral edge of the lens portion F is integrally connected to an intermediate height position of the inner wall of the rib portion G of the rectangular annular frame type.
Further, in the aspheric plastic lens portion F shown in FIG. 7, the thicknesses of the portions ty1 to ty3 in the longitudinal direction are different. The shape of the rib part G, in particular the width (rib thickness) of the outer peripheral parts Ga and Gb, can be arbitrarily set by the optical designer for improving the strength of the lens part F or by the optical scanning device layout. Changes in the thickness Ga and Gb (rib thickness difference) are small over the entire length.
The plastic lens 2 fills the molded product forming portion (molding space) in the mold apparatus with the molding resin heated at the melting temperature or higher in the injection mold apparatus, and after the filling is completed, the resin solidification temperature. The desired shape is obtained by conventional injection molding in which a slow cooling period is provided until the temperature reaches the resin solidification temperature and the plastic lens is taken out when the resin solidification temperature is reached.

However, as described in FIG. 7, the lens portion F has a different longitudinal cross-sectional thickness along the longitudinal direction, and the relationship (thickness ratio) between the rib thickness tx and the lens thickness ty shown in FIG. It differs in the position (longitudinal direction position) which takes AA-AA '. The rib thickness tx is the rib thickness (rib width seen from the plane direction) in the section AA-AA ′ in FIG. 4, and the lens thickness ty is the lens thickness (longitudinal section) on the generatrix viewed in the section AA-AA ′ in FIG. Thickness).
When the plastic lens 2 is injection-molded, the molding resin heated at the melting temperature or higher is filled in the lens forming portion in the mold apparatus and is cooled gradually until the resin solidification temperature is reached. Since the thicknesses of the respective portions ty1 to ty3 in the longitudinal direction are different, there is a difference in the solidification timing of the molten resin with respect to the rib portion tx having a substantially uniform thickness over the entire length.
Actually, in the process of gradual cooling in the lens forming part in the mold apparatus, the longitudinal sectional thickness of the lens part F is not constant in each part in the longitudinal direction, whereas the thickness in the width direction of the rib part G is substantially uniform. Therefore, when the timing of solidification of the molten resin is ty3: tx3, the thickness of the cross section is almost uniform, so there is little difference in timing. That is, when the longitudinal cross-sectional thickness of the lens portion ty3 and the width of the rib portion tx3 are equal, the solidification time is substantially equal.
However, in the relationship between the lens portion ty1 and the corresponding rib portion tx1, the relationship between the lens portion ty2 and the corresponding lens portion tx2, there is a difference between the cross-sectional thickness and the planar width dimension. There is a difference in the time required for solidification, and due to the relationship between ty1 and tx1 and the difference in cross-sectional thickness between ty2 and tx2, solidification does not progress uniformly in each cross section, and the thickness of the lens portion is large. In the relationship between the parts ty2 and ty1 and the corresponding rib portions tx2 and tx1, the difference in the solidification speed between the lens portion and the corresponding rib portion is large, and the solidification speed is slow and in the vicinity of ty2 and ty1. In this case, the density becomes rough due to a decrease in the resin pressure, so that sink marks occur.

Therefore, the feature configuration described in Reference Embodiment, by applying to the plastic lens according to embodiment of the present invention can prevent the occurrence of sink marks. That is, the rib thickness (plane direction width) in the orthogonal direction at any point tx1 to tx3 on the lens portion bus J in FIG. 6 as viewed from the arrow AAA in FIG. 4, and the lens thickness center line K in FIG. The thickness of the rib portions Ga and Gb having no optical function so that the ratio between the lens thicknesses in the orthogonal direction at any of the above arbitrary points ty1 to ty3 becomes a constant ratio in relation to tx: ty in FIG. The thickness is controlled by varying it in the longitudinal direction.
At this time, the position of the arbitrary point in the above description is arranged at the center on the generatrix J, and at the center on the lens center line, the same base point in the longitudinal direction and the short direction. In the case of FIG. 5, the rib portions G, Ga, Gb to be controlled and the means for making the wall thickness of the cross section constant are as shown in FIG. 6 in the rib portion inner shapes la and lb and the rib portion outer shapes Ha and Hb. In this case, the thickness of the cross section may be controlled by either the rib part inner shape I or the rib part outer shape H. In other words, in order to prevent the occurrence of sink marks in each part due to the difference in thickness at the respective points tx1 to tx3 in the longitudinal direction of the lens part F, the width direction dimension of the rib part corresponding to each point tx1 to tx3 is controlled to be wide or narrow. Specifically, a method of making the thickness of each part of the rib different by changing the inner surface while keeping the outer surface of the rib part flat (FIGS. 8 and 9), and the inner surface of the rib part There is a method (FIGS. 10 and 11) in which the thickness of each part of the rib is changed by changing the outer surface while keeping the flat surface.
Further, it is possible to use a combined control of a method for deforming the rib inner shape and a method for deforming the outer shape according to the developing method. As described above, the thickness ratio of the longitudinal cross-sectional thickness ty of the lens portion to the thickness (width in the plane direction) tx of the adjacent rib portion is made constant (example in FIGS. 12 and 13). As a result, as confirmed by the configuration of the reference embodiment, in the embodiment of the present invention , the lens portion thickness ty and the length ty of the plastic lens elongated in terms of optical function over the entire length in the longitudinal direction are also provided. By obtaining a uniform thickness ratio with the thickness in the width direction (planar width) of the adjacent rib portion tx and making the solidification time of each portion substantially uniform, a highly accurate plastic molded product free from deformation and sink marks can be obtained. Can do.
In addition, the plastic lens has a lens portion F in a longitudinal section (cross section perpendicular to the generatrix J) of a lens portion F having an optical function that requires high transferability and a rib portion G that does not have an optical function adjacent thereto. The ratio of the vertical cross-sectional thickness to the thickness in the width direction of the rib portion G is controlled to be constant by variously changing the inner shape (the thickness of the rib portion) of the rib portion G.

The plastic molding method in the embodiment of the present invention is the same as the injection molding method described in the operation of the reference embodiment , and FIG. 4 shows a plastic lens obtained by the injection molding. The generation mechanism of deformation and sink marks is the same as that described in the operation of the reference embodiment .
As can be seen from FIG. 7, since the cross-sectional lens thickness in the direction orthogonal to the plastic lens center line K is different in each part, the rib part G is formed in a rectangular annular frame shape. In the lens body, sinking and deformation are likely to occur in each of the longitudinal portions ty2 and ty1 having a longitudinal section thickness different from the thickness in the width direction of the rib portion, and the width direction thickness and the longitudinal section thickness of the rib portion are almost equal. In the vicinity of the equivalent central portion ty3, it is difficult to sink or deform.
Here, the relationship between the width and thickness of the rib portion tx in FIG. 5 adjacent to each portion ty in FIG. 7 and the thickness at the lens portion ty is that the thickness of the rib portion is tx and the center thickness of the lens portion is ty. Sometimes, the thickness ratio R of both is represented by R = ty / tx. At this time, the thickness (plane width) tx of the rib portion G is changed according to the change of the lens thickness ty so that the ratio of the maximum value and the minimum value of R in each cross section becomes Rmax / Rmin <1.2. Is desirable.
Although the width and thickness of the rib portion in FIG. 5 seems to be drawn constant, the width and thickness of the rib portion are not uniform because the die-cutting direction is the vertical direction in FIG. Tend to be thin.
From the above relationship, the thickness ratio between the lens thickness ty and the rib thickness tx adjacent to the lens thickness ty can be optimized, and the thickness ty of the short cross section with respect to the longitudinal direction of the elongated plastic lens is considered in terms of optical function. Since the rib thickness tx can be designed, a highly accurate product can be obtained.

In FIG. 8, the thickness ratio between the lens part and the rib part is controlled by partially changing the inner shape (degree of protrusion inward) of the rib part that does not have an optical function to form the plastic lens body. It is the schematic which shows the example which is. In FIG. 8, the thickness ratio with the lens surface is controlled by providing a curved rib surface (inner curved rib portion inner shape) L inside the rib portion G of the plastic lens 2. In other words, by changing the amount of protrusion to the inside of the rib inner wall in a curved manner according to the change in the thickness of the lens part, the longitudinal cross-sectional thickness of the lens part in each part in the longitudinal direction, the width thickness of the rib part, The ratio is controlled to be uniform.
The configuration of the curved surface of the rib inner wall may be a set of large and small arcs or ellipses according to the thickness control, and may not be an arc or ellipse having an accurate contour. In FIG. 8, H is the rib portion outer shape, J is the bus bar, and tx1, tx2, and tx3 are rib portion outer thicknesses.
In the plastic lens lengthened in terms of optical function, the thickness of the lens portion in each short cross section (cross section along the line perpendicular to the longitudinal direction) and the width of the rib portion G having no optical function adjacent thereto By making the ratio with thickness constant and equalizing the solidification time of each part, it is possible to obtain a highly accurate plastic molded product free from deformation and sink.
FIG. 9 is a schematic diagram for explaining that the thickness ratio between the lens portion and the rib portion is controlled by the inner shape of the rib portion having no optical function for forming the plastic lens body. By providing the discontinuous rib surface M inside the rib portion G of the plastic lens 2, the thickness ratio with the lens surface is controlled.
Further, the configuration of the discontinuous surface may be a set of large and small cubic shapes or rectangular shapes according to the thickness control, and the corner portion may not be an edge. In FIG. 9, J represents a bus bar, and tx1, tx2, and tx3 represent rib portion outer thicknesses.
The inner thickness of the rib part G that does not have an optical function for forming the plastic lens body is laminated on a discontinuous plane, so that the lens thickness in each short cross section is increased with a plastic lens that is elongated in terms of optical function. In addition, the solidification timing in the orthogonal direction of the rib portion G having no optical function adjacent thereto can be made substantially uniform, and a highly accurate plastic molded product free from deformation and sink can be obtained.
Further, the plastic lens 2 has a plastic thickness ratio between the lens portion and the rib portion in an arbitrary cross section perpendicular to the lens portion having an optical function that requires high transferability and the rib portion having no optical function adjacent thereto. The outer shape of the rib portion that does not have an optical function for forming the lens body is controlled.

FIG. 10 is a schematic diagram for explaining that the thickness ratio between the lens portion and the rib portion is controlled by the outer shape of the rib portion having no optical function for forming the plastic lens body. By providing a curved rib surface (outer curved rib portion outer shape) N on the outside of the rib portion G of the plastic lens 2, the thickness ratio with the lens surface is controlled.
Further, the curved surface may be configured as a set of large and small arcs or ellipses according to the thickness control, and the shape portion may not be an arc or ellipse having an accurate contour. In FIG. 10, I is the rib part inner shape, J is the bus bar, tx1, tx2, and tx3 are the rib part outer thicknesses.
In this plastic molded product (plastic lens), the thickness ratio of the lens part to the rib part in the arbitrary cross section perpendicular to the lens part having an optical function that requires high transferability and the rib part not having the optical function is the main body. The outer shape of the rib portion having no optical function is controlled.
This makes the lens thickness in each short cross section and the solidification timing in the orthogonal direction of the rib part that does not have the optical function adjacent to each other in the plastic lens elongated in terms of optical function almost uniform, and there is no deformation or sink. An accurate plastic molded product can be obtained.
The plastic molded product (plastic lens) 2 has a thickness of the lens portion and the rib portion in an arbitrary cross section orthogonal to the lens portion having an optical function required to have high transferability and the adjacent rib portion having no optical function. The ratio is controlled by the inner shape of the rib portion having no optical function to form the plastic lens body.

FIG. 11 is a schematic diagram for explaining that the thickness ratio between the lens portion and the rib portion is controlled by the outer shape of the rib portion having no optical function for forming the plastic lens body. By providing a discontinuous rib surface (discontinuous rib outer shape) O outside the rib portion G of the plastic lens 2, the thickness ratio with the lens surface is controlled.
In addition, the discontinuous surface may be a large or small cubic shape or a rectangular shape depending on the thickness control, and the corner portion may be rounded instead of square. In FIG. 11, I is the rib part inner shape, J is the bus bar, tx1, tx2, tx3, and tx4 are the rib part outer thicknesses.
In this plastic molded product (plastic lens), the outer shape of the rib portion that does not have an optical function for forming the plastic lens body is laminated on a discontinuous plane. As a result, in terms of optical function, the lens thickness in each short cross-section of the plastic lens that has been elongated and the solidification timing in the orthogonal direction of the rib portion that does not have an optical function adjacent thereto are almost uniform, and there is no deformation or sink. A highly accurate plastic molded product can be obtained.
The plastic molded product (plastic lens) 2 has a thickness of the lens portion and the rib portion in an arbitrary cross section orthogonal to the lens portion having an optical function required to have high transferability and the adjacent rib portion having no optical function. The ratio is controlled by the outer shape of the rib portion having no optical function for forming the plastic lens body.

FIG. 12 is a schematic diagram for explaining that the thickness ratio between the lens portion and the rib portion is controlled by the inner shape and the outer shape of the rib portion having no optical function for forming the plastic lens body. By providing the curved rib surface (inner shape of the curved rib portion) L and the curved rib surface (outer shape of the curved rib portion) N on the inner side and the outer side of the rib portion G of the plastic lens 2, the thickness ratio with the lens surface is controlled.
Further, the curved surface may be a set of large and small arcs or ellipses according to the thickness control, and the shape portion may not be an arc or ellipse having an accurate contour. In FIG. 12, J represents a bus bar, and tx1, tx2, and tx3 represent rib portion outer thicknesses.
In this plastic molded product (plastic lens), the thickness ratio of the lens part to the rib part in the arbitrary cross section perpendicular to the lens part having an optical function that requires high transferability and the rib part not having the optical function is the main body. The outer shape of the rib portion having no optical function is controlled.
This makes the lens thickness in each short cross section and the solidification timing in the orthogonal direction of the rib part that does not have the optical function adjacent to each other in the plastic lens elongated in terms of optical function almost uniform, and there is no deformation or sink. An accurate plastic molded product can be obtained.
The plastic molded product (plastic lens) 2 has a thickness of the lens portion and the rib portion in an arbitrary cross section orthogonal to the lens portion having an optical function required to have high transferability and the rib portion adjacent to the lens portion having no optical function. The ratio is controlled by the inner shape of the rib portion having no optical function to form the plastic lens body.

FIG. 13 is a schematic diagram for explaining that the thickness ratio between the lens portion and the rib portion is controlled by the inner shape and the outer shape of the rib portion having no optical function for forming the plastic lens body. By providing a discontinuous rib surface (discontinuous rib inner shape) M and a discontinuous rib surface (discontinuous rib outer shape) O on the inner and outer sides of the rib part G of the plastic lens 2, the thickness ratio with the lens surface is controlled. ing.
Further, the discontinuous surface may be configured as a set of large and small cubic shapes or rectangular shapes according to the thickness control, and the corner portion may not be an edge. In FIG. 13, J indicates a bus, and tx1, tx2, and tx3 indicate rib portion outer thicknesses.
In this plastic molded product (plastic lens), the inner and outer shapes of rib portions that do not have an optical function for forming a plastic lens body are laminated on a discontinuous plane. As a result, in terms of optical function, the lens thickness in each short cross-section of the plastic lens that has been elongated and the solidification timing in the orthogonal direction of the rib portion that does not have an optical function adjacent thereto are almost uniform, and there is no deformation or sink. A highly accurate plastic molded product can be obtained.
In the shape as shown in FIGS. 10 to 13 described above, the cross-sectional area ratio is larger than that of the original shape, which is different from the conventional techniques of Patent Documents 1 and 2. The present invention is intended to keep the cooling state in each part uniform in the cooling process of the optical plastic component, thereby suppressing molding defects and shape deformation (deterioration of shape accuracy) and achieving a shorter tact time. It becomes possible.

It is a schematic front view for explaining the function portion and a non-functional portion of the referential embodiment of the plastic molded article. It is a side view of the plastic molded product of FIG. (A) is a top view of the plastic molded article of FIG. 1, (b) is a perspective view. It is a schematic perspective view illustrating a functional portion and a non-functional part of the implementation in the form of a plastic molded article according to the present invention. It is sectional drawing which follows the cross section AA-AA 'of the plastic molded product of FIG. FIG. 5 is an arrow view seen from the arrow AAA in FIG. 4. FIG. 5 is a sectional view taken along a section BB-BB ′ of the plastic molded product of FIG. 4. It is the schematic explaining that the thickness ratio of a lens part and a rib part is controlled by the internal shape of the rib part which does not have the optical function which forms a plastic lens main body. It is the schematic explaining that the thickness ratio of a lens part and a rib part is controlled by the internal shape of the rib part which does not have the optical function which forms a plastic lens main body. It is the schematic explaining that the thickness ratio of a lens part and a rib part is controlled by the external shape of the rib part which does not have the optical function which forms a plastic lens main body. It is the schematic explaining that the thickness ratio of a lens part and a rib part is controlled by the external shape of the rib part which does not have the optical function which forms a plastic lens main body. It is the schematic explaining that the thickness ratio of a lens part and a rib part is controlled by the inner shape and outer shape of the rib part which does not have the optical function which forms a plastic lens main body. It is the schematic explaining that the thickness ratio of a lens part and a rib part is controlled by the inner shape and outer shape of the rib part which does not have the optical function which forms a plastic lens main body.

Explanation of symbols

1 Plastic molded product 2 Plastic molded product (plastic lens)
A Functional part B Non-functional part CA Additional thickness part Cb Additional thickness part D1 Functional surface thickness D2 Functional surface thickness F Lens part G Rib part H Rib part outline I Rib part inner shape K Lens thickness center line L Internal curved rib Inner part type M Inner discontinuous rib part inner form N Outer curved rib part outer shape O Discontinuous rib part outer shape

Claims (6)

In a plastic lens having an elongated lens portion requiring at least one surface with high transferability and at least one rib portion adjacent to the lens portion, the thickness of the lens portion in the optical axis direction And the thickness ratio of the rib portion in the direction perpendicular to the optical axis direction is controlled by changing the inner shape of the rib portion corresponding to the change in the thickness of the lens portion. and, a plastic lens, characterized in that set to be constant at each longitudinal position. Internal shape of the rib portion, the plastic lens according to claim 1, characterized in that it is constituted by continuously provided multiple facets discontinuously. In a plastic lens having an elongated lens portion requiring at least one surface with high transferability and at least one rib portion adjacent to the lens portion, the thickness of the lens portion in the optical axis direction And the thickness ratio of the rib portion in the direction orthogonal to the optical axis direction, and the thickness ratio of the lens portion to the rib portion is the outer shape of the rib portion forming the plastic lens body A plastic lens that is controlled by changing and is set constant at each longitudinal position. 4. The plastic lens according to claim 3, wherein the outer shape of the rib portion is constituted by discontinuously connecting a plurality of small planes. In a plastic lens having an elongated lens portion requiring at least one surface with high transferability and at least one rib portion adjacent to the lens portion, the thickness of the lens portion in the optical axis direction And the thickness ratio of the rib portion in the direction perpendicular to the optical axis direction, and the thickness ratio of the lens portion to the rib portion is the inner diameter of the rib portion forming the plastic lens body. A plastic lens which is controlled by changing a shape and an outer shape, and is set to be constant at each longitudinal position. 6. The plastic lens according to claim 5, wherein an inner shape and an outer shape of the rib portion are formed by discontinuously connecting a plurality of small planes.

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