JP2511648Z

JP2511648Z -

Info

Publication number: JP2511648Z
Authority: JP
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Publication date: 1998-05-13

Description

【考案の詳細な説明】〔産業上の利用分野〕本考案は、移動体の駆動装置に関するものである。〔従来の技術〕１つの移動体と、別の移動体とをそれぞれ２：１の速度比で往復駆動する移動
体の駆動装置は、例えば、画像形成装置などに用いられている。第２図は、その画像形成装置の一例である電子写真式の複写機を示す。図のコンタクトガラス１上には原稿２が載置され、この原稿２は照明光源３に
より照明され、このときの反射光像がミラー４，５，６、結像レンズ７、ミラー
８，９，１０のところをそれぞれ通って感光体ドラム１３の表面に結像投影される。照明光源３とミラー４とは光学走査体１１内に、ミラー５，６は光学走査体１
２内にそれぞれ組み込まれ、光学走査体１１と１２とがそれぞれ２：１の速度比
で矢印方向に駆動されることにより、所謂、スリット露光走査が行われて、感光
体ドラム１３上には原稿画像に対応した静電潜像が形成される。光学走査体１１，１２は、このようなスリット露光走査を終了したのち、今ま
での方向とは反対方向に移動し、図のホームポジションに戻る。光学走査体１１
，１２は、このように、２：１の速度比をもって往復駆動されるのである。第３図は、かような光学走査体の如き移動体の従来の駆動装置を示し、符号１
５は駆動回転体の一例の駆動モータを示し、これは正逆回転可能なモータとなっ
ている。なお、駆動回転体には、かような駆動モータの他、別の駆動モータから
の伝達を受けて正逆回転する定滑車のような駆動回転体が用いられる場合もある
。駆動回転体というのはこのようなものも含む。仮に、これに駆動モータが用いられるものとして、これのモータプーリ１５Ａ
には２本のワイヤ、すなわち実線で示すワイヤ１６と一点鎖線で示すワイヤ１６
ａが巻き付けられ、更に実線で示したワイヤ１６は６個の定滑車１７，１７ａに
巻き掛けられ、一点鎖線で示したワイヤ１６ａは４個の定滑車１７に巻き掛けら
れている。ここで、符号１１で示す光学走査体を第１光学走査体と称し、１２で示す光学
走査体を第２光学走査体と称するものとして、第１の光学走査体１１の両側の底
部は、クランパ１８（第４図）を介して各ワイヤ１６，１６ａに係止されている
。又、第２光学走査体１２の両端部には動滑車１９が回転自在に軸装され、図示
手前側の動滑車１９には、矢印ａの方向から来るワイヤ１６が折り返えすように
して半周分巻き掛けられ、そのワイヤ端部が固定端２１に係止されている。又、
矢印ｂ方向から来るワイヤ１６が動滑車１９に折り返えすようにして半周分巻き
掛けられ、そのワイヤ端部が引っ張りばね２２を介して図示されない不動部材に係止されている。同様にして奥側の動滑車１９にも一点鎖線で
示すワイヤ１６ａが巻き掛けられている。駆動モータ１５が回転すると、ワイヤ１６，１６ａが引っ張られて駆動される
のであるが、このとき、第１光学走査体１１は、そのワイヤ１６，１６ａに直接
係止され、第２光学走査体１２は、動滑車１９を介してワイヤ１６，１６ａに連
結されているため、第１及び第２光学走査体１１，１２はそれぞれ２：１の速度
比で矢印方向に移動する。次いで、先に述べたようなスリット露光走査を終了したのち、モータ１５が逆
転して、第１及び第２光学走査体１１，１２は、矢印と反対方向に移動して元の
ホームポジションに戻る。すなわち、それらはモータ１５の正逆回転により往復
走行駆動されるのである。〔考案が解決しようとする課題〕光学走査体のような移動体を往復走行駆動する従来の駆動装置においては、第
４図に示すように光学走査体を往復させるべくワイヤを矢印方向に引っ張って駆
動する場合、第１及び第２光学走査体１１，１２に対して、それぞれの重心Ｇ₁
，Ｇ₂の回りに、Ｍ₁，Ｍ₂なるモーメントが付与されてしまうため、光学走査体
の如き移動体に振動が生じ易くなる。例えば、かような駆動装置を複写機などの
画像形成装置で使用すると、露光走査時に、光学走査体が振動してしまい、「画
像ブレ」を生じたりして、複写画像の画質が低下する。本考案の目的は、上述の如きモーメントを生じにくい駆動装置として、移動体
を円滑に走行駆動できるようにすることにある。〔課題を解決するための手段〕本考案は前述の目的を達成するため、正逆回転可能な駆動回転体と、該駆動回
転体及び複数の定滑車に巻き掛けられるワイヤと、該ワイヤに係止される少なく
とも１つの移動体と、前記ワイヤを巻き掛けた動滑車を回転自在に軸装した少な
くとも１つの移動体とを有し、前記駆動回転体の正逆回転により、ワイヤを介して前者と後者の移動体をそれぞれ２：１の速度比で往復駆動するように
した移動体の駆動装置において、前者の移動体のワイヤに対する係止部分を、該
移動体の重心を通る該移動体の長手方向軸線上の位置に、動滑車の回転中心を、
後者の移動体の重心を通る該移動体の長手方向軸線上の位置にそれぞれ設定する
と共に、動滑車から離れた直後の両ワイヤ部分が、後者の移動体の移動方向に対
してほぼ平行に延びるように、該ワイヤと動滑車の位置を設定した構成を提案す
るものである。なお、移動体を複写機の光学走査体とすると、効果的である。〔実施例〕以下、本考案を一実施例に基づき説明する。第１図において、符号１１，１２は先にも述べたように移動体の一例の光学走
査体を示し、このうちの第１光学走査体１１の、ワイヤ１６，１６ａに対する係
止部分は、その光学走査体の重心Ｇ₁を通る当該走査体１１の長手方向軸線Ｌ₁（
第３図）上の位置に設定されている。すなわち、ワイヤ１６，１６ａの上下方向
の位置を、重心位置Ｇ₁に合わせた上、この重心Ｇ₁を通る軸線Ｌ₁上の位置で第
１光学走査体１１を係止せしめるのである。一方、第２光学走査体１２の重心Ｇ₂を通る当該走査体１２の長手方向軸線Ｌ₂
（第３図）上の位置に、動滑車１９の回転中心を合わせる。そして、又、重心Ｇ
₂を通る軸線Ｌ₂とワイヤ１６，１６ａまでの距離がｒであるものとして、動滑車
１９を、かようなｒを半径とした滑車にする。他の構成は、第２図及び第３図を参照して先に説明した従来のものと変りはな
い。第４図の従来例では、第１光学走査体１１につき、この重心Ｇ₁の位置が、ワ
イヤ１６から離れているために、ワイヤ１６を矢印方向に引っ張るとき、Ｍ₁な
るモーメントが生じていたが、第１図の実施例では、重心Ｇ₁とワイヤ１６との
間に、かかるモーメントを生ぜしめる距離が存在しないために、モーメントが生じる余地はない。又、第４図の従来例では、動滑車１９の移動力Ｆと、距離Ｌ（重心Ｇ₂と動滑
車の回転中心との間の距離）とを乗じたモーメントＭ₂が生じていたが、本例で
は、その距離Ｌがゼロになるために、かかるモーメントが生じ得ない。更に、第１図に示すように、重心Ｇ₂を通る軸線Ｌ₂からワイヤ１６，１６ａま
での距離がｒであるものとして、この距離ｒを半径とする動滑車とすることで、
上下方向の力がそれには付与されず、光学走査体の動きが一層円滑になる。換言
すれば、動滑車から離れた直後の両ワイヤ部分が、その動滑車を軸装した移動体
の移動方向に対してほぼ平行に延びるように、該ワイヤと動滑車の位置を設定す
る。これにより、動滑車に上下方向の力が付与されず、光学走査体の動きが円滑
となるのである。かくの如くモーメントが生じなくなることで、各光学走査体の走行時の振動が
無くなるか、若しくは、大幅に低減化され、それの走行が安定化する。特に、複
写機などの場合は、「画像ブレ」などが無くなって、コピー画質が一段と向上す
る。なお、ワイヤ１６，１６ａに直接係止される移動体や、動滑車を介してワイヤ
に取り付けられる移動体としては、各々につき、必ずしも１つではなく、２つ以
上であっても構わず、これらを円滑に走行駆動することができる。〔考案の効果〕本考案の請求項１に記載の構成によれば、それぞれ異なる速度で移動する各移
動体に、振動などの原因となるモーメントが加わらないため、それらを円滑に安
定的に走行駆動することができ、又、その安定化のための手段を特別に設ける必
要もない。請求項２に記載の構成によれば、振動の生じにくい状態で、光学走査体を走行
駆動することができるので、「画像ブレ」などが発生しにくくなり、複写画像の
画質を一段と向上させることができる。 DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a driving device for a moving body. 2. Description of the Related Art A driving apparatus for a moving body that reciprocates one moving body and another moving body at a speed ratio of 2: 1 is used in, for example, an image forming apparatus. FIG. 2 shows an electrophotographic copying machine as an example of the image forming apparatus. A document 2 is placed on a contact glass 1 shown in the figure, and the document 2 is illuminated by an illumination light source 3, and reflected light images at this time are reflected by mirrors 4, 5, 6, an imaging lens 7, mirrors 8, 9, and The image is projected on the surface of the photosensitive drum 13 through each of the portions 10. The illumination light source 3 and the mirror 4 are provided in the optical scanning body 11, and the mirrors 5 and 6 are provided in the optical scanning body 1.
The optical scanning members 11 and 12 are driven in the direction of the arrow at a speed ratio of 2: 1 respectively, so that a so-called slit exposure scan is performed, and a document is placed on the photosensitive drum 13. An electrostatic latent image corresponding to the image is formed. After finishing such slit exposure scanning, the optical scanning bodies 11 and 12 move in a direction opposite to the previous direction and return to the home position in the figure. Optical scanning body 11
, 12 are reciprocally driven at a speed ratio of 2: 1. FIG. 3 shows a conventional driving device for a moving body such as an optical scanning body.
Reference numeral 5 denotes a driving motor as an example of a driving rotating body, which is a motor that can rotate forward and backward. In addition, in addition to such a driving motor, a driving rotator such as a constant pulley that rotates forward and reverse by receiving a transmission from another driving motor may be used as the driving rotator. The driving rotating body includes such a thing. Assuming that a drive motor is used for this, the motor pulley 15A
Has two wires, a wire 16 shown by a solid line and a wire 16 shown by a dashed line.
The wire 16a is wound around six constant pulleys 17 and 17a, and the wire 16a indicated by a dashed line is wound around four constant pulleys 17. Here, the optical scanning member indicated by the reference numeral 11 is referred to as a first optical scanning member, and the optical scanning member indicated by the reference numeral 12 is referred to as a second optical scanning member. It is locked to each of the wires 16, 16a via 18 (FIG. 4). A moving pulley 19 is rotatably mounted on both ends of the second optical scanning body 12, and the wire 16 coming from the direction of arrow a is folded back on the moving pulley 19 on the near side in the drawing so as to be half-turned. The wire is wound separately and its wire end is locked to the fixed end 21. or,
The wire 16 coming from the direction of the arrow b is wound around the moving pulley 19 by a half turn so as to be folded, and the end of the wire is locked to a stationary member (not shown) via a tension spring 22. Similarly, a wire 16a indicated by a dashed line is wound around the moving pulley 19 on the back side. When the drive motor 15 rotates, the wires 16 and 16a are pulled and driven. At this time, the first optical scanning body 11 is directly locked to the wires 16 and 16a, and the second optical scanning body 12 Is connected to the wires 16 and 16a via the moving pulley 19, so that the first and second optical scanning bodies 11 and 12 move in the direction of the arrow at a speed ratio of 2: 1 respectively. Next, after the above-described slit exposure scanning is completed, the motor 15 rotates in the reverse direction, and the first and second optical scanning bodies 11 and 12 move in the directions opposite to the arrows and return to the original home positions. . That is, they are driven to reciprocate by the forward and reverse rotation of the motor 15. [Problem to be Solved by the Invention] In a conventional driving device for driving a moving body such as an optical scanning body in a reciprocating manner, a wire is pulled in the direction of an arrow to reciprocate the optical scanning body as shown in FIG. In the case of driving, the respective centers of gravity G _{1 with} respect to the first and second optical scanning bodies 11 and 12 are set.
, G _2, the moments M ₁ and M ₂ are applied to the moving body such as the optical scanning body. For example, when such a driving device is used in an image forming apparatus such as a copying machine, the optical scanning member vibrates during exposure scanning, thereby causing "image blur" and deteriorating the image quality of a copied image. An object of the present invention is to make it possible to smoothly drive a moving body as a driving device that hardly generates a moment as described above. [Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention relates to a driving rotator capable of rotating forward and reverse, a wire wound around the driving rotator and a plurality of fixed pulleys, and a wire connected to the wire. At least one moving body to be stopped, and at least one moving body rotatably mounted with a moving pulley around which the wire is wound, and the former is rotated via a wire by forward and reverse rotation of the driving rotating body. And a moving device for reciprocatingly driving the latter at a speed ratio of 2: 1 respectively, wherein a locking portion of the former moving body with respect to the wire is fixed to the moving body passing through the center of gravity of the moving body. At the position on the longitudinal axis, the center of rotation of the
Set at a position on the longitudinal axis of the latter which passes through the center of gravity of the latter.
At the same time, the two wire portions immediately after leaving the moving pulley correspond to the movement direction of the latter moving body.
The present invention proposes a configuration in which the positions of the wire and the moving pulley are set so as to extend substantially in parallel . It is effective if the moving body is an optical scanning body of a copying machine. [Embodiment] Hereinafter, the present invention will be described based on one embodiment. In FIG. 1, reference numerals 11 and 12 denote an optical scanning body as an example of the moving body as described above. Of these, the locking portion of the first optical scanning body 11 with respect to the wires 16 and 16a is the same. The longitudinal axis L _{1 of the} scanning body 11 passing through the center of gravity G ₁ of the optical scanning body (
(Fig. 3). That is, the vertical position of the wire 16, 16a, on matching the gravity center position G _1, is the allowed to lock the first optical scanning element 11 at a position on the axis L ₁ passing through the center of gravity G _1. On the other hand, the longitudinal axis L _{2 of the} scanning body 12 passing through the center of gravity G ₂ of the second optical scanning body 12
(FIG. 3) The rotation center of the moving pulley 19 is aligned with the upper position. And again, the center of gravity G
As the distance to the axis L ₂ and the wire 16,16a through ₂ is r, the movable pulley 19, to a such a r was the radius pulley. The other structure is the same as the conventional structure described above with reference to FIGS. 2 and 3. In the conventional example of FIG. 4, per the first optical scanning element 11, the position of the center of gravity G ₁ is, for away from the wire 16, when pulling the wire 16 in the direction of the arrow, M ₁ becomes moment has occurred However, in the embodiment shown in FIG. ₁ , there is no room for generating a moment because there is no distance between the center of gravity G1 and the wire 16 that generates such a moment. Further, in the conventional example of FIG. 4, the moving force F of the movable pulley 19, the distance L is the moment M ₂ obtained by multiplying the (distance between the rotational center of the center of gravity G ₂ and movable pulley) has occurred, In this example, such a moment cannot occur because the distance L becomes zero. Further, as shown in FIG. 1, the distance from the axis L ₂ passing through the center of gravity G ₂ to the wires 16 and 16 a is r, and a moving pulley having a radius equal to this distance r is used.
No vertical force is applied to it, making the movement of the optical scanning body smoother. Paraphrase
In this case, the two wire parts immediately after leaving the moving pulley are the moving body on which the moving pulley is mounted.
The position of the wire and the moving pulley is set so as to extend substantially parallel to the
You. As a result, no vertical force is applied to the moving pulley, and the movement of the optical scanning body is smooth.
It becomes. By eliminating the moment as described above, the vibration of each optical scanning body during traveling is eliminated or greatly reduced, and the traveling thereof is stabilized. In particular, in the case of a copying machine or the like, "image blur" is eliminated, and the copy image quality is further improved. The moving body directly locked to the wires 16 and 16a and the moving body attached to the wire via the moving pulley are not necessarily one, and may be two or more. Can be smoothly driven. [Effects of the Invention] According to the configuration of the first aspect of the present invention, since a moment causing vibration or the like is not applied to each of the moving bodies moving at different speeds, the moving bodies run smoothly and stably. It can be driven and there is no need to provide any special means for stabilization. According to the configuration of the second aspect, the optical scanning body can be driven to travel in a state in which vibration is unlikely to occur, so that "image blur" is less likely to occur, and the image quality of a copied image is further improved. Can be.

【図面の簡単な説明】第１図は本考案一実施例の概略図、第２図は上記実施例の一適用例である複写
機の概略図、第３図はその複写機に設けられる光学走査体の駆動装置の斜視図で
あって、従来例と本考案実施例の説明に供した図、第４図は従来例の問題点につ
いて説明するための光学走査部の構成図である。１１，１２…移動体としての光学走査体１５…駆動回転体としての駆動モータ１６，１６ａ…ワイヤ１７…定滑車１９…動滑車Ｇ₁，Ｇ₂…重心Ｌ₁，Ｌ₂…軸線BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of one embodiment of the present invention, FIG. 2 is a schematic diagram of a copying machine which is an application example of the above embodiment, and FIG. FIG. 4 is a perspective view of a driving device of a scanning body, which is used for explaining a conventional example and an embodiment of the present invention, and FIG. 4 is a configuration diagram of an optical scanning unit for explaining problems of the conventional example. 11, 12, drive motor 16,16a as an optical scanning element 15 ... drive rotor as mobile ... wire 17 ... fixed pulleys 19 ... movable pulley G _1, G ₂ ... centroids L _1, L ₂ ... axis

Claims

(1) A driving rotator capable of rotating forward and reverse, a wire wound around the driving rotator and a plurality of fixed pulleys, and at least one moving body locked by the wire. And at least one moving body on which a movable pulley around which the wire is wound is rotatably mounted on the shaft. The forward and reverse rotations of the driving rotating body allow the former and the latter moving bodies to be respectively connected via wires: In a driving apparatus for a moving body reciprocatingly driven at a speed ratio of 1, the locking portion of the former moving body with respect to the wire is moved to a position on the longitudinal axis of the moving body passing through the center of gravity of the moving body. The center of rotation of the pulley is set at a position on the longitudinal axis of the moving body passing through the center of gravity of the latter moving body, and both wires immediately after leaving the moving pulley
The wire extends so as to be substantially parallel to the moving direction of the latter moving body.
A driving device for a moving body in which the position of the moving pulley is set . (2) The driving device for a moving body according to claim 1, wherein the moving body is an optical scanning body of a copying machine.