JPH0643079B2 - Resin polygonal column, its manufacturing method and its molding die - Google Patents
Resin polygonal column, its manufacturing method and its molding dieInfo
- Publication number
- JPH0643079B2 JPH0643079B2 JP1062156A JP6215689A JPH0643079B2 JP H0643079 B2 JPH0643079 B2 JP H0643079B2 JP 1062156 A JP1062156 A JP 1062156A JP 6215689 A JP6215689 A JP 6215689A JP H0643079 B2 JPH0643079 B2 JP H0643079B2
- Authority
- JP
- Japan
- Prior art keywords
- polygonal columnar
- resin
- molding
- polygonal
- central axis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Optical Elements Other Than Lenses (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、樹脂性の、例えばポリゴンミラー等のような
多角柱状物に、または、その製造方法に、またはその成
形に用いられる成形型に関し、特に、成形時の引けに起
因する表面の平面度の低下の防止に関する。TECHNICAL FIELD The present invention relates to a resin, for example, a polygonal columnar object such as a polygon mirror, a manufacturing method thereof, or a molding die used for molding the same. In particular, it relates to prevention of reduction in flatness of the surface due to shrinkage during molding.
［従来の技術］ 例えばレーザビームプリンタ等に使われるポリゴンミラ
ーの平面度に対する要求精度はおよそ、λ／３〜λ／８
（ビームの波長を例えば６３３ｎｍ）と言われている。[Prior Art] For example, the required accuracy for flatness of a polygon mirror used in a laser beam printer or the like is approximately λ / 3 to λ / 8.
(The wavelength of the beam is, for example, 633 nm).
一方、ポリゴンミラーは最近コストの低減の要請から合
成樹脂製のものが提案されている。On the other hand, recently, a polygon mirror made of synthetic resin has been proposed in order to reduce the cost.
また、本願出願人は実開平６３−９８５１９号の「回転
多面反射鏡体の構造」において、プラスチック製の回転
多面反射鏡体を提案している。Further, the applicant of the present application has proposed a rotating polygonal reflecting mirror body made of plastic in "Structure of the rotating polygonal reflecting mirror body" of Japanese Utility Model Laid-Open No. 63-98519.
［発明が解決しようとする課題］ ところが、このポリゴンミラーを例えば射出成形で成形
する場合には、成形収縮による「引け」により要求精度
を満たすことができない。[Problems to be Solved by the Invention] However, when this polygon mirror is molded by, for example, injection molding, the required accuracy cannot be satisfied due to "shrinkage" due to molding shrinkage.
第４図は、この「引け」による平面度の低下を現象的に
説明する図である。図中、１００はポリゴンミラーであ
り、同図には、その平面が示されている。また、１，
２，…６はポリゴンミラー１００の６つの側壁面であ
る。また、１０〜１５の各々は２つの壁面の接合部で、
この接合部は、ポリゴンミラー１００の回転中心２０に
平行な直線である。「引け」により、成形後は、例えば
壁面１の形状は３０のような凹面状となる。FIG. 4 is a diagram for explaining the decrease in flatness due to the "closed" phenomenon. In the figure, 100 is a polygon mirror, and its plane is shown in the figure. Also, 1,
2, 6 are six side wall surfaces of the polygon mirror 100. Further, each of 10 to 15 is a joint portion of two wall surfaces,
This joint is a straight line parallel to the rotation center 20 of the polygon mirror 100. Due to the “shrinking”, the shape of the wall surface 1 becomes a concave shape such as 30 after molding.
このために、壁面の平面度は、もはや、λ／３〜λ／８
を保てない。そして、かかる問題は、ポリゴンミラーに
限られず、樹脂製のもので多角柱状のものであれば、全
てに伴う問題である。For this reason, the flatness of the wall surface is no longer λ / 3 to λ / 8.
Can't keep The problem is not limited to the polygon mirror, but is a problem associated with any resin-made polygonal prism.
そこで、本発明は、収縮力の不均一による多角柱状物の
側壁面の平面度の低下の防止を、形状の変更により回避
したものである。Therefore, the present invention avoids the reduction of the flatness of the side wall surface of the polygonal columnar body due to the non-uniform contracting force by changing the shape.
［課題を達成するための手段及び作用］ 上述した課題を達成するために、本発明の多角柱状物は
本体が射出成形された樹脂からなり、複数の矩形面を表
面とする多角柱状の形状をした多角柱状物であって、矩
形面同士の接合部において、成形収縮時の引け応力を逃
がすために、多角柱状物の中心軸に対して略平行で、か
つ表面から前記中心軸方向と反対方向に伸びた突起部を
設けている。[Means and Actions for Achieving the Object] In order to achieve the above-mentioned object, the polygonal columnar article of the present invention has a main body made of an injection-molded resin and has a polygonal columnar shape having a plurality of rectangular surfaces as the surface. A polygonal columnar article, which is substantially parallel to the central axis of the polygonal columnar body in the joint portion between the rectangular surfaces so as to release shrinkage stress at the time of molding shrinkage, and in a direction opposite to the central axis direction from the surface. It is provided with a protruding part.
また、好ましくは、本体が樹脂からなる多角柱状物の製
造方法であって、多角柱状物の矩形面同士の接合部に対
応する型部分に、樹脂の成形収縮時の引け応力を逃がす
ための切欠部または突起部が形成された型に対して、高
圧の樹脂を射出すると共に、この射出圧力を、矩形面に
対し弾性回復による応力が成形後に凹状分布に発生する
程度に設定している。Further, preferably, in the method for manufacturing a polygonal columnar body whose main body is made of resin, a notch for escaping shrinkage stress at the time of molding shrinkage of the resin in a mold portion corresponding to a joint portion between rectangular surfaces of the polygonal columnar article. High-pressure resin is injected into the mold in which the parts or protrusions are formed, and the injection pressure is set to such an extent that the stress due to elastic recovery on the rectangular surface is generated in a concave distribution after molding.
また、好ましくは、複数の矩形面を表面とする多角柱物
を射出成形するための成形型であって、この多角柱状物
の矩形面同士の接合部に対応する型部分に、樹脂の成形
収縮時の引け応力を逃がす切欠部または突起部が形成さ
れている。Further, preferably, a molding die for injection-molding a polygonal columnar object having a plurality of rectangular surfaces as a surface, in which a resin molding shrinkage is applied to a die portion corresponding to a joint portion between the rectangular surfaces of the polygonal columnar object. Notches or protrusions are formed to release shrinkage stress.
また、好ましくは、成形型の切欠部は、型部の柱方向の
中心軸に平行で、表面から軸方向に伸びている。Further, preferably, the cutout portion of the molding die is parallel to the central axis of the die portion in the column direction and extends axially from the surface.
そして、好ましくは、成形型の突起部は、型部の柱方向
の中心軸に平行で、表面から中心軸方向と反対方向に伸
びている。And preferably, the protrusion of the mold is parallel to the central axis of the mold in the column direction and extends from the surface in the direction opposite to the central axis.
［実施例］ 以下添付図面を参照して、本発明を、ポリゴンミラーに
適用した実施例について説明する。[Embodiment] An embodiment in which the present invention is applied to a polygon mirror will be described below with reference to the accompanying drawings.
本願の発明者の観察によると、収縮応力について見れ
ば、中心軸２０から見て、各方向について内部応力は均
一であると考えられる。第４図の例では、 Ｆａ≒Ｆｂ である。しかし、製品形状による「補強効果」が発生し
て、この効果が上記均一な応力とあいまって、不均一な
収縮力を発生すると考えた。According to the observation of the inventor of the present application, regarding the contraction stress, it is considered that the internal stress is uniform in each direction when viewed from the central axis 20. In the example of FIG. 4, F a ≈F b . However, it was considered that a "reinforcing effect" due to the shape of the product occurs, and this effect is combined with the above-mentioned uniform stress to generate an uneven contracting force.
第５図は、この補強効果の発生を説明する図である。第
５図において、点Ａ，Ｂを支点として、射出圧力に起因
する等分布荷重Ｗ（Kg/cm）が作用すると、中央の点で
最大曲げモーメントＭmaxが発生する。FIG. 5 is a diagram for explaining the occurrence of this reinforcing effect. In FIG. 5, when the uniformly distributed load W (Kg / cm) caused by the injection pressure acts on the points A and B as fulcrums, the maximum bending moment M max occurs at the central point.
これが、側壁面の凹状の原因になる。 This causes the side wall surface to be concave.
発明者は、成形加工時に高圧力を加えると、収縮が減少
し、また、弾性回復により平面精度が若干向上すること
を見出したが、まだ完全ではなかった。そこで、この補
強効果を実質的に除去するために、ポリゴンミラーの形
状、特に、接合部の形状を変更した。The inventor has found that when high pressure is applied during the molding process, shrinkage is reduced, and the plane accuracy is slightly improved due to elastic recovery, but it has not been completed yet. Therefore, in order to substantially eliminate this reinforcing effect, the shape of the polygon mirror, in particular, the shape of the joint portion was changed.
第１Ａ図はその一例の平面図を示す。１〜６はポリゴン
ミラーの側壁面である。第１Ｂ図に斜視図を示す。第２
図及び第３Ａ図，第３Ｂ図は他の実施例のポリゴンミラ
ーの構造を示す。第１図の実施例は断面形状が略半楕円
の切り欠きである。第２図は断面形状が三角形の切り欠
きである。第３図は断面形状が略Ｍ字形の突状である。FIG. 1A shows a plan view of the example. Reference numerals 1 to 6 are side wall surfaces of the polygon mirror. A perspective view is shown in FIG. 1B. Second
FIGS. 3A and 3B show the structure of a polygon mirror of another embodiment. The embodiment shown in FIG. 1 is a notch having a substantially semi-elliptical cross section. FIG. 2 shows a notch having a triangular cross section. FIG. 3 shows a protrusion having a substantially M-shaped cross section.
これらの図面に示された接合部の切り欠き若しくは突状
により、補強効果は分散され、結果として凹面形状は回
復し、平面精度はポリゴンミラーとして実用上問題無い
程度にまで向上した。Due to the notch or protrusion of the joint shown in these drawings, the reinforcing effect is dispersed, the concave shape is restored as a result, and the plane accuracy is improved to the extent that there is no practical problem as a polygon mirror.
尚、成形時に、金型内樹脂圧力を１０００Kg/cm2にまで
高めると、弾性回復により、第１Ａ図の点線５０のよう
な膨張力が働く。この高圧の射出圧力に伴なう弾性回復
により、平面精度は更に向上する。即ち、換言すれば、
ポリゴンミラーの反射面同士の接合部の切り欠き（若し
くは突状）形状の効果と、成形加工時の圧力条件でポリ
ゴンミラーの平面度（反り）の調整が可能となる。If the resin pressure in the mold is increased to 1000 kg / cm 2 during molding, elastic recovery causes expansion force as shown by the dotted line 50 in FIG. 1A. The plane accuracy is further improved by the elastic recovery accompanying the high injection pressure. That is, in other words,
It becomes possible to adjust the flatness (warp) of the polygon mirror by the effect of the notch (or projecting) shape of the joining portion between the reflecting surfaces of the polygon mirror and the pressure condition during molding.
また、本発明をポリゴンミラーに適用した場合に、壁面
の接合部の切り欠き若しくは突状部分にレーザビームが
当って反射した場合に、その反射光が感光体方向に向く
恐れがある。そこで、前記切り欠き若しくは突状部分部
分には、アルミニュームの蒸着は行なわないとか、また
は、積極的に反射防止の塗料を塗布する等の加工を行な
う。Further, when the present invention is applied to a polygon mirror, when the laser beam hits a notch or a projecting portion of the joint portion of the wall surface and is reflected, the reflected light may be directed toward the photoconductor. Therefore, aluminum is not vapor-deposited or the anti-reflection coating is positively applied to the notch or the protruding portion.
本発明は、また、第１図〜第３図に示したような成形物
を成形するための型も提案する。この型の形状は、第１
図〜第３図に示した成形物の形状と同じでよい。そし
て、射出口は回転中心付近に設ける。The present invention also proposes a mold for molding a molding as shown in FIGS. The shape of this mold is
It may have the same shape as that of the molded product shown in FIGS. The injection port is provided near the center of rotation.
［発明の効果］ 以上説明したように、本発明によれば、本発明をポリゴ
ンミラーを含む樹脂製の多角柱状物に適用した場合は、
その効果として、側壁面の平面精度が要求値を満たすこ
とが可能となる。[Effects of the Invention] As described above, according to the present invention, when the present invention is applied to a resin-made polygonal columnar article including a polygon mirror,
As a result, the plane accuracy of the side wall surface can satisfy the required value.
即ち、平面度の高い多角柱物もしくはそのような物を作
るための成形型を提供できる。That is, it is possible to provide a polygonal prism having a high degree of flatness or a molding die for making such a prism.
また、上記型を用い、更に、高射出圧力に設定すると、
平面精度の更なる向上が得られる。In addition, when using the above mold and setting a high injection pressure,
Further improvement of plane accuracy can be obtained.
第１Ａ図，第１Ｂ図は本発明の一実施例に係るポリゴン
ミラーの平面図及び斜視図、 第２図は他の実施例の形状を示す平面図、 第３Ａ図，第３Ｂ図は本発明の更に他の実施例に係るポ
リゴンミラーの平面図及び斜視図、 第４図，第５図は従来技術に係るポリゴンミラーの形状
及び欠点を説明する図である。 図中、 １〜６……側壁面、１０〜１５……壁面接合部、２０…
…回転中心、４１〜４６，５１〜５６……切り欠き、６
１〜６６……突状、１００……ポリゴンミラーである。1A and 1B are a plan view and a perspective view of a polygon mirror according to one embodiment of the present invention, FIG. 2 is a plan view showing the shape of another embodiment, and FIGS. 3A and 3B are the present invention. FIG. 4 is a plan view and a perspective view of a polygon mirror according to still another embodiment of the present invention, and FIGS. 4 and 5 are views for explaining the shape and defects of the conventional polygon mirror. In the figure, 1 to 6 ... Side wall surface, 10 to 15 ... Wall surface joint portion, 20 ...
… Rotation centers 41-46, 51-56 …… Notches, 6
1 to 66 ... Projection, 100 ... Polygon mirror.
Claims (5)
の矩形面を表面とする多角柱状の形状をした多角柱状物
であって、 前記矩形面同士の接合部において、成形収縮時の引け応
力を逃がすために、該多角柱状物の中心軸に対して略平
行で、かつ表面から前記中心軸方向と反対方向に伸びた
突起部を設けたことを特徴とする樹脂性多角柱状物。1. A polygonal columnar article having a polygonal columnar shape having a plurality of rectangular planes as a surface, the main body being made of an injection-molded resin, wherein the joint between the rectangular planes has a shrinkage during molding contraction. In order to release stress, a resinous polygonal columnar article is provided, which is provided with a projection portion which is substantially parallel to the central axis of the polygonal columnar article and which extends from the surface in a direction opposite to the central axis direction.
であって、 該多角柱状物の矩形面同士の接合部に対応する型部分
に、樹脂の成形収縮時の引け応力を逃がすための切欠部
または突起部が形成された型に対して、高圧の樹脂を射
出すると共に、 この射出圧力を、前記矩形面に対し弾性回復による応力
が成形後に凹状分布に発生する程度に設定したことを特
徴とする樹脂性多角柱状物の製造方法。2. A method of manufacturing a polygonal columnar body, the main body of which is made of resin, for releasing shrinkage stress at the time of molding shrinkage of the resin to a mold portion corresponding to a joint portion between rectangular surfaces of the polygonal columnar article. High-pressure resin is injected into the mold with the cutouts or projections, and the injection pressure is set to such a degree that the stress due to elastic recovery on the rectangular surface is generated in the concave distribution after molding. A method for producing a resinous polygonal column having the characteristics.
成形するための成形型であって、 この多角柱状物の矩形面同士の接合部に対応する型部分
に、樹脂の成形収縮時の引け応力を逃がす切欠部または
突起部が形成されたことを特徴とする多角柱状物用の成
形型。3. A molding die for injection-molding a polygonal columnar object having a plurality of rectangular surfaces as a surface, wherein molding die shrinkage of resin is applied to a die portion corresponding to a joint portion between the rectangular surfaces of the polygonal columnar object. A molding die for a polygonal columnar article, characterized in that a notch or a protrusion is formed to release shrinkage stress at the time.
に平行で、表面から軸方向に伸びていることを特徴とす
る請求項の第３項に記載の樹脂性多角柱状物用の成形
型。4. The resinous polygonal columnar article according to claim 3, wherein the cutout portion is parallel to the central axis of the mold portion in the column direction and extends from the surface in the axial direction. Molds for.
に平行で、表面から中心軸方向と反対方向に伸びている
ことを特徴とする請求項の第３項に記載の樹脂性多角柱
状物用の成形型。5. The resin according to claim 3, wherein the protruding portion is parallel to a central axis of the mold portion in the column direction and extends from the surface in a direction opposite to the central axis direction. Mold for flexible polygonal column.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1062156A JPH0643079B2 (en) | 1989-03-16 | 1989-03-16 | Resin polygonal column, its manufacturing method and its molding die |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1062156A JPH0643079B2 (en) | 1989-03-16 | 1989-03-16 | Resin polygonal column, its manufacturing method and its molding die |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02241714A JPH02241714A (en) | 1990-09-26 |
| JPH0643079B2 true JPH0643079B2 (en) | 1994-06-08 |
Family
ID=13191970
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1062156A Expired - Fee Related JPH0643079B2 (en) | 1989-03-16 | 1989-03-16 | Resin polygonal column, its manufacturing method and its molding die |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0643079B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2019191335A (en) * | 2018-04-24 | 2019-10-31 | キヤノン株式会社 | Method for manufacturing polygon mirror, polygon mirror, deflector, optical scanner and image formation device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5832912Y2 (en) * | 1975-09-26 | 1983-07-22 | 株式会社日立製作所 | Boss shape of plastic injection molded products |
-
1989
- 1989-03-16 JP JP1062156A patent/JPH0643079B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2019191335A (en) * | 2018-04-24 | 2019-10-31 | キヤノン株式会社 | Method for manufacturing polygon mirror, polygon mirror, deflector, optical scanner and image formation device |
| EP3561555A3 (en) * | 2018-04-24 | 2020-03-18 | Canon Kabushiki Kaisha | Manufacturing method of polygonal mirror, polygonal mirror, deflector, optical scanning apparatus and image forming apparatus |
| US11383413B2 (en) | 2018-04-24 | 2022-07-12 | Canon Kabushiki Kaisha | Manufacturing method of polygonal mirror, polygonal mirror, deflector, optical scanning apparatus and image forming apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02241714A (en) | 1990-09-26 |
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