JP2008225009A

JP2008225009A - Image forming apparatus

Info

Publication number: JP2008225009A
Application number: JP2007062598A
Authority: JP
Inventors: Tetsuji Nishikawa; 哲治西川; Kazuyoshi Suzuki; 一喜鈴木; Masahiro Ishida; 雅裕石田; Yasuhiro Maebatake; 康広前畠; Makoto Kikura; 真木倉; Takayuki Niihara; 貴之新原
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2007-03-12
Filing date: 2007-03-12
Publication date: 2008-09-25
Anticipated expiration: 2027-03-12
Also published as: JP4993701B2

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a phase adjusting means composed of a smaller number of components than heretofore in an image forming apparatus having a plurality of photoreceptors driven by a single drive source and a transfer body to which the images of the photoreceptors are transferred. <P>SOLUTION: The phase adjusting means has a photoreceptor driving gear (driving) 5 and a photoreceptor driven gear (to be driven) 4 provided with a pair of recessed and projecting shaped parts 9 and 11 meshed with each other. The gears have the different recessed and projecting shapes 10 and 12 of the recessed and projecting shaped parts for every photoreceptor, and driving force is transmitted to the photoreceptor by meshing of the recessed and projecting shapes. When driving of the driving source, reverse rotation and normal rotation are repeated in a rotating direction, whereby the meshing position between the recessed and projecting shapes is deviated to adjust phase relation in the speed variation of each photoreceptor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、複写機、プリンタ、ファクシミリ、複合機等の画像形成装置に関する。 The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction machine.

それぞれ異なる色のトナー画像を形成する複数個の感光体を有し、各感光体上の画像を重ね転写してカラー画像を得る所謂静電方式のカラー画像形成装置において、各感光体の速度変動等位相ずれに起因する色ずれの低減のために、１つの駆動源で１つの感光体を駆動する方式を用い、ギヤの目印をもとに回転位相を合わせる方法や、感光体の回転速度を制御する手法が良く知られている。しかし、この方法では例えば４つの感光体を駆動するのに、４つの駆動源が必要であり、かつ多くのスペースも必要である。 In a so-called electrostatic color image forming apparatus that has a plurality of photoconductors that form toner images of different colors and obtains a color image by superimposing and transferring the images on the photoconductors, the speed variation of each photoconductor In order to reduce color misregistration caused by equal phase shift, a method of driving one photoconductor with one drive source, adjusting the rotation phase based on the mark of the gear, and adjusting the rotation speed of the photoconductor Control techniques are well known. However, in this method, for example, four driving sources are required to drive four photosensitive members, and a lot of space is also required.

そこで、単一の駆動源により複数個の感光体を駆動する方式が提案された（例えば、特許文献１参照）。この駆動構成は、複数の感光体ドラムと該複数の感光体ドラムを回転駆動するための駆動モータと、駆動モータから前記複数の感光体ドラムに駆動力を伝達するギア列を有し、複数の感光体ドラムが駆動モータからギア列によって同一周期で回転駆動される画像形成装置において、ギア列が駆動力を伝達する複数の感光体ドラムのうち、少なくとも一つの感光体ドラムの回転時の位相を、他の感光体ドラムの停止時の位相に対して変位させる位相変位手段を有するものである。 Therefore, a method of driving a plurality of photoconductors with a single drive source has been proposed (see, for example, Patent Document 1). This drive configuration includes a plurality of photosensitive drums, a drive motor for rotationally driving the plurality of photosensitive drums, and a gear train for transmitting a driving force from the drive motor to the plurality of photosensitive drums. In an image forming apparatus in which a photosensitive drum is rotationally driven by a gear train from a drive motor at the same period, a phase at the time of rotation of at least one of the plurality of photosensitive drums to which the gear train transmits driving force is determined. And a phase displacement means for displacing with respect to the phase when the other photosensitive drums are stopped.

この位相伝達手段は、駆動力の伝達を切断、接続するクラッチ手段、また、駆動力の伝達を遅延する遅延手段とされる。しかし、この方法では独立した部品であるクラッチ手段、遅延手段などを用いることで部品点数が増えている。 This phase transmission means is a clutch means for cutting and connecting the transmission of the driving force, and a delay means for delaying the transmission of the driving force. However, in this method, the number of parts is increased by using clutch means and delay means which are independent parts.

軸位相調整手段として斜歯歯車及びカムを用いたもの（例えば、特許文献２参照）においても、同様に独立した部品である斜歯歯車及びカムを用いる点で部品点数が増えている。 Even in the case of using an inclined gear and a cam as the shaft phase adjusting means (see, for example, Patent Document 2), the number of parts is increased in that the inclined gear and the cam, which are independent parts, are similarly used.

特開２００５−１５７１６９号公報JP 2005-157169 A 特開２００６−１０６５９１号公報JP 2006-106591 A

本発明は、従来よりも部品点数の少ない構成による位相調整手段を実現することを課題とする。 An object of the present invention is to realize a phase adjusting means having a configuration with a smaller number of parts than in the past.

前記課題を達成するため請求項１に係る発明は、単一の駆動源により駆動されるように連結された複数個の感光体と、これら感光体の画像が転写される転写体を有する画像形成装置において、同一の軸線上に隣接配置されていて、その側面部に互いに噛み合い可能な一対の凹凸形状部が設けられた感光体駆動ギヤ（駆動）と感光体駆動ギヤ（被駆動）を有し、これらのギヤは駆動する感光体毎に前記凹凸形状部の凹凸形状が異なり、凹凸形状同士の噛み合いにより感光体に駆動力が伝達される構成であり、前記駆動源の駆動時に、回転方向を逆転と正転とを繰り返すことで、凹凸形状同士の噛み合い位置をずらし各感光体の速度変動の位相関係を調整することとした。
請求項２に係る発明は、請求項１記載の画像形成装置において、前記凹凸形状部は前記軸線を中心とする円の円周に沿って形成された複数の凹凸からなり、凸部は感光体駆動ギヤ（駆動）が一方向に回転するとき感光体駆動ギヤ（被駆動）の凸部と当接して動力伝達する当接面と、噛み合い状態のまま感光体駆動ギヤ（駆動）が感光体駆動ギヤ（被駆動）に対して前記一方向と逆向きに回転することを許容するスライド面とで形成される山形をなしていることとした。
請求項３に係る発明は、転写体上に描いた画像パターンを読み取るための読み取り手段を有し、その読み取り結果に応じて前記駆動源を駆動制御し、各感光体の速度変動の位相ずれを調整することとした。
請求項４に係る発明は、請求項２乃至３の何れかに記載の画像形成装置において、前記当接面は前記軸線方向に平行な面からなり、前記スライド面は前記軸線方向と交差する傾斜面からなることとした。
請求項５に係る発明は、請求項２乃至４の何れかに記載の画像形成装置において、前記凹凸形状部で駆動連結される前記２つの感光体駆動ギヤ同士を加圧体により接近する方向に加圧することとした。
請求項６に係る発明は、請求項２乃至５の何れかに記載の画像形成装置において、凹凸形状部で駆動連結される駆動側のギヤにハスバ歯車を用い、ギヤの正転時に２つのギヤが接近する方向に力が働くようねじれ方向が設定されていることとした。
請求項７に係る発明は、請求項２乃至６の何れかに記載の画像形成装置において、ギヤ部と凹凸形状部とを別体とし一体的に構成した。
請求項８に係る発明は、請求項１乃至７の何れかに記載の画像形成装置において、前記駆動源としてブレーキ機能を有したＤＣモータを用いることとした。
請求項９に係る発明は、請求項１乃至７の何れかに記載の画像形成装置において、駆動源としてステッピングモータを用いることとした。
請求項１０に係る発明は、請求項２乃至９の何れかに記載の画像形成装置において、前記２つのギヤの中、感光体駆動ギヤ（被駆動）と感光体との駆動連結にギヤによる駆動連結方式を用いた。
請求項１１に係る発明は、請求項２乃至９の何れかに記載の画像形成装置において、前記２つのギヤの中、従動側のギヤと感光体との駆動連結にジョイントによる駆動連結方式を用いた。
請求項１２に係る発明は、請求項１乃至１１の何れかに記載の画像形成装置において、単一駆動源に代えて、カラー作像用感光体とモノクロ作像用感光体の駆動源を別にした複数駆動源とした。
請求項１３に係る発明は、請求項１２に記載の画像形成装置において、感光体の回転位置を検出するための手段を設けた。
請求項１４に係る発明は、請求項１乃至１３の何れかに記載の画像形成装置において、前記転写体と前記感光体とを接離可能とした。
請求項１５に係る発明は、請求項１乃至１４の何れかに記載の画像形成装置において、前記感光体または前記感光体を含む交換可能なユニットの交換時期を検知する手段を有していることとした。
請求項１６に係る発明は、請求項１乃至１４の何れかに記載の画像形成装置において、前記感光体または前記感光体を含む交換可能なユニットの回転数を検知する手段を有していることとした。 In order to achieve the above object, an invention according to claim 1 is directed to image formation comprising a plurality of photoconductors coupled so as to be driven by a single drive source, and a transfer body onto which images of these photoconductors are transferred. The apparatus includes a photosensitive member driving gear (driving) and a photosensitive member driving gear (driven) that are disposed adjacent to each other on the same axis and are provided with a pair of concave and convex portions that can mesh with each other on the side surface portion. These gears have a configuration in which the concavo-convex shape of the concavo-convex shape portion is different for each driven photoconductor, and the driving force is transmitted to the photoconductor by meshing of the concavo-convex shapes, and the rotation direction is changed when the drive source is driven. By repeating the reverse rotation and the normal rotation, the meshing positions of the concavo-convex shapes are shifted to adjust the phase relationship of the speed fluctuation of each photoconductor.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the concavo-convex shape portion includes a plurality of concavo-convex portions formed along a circumference of a circle centering on the axis, and the convex portion is a photoconductor. When the drive gear (drive) rotates in one direction, the photoconductor drive gear (drive) is driven by the photoconductor drive gear (driven) in contact with the convex surface of the photoconductor drive gear (driven). A chevron formed with a sliding surface that allows rotation in the direction opposite to the one direction with respect to the gear (driven) is formed.
According to a third aspect of the invention, there is provided reading means for reading an image pattern drawn on the transfer body, and the drive source is driven and controlled in accordance with the reading result, so that the phase shift of the speed variation of each photoconductor is detected. It was decided to adjust.
According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the second to third aspects, the contact surface is a surface parallel to the axial direction, and the slide surface is inclined so as to intersect the axial direction. It was decided to consist of surfaces.
According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the second to fourth aspects, the two photosensitive member driving gears that are driven and connected by the concave-convex shape portion are brought closer to each other by a pressure member. It was decided to pressurize.
According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the second to fifth aspects, a helical gear is used as a drive-side gear that is driven and connected by the concavo-convex shape portion, and two gears are used during forward rotation of the gear. The torsional direction is set so that force acts in the direction in which the two approach.
According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the second to sixth aspects, the gear portion and the concavo-convex shape portion are formed separately and integrally configured.
According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, a DC motor having a brake function is used as the drive source.
According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, a stepping motor is used as a drive source.
According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the second to ninth aspects, the driving connection between the photosensitive member driving gear (driven) and the photosensitive member among the two gears is driven by a gear. A concatenation method was used.
According to an eleventh aspect of the present invention, in the image forming apparatus according to any one of the second to ninth aspects, a driving connection system using a joint is used for driving connection between the driven gear and the photoconductor among the two gears. It was.
According to a twelfth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, instead of the single drive source, the drive source for the color image forming photoreceptor and the monochrome image forming photoreceptor is separated. Multiple drive sources were used.
According to a thirteenth aspect of the present invention, in the image forming apparatus according to the twelfth aspect, means for detecting the rotational position of the photosensitive member is provided.
According to a fourteenth aspect of the present invention, in the image forming apparatus according to any one of the first to thirteenth aspects, the transfer member and the photosensitive member can be contacted and separated.
A fifteenth aspect of the present invention is the image forming apparatus according to any one of the first to fourteenth aspects, further comprising means for detecting a replacement time of the photoconductor or a replaceable unit including the photoconductor. It was.
According to a sixteenth aspect of the present invention, in the image forming apparatus according to any one of the first to fourteenth aspects, the image forming apparatus includes means for detecting the number of rotations of the photoconductor or a replaceable unit including the photoconductor. It was.

請求項１、２に記載の発明によれば、１つの駆動源で複数個の感光体を駆動する電装部品の少ない駆動構成においても、駆動系として本来必要なギヤに凹凸形状部を付帯させることで部品点数を増やすことなく、１つの駆動源で１つの感光体を駆動する駆動構成と同様に感光体の速度変動の位相を合わせることが可能で、副走査方向の色ずれを低減することができる。
請求項３に記載の発明によれば、感光体の交換による位相のずれ、感光体の負荷変動やジョイント部の偏角などが原因で発生する感光体の速度変動の位相も含めた状態で位相を合わせをすることができる。
請求項４に記載の発明によれば、感光体駆動時と逆転する時に感光体駆動ギヤ（駆動）の凸部が感光体駆動ギヤ（被駆動）のスライド部で乗り上げてスライドし、感光体駆動ギヤ（被駆動）は回転せず、この乗り上げた量と回転方向を組み合わせることにより、位相をずらすことが可能となり、位相調整を行うことができる。
請求項５に記載の発明によれば、加圧体で感光体駆動ギヤ（被駆動）をスラスト方向に加圧することで、スライド部への凸部の乗り上げ後駆動力を利用して元の位置関係に戻すことができ、その後の駆動伝達に支障をきたさない。
請求項６に記載の発明によれば、加圧手段を用いることなくスライド部への凸部の乗り上げ後駆動力を利用して元の位置関係に戻すことができ、その後の駆動伝達に支障をきたさない。
請求項７に記載の発明によれば、ギヤの偏心量に大きなバラツキが生じることを防ぐことができ、結果として色ずれ低減の効果が増す。
請求項８に記載の発明によれば、発明を実施中、正転逆転時におけるギヤ停止位置の精度が高くなり、位相合わせの精度向上を図ることができる。
請求項９に記載の発明によれば、発明を実施中、正転逆転時におけるギヤ停止位置の精度が高くなり、位相合わせの精度向上を図ることができる。
請求項１０に記載の発明によれば、感光体ギヤの位相が合わせやすくなり色ずれの低減効果が得られる。
請求項１１に記載の発明によれば、ジョイント部で発生する位相ずれを含めた位相調整が可能である。
請求項１２に記載の発明によれば、モノクロ感光体とフルカラー感光体の駆動を別駆動源にしたことで感光体の寿命を延ばす効果に加え、フルカラーの感光体間の速度変動の位相を合わせることでの色ずれ低減の効果が得られる。
請求項１３に記載の発明によれば、モノクロ感光体とフルカラー感光体間の速度変動の位相を合わせることができ、モノクロ感光体とカラー感光体の駆動源を共通の単一とする場合に比べ色ずれ低減の効果が大きくなる。
請求項１４に記載の発明によれば、位相調整実施時における転写体と感光体のコスレを回避して寿命の低下を防ぐことができる。
請求項１５に記載の発明によれば、ユニットの交換時期に合わせて位相調整を実施することにより、画像形成装置のダウンタイムの発生時間を最小限に抑えることが可能である。
請求項１６に記載の発明によれば、ユニットの交換時期がわかるので、定期的なタイミングで位相調整が可能となり、これにより、感光体の負荷変動などにより径時的に位相関係がずれてしまったとしても、定期的に最適な位相関係に合わせることが可能である。 According to the first and second aspects of the present invention, even in a drive configuration in which a plurality of photosensitive members are driven by a single drive source, an uneven portion is attached to a gear that is originally required as a drive system. Thus, without increasing the number of parts, it is possible to adjust the phase of the speed fluctuation of the photoconductor in the same manner as in the drive configuration in which one photoconductor is driven by one drive source, and to reduce color misregistration in the sub-scanning direction. it can.
According to the third aspect of the present invention, the phase including the phase of the speed fluctuation of the photosensitive member caused by the phase shift due to the replacement of the photosensitive member, the load fluctuation of the photosensitive member, the deflection angle of the joint portion, and the like is included. Can be combined.
According to the fourth aspect of the present invention, when the photosensitive member is driven reversely, the convex portion of the photosensitive member driving gear (driving) rides on and slides on the sliding portion of the photosensitive member driving gear (driven) to drive the photosensitive member. The gear (driven) does not rotate, and the phase can be shifted and phase adjustment can be performed by combining this amount and the rotation direction.
According to the fifth aspect of the present invention, the pressure applied to the photosensitive member drive gear (driven) in the thrust direction by the pressurizing member makes it possible to use the driving force after the protrusion on the slide portion to restore the original position. The relationship can be restored, and subsequent drive transmission is not hindered.
According to the sixth aspect of the present invention, it is possible to return to the original positional relationship by using the driving force after the protrusion on the slide portion without using the pressurizing means, which hinders the subsequent drive transmission. Do not come.
According to the seventh aspect of the invention, it is possible to prevent a large variation in the amount of eccentricity of the gear, and as a result, the effect of reducing color misregistration is increased.
According to the eighth aspect of the present invention, the accuracy of the gear stop position at the time of forward / reverse rotation is increased during implementation of the invention, and the phase alignment accuracy can be improved.
According to the ninth aspect of the present invention, the accuracy of the gear stop position at the time of forward / reverse rotation is increased and the phase alignment accuracy can be improved during the invention.
According to the tenth aspect of the present invention, the phase of the photoconductor gear can be easily matched and an effect of reducing color misregistration can be obtained.
According to the eleventh aspect of the invention, it is possible to adjust the phase including the phase shift generated at the joint portion.
According to the twelfth aspect of the present invention, in addition to the effect of extending the life of the photosensitive member by driving the monochrome photosensitive member and the full-color photosensitive member separately, the phase of the speed fluctuation between the full-color photosensitive members is matched. Thus, the effect of reducing color misregistration can be obtained.
According to the thirteenth aspect of the present invention, the phase of the speed fluctuation between the monochrome photosensitive member and the full-color photosensitive member can be matched, compared with the case where the driving source of the monochrome photosensitive member and the color photosensitive member is a single unit. The effect of reducing color misregistration is increased.
According to the fourteenth aspect of the present invention, it is possible to prevent the transfer member and the photosensitive member from collapsing when the phase adjustment is performed, thereby preventing the lifetime from being shortened.
According to the fifteenth aspect of the present invention, it is possible to minimize the occurrence time of the downtime of the image forming apparatus by performing the phase adjustment in accordance with the unit replacement time.
According to the sixteenth aspect of the invention, since it is possible to know the replacement time of the unit, it is possible to adjust the phase at a regular timing. As a result, the phase relationship is shifted over time due to load fluctuations of the photosensitive member. Even so, it is possible to adjust to the optimum phase relationship periodically.

以下、本発明を適用した画像形成装置を説明する。
例１：単一の駆動源で複数個の感光体を駆動する構成
図１において、異なる色のトナー画像が形成されるドラム状をした同径の感光体１Ａ、１Ｂ、１Ｃ、１Ｄがベルト状をした転写体２に沿って間隔をおいて並置されている。各感光体１Ａ、１Ｂ、１Ｃ、１Ｄの軸方向端部にはそれぞれ感光体の径と略同径の感光体ギヤ３が固定されている。各感光体ギヤ３にはそれぞれ感光体駆動ギヤ（被駆動）４が噛み合わされている。 Hereinafter, an image forming apparatus to which the present invention is applied will be described.
Example 1: Configuration in which a plurality of photoconductors are driven by a single drive source In FIG. 1, photoconductors 1A, 1B, 1C, and 1D having the same diameter in the form of drums on which toner images of different colors are formed are belt-like. They are juxtaposed along the transfer body 2 with a gap. Photosensitive member gears 3 having substantially the same diameter as the photosensitive member are fixed to axial ends of the respective photosensitive members 1A, 1B, 1C, and 1D. Each photoconductor gear 3 is meshed with a photoconductor drive gear (driven) 4.

このように、感光体駆動ギヤ（被駆動）４と感光体ギヤ３とをギヤ連結し、かつ原動ギヤ７を駆動する１つのモータで複数個の感光体１Ａ〜１Ｄを連結駆動している構成では、感光体ギヤ３と感光体駆動ギヤ（被駆動）４の噛み合い位置は感光体の交換時に変動するため、本体駆動の組み付け時の位相合わせは不可能である。そこで、本例では、感光体ギヤの位相を合わせることで色ずれの低減効果を得ることができる。 In this manner, the photosensitive member driving gear (driven) 4 and the photosensitive member gear 3 are gear-connected, and the plurality of photosensitive members 1A to 1D are connected and driven by one motor that drives the driving gear 7. In this case, the meshing position of the photoconductor gear 3 and the photoconductor drive gear (driven) 4 varies when the photoconductor is replaced, so that phase alignment at the time of assembly of the main body drive is impossible. Therefore, in this example, the effect of reducing color misregistration can be obtained by matching the phase of the photoconductor gear.

各感光体駆動ギヤ（被駆動）４と同軸上には感光体駆動ギヤ（駆動）５が設けられていて、感光体駆動ギヤ（駆動）４と感光体駆動ギヤ（従動）５とはこれらギヤに付帯してそれぞれ設けられた凹凸形状部の噛み合いにより動力伝達されるようになっている。図１に示すように、隣接する各感光体駆動ギヤ（駆動）５間には共通に噛み合う動力伝達ギヤ６が設けられている。 A photoconductor drive gear (drive) 5 is provided coaxially with each photoconductor drive gear (driven) 4, and the photoconductor drive gear (drive) 4 and the photoconductor drive gear (driven) 5 are these gears. The power is transmitted by the meshing of the concavo-convex portions provided respectively. As shown in FIG. 1, a power transmission gear 6 that meshes in common is provided between adjacent photosensitive member drive gears (drives) 5.

図１において、４つの各感光体駆動ギヤ（駆動）５中の任意の一つ、本例では左から２番目の感光体１Ｂの系列に属する感光体駆動ギヤ（駆動）５に、正逆転可能なモータに連結された駆動源としての原動ギヤ７が噛み合わされている。 In FIG. 1, any one of the four photosensitive member driving gears (drives) 5 can be rotated forward or backward to any one of the photosensitive member drive gears (drives) 5 belonging to the second photosensitive member 1B from the left in this example. A driving gear 7 as a driving source connected to a simple motor is meshed.

かかる構成により、原動ギヤ７が回転することで、感光体駆動ギヤ（駆動）５→凸凹形状部の噛み合い→感光体駆動ギヤ（被駆動）４→感光体ギヤ３の順に動力が伝達されて４つの感光体１Ａ、１Ｂ、１Ｃ、１Ｄ共同じ方向に回転駆動される。 With this configuration, when the driving gear 7 rotates, the power is transmitted in the order of the photosensitive member driving gear (driving) 5 → engagement of the convex and concave portions → the photosensitive member driving gear (driven) 4 → the photosensitive member gear 3 in order. The two photoconductors 1A, 1B, 1C, and 1D are rotationally driven in the same direction.

転写体２は感光体の軸線と平行な軸線をもつように配置された駆動軸８、従動軸８’間に掛け回されている。転写体２を駆動する駆動軸８の駆動源は図示していないが、感光体駆動用の原動ギヤ７とは別の駆動源である。 The transfer member 2 is wound around a drive shaft 8 and a driven shaft 8 'arranged so as to have an axis parallel to the axis of the photosensitive member. A drive source of the drive shaft 8 for driving the transfer body 2 is not shown, but is a drive source different from the driving gear 7 for driving the photosensitive member.

感光体１Ａ、１Ｂ、１Ｃ、１Ｄはそれぞれ異なる色の画像に対応し、例えば、感光体１Ａはブラック、感光体１Ｂはマゼンタ、感光体１Ｃはシアン、感光体１Ｄはイエローの各色のトナー画像が担持される。 The photoconductors 1A, 1B, 1C, and 1D correspond to images of different colors. For example, the photoconductor 1A is black, the photoconductor 1B is magenta, the photoconductor 1C is cyan, and the photoconductor 1D is a yellow toner image. Supported.

感光体１Ａまわりの駆動系を含む構成をステーションＡ、感光体１Ｂまわりの同構成をステーションＢ、感光体１Ｃまわりの同構成をステーションＣ、感光体１Ａまわりの同構成をステーションＤと呼ぶ。 The configuration including the drive system around the photoconductor 1A is called station A, the same configuration around the photoconductor 1B is called station B, the same configuration around the photoconductor 1C is called station C, and the same configuration around the photoconductor 1A is called station D.

各ステーション共、機械的な構成は共通であるので、代表例としてステーションＡについて、図２により感光体駆動ギヤ（被駆動）４と感光体駆動ギヤ（駆動）５とを連結する凹凸形状部の構成を説明する。 Since each station has the same mechanical configuration, as a representative example, for station A, an uneven shape portion for connecting the photosensitive member driving gear (driven) 4 and the photosensitive member driving gear (driving) 5 according to FIG. The configuration will be described.

図２において、感光体駆動ギヤ（被駆動）４と感光体駆動ギヤ（駆動）５とは同一軸線Ｏ‐Ｏ上に隣接配置されていて、各対向する側面部に互いに噛み合い可能な一対の凹凸形状部を有している。 In FIG. 2, the photosensitive member driving gear (driven) 4 and the photosensitive member driving gear (driving) 5 are disposed adjacent to each other on the same axis OO and can be engaged with each other on opposite side portions. It has a shape part.

感光体駆動ギヤ（駆動）５の側面に形成された凹凸形状部９は、軸線Ｏ−Ｏを中心とする仮想円に沿って等間隔に形成された４つの凹凸からなる。凹部は隣接する凸部の間に相対的に形成される。 The concavo-convex shape portion 9 formed on the side surface of the photosensitive member driving gear (drive) 5 includes four concavo-convex portions formed at equal intervals along a virtual circle centered on the axis OO. The concave portion is relatively formed between adjacent convex portions.

図２では感光体駆動ギヤ（被駆動）４について、感光体駆動ギヤ（駆動）５に対向する側面部が視点の関係で見えないので図３に視点を変えて示している。図３において、感光体駆動ギヤ（被駆動）４の側面に形成された凹凸形状部１１は、軸線Ｏ−Ｏを中心とする仮想円に沿って等間隔に形成された４つの凹凸からなる。凹部は、隣り合う凸部の間に相対的に形成される凹んだ部分である。 In FIG. 2, the side surface of the photosensitive member driving gear (driven) 4 facing the photosensitive member driving gear (driving) 5 cannot be seen due to the viewpoint, and therefore, the viewpoint is changed in FIG. In FIG. 3, the concavo-convex shape portion 11 formed on the side surface of the photosensitive member driving gear (driven) 4 is composed of four concavo-convex portions formed at equal intervals along a virtual circle centered on the axis OO. A recessed part is a recessed part formed relatively between adjacent convex parts.

感光体駆動ギヤ（被駆動）４の凹凸形状部９と感光体駆動ギヤ（駆動）５の凹凸形状部１１とは互いの凹凸が噛み合い状態となったり、また、噛み合いを解除された状態となったりすることができる。 The concavo-convex shape portion 9 of the photosensitive member driving gear (driven) 4 and the concavo-convex shape portion 11 of the photosensitive member driving gear (driving) 5 are engaged with each other, or the engagement is released. Can be.

図２、図３において、感光体駆動ギヤ（駆動）５について任意の一つの凸部１０に着目すると、この凸部１０は、感光体駆動ギヤ（駆動）５が一方向（矢印で示す時計回りの方向）に回転するとき感光体駆動ギヤ（被駆動）の凸部１２（詳しくは当接面１２ａ）と当接して動力伝達する当接面１０ａと、噛み合い状態のまま感光体駆動ギヤ（駆動）５が感光体駆動ギヤ（被駆動）４に対して前記一方向と逆向きに回転することを許容する傾斜したスライド面１０ｂとで形成される山形をなしている。また、感光体駆動ギヤ（被駆動）の凸部１２を構成する山形は、前記当接面１２と当接する当接面１２ａと、前記スライド面１０ｂと摺動する傾斜したスライド面１２ｂとで形成されている。 2 and 3, when attention is paid to any one convex portion 10 with respect to the photosensitive member driving gear (driving) 5, the convex portion 10 has the photosensitive member driving gear (driving) 5 in one direction (clockwise indicated by an arrow). The contact surface 10a that transmits power by contacting the convex portion 12 (specifically, the contact surface 12a) of the photosensitive member drive gear (driven) when rotating in the direction of the photosensitive member drive gear (drive). ) 5 has a chevron shape formed by an inclined slide surface 10b that allows the photoconductor drive gear (driven) 4 to rotate in the direction opposite to the one direction. Further, the chevron forming the convex portion 12 of the photosensitive member driving gear (driven) is formed by a contact surface 12a that contacts the contact surface 12 and an inclined slide surface 12b that slides on the slide surface 10b. Has been.

このように、軸線方向に平行な当接面、軸線方向と交差する傾斜面を設けたので、当接面により正転時の動力伝達を確かなものにし、傾斜面によりギヤの逆転時に凹凸部で乗り上げが生じ、従動側のギヤは逆転時には回転しない。この乗り上げた量と回転方向を組み合わせることにより、位相をずらすことが可能となり、位相調整を行うことができる。 As described above, since the contact surface parallel to the axial direction and the inclined surface intersecting the axial direction are provided, the contact surface ensures the power transmission during the forward rotation, and the inclined surface causes the uneven portion during the reverse rotation of the gear. As a result, the driven gear does not rotate during reverse rotation. By combining this amount and the direction of rotation, the phase can be shifted and phase adjustment can be performed.

図４に、凸部１０を含む凹凸形状部９と凸部１２を含む凹凸形状部１１との噛み合い状態を模式的に示す。この例では、軸１３上に感光体駆動ギヤ（駆動）５と感光体駆動ギヤ（被駆動）４とが回転可能に設けられている。上記凹凸部同士の噛み合い状態を確保するため、感光体駆動ギヤ（駆動）５は加圧ばね１４により感光体駆動ギヤ（被駆動）４側に押圧する構成としている。つまり、凹凸形状部で駆動連結される２つの感光体駆動ギヤ同士を加圧ばね１４により接近する方向に加圧している。加圧ばね１４による加圧力は凹凸形状部１１、１２の噛み合い部を介して感光体駆動ギヤ（被駆動）４に及ぶので、軸１３にストッパ６を設けて加圧ばね１４による感光体駆動ギヤ（被駆動）４のずれを阻止している。
傾斜したスライド面を乗り越えることで位相をずらす場合に、ギヤ同士が離れた状態のままでは正転時にギヤが連結されない。本例では凸部１０がスライド面１２ｂを乗り越えた後に、もとの連結状態に戻す目的で加圧ばね１４により加圧する構成を用いている。 FIG. 4 schematically shows the meshing state of the concavo-convex shape portion 9 including the convex portion 10 and the concavo-convex shape portion 11 including the convex portion 12. In this example, a photosensitive member driving gear (driving) 5 and a photosensitive member driving gear (driven) 4 are rotatably provided on the shaft 13. In order to secure the meshing state of the concave and convex portions, the photosensitive member driving gear (drive) 5 is configured to be pressed toward the photosensitive member driving gear (driven) 4 side by a pressure spring 14. That is, the two photoconductor driving gears that are driven and connected by the concavo-convex shape portion are pressed in the direction approaching by the pressing spring 14. The pressure applied by the pressure spring 14 reaches the photosensitive member driving gear (driven) 4 through the meshing portions of the concavo-convex portions 11 and 12, so that a stopper 6 is provided on the shaft 13 and the photosensitive member driving gear by the pressing spring 14 is provided. (Driven) 4 is prevented from shifting.
When shifting the phase by getting over an inclined slide surface, the gears are not connected during forward rotation if the gears are separated from each other. In this example, after the convex part 10 gets over the slide surface 12b, the structure pressurized with the pressurization spring 14 is used for the purpose of returning to the original connection state.

図４に示した噛み合い状態のもとで、原動ギヤ７が正転すると、駆動伝達ギヤ６からの動力が感光体駆動ギヤ（駆動）５に伝達されて矢印の向きに回転し、当接部１０ａが当接部１２ａを押し動かし、感光体駆動ギヤ（被駆動）４も同方向に回転され、感光体ギヤ３と感光体１Ａとが一体として回転される。 When the driving gear 7 rotates in the forward direction under the meshing state shown in FIG. 4, the power from the drive transmission gear 6 is transmitted to the photosensitive member driving gear (drive) 5 and rotates in the direction of the arrow. 10a pushes and moves the contact portion 12a, the photosensitive member driving gear (driven) 4 is also rotated in the same direction, and the photosensitive member gear 3 and the photosensitive member 1A are rotated together.

加圧ばね１４で加圧されている感光体駆動ギヤ（駆動）５は軸方向に摺動可能である。原動ギヤ７が逆転に切り替わると、感光体駆動ギヤ（駆動）５が矢印の向きと逆向きに回転する。その際、感光体駆動ギヤ（被駆動）４は回転負荷がある感光体ギヤ３と連結されているため連れ回りすることはなく、固定的な凹凸形状部１１に対して凹凸形状部９のスライド面１０ｂがスライド面１２ｂに対して摺動して、スライド面１２ｂに乗り上げ、噛み合い状態を自動解除することが可能である。その際、感光体駆動ギヤ（駆動）５は軸１３上を加圧ばね１４の弾性に抗して左行する。 The photosensitive member drive gear (drive) 5 pressed by the pressure spring 14 is slidable in the axial direction. When the driving gear 7 is switched to reverse rotation, the photosensitive member driving gear (driving) 5 rotates in the direction opposite to the direction of the arrow. At this time, since the photosensitive member driving gear (driven) 4 is connected to the photosensitive member gear 3 having a rotational load, the photosensitive member driving gear (driven) 4 does not rotate and slides the concave and convex portion 9 with respect to the fixed concave and convex portion 11. The surface 10b slides on the slide surface 12b, rides on the slide surface 12b, and the meshing state can be automatically released. At this time, the photosensitive member drive gear (drive) 5 moves left on the shaft 13 against the elasticity of the pressure spring 14.

この逆転する回動量によっては、逆転前の当初の噛み合い位置に対して回転方向に噛み合い位置がずれた位置まで感光体駆動ギヤ（駆動）５を回転することができ、原動ギヤ７を正転にすることにより、当接面１０ａと当接面１２ａとを当接させて、このずれた位置で正規の噛み合い状態を得る。 Depending on the amount of reverse rotation, the photosensitive member drive gear (drive) 5 can be rotated to a position where the meshing position is shifted in the rotational direction with respect to the initial meshing position before the reverse rotation, and the driving gear 7 is rotated forward. By doing so, the contact surface 10a and the contact surface 12a are brought into contact with each other, and a normal meshing state is obtained at this shifted position.

ステーションＡにおける凹凸形状部９と凹凸形状部１１と同様の構成は他のステーションＢ、Ｃ、Ｄにおいても設けられているが、その凹凸の形状はステーションＡ、Ｂ、Ｃ、Ｄについてそれぞれ異なった形状である。 The same configuration as the uneven shape portion 9 and the uneven shape portion 11 in the station A is also provided in the other stations B, C, and D, but the uneven shapes are different for the stations A, B, C, and D, respectively. Shape.

ステーションＡ、Ｂ、Ｃ、Ｄ間での位相調整の構成を説明する。
図５にステーションＡ、Ｂ、Ｃ、Ｄのそれぞれについて凹凸形状部１１を１周の１／４分について展開して模視的に例示した。図５に示す通り、凹凸の形状がステーションＡ、Ｂ、Ｃ、Ｄについてそれぞれ異なっているとは、各ステーションＡ、Ｂ、Ｃ、Ｄでそれぞれ、凸部（凹部）の間隔が異なっていることを表している。色間の位相をずらすためには、凹凸形状が色毎に異なっていることが必要である。例えば、図３では凸部１０（或いは凸部１２）が１周に４本あり、これを図５においてステーションＡに当てはめると、ステーションＡでは４本、Ｂでは８本、Ｃでは１６本と考えればよい。凹凸形状部９においても同様である。 A configuration of phase adjustment among the stations A, B, C, and D will be described.
FIG. 5 schematically illustrates the concavo-convex shape portion 11 for each of the stations A, B, C, and D developed for ¼ of one round. As shown in FIG. 5, the uneven shape is different for each of the stations A, B, C, and D. The intervals between the convex portions (concave portions) are different in each of the stations A, B, C, and D. Represents. In order to shift the phase between colors, it is necessary that the uneven shape is different for each color. For example, in FIG. 3, there are four convex portions 10 (or convex portions 12) in one circumference, and when this is applied to station A in FIG. 5, it is considered that there are four in station A, eight in B, and sixteen in C. That's fine. The same applies to the uneven portion 9.

実際に位相を調整するためにはモータ５を逆転させることが必要である。モータにより原動ギヤ７を逆転すると、原動ギヤ７から各感光体駆動ギヤ（駆動）５、各感光体駆動ギヤ（駆動）５から各感光体駆動ギヤ（被駆動）４、各感光体駆動ギヤ（被駆動）４から各感光体ギヤ３へと駆動が伝達される。前記したように、感光体ギヤ３、感光体駆動ギヤ（被駆動）４は回転負荷がかかっているため、負荷以上のトルクがかからないと回転しない。 In order to actually adjust the phase, it is necessary to reverse the motor 5. When the driving gear 7 is reversely rotated by the motor, the driving gear 7 drives the photosensitive member driving gears (drives) 5, the photosensitive member driving gears (driving) 5 to the photosensitive member driving gears (driven) 4, and the photosensitive member driving gears ( The drive is transmitted from the (driven) 4 to each photoconductor gear 3. As described above, since the photoconductor gear 3 and the photoconductor drive gear (driven) 4 are subjected to a rotational load, the photoconductor gear 3 and the photoconductor drive gear (driven) 4 do not rotate unless a torque greater than the load is applied.

感光体駆動ギヤ（被駆動）４と感光体駆動ギヤ（駆動）５の駆動連結は凹凸形状部９、１０のかみ合わせで行っており、逆回転時には凸部１０がスライド面１２ｂを乗り越える形状となっているので、原動ギヤ７（モータ）を逆回転させると、原動ギヤ７と各感光体駆動ギヤ（駆動）５は回転し、各感光体ギヤ３、感光体駆動ギヤ（被駆動）４は停止状態を保持する。 Driving connection of the photosensitive member driving gear (driven) 4 and the photosensitive member driving gear (driving) 5 is performed by meshing the concavo-convex shape portions 9 and 10, and the convex portion 10 gets over the slide surface 12b during reverse rotation. Therefore, when the driving gear 7 (motor) is rotated in the reverse direction, the driving gear 7 and each photosensitive member driving gear (driving) 5 are rotated, and each photosensitive member gear 3 and the photosensitive member driving gear (driven) 4 are stopped. Keep state.

これにより、各ステーションＡ、Ｂ、Ｃ、Ｄにおいて、感光体駆動ギヤ（駆動）５が回転するのに伴い凸部１０が感光体駆動ギヤ（被駆動）４のスライド面１２ｂを乗り上げるので、加圧ばね１４の弾性に抗して軸方向に移動しながら回転し位相をずらすことができる。「スライド面１０ｂ、１２ｂでの摩擦負荷＜感光体ギヤ３、感光体駆動ギヤ（被駆動）４にかかる負荷」の場合に、上記のような動作が可能となる。原動ギヤ７の正転時には凹凸形状部９、１１部はスライド面１０ｂ、１２ｂ同士のみでの接触ではなく、当接面１０ａ、１２ａ同士でも接触するため逆転時のような乗り上げは発生せず、単純に駆動を伝達することが可能である。 As a result, at each of the stations A, B, C, and D, the convex portion 10 rides on the slide surface 12b of the photosensitive member driving gear (driven) 4 as the photosensitive member driving gear (driving) 5 rotates. It can rotate and shift its phase while moving in the axial direction against the elasticity of the pressure spring 14. In the case of “friction load on the slide surfaces 10b and 12b <load applied to the photoconductor gear 3 and the photoconductor drive gear (driven) 4”, the above operation is possible. During forward rotation of the driving gear 7, the concave and convex portions 9 and 11 are not in contact only with the slide surfaces 10b and 12b, but are also contacted with the contact surfaces 10a and 12a. It is possible to simply transmit the drive.

位相の調整方法について説明する。図５は、円上に配置した凹凸からなる凹凸形状部１１を直線上に展開して示したものと考える。右向きの矢印を感光体駆動ギヤ（駆動）５の逆転方向、左向きの矢印を正転方向とする。前記した通り、逆転時には感光体駆動ギヤ（被駆動）４の凸部１２を感光体駆動ギヤ（駆動）５の凸部１０が乗り越え、正転時には乗り越えない。 A method for adjusting the phase will be described. FIG. 5 considers that the uneven | corrugated shaped part 11 which consists of the unevenness | corrugation arrange | positioned on the circle | round | yen expand | deployed and showed on the straight line. The arrow pointing to the right is the reverse direction of the photosensitive member drive gear (drive) 5, and the arrow pointing to the left is the normal direction. As described above, the convex portion 12 of the photosensitive member driving gear (drive) 5 gets over the convex portion 12 of the photosensitive member driving gear (driven) 4 at the time of reverse rotation, and does not get over at the time of forward rotation.

各ステーションＡ、Ｂ、Ｃ、Ｄにおいて、例えば各当接面１２ａの位相が揃っている角度α→任意の角度βへと感光体駆動ギヤ（駆動）５を逆回転させた場合に、感光体駆動ギヤ（駆動）５の凸部１０は、ステーションＡ、Ｂについて隣の凸部１２ｂを乗り越えるに至らないがステーションＡでは１つの凸部１２ｂ、ステーションＢでは２つの凸部１２ｂをそれぞれ乗り越えた位置にある。βの状態から感光体駆動ギヤ（駆動）５を正回転させると、ステーションＡ、Ｂについてはαの位置に戻り、ステーションＣでは凸部１２について１ピッチ、ステーションＤでは凸部１２について２ピッチ分だけ位相がずれることになる。本例では、ステーションＣについての凸部１２の１ピッチの距離はステーションＤについての凸部１２の１ピッチの距離の２倍あるので、結果的にα→βへ逆回転させたことで、「ステーションＡ、Ｂ」と「ステーションＣ、Ｄ」の間では（β―α）の角度だけ位相がずれることになる。また、このとき、ステーションＡ、Ｂ間、ステーションＣ、Ｄ間の位相は変化していない。同様の手法を用いて、例えばα→γへと逆回転させれば、「ステーションＡ」と「ステーションＢ、Ｃ、Ｄ」の間で（γ―α）の位相差を設けることが可能である。 In each of the stations A, B, C, and D, for example, when the photosensitive member driving gear (drive) 5 is reversely rotated from the angle α at which the phases of the contact surfaces 12a are aligned to an arbitrary angle β, the photosensitive member The convex portion 10 of the drive gear (drive) 5 does not go over the adjacent convex portion 12b for the stations A and B, but is a position where the convex portion 10b passes over one convex portion 12b in the station A and two convex portions 12b in the station B. It is in. When the photosensitive member drive gear (drive) 5 is rotated forward from the state β, the stations A and B return to the position α, and the station C has one pitch for the convex portion 12 and the station D has two pitches for the convex portion 12. Will be out of phase only. In this example, since the distance of one pitch of the convex portion 12 for the station C is twice the distance of one pitch of the convex portion 12 for the station D, as a result of reverse rotation from α to β, “ The phase is shifted by an angle of (β−α) between “Stations A and B” and “Stations C and D”. At this time, the phases between the stations A and B and between the stations C and D are not changed. If the same method is used to reversely rotate from α to γ, for example, it is possible to provide a phase difference of (γ−α) between “station A” and “stations B, C, D”. .

このように、駆動源としてのモータ（原動ギヤ７）の駆動時に、感光体駆動ギヤ（駆動）５の回転方向を逆転と正転とを繰り返すことで、感光体駆動ギヤ（駆動）５と感光体駆動ギヤ（被駆動）４の凹凸形状同士の噛み合い位置をずらし各感光体の速度変動の位相関係を調整することができる。これによれば、感光体駆動系のギヤに予め目印を設けておき、目印の位相が合うように位相調整することで色ずれ低減を図ることも可能である。凹凸形状部９と感光体駆動ギヤ（駆動）５や凹凸形状部１０と感光体駆動ギヤ（被駆動）４とをそれぞれ一体化または実質的に一体化すれば、部品点数が増すこともない。
また、１つのモータで複数個の感光体を駆動する電装部品の少ない駆動構成においても、１つのモータで１つの感光体を駆動する駆動構成と同様に感光体の速度変動の位相を合わせることが可能で、副走査方向の色ずれを低減することができる。 In this way, when the motor (primary gear 7) as a driving source is driven, the photosensitive member driving gear (driving) 5 and the photosensitive member driving gear (driving) 5 are repeatedly rotated in the reverse direction and forward rotation. It is possible to adjust the phase relationship of the speed fluctuations of the respective photosensitive members by shifting the meshing positions of the concave and convex shapes of the body driving gear (driven) 4. According to this, it is also possible to reduce the color misregistration by providing a mark in advance on the gear of the photosensitive member driving system and adjusting the phase so that the mark is in phase. If the concave and convex portion 9 and the photosensitive member driving gear (drive) 5 and the concave and convex portion 10 and the photosensitive member driving gear (driven) 4 are integrated or substantially integrated, the number of parts does not increase.
Further, even in a drive configuration in which a plurality of photoconductors are driven by a single motor, the phase of the speed fluctuation of the photoconductor can be matched in the same manner as in a drive configuration in which a single photoconductor is driven by a single motor. This is possible, and color misregistration in the sub-scanning direction can be reduced.

例２：画像パターンの読み取り結果に応じて駆動源を制御する構成
例１における構成、手法をそのまま用い、さらに画像パターンの読み取り結果に応じて駆動源を制御して各感光体の速度変動の位相ずれを調整する。図１に示すように転写体２に対面して画像パターンを読み取る検知手段１５を配置しておく。図６に示すように、転写体２上に各感光体１Ａ〜１Ｄにより画像形成したテストパターン１６を検知手段１５で読み取り、波形を元に、色ずれを生じないに最適な位相位置を算出し、最適な位相関係に合わせることができる。 Example 2: Configuration for controlling drive source according to image pattern reading result Using the configuration and method in Example 1 as they are, and further controlling the driving source according to the image pattern reading result, the phase of speed fluctuation of each photoconductor Adjust the deviation. As shown in FIG. 1, a detection means 15 that reads the image pattern is arranged facing the transfer body 2. As shown in FIG. 6, the test pattern 16 formed on the transfer body 2 by the respective photoreceptors 1A to 1D is read by the detection means 15, and the optimum phase position is calculated based on the waveform without causing color misregistration. , It can be adjusted to the optimum phase relationship.

図示しない制御手段は検知手段１５からの情報を入力するようになっていて、読み取られたテストパターンの波形から最適な位相関係に合わせるために必要な感光体駆動ギヤ（駆動）５の逆転、正転の回数、逆転の回転量などを算出して、原動ギヤ７を駆動するモータにその回転を実行するように指示する構成とする。 A control means (not shown) is adapted to input information from the detection means 15, and the reverse and correct rotation of the photosensitive member drive gear (drive) 5 necessary for matching the optimum phase relationship from the waveform of the read test pattern. The number of rotations, the amount of reverse rotation, and the like are calculated, and the motor that drives the driving gear 7 is instructed to execute the rotation.

上記制御手段における位相調整の手順の一例を図７に示したフローチャートにより説明する。この例は、感光体の交換により回転位置の位相が感光体相互でずれるので、ステップＰ１では感光体の交換をセンサで検知することにより位相調整を実行するようにしている。 An example of the phase adjustment procedure in the control means will be described with reference to the flowchart shown in FIG. In this example, the phase of the rotational position is shifted between the photoconductors due to the replacement of the photoconductors. Therefore, in step P1, the phase adjustment is performed by detecting the replacement of the photoconductors with a sensor.

ステップＰ２で位相合わせ制御を開始する。その内容は、ステップＰ２−１で前記したように転写体２上にテストパターン１６を形成する。ステップＰ２−２で、テストパターン１６を検知手段１５で読み取り、情報を制御手段に取り込む。ステップＰ２−３で、予め記憶手段に格納されたデータを用い、最適値との位相差を算出する。ステップＰ２−４で、最適値との位相差が基準以内かどうかを判定する。基準以内なら終了するし、基準から外れていれば、位相調整を実行するためステップＰ２−５へ進む。 In step P2, phase matching control is started. The test pattern 16 is formed on the transfer body 2 as described above in step P2-1. In step P2-2, the test pattern 16 is read by the detection means 15 and information is taken into the control means. In step P2-3, the phase difference from the optimum value is calculated using data stored in advance in the storage means. In Step P2-4, it is determined whether or not the phase difference from the optimum value is within the reference. If it is within the reference, the process ends. If the reference is not satisfied, the process proceeds to Step P2-5 to execute the phase adjustment.

ステップＰ２−５では、駆動系を逆転の後に正転するにともない、感光体１Ａ〜１Ｄと転写体２とが擦れないように予め感光体１Ａ〜１Ｄと転写体２とを離間させるための処置をする。一例を示すと、図５において、正転時にβからαへ正転する際に、ステーションＡでは感光体１Ａは回転しないが、他のステーションＢ、Ｃ、Ｄでは静止している転写体２に対して感光体１Ｂ、１Ｃ、１Ｄが回転するため、擦れから感光体を保護するためである。ステップＰ２−６で所要の量及び数の逆転、正転動作を実行して位相差を基準内に収める。 In Step P2-5, a measure for separating the photoreceptors 1A to 1D and the transfer body 2 in advance so that the photoreceptors 1A to 1D and the transfer body 2 are not rubbed with each other as the drive system is rotated forward and then rotated forward. do. As an example, in FIG. 5, when rotating forward from β to α during forward rotation, the photosensitive member 1 </ b> A does not rotate at the station A, but at the other stations B, C, and D, the transfer member 2 is stationary. On the other hand, since the photoconductors 1B, 1C, and 1D rotate, the photoconductor is protected from rubbing. In Step P2-6, the necessary amount and number of reverse and forward rotation operations are executed to bring the phase difference within the standard.

本発明では例１で記したように、感光体駆動系のギヤに予め目印を設けておき、目印の位相が合うように位相調整することで、ギヤの偏心により発生する感光体の速度変動の位相を合わせて色ずれ低減を図ることができる。しかし、この方法ではギヤの成型時に発生する偏心の位相を合わせることは可能であるが、ギヤの偏心以外の要因で発生する速度変動の位相を合わせることはできない。また、感光体ギヤの位相はユーザの設置時に噛み合い位置が変わることで変動するため、組み立て時に位相を合わせても、ユーザが感光体を交換するたびに変動してしまう。それに対し、本例では、感光体の交換による位相のずれ、テストパターンに基づき調整するので、感光体の負荷変動やジョイント部の偏角などが原因で発生する感光体の速度変動の位相も含めた状態で位相を合わせることができ、より色ずれ低減効果が大きくなる。 In the present invention, as described in Example 1, a mark is provided in advance on the gear of the photosensitive member drive system, and phase adjustment is performed so that the phase of the mark is matched, so that the speed fluctuation of the photosensitive member caused by the eccentricity of the gear is detected. Color shift can be reduced by matching the phase. However, in this method, it is possible to match the phase of the eccentricity generated at the time of molding the gear, but it is not possible to match the phase of the speed fluctuation caused by factors other than the gear eccentricity. Further, since the phase of the photoconductor gear changes due to the change of the meshing position when the user is installed, even if the phase is adjusted during assembly, the phase changes every time the user replaces the photoconductor. In contrast, in this example, adjustment is performed based on the phase shift caused by replacement of the photoconductor and the test pattern, so the phase of the photoconductor speed fluctuation caused by the photoconductor load fluctuation and joint deflection angle is also included. In this state, the phase can be adjusted, and the effect of reducing color shift is further increased.

例３：一部のステーションの凹凸形状部はスライド面を有さない構成
ステーションＡを基準とし、そのステーションＡに他のステーションＢ、Ｃ、Ｄの位相を合わせる場合、図８に示したようにステーションＡでの凹凸形状部９、１１部にはスライド面１０ｂ、１２ｂを設けず、正転、逆転時にも噛み合い状態のままとすれば、ステーションＡのみ逆転時にも感光体駆動ギヤ（駆動）５、感光体駆動ギヤ（被駆動）４が回転することになり、このステーションＡを基準にして位相を合わせることになる。 Example 3: Concave and convex portions of some stations do not have a sliding surface. When station A is used as a reference and the phases of other stations B, C, and D are aligned with station A, as shown in FIG. If the concavo-convex shape portions 9 and 11 at the station A are not provided with the slide surfaces 10b and 12b and are kept in the meshed state at the time of normal rotation and reverse rotation, only the station A has the photosensitive member drive gear (drive) 5 at the time of reverse rotation. Then, the photosensitive member driving gear (driven) 4 is rotated, and the phase is adjusted with reference to the station A.

基準となるステーションＡの感光体１Ａを原動ギヤ（モータ）の逆転時に回転させるか、させないかは凸部１０にスライド面１０ｂを設けるか否かで選択可能であり、前者の利点は基準の位相がずれることがないので、位相調整の精度は後者と同じで凹凸形状部９、１１の形状を前者と比較して細かくする必要がなくなる利点がある。しかし、前者のデメリットは感光体が逆回転することであり、逆回転することで品質上の問題が発生する感光体では前者を用いることができない。いずれにしても、位相を調整するためにはステーション毎に凹凸形状部９、１１の形状が異なっていることが必要条件である。 Whether the photoconductor 1A of the reference station A is rotated or not when the driving gear (motor) is reversed can be selected depending on whether or not the slide surface 10b is provided on the convex portion 10, and the former advantage is the phase of the reference Therefore, there is an advantage that the accuracy of phase adjustment is the same as that of the latter, and it is not necessary to make the shapes of the uneven portions 9 and 11 finer than the former. However, the former demerit is that the photoconductor rotates in the reverse direction, and the former cannot be used in the photoconductor that causes a problem in quality due to the reverse rotation. In any case, in order to adjust the phase, it is a necessary condition that the shapes of the concave and convex portions 9 and 11 are different for each station.

例４：加圧手段としてハスバ歯車を用いる例
図９に示したように、感光体駆動ギヤ（駆動）５’（図４における感光体駆動ギヤ（駆動）５に対応する）をハスバ歯車で構成している。これと噛み合う動力伝達ギヤ６’ （図４における動力伝達ギヤ６に対応する）についても同様である。
ハスバ歯車はその性質上、回転方向へのトルク伝達以外にスラスト方向に力が働く。感光体駆動ギヤ（駆動）５’が正転時に感光体駆動ギヤ（被駆動）４に近づく方向にねじれ方向を設定することで、正転時に感光体駆動ギヤ（被駆動）４と感光体駆動ギヤ（駆動）５’は駆動連結状態にあり、逆転時には非駆動連結状態となる。後は上記の手法と同じように、凹凸形状部９’、凹凸形状部１１’部の形状をステーション毎に異ならせることにより、正転、逆転を用いて位相調整が可能である。凹凸形状部９’、凹凸形状部１１’の形状は前記例のようにスライド面を有しない構成（例えば図５におけるステーションＡにおけるような構成）であっても、ハスバ歯車のスラスト力で感光体駆動ギヤ（被駆動）４と感光体駆動ギヤ（駆動）５’が離間されるので、目的を達成できる。軸１３には感光体駆動ギヤ（駆動）５’が余計にずれないようにストッパを設ける。本例において、凹凸形状部をスライド面を有する構成とし、また、加圧ばねを付設することはもちろん可能である。 Example 4: Example of using Hasuba gear as pressurizing means As shown in FIG. 9, the photoreceptor driving gear (drive) 5 ′ (corresponding to the photoreceptor driving gear (drive) 5 in FIG. 4) is composed of a Hasuba gear. is doing. The same applies to the power transmission gear 6 'meshing with this (corresponding to the power transmission gear 6 in FIG. 4).
Due to the nature of the helical gear, a force acts in the thrust direction in addition to torque transmission in the rotational direction. By setting the twist direction so that the photosensitive member driving gear (driving) 5 ′ approaches the photosensitive member driving gear (driven) 4 during forward rotation, the photosensitive member driving gear (driven) 4 and the photosensitive member drive during forward rotation are set. The gear (drive) 5 ′ is in a drive connection state, and is in a non-drive connection state during reverse rotation. Thereafter, in the same manner as in the above-described method, the phase can be adjusted using forward rotation and reverse rotation by making the shapes of the uneven shape portion 9 ′ and the uneven shape portion 11 ′ different for each station. Even if the shape of the concavo-convex shape portion 9 ′ and the concavo-convex shape portion 11 ′ is a configuration that does not have a slide surface as in the above example (for example, a configuration as in the station A in FIG. 5), Since the driving gear (driven) 4 and the photosensitive member driving gear (driving) 5 ′ are separated from each other, the object can be achieved. A stopper is provided on the shaft 13 so that the photosensitive member driving gear (driving) 5 'is not displaced excessively. In this example, it is of course possible that the concavo-convex shape portion has a slide surface and a pressure spring is attached.

例５：ギヤ部と凹凸形状部とを別体とし一体的に構成した
感光体駆動ギヤ（被駆動）４、感光体駆動ギヤ（駆動）５、５’などにおいて、ギヤ部と凹凸形状部９、９’、１１、１１’などを別体としている。位相調整を行うには前述しているように、ステーションごとに凹凸形状部９、９’、１１、１１’の形状が異なることが必要である。 Example 5: The gear portion and the concavo-convex shape portion are formed separately and integrally formed. In the photoconductor drive gear (driven) 4, the photoconductor drive gear (drive) 5, 5 ′, etc., the gear portion and the concavo-convex shape portion 9 are provided. , 9 ′, 11, 11 ′, etc. are separated. In order to perform the phase adjustment, as described above, it is necessary that the shapes of the uneven portions 9, 9 ′, 11, 11 ′ differ for each station.

例えば、感光体駆動ギヤ（駆動）５と凹凸形状部９部を同一の金型で成型した場合、ステーション毎に感光体駆動ギヤ（駆動）５の偏心にバラツキが生じ、結果、感光体の速度変動の振幅がステーション毎に大きくことなってしまう怖れがある。図１０に示すように、各感光体１Ａ〜１Ｄで形成した４つの曲線で示すように時間軸方向に位相が合っていたとしても、速度変動の振幅の差が大きくなるにつれ、例えば、一つの感光体について大きな色ずれ要因となるずれΔが生じると位相合わせの効果が薄れてしまう。
そこで、感光体駆動ギヤ（被駆動）４、感光体駆動ギヤ（駆動）５、５’については、すべてのステーションにおいて同一の部品を用い、凹凸形状部９、９’、１１、１１’のみを別部材として組み合わせることで上記の問題を解決している。 For example, when the photosensitive member drive gear (drive) 5 and the concavo-convex portion 9 are molded with the same mold, the eccentricity of the photosensitive member drive gear (drive) 5 varies from station to station, resulting in the speed of the photosensitive member. There is a fear that the amplitude of the fluctuation becomes large for each station. As shown in FIG. 10, even if the phase in the time axis direction is in phase as shown by the four curves formed by the photoconductors 1A to 1D, as the difference in the amplitude of the speed fluctuation increases, for example, When a shift Δ that causes a large color shift occurs on the photosensitive member, the effect of phase matching is reduced.
Therefore, for the photosensitive member driving gear (driven) 4 and the photosensitive member driving gears (driving) 5, 5 ′, the same parts are used in all stations, and only the concave and convex portions 9, 9 ′, 11, 11 ′ are used. The above problems are solved by combining them as separate members.

例６：駆動源として用いるモータの例
原動ギヤ７を駆動するモータに関し、位相調整を精度良く行うためには停止位置の精度が求められる。原動ギヤ７と感光体駆動ギヤ（駆動）５、５’との減速比を大きくとる方が有利である。減速比以外に、原動ギヤ７を駆動するモータとしては、単純なＤＣモータではなくブレーキ機能を有したＤＣモータが望ましい。ブレーキ機能を有していないＤＣモータでは単に駆動伝達を切るだけなので、停止指令から停止までに時間遅れが生じ、狙い通りの位置で停止させることは難しい。また、負荷やイナーシャーにより遅れ時間もばらついてしまう。ブレーキ機能を有していれば、感光体駆動ギヤ（駆動）５、５’が目標の角度だけ逆回転した位置で精度よく停止させることができる。 Example 6: Example of motor used as drive source With respect to the motor that drives the driving gear 7, accuracy of the stop position is required in order to perform phase adjustment with high accuracy. It is advantageous to increase the reduction ratio between the driving gear 7 and the photosensitive member driving gears (drives) 5 and 5 ′. In addition to the reduction ratio, the motor that drives the driving gear 7 is preferably a DC motor having a brake function instead of a simple DC motor. Since a DC motor that does not have a brake function simply cuts off drive transmission, there is a time delay from the stop command to the stop, and it is difficult to stop at the intended position. Also, the delay time varies depending on the load and inertia. If the brake function is provided, the photosensitive member drive gears (drives) 5 and 5 'can be accurately stopped at a position where the photoreceptor drive gears 5 and 5' are reversely rotated by a target angle.

感光体駆動ギヤ（駆動）５、５’の回転角度と上記モータと感光体駆動ギヤ（駆動）５、５’の間の減速比が分かれば、モータの必要な逆転量が分かるので必要な回転数だけ逆転させ、停止すれば良い。この時、ステッピングモータを用いれば、ステップ数による回転数の制御が可能となるので、さらに高い精度で感光体駆動ギヤ（駆動）５、５’を回転、停止させることが可能である。 If the rotation angle of the photosensitive member drive gears (drives) 5 and 5 ′ and the reduction ratio between the motor and the photosensitive member drive gears (drives) 5 and 5 ′ are known, the necessary reverse rotation amount of the motor can be known, and thus the necessary rotations. Just reverse the number and stop. At this time, if the stepping motor is used, the number of rotations can be controlled by the number of steps, so that the photosensitive member drive gears (drives) 5 and 5 ′ can be rotated and stopped with higher accuracy.

例７：感光体駆動ギヤ（被駆動）と感光体との駆動連結にジョイントを用いた例
図１１において、原動ギヤ７、動力伝達ギヤ６、感光体駆動ギヤ（駆動）５及び転写体２の構成は図１と同じである。異なるのは、各感光体駆動ギヤ（駆動）５と各感光体１Ａ〜１Ｄ間に駆動ジョイント１８と感光体ジョイント１９を設けてこれらジョイントにより連結している点である。 Example 7: An example in which a joint is used for driving connection between the photosensitive member driving gear (driven) and the photosensitive member. In FIG. 11, the driving gear 7, the power transmission gear 6, the photosensitive member driving gear (driving) 5, and the transfer member 2 The configuration is the same as in FIG. The difference is that a drive joint 18 and a photoconductor joint 19 are provided between the photoconductor drive gears (drives) 5 and the photoconductors 1A to 1D and are connected by these joints.

図１２において、ステーションＡについて説明する。感光体ジョイント１９は感光体１Ａの端部に装着固定される。駆動ジョイント１８は感光体ジョイント１９と感光体駆動ギヤ（駆動）５とを連結する。感光体駆動ギヤ（駆動）５、駆動ジョイント１８、感光体ジョイント１９、感光体１Ａは同一軸線上に構成されている。 The station A will be described with reference to FIG. The photoconductor joint 19 is attached and fixed to the end of the photoconductor 1A. The drive joint 18 connects the photoreceptor joint 19 and the photoreceptor drive gear (drive) 5. The photoconductor drive gear (drive) 5, the drive joint 18, the photoconductor joint 19, and the photoconductor 1A are configured on the same axis.

駆動ジョイント１８の感光体ジョイント１９と対面する側の端部には軸線を中心とする円上に４つの突起が軸方向には出ていてこれらが感光体ジョイント１９に嵌合して結合される。駆動ジョイント１８の感光体駆動ギヤ（駆動）５と対面する側の端部には、前記例における感光体駆動ギヤ（被駆動）４に設けられていた凹凸形状部１１と同様のものが形成されており、例１で説明したのと同様の態様で位相をずらして動力伝達することができる。
感光体駆動ギヤ（駆動）５と感光体ギヤ３とをジョイント連結し、かつ１つのモータで複数個の感光体を連結駆動している構成では、組み付け時に、感光体駆動ギヤ（駆動）５の偏心の位相を合わせた状態で組付けることは可能であるが、ギヤの偏心以外の速度変動要因である「感光体の負荷変動」「ジョイント結合による位相ずれ」などの成分を合わせることができない。
本例におけるジョイントによる連結でも同様に、感光体駆動ギヤ（駆動）５と駆動ジョイント１８は凹凸形状部９と凹凸形状部１１により駆動連結される。係る構成では、ジョイント部で発生する位相ずれを含めた位相調整が可能である。 At the end of the drive joint 18 facing the photoconductor joint 19, four protrusions protrude in the axial direction on a circle centering on the axis, and these are fitted and coupled to the photoconductor joint 19. . At the end of the drive joint 18 facing the photoconductor drive gear (drive) 5, the same shape as the concavo-convex shape portion 11 provided on the photoconductor drive gear (driven) 4 in the above example is formed. Thus, power can be transmitted with the phase shifted in the same manner as described in Example 1.
In the configuration in which the photosensitive member driving gear (driving) 5 and the photosensitive member gear 3 are jointly connected and a plurality of photosensitive members are connected and driven by one motor, the photosensitive member driving gear (driving) 5 of the photosensitive member driving gear (driving) 5 is assembled. Although it is possible to assemble with the phase of the eccentricity being matched, components such as “photoconductor load fluctuation” and “phase shift due to joint coupling” which are speed fluctuation factors other than the gear eccentricity cannot be matched.
Similarly, in the connection by the joint in this example, the photosensitive member driving gear (driving) 5 and the driving joint 18 are drivingly connected by the uneven portion 9 and the uneven portion 11. In such a configuration, it is possible to adjust the phase including a phase shift that occurs in the joint portion.

例８：駆動源を分けた例
単一駆動源に代えてカラー作像用感光体とモノクロ作像用感光体の駆動源を別にした複数駆動源としたものである。
図１３に示すように、モノクロ画像用のステーションＡについて、フルカラー用のステーションＢ、Ｃ、Ｄを駆動するための原動ギヤ７とは別に別のモータで駆動雄される原動ギヤ７’を新たに設け、感光体駆動ギヤ（駆動）５に噛み合わせている。このようにカラー作像用感光体とモノクロ作像用感光体の駆動源を別駆動にしたことで感光体の寿命を延ばす効果に加え、フルカラーの感光体間の速度変動の位相を合わせることでカラー３色間での色ずれ低減を図ることができる。また、この方式はモノクロの画像の印刷時にフルカラー感光体を駆動しないので、消費電力、感光体の寿命に対して有利な方式である。 Example 8: Example in which driving sources are separated A plurality of driving sources are provided in which the driving source for the color image forming photoconductor and the monochrome image forming photoconductor is replaced with a single driving source.
As shown in FIG. 13, for the monochrome image station A, a new driving gear 7 ′ driven by a motor other than the driving gear 7 for driving the full-color stations B, C, D is newly provided. And is meshed with the photosensitive member drive gear (drive) 5. In addition to the effect of extending the life of the photoconductor by separately driving the color image forming photoconductor and the monochrome image forming photoconductor in this way, the phase of the speed fluctuation between the full-color photoconductors is matched. It is possible to reduce color misregistration between three colors. Further, this method is advantageous for power consumption and the life of the photoconductor because the full color photoconductor is not driven when printing a monochrome image.

例９：感光体の回転位置を検出するための手段を設けた例
各感光体１Ａ〜１Ｄのまわりに、それぞれ、感光体の回転位置を検出するための手段を設ける。この構成によれば、モノクロ感光体１Ａとフルカラー感光体１Ｂ〜Ｄ間の速度変動の位相を合わせることができる。 Example 9: Example in which means for detecting rotational position of photoconductor is provided Around each of the photoconductors 1A to 1D, means for detecting the rotational position of the photoconductor is provided. According to this configuration, the phase of the speed fluctuation between the monochrome photoconductor 1A and the full color photoconductors 1B to 1D can be matched.

例１０：転写体と前記感光体とを接離可能とした例
凹凸形状部を用いた位相調整実施時に、感光体は回転、停止を繰り返す。その時の回転状態が色毎に異なるため、転写体と感光体の間には速度差が生じてしまう。この速度差によって、感光体表面と転写体の表面では擦れが発生し、感光体、転写体の寿命低下の原因となってしまう。本例では、転写体２、駆動軸８、従動軸８’、駆動源などを含むユニットの一端側を支点として揺動する構成とし、支点の反対側をカムで揺動可能な構成とすることで、転写体２を感光体１Ａ〜１Ｄに対して接離可能とする。或いは感光体が鉛直方向に移動する手段を設けたり、転写体を鉛直方向に移動させる方法を採用してもよい。これにより、位相調整時に転写体２と感光体１Ａ〜１Ｄとを離間状態にすることができるので、転写体及び感光体１Ａ〜１Ｄの寿命の低下を防ぐことができる。 Example 10: Example in which the transfer member and the photosensitive member can be brought into contact with and separated from each other. When the phase adjustment using the concavo-convex shape portion is performed, the photosensitive member is repeatedly rotated and stopped. Since the rotation state at that time is different for each color, a speed difference is generated between the transfer member and the photosensitive member. Due to this speed difference, rubbing occurs between the surface of the photosensitive member and the surface of the transfer member, which causes a reduction in the lifetime of the photosensitive member and the transfer member. In this example, the structure including the transfer body 2, the drive shaft 8, the driven shaft 8 ′, the drive source, and the like is swung around one end side of the unit, and the opposite side of the fulcrum is swung by the cam. Thus, the transfer body 2 can be brought into contact with and separated from the photoreceptors 1A to 1D. Alternatively, a means for moving the photosensitive member in the vertical direction or a method for moving the transfer member in the vertical direction may be employed. Thereby, since the transfer body 2 and the photoconductors 1A to 1D can be separated from each other at the time of phase adjustment, it is possible to prevent the life of the transfer body and the photoconductors 1A to 1D from being reduced.

例１１：感光体または感光体を含む交換可能ユニットの交換時期を検知する例
感光体１Ａ〜１Ｄをそれぞれ単独で、またはこれら感光体と現像装置を含む構成を一体的なユニット、カートリッジとして構成して周期的なメンテナンスを行うようにした構成では、これらユニット等の交換時期を例えば、印刷処理枚数の累計値をカウントすることにより可能である。感光体の回転数が分かればよいので、印刷枚数から回転数を計算したり、実際に回転数の検知手段を設けても良い。このカウント手段によりによりユニットの交換時期を検知すれば、これら感光体或いはユニット、カートリッジ等を交換する時期に合わせて、本発明の位相調整を行うことができ、そのようにすれば、画像形成装置停止時に２つの作業を重ねて行なうことにより最も必要な状況のみで位相調整をすることが可能となるので、画像形成装置のダウンタイムの発生時間を最小限に抑えることが可能である。 Example 11: Example of detecting the replacement timing of a photoconductor or a replaceable unit including the photoconductor The photoconductors 1A to 1D are each configured as a single unit or a cartridge including the photoconductor and the developing device. In the configuration in which periodic maintenance is performed, it is possible to replace these units or the like by, for example, counting the cumulative value of the number of print processing sheets. Since it is only necessary to know the rotational speed of the photoconductor, the rotational speed may be calculated from the number of printed sheets or an actual rotational speed detecting means may be provided. If the replacement time of the unit is detected by the counting means, the phase adjustment of the present invention can be performed in accordance with the replacement time of the photosensitive member, the unit, the cartridge, or the like. By performing the two operations in a stopped state, it is possible to adjust the phase only in the most necessary situation, and therefore it is possible to minimize the down time of the image forming apparatus.

本発明にかかる画像形成装置の要部を説明した正面図である。1 is a front view illustrating a main part of an image forming apparatus according to the present invention. 感光体駆動ギヤ（駆動）を含む感光体駆動系ギヤ列の主要部を示した分解斜視図である。FIG. 3 is an exploded perspective view showing a main part of a photoconductor drive system gear train including a photoconductor drive gear (drive). 感光体駆動ギヤ（被駆動）の斜視図である。It is a perspective view of a photoreceptor driving gear (driven). 感光体駆動系ギヤ列の主要部を示した正面図である。FIG. 3 is a front view showing a main part of a photoconductor drive system gear train. 凹凸形状部１１の半円周分を直線上に展開して示した図である。It is the figure which expanded and showed the part for semicircle of the uneven | corrugated shaped part 11 on the straight line. テストパターンが形成された転写体体の部分正面図である。It is a partial front view of a transfer body on which a test pattern is formed. 制御手段における位相調整の手順を説明したフローチャートである。It is the flowchart explaining the procedure of the phase adjustment in a control means. 凹凸形状部１１の半円周分を直線上に展開して示した図である。It is the figure which expanded and showed the part for semicircle of the uneven | corrugated shaped part 11 on the straight line. 感光体駆動系ギヤ列の主要部を示した正面図である。FIG. 3 is a front view showing a main part of a photoconductor drive system gear train. 各感光体の速度変動を説明した図である。It is a figure explaining the speed fluctuation of each photoconductor. 感光体駆動系にジョイントを用いた構成の画像形成装置の要部を説明した正面図である。FIG. 2 is a front view illustrating a main part of an image forming apparatus having a configuration using a joint in a photosensitive member driving system. ジョイントを用いた構成を説明した分解斜視図である。It is a disassembled perspective view explaining the structure using a joint. 駆動手段をモノクロ用とフルカラー用で分けた画像形成装置の要部を説明した正面図である。FIG. 2 is a front view illustrating a main part of an image forming apparatus in which a driving unit is divided for monochrome and full color.

符号の説明Explanation of symbols

１Ａ、１Ｂ、１Ｃ、１Ｄ感光体
２転写体
３感光体ギヤ
４感光体駆動ギヤ（被駆動）
５、５’感光体駆動ギヤ（駆動）
６、６’ 動力伝達ギヤ
７、７’ 原動ギヤ
９、９’ 凹凸形状部
１０凸部
１０ａ当接面
１０ｂスライド面
１１、１１’ 凹凸形状部
１２凸部
１２ａ当接面
１２ｂスライド面
１３軸
１４加圧ばね
１５検知手段
１６テストパターン
１７ストッパ
１８駆動ジョイント
１９感光体ジョイント
Ａ、Ｂ、Ｃ、Ｄステーション 1A, 1B, 1C, 1D Photoconductor 2 Transfer body 3 Photoconductor gear 4 Photoconductor drive gear (driven)
5, 5 'photoreceptor drive gear (drive)
6, 6 'Power transmission gear 7, 7' Driving gear 9, 9 'Concavity and convexity portion 10 Convex portion 10a Contact surface 10b Slide surface 11, 11' Concavity and convexity portion 12 Convex portion 12a Contact surface 12b Slide surface 13 Axis 14 Pressure spring 15 Detection means 16 Test pattern 17 Stopper 18 Drive joint 19 Photoconductor joint A, B, C, D Station

Claims

単一の駆動源により駆動されるように連結された複数個の感光体と、これら感光体の画像が転写される転写体を有する画像形成装置において、
同一の軸線上に隣接配置されていて、その側面部に互いに噛み合い可能な一対の凹凸形状部が設けられた感光体駆動ギヤ（駆動）と感光体駆動ギヤ（被駆動）を有し、
これらのギヤは駆動する感光体毎に前記凹凸形状部の凹凸形状が異なり、凹凸形状同士の噛み合いにより感光体に駆動力が伝達される構成であり、
前記駆動源の駆動時に、回転方向を逆転と正転とを繰り返すことで、凹凸形状同士の噛み合い位置をずらし各感光体の速度変動の位相関係を調整することを特徴とする画像形成装置。 In an image forming apparatus having a plurality of photoconductors coupled so as to be driven by a single drive source, and a transfer body to which an image of these photoconductors is transferred,
It has a photosensitive member driving gear (driving) and a photosensitive member driving gear (driven) that are disposed adjacent to each other on the same axis and are provided with a pair of concave and convex portions that can mesh with each other on the side surfaces thereof,
These gears have a configuration in which the concavo-convex shape of the concavo-convex shape portion is different for each photoconductor to be driven, and a driving force is transmitted to the photoconductor by meshing of the concavo-convex shapes,
An image forming apparatus characterized in that, when the drive source is driven, by rotating the rotation direction in reverse and forward rotation, the meshing positions of the concavo-convex shapes are shifted to adjust the phase relationship of the speed fluctuation of each photoconductor.

請求項１記載の画像形成装置において、
前記凹凸形状部は前記軸線を中心とする円の円周に沿って形成された複数の凹凸からなり、凸部は感光体駆動ギヤ（駆動）が一方向に回転するとき感光体駆動ギヤ（被駆動）の凸部と当接して動力伝達する当接面と、噛み合い状態のまま感光体駆動ギヤ（駆動）が感光体駆動ギヤ（被駆動）に対して前記一方向と逆向きに回転することを許容するスライド面とで形成される山形をなしていることを特徴とする画像形成装置。 The image forming apparatus according to claim 1.
The concavo-convex shape portion includes a plurality of concavo-convex portions formed along the circumference of a circle centered on the axis, and the ridge portion is formed on the photosensitive member driving gear (covered) when the photosensitive member driving gear (driving) rotates in one direction. The photosensitive member driving gear (driving) rotates in a direction opposite to the one direction with respect to the photosensitive member driving gear (driven) while meshing with the abutting surface that contacts the convex portion of the driving) and transmits the power. An image forming apparatus having a mountain shape formed with a slide surface that allows the

転写体上に描いた画像パターンを読み取るための読み取り手段を有し、その読み取り結果に応じて前記駆動源を駆動制御し、各感光体の速度変動の位相ずれを調整することを特徴とする画像形成装置。 An image having reading means for reading an image pattern drawn on a transfer body, and controlling the driving of the driving source according to the reading result to adjust the phase shift of speed fluctuation of each photoconductor. Forming equipment.

請求項２乃至３の何れかに記載の画像形成装置において、
前記当接面は前記軸線方向に平行な面からなり、前記スライド面は前記軸線方向と交差する傾斜面からなることを特徴とする画像形成装置。 The image forming apparatus according to any one of claims 2 to 3,
2. The image forming apparatus according to claim 1, wherein the contact surface is a surface parallel to the axial direction, and the slide surface is an inclined surface intersecting the axial direction.

請求項２乃至４の何れかに記載の画像形成装置において、
前記凹凸形状部で駆動連結される前記２つの感光体駆動ギヤ同士を加圧体により接近する方向に加圧することを特徴とする画像形成装置。 The image forming apparatus according to any one of claims 2 to 4,
An image forming apparatus characterized in that the two photosensitive member driving gears driven and connected by the concavo-convex shape portion are pressed in a direction approaching a pressing body.

請求項２乃至５の何れかに記載の画像形成装置において、
凹凸形状部で駆動連結される駆動側のギヤにハスバ歯車を用い、ギヤの正転時に２つのギヤが接近する方向に力が働くようねじれ方向が設定されていることを特徴とする画像形成装置。 The image forming apparatus according to claim 2,
An image forming apparatus characterized in that a helical gear is used as a driving-side gear that is driven and connected by a concavo-convex shape portion, and a twisting direction is set so that a force acts in a direction in which the two gears approach when the gear rotates forward. .

請求項２乃至６の何れかに記載の画像形成装置において、
ギヤ部と凹凸形状部とを別体とし一体的に構成したことを特徴とする画像形成装置。 The image forming apparatus according to claim 2,
An image forming apparatus characterized in that a gear part and a concavo-convex shape part are formed separately and configured integrally.

請求項１乃至７の何れかに記載の画像形成装置において、
前記駆動源としてブレーキ機能を有したＤＣモータを用いることを特徴とする画像形成装置。 The image forming apparatus according to claim 1,
An image forming apparatus using a DC motor having a brake function as the driving source.

請求項１乃至７の何れかに記載の画像形成装置において、
駆動源としてステッピングモータを用いることを特徴とする画像形成装置。 The image forming apparatus according to claim 1,
An image forming apparatus using a stepping motor as a drive source.

請求項２乃至９の何れかに記載の画像形成装置において、
前記２つのギヤの中、感光体駆動ギヤ（被駆動）と感光体との駆動連結にギヤによる駆動連結方式を用いたことを特徴とする画像形成装置。 The image forming apparatus according to any one of claims 2 to 9,
An image forming apparatus using a drive connection system using a gear for driving connection between the photosensitive member driving gear (driven) and the photosensitive member among the two gears.

請求項２乃至９の何れかに記載の画像形成装置において、
前記２つのギヤの中、従動側のギヤと感光体との駆動連結にジョイントによる駆動連結方式を用いたことを特徴とする特徴とする画像形成装置。 The image forming apparatus according to any one of claims 2 to 9,
2. An image forming apparatus according to claim 1, wherein a driving connection method using a joint is used for driving connection between the driven gear and the photosensitive member among the two gears.

請求項１乃至１１の何れかに記載の画像形成装置において、
単一駆動源に代えてカラー作像用感光体とモノクロ作像用感光体の駆動源を別にした複数駆動源としたことを特徴とする画像形成装置。 The image forming apparatus according to claim 1,
An image forming apparatus characterized in that, instead of a single drive source, a plurality of drive sources are provided separately for a color image forming photosensitive member and a monochrome image forming photosensitive member.

請求項１２に記載の画像形成装置において、
感光体の回転位置を検出するための手段を設けたことを特徴とする画像形成装置。 The image forming apparatus according to claim 12.
An image forming apparatus comprising means for detecting a rotational position of a photosensitive member.

請求項１乃至１３の何れかに記載の画像形成装置において、
前記転写体と前記感光体とを接離可能としたことを特徴とする画像形成装置。 The image forming apparatus according to claim 1,
An image forming apparatus, wherein the transfer member and the photosensitive member can be contacted and separated.

請求項１乃至１４の何れかに記載の画像形成装置において、
前記感光体または前記感光体を含む交換可能なユニットの交換時期を検知する手段を有していることを特徴とする画像形成装置。 The image forming apparatus according to claim 1,
An image forming apparatus comprising: means for detecting a replacement timing of the photosensitive member or a replaceable unit including the photosensitive member.

請求項１乃至１４の何れかに記載の画像形成装置において、
前記感光体または前記感光体を含む交換可能なユニットの回転数を検知する手段を有していることを特徴とする画像形成装置。 The image forming apparatus according to claim 1,
An image forming apparatus, comprising: means for detecting a rotation speed of the photosensitive member or a replaceable unit including the photosensitive member.