JPH0398011A - Polygon mirror - Google Patents

Abstract

PURPOSE:To evade discontinuous cutting and to work an object surface with high flatness accuracy by forming a relief groove which is deeper than a working margin to width covering a hole concentrically with the center of rotation of a polygon mirror. CONSTITUTION:The relief groove 7 which is wider than the diameter of the hole 3 and has depth (t) larger than the working margin is formed concentrically with the axis 0 of rotation. Consequently, the surface 1 is fitted to a spindle 4 by a vacuum by aligning the axis 0 of rotation with the center of rotation of the spindle and when the surface is cut while rotated, a cutting tool 6 moves along the relief groove 7, so intermittent cutting is evaded. Lapping is the same in this regard. Consequently, the discontinuous cutting is not performed, so a defect in the working state of the periphery of the hole is eliminated and overall plane accuracy is secured.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は工作精度が要求されるポリゴンミラーに関する
． （従来の技術） 各種プリンタや画像読取手段のスキャナーに用いられる
ポリゴンミラーはモーター側のフランジ面に取り付けて
回転廓動されるが、この取付けに際し、モーター側、ミ
ラー側両者につき、各取付面の平面度が出ていないと所
請面倒れを生ずる等の不都合を生ずる． この取付けに関する公知技術としては、特開昭６２−２
０４２２４号公報、特開昭６３−３２５１６３号公報、
実開昭６３−１２２８１３号公報に開示のものがあるが
、これらは何れもモーター側のフランジ形状に関するも
のであり、もう一方の取付面であるポリゴンミラーに関
するものではない． ポリゴンミラーは良く知られるように第２図に示す如き
形状をしている．第２図（ａ）は第２図（ｂ）のＡ−Ａ
矢視断面を示す．同図中，符号Ｍはミラー面を示し、符
号ｌを表面、符号２を裏面とする． 裏面２がモーター側フランジ面への取付面であり、高度
な平面度を要求される．当該ポリゴンミラーには、表面
ｌから裏面２へ貫通する取付用の穴３が回転軸○から等
距離かつ円周上等間隔に３つあけてある． 基準面たる裏面２の加工は切削ないしはラップ仕上げで
行なわれる。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a polygon mirror that requires high machining accuracy. (Prior art) Polygon mirrors used in various printers and scanners for image reading means are attached to the flange surface on the motor side and rotated. If flatness is not achieved, inconveniences such as unevenness of the required surface will occur. As a known technique regarding this installation, Japanese Patent Application Laid-Open No. 62-2
No. 04224, Japanese Unexamined Patent Publication No. 63-325163,
There are some disclosures in Japanese Utility Model Application Publication No. 122813/1982, but these are all related to the flange shape on the motor side, and do not relate to the polygon mirror that is the other mounting surface. As is well known, a polygon mirror has a shape as shown in Figure 2. Figure 2(a) is A-A in Figure 2(b)
The cross section is shown in the direction of arrows. In the figure, the symbol M indicates a mirror surface, the symbol 1 is the front surface, and the symbol 2 is the back surface. Back surface 2 is the mounting surface for the motor side flange surface, and requires a high degree of flatness. The polygon mirror has three mounting holes 3 penetrating from the front surface 1 to the back surface 2 at equal distances from the rotation axis ○ and at equal intervals on the circumference. The back surface 2, which is the reference surface, is processed by cutting or lapping.

加工に際しては、例えば第３図に示されるように工作機
械のスピンドル４にポリゴンミラーの表面１を真空チャ
ックで取付け，スピンドルを回転させると同時にバイト
６に矢印Ｂの送りをかけつつ切削を行なう． （発明が解決しようとする課Ｍ） 前記第３図に示す如き加工法では，切削面３があるため
第４図に斜線で示した領域が断続切削となり，切削抵抗
の変動を生じ結果として平面度を所要の精度におさめる
ことが困難であるとの問題がある． 同様にラップ加工においても第５図に斜線で示した穴３
の周辺領域に砥粒が溜り易くなり，加工が他よりも進み
、結果として当該部分が他より凹んだ状態となって平面
度をだし難いとの問題がある． なお、この問題に対処する方法の一案として穴加工を平
面加工の後にすることも考えられるが、せっかく平面度
をだしても、穴加工時の熱変形で平面度が崩れることか
ら実際的でない．本発明は基準面として高精度の平面度
を要求される被加工面に穴が形成されているポリゴンミ
ラーにおいて、この穴に起因する平面度の加工不良を解
消することのできるポリゴンミラーを提供することを目
的とする。During machining, the surface 1 of the polygon mirror is attached to the spindle 4 of a machine tool using a vacuum chuck, as shown in FIG. (Problem M to be Solved by the Invention) In the machining method shown in FIG. 3 above, since there is a cutting surface 3, the shaded area in FIG. The problem is that it is difficult to keep the degree of accuracy within the required level. Similarly, in lapping processing, hole 3 shown with diagonal lines in Fig.
The problem is that abrasive grains tend to accumulate in the surrounding area, processing progresses more than other areas, and as a result, that area becomes more concave than others, making it difficult to achieve flatness. Note that one possible way to deal with this problem is to perform hole drilling after flat surface machining, but even if you go to great lengths to achieve flatness, it is impractical because the flatness will collapse due to thermal deformation during hole drilling. ．． The present invention provides a polygon mirror in which a hole is formed in a processed surface that requires highly accurate flatness as a reference surface, and can eliminate flatness processing defects caused by the hole. The purpose is to

（課題を解決するための手段） 上記目的を達成するために、本発明に係るポリゴンミラ
ーについては、穴を包含する幅でかっ、加工代よりも深
い深さの逃げ溝を加工時の工具または当該ポリゴンミラ
ーの回転中心と同心状に形成することとした。(Means for Solving the Problems) In order to achieve the above object, in the polygon mirror according to the present invention, a relief groove with a width that includes the hole and a depth that is deeper than the machining allowance is formed using a tool during machining or It was decided to form it concentrically with the rotation center of the polygon mirror.

（作　用） 穴は切削工具の軌跡上に形成された逃げ溝中にあり，断
続切削を生ぜしぬる穴としては存在しなくなる． （実　施　例） 第１図に示すように、穴３の直径より広い幅でかつ加工
代より深い深さｔの逃げ溝７を回転軸０を中心とする同
心円状に形或する． このようにすれば、第３図のようにして、表面１をスピ
ンドル４に回転軸Ｏをスピンドルの回転中心にあわせて
真空チャックで取付け、回転させつつ切削するに際し、
バイド６は逃げ溝７に沿って運動するので断続切削とは
ならない．このことはラップ加工においても同様である
． なお、工具が回転し、ワークに送りがかけられる加工法
では、工具の回転中心に逃げ溝の回転中心を合わせる． 断続切削とならない結果、従来生じていた穴近傍の加工
状態の不良が解消され、全体として平面精度が確保され
る． なお、裏面２の加工の前提として、表面１を真空チャッ
クで取り付ける際の精度が要求されるので、表面ｌにつ
いても断続切削を回避する必要がある． その手段としては、同様の要領で逃げ溝を形或すれば良
い．この場合、逃げ溝が穴３の座ぐり８の機能を兼用す
るので、座ぐり８が不要となる．同一の切削条件の下で
、従来の逃げ溝がないポリゴンミラーと、本発明に係る
逃げ溝のあるボリゴンミラーについての加工面の状態を
位相測定干渉システムＺＩＧＯマーク■（商品名）によ
り測定した結果を比較してみる． 従来のポリゴンミラーについての被加工面の干渉縞（第
６図参照）よりも本発明に係るポリゴンミラーについて
の干渉縞（第８図参照）の方が縞に乱れがなく、平面度
が良くでていることが分かる．このことは、同システム
により、同干渉縞から求めた表面形状を表した従来技術
に係る第７図と本発明に係る第９図との比較においても
顕著であり、第９図では円周方向でのうねりが小さいこ
とから同様の結論が裏付けられる． （発明の効果） 本発明によれば断続切削が回避され、被加工面の平面度
を高精度に加工できる。(Function) The hole is located in the relief groove formed on the trajectory of the cutting tool, causing interrupted cutting and no longer exists as a slippery hole. (Example) As shown in Fig. 1, a relief groove 7 having a width wider than the diameter of the hole 3 and a depth t deeper than the machining allowance is formed in a concentric shape with the rotation axis 0 as the center. In this way, as shown in Fig. 3, when attaching the surface 1 to the spindle 4 with a vacuum chuck with the rotation axis O aligned with the rotation center of the spindle and cutting while rotating it,
Since the bide 6 moves along the relief groove 7, interrupted cutting does not occur. This also applies to lapping processing. In addition, in machining methods where the tool rotates and feed is applied to the workpiece, the rotation center of the relief groove should be aligned with the rotation center of the tool. As a result of no interrupted cutting, the poor machining conditions near the hole that previously occurred are eliminated, and overall plane accuracy is ensured. Note that as a prerequisite for machining the back surface 2, accuracy is required when attaching the surface 1 with a vacuum chuck, so it is necessary to avoid interrupted cutting on the surface 1 as well. As a means of doing so, it is sufficient to form relief grooves in the same manner. In this case, the relief groove also serves as the counterbore 8 of the hole 3, so the counterbore 8 becomes unnecessary. Under the same cutting conditions, the state of the machined surfaces of a conventional polygon mirror without relief grooves and a polygon mirror with relief grooves according to the present invention were measured using a phase measurement interference system ZIGO Mark ■ (product name). Let's compare. The interference fringes on the processed surface of the polygon mirror according to the present invention (see Fig. 8) are more uniform and have better flatness than the interference fringes on the processed surface of the conventional polygon mirror (see Fig. 6). It can be seen that This is also noticeable when comparing FIG. 7 according to the prior art and FIG. 9 according to the present invention, which show the surface shape determined from the interference fringes by the same system. A similar conclusion is supported by the small waviness at . (Effects of the Invention) According to the present invention, interrupted cutting can be avoided, and the flatness of the processed surface can be processed with high precision.

【図面の簡単な説明】[Brief explanation of drawings]

第ｌ図は本発明に係るポリゴンミラーの説明図、第２図
は従来のポリゴンミラーの説明図、第３図は加工状態の
説明図，第４図，第５図はそれぞれ断続切削による不良
領域を説明した図、第６図は従来技術に係る被加工面の
干渉縞を模写した図，第７図は従来技術に係る被加工面
のうねりを説明した図、第８図は本発明に係る被加工面
の干渉縞を摸写した図、第９図は本発明に係る被加工面
のうねりを説明した図である。 ７・・・逃げ溝。 第２幻 形４幻 箔δの 帯４ ７ｉ？５δの Ｂ一冫一Fig. 1 is an explanatory diagram of the polygon mirror according to the present invention, Fig. 2 is an explanatory diagram of the conventional polygon mirror, Fig. 3 is an explanatory diagram of the machining state, and Figs. 4 and 5 are defective areas due to interrupted cutting, respectively. FIG. 6 is a diagram illustrating the interference fringes on the processed surface according to the prior art, FIG. 7 is a diagram illustrating the waviness of the processed surface according to the conventional technology, and FIG. FIG. 9, which is a diagram illustrating interference fringes on the processed surface, is a diagram illustrating the waviness of the processed surface according to the present invention. 7...Escape groove. 2nd phantom form 4 phantom foil δ band 4 7i? 5δ's B-1

Claims (1)

【特許請求の範囲】 基準面として高精度の平面度を要求される被加工面に穴
が形成されているポリゴンミラーにおぃて、 穴を包含する幅でかつ、加工代より深い深さの逃げ溝を
加工時の工具またはポリゴンミラーの回転中心と同心状
に形成したことを特徴とするポリゴンミラー。[Scope of Claims] In a polygon mirror in which a hole is formed in a workpiece surface that requires high-precision flatness as a reference surface, A polygon mirror characterized in that a relief groove is formed concentrically with a tool during machining or the rotation center of the polygon mirror.