JPH0643711A - Image forming device with intermediate tray - Google Patents

Abstract

PURPOSE:To make the breadth of the device main body of an image forming device small and its height low, and moreover, to make the checking work of jam processing, etc., easy. CONSTITUTION:The image forming device has a vertical path 29 branching from an electing path 25, a nearly horizontal reversing path 33, a nearly horizontal intermediate ejecting path 37, a nearly horizontal intermediate tray 38 provided between the reversing path 33 and the intermediate electing path 37, and a vertical return path 20 provided on the downstream of the intermediate tray 38 and leading a sheet to an image forming part 4.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、中間トレイを備える画
像形成装置に係り、詳しくは、一面に画像が形成された
所望枚数のシート材（例えば転写材）を、その他面又は
同一面に再び画像形成を行うように構成された自動両面
・自動多重画像形成装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus provided with an intermediate tray, and more specifically, a desired number of sheet materials (for example, transfer materials) having an image formed on one surface thereof are again formed on the other surface or the same surface. The present invention relates to an automatic double-sided / automatic multiplex image forming apparatus configured to form an image.

【０００２】[0002]

【従来の技術】近年、複写機等の画像形成装置は、シス
テム化によってその各種作動の自動化が進められ、自動
両面複写機構および自動多重複写機構を備えるようにし
た装置が開発されている。そして、上記自動両面複写機
構等を構成するにあたっては、一般的に中間トレイ装置
と称せられるシートの集積部が使用され、そこに一面に
複写が終了した所望枚数のシートが一旦集積され、そこ
から再び複写部へと給紙が行われて、上記一面に複写済
のシートの他面あるいは同一面に再度複写がなされる方
法が採用されており、この様な方法は特に両面複写ある
いは多重複写される複写物を多数作成する際に極めて有
効なものとなっている。2. Description of the Related Art In recent years, in image forming apparatuses such as copying machines, various operations have been automated by systematization, and apparatuses having an automatic double-sided copying mechanism and an automatic multiplex copying mechanism have been developed. When constructing the automatic double-sided copying mechanism or the like, a sheet stacking unit generally called an intermediate tray device is used, and a desired number of sheets for which copying has been completed is once stacked on one side of the stacking unit. A method is adopted in which the sheet is fed again to the copying section and is copied again to the other side or the same side of the sheet which has already been copied on one side. Such a method is particularly double-sided copying or multiple copying. It is extremely effective when creating many copies.

【０００３】そして、従来、両面又は多重複写を具体化
するにあたり、一面に複写済のシートを、両面複写時に
は画像面を上にして中間トレイに収納させるべく、また
多重複写時には画像面を下にして中間トレイに収納させ
るべく、夫々適宜経路を通過させて中間トレイに収納
し、そこから複写部へ再給紙してシートに両面又は多重
画像を形成する方法が一般的に採用されている。In the past, when embodying double-sided or multiplex copying, a sheet that has already been copied on one side should be stored in an intermediate tray with the image side facing up during double-sided copying, and with the image side facing down during multiplex copying. In order to store the sheets in the intermediate tray, the sheets are passed through appropriate paths, stored in the intermediate tray, and then re-fed to the copying section to form double-sided or multiple images on a sheet.

【０００４】次に、それらの方法を概略構成図を用いて
説明すると、 （１） 図３（ａ）の如き複写機では、給紙部Ａより供
給されたシートは、画像形成部Ｂにおいてその一面に画
像を形成され、定着部Ｃを通過し、片面複写モードの場
合、第１フラッパーａは実線状態となり、正転する排出
ローラ対Ｒにより定着済のシートは排紙部Ｄへと排出さ
れる。そして、両面又は多重複写モードの場合には、第
１フラッパーａは鎖線状態に切換えられ、シートは搬送
経路Ｉを通り、両面複写モードの場合実線状態の第２の
フラッパーｂを経て搬送経路ＩＩを通り、シートは画像
面を上にした状態で中間トレイ部即ち再給紙部Ｅへ収納
される。また、多重複写モードの場合は、鎖線状態の第
２フラッパーｂを経て搬送経路ＩＩＩを通り、シートは
画像面を下にした状態で再給紙部Ｅへ収納される。その
後、両面又は多重複写モードの何れの場合も、シートは
再給紙部Ｅより搬送経路ＩＶを経て再び画像形成部Ｂへ
搬送されて両面又は多重複写が行われ、その後複写済の
シートは実線状態の第１フラッパーａを経て排紙部Ｄへ
と排出される。Next, those methods will be described with reference to a schematic configuration diagram. (1) In the copying machine as shown in FIG. In the single-sided copy mode, the image is formed on one side, passes through the fixing section C, and the first flapper a is in the solid line state, and the fixed sheet is discharged to the sheet discharging section D by the pair of forward discharging rollers R. It Then, in the double-sided or multi-copy mode, the first flapper a is switched to the chain line state, the sheet passes through the conveyance path I, and in the double-sided copy mode, the sheet passes through the second flapper b in the solid line state to the conveyance path II. As described above, the sheet is stored in the intermediate tray unit, that is, the re-feeding unit E with the image side facing up. In the case of the multiple copy mode, the sheet passes through the conveyance path III via the second flapper b in the chain line state, and the sheet is stored in the sheet re-feeding section E with the image side facing down. After that, in either of the double-sided or multi-copy mode, the sheet is conveyed again from the re-feeding section E to the image forming section B through the conveyance path IV and double-sided or multi-copying is performed, and then the copied sheet is indicated by a solid line. The sheet is discharged to the sheet discharge section D through the first flapper a in the state.

【０００５】（２） 図３（ｂ）の如き複写機では、片
面複写モードの場合、上記（１）と同様にして排出部Ｄ
へと排出され、両面複写モ−ドの場合、実線状態のフラ
ッパーａを経てシートは正転状態の排出ローラ対Ｒによ
り排紙部Ｄ方向へと搬送された後、センサＸにてシート
の後端が検出されると、シートは排出ローラ対Ｒの逆回
転により搬送経路Ｉ、ＩＩＩを経由し、画像面を上にし
た状態で再給紙部Ｅへ収納される。又、多重複写モ−ド
の場合、フラッパーａは鎖線の状態に切換えられ、シー
トは搬送経路ＩＩ、ＩＩＩを経由し、画像面を下にした
状態で再給紙部Ｅへと収納される。その後は上記（１）
と同様にして、両面又は多重画像形成済のシートは排出
部Ｄへと排出される。(2) In the copying machine as shown in FIG. 3B, in the case of the single-sided copying mode, the discharging section D is carried out in the same manner as in the above (1).
In the case of the double-sided copy mode, the sheet is conveyed in the direction of the sheet discharge section D by the discharge roller pair R in the forward rotation state through the flapper a in the solid line state, and then the sheet is detected by the sensor X after the sheet. When the edge is detected, the sheet is stored in the sheet re-feeding section E with the image side facing up through the conveyance paths I and III by the reverse rotation of the discharge roller pair R. Further, in the case of the multiple copy mode, the flapper a is switched to the chain line state, and the sheet is stored in the sheet re-feeding section E with the image side facing down via the conveying paths II and III. Then (1) above
In the same manner as described above, the double-sided or multi-image formed sheet is discharged to the discharge section D.

【０００６】（３） 図３（ｃ）の如き複写機では、片
面複写モ−ドの場合、やはり上記（１）と同様にして排
出部Ｄへと排出され、両面複写モ−ドの場合、上記片面
複写モ−ドの場合と同様にして排出部Ｄと兼用の機外の
再給紙部Ｅへ収納される。また、多重複写モ−ドの場
合、フラッパーａは鎖線状態に切換えられ、シートは搬
送経路Ｉを通り、更に正転状態のローラ対Ｒ′により搬
送経路ＩＩ方向に搬送された後、センサＸによりシート
の後端が検出されると、シートはローラ対Ｒ′の逆回転
により搬送経路ＩＩＩを経て、画像面を下にした状態で
機外の再給紙部Ｅへと収納される。その後は上記（１）
と同様にして両面又は多重画像が形成されたシートは排
出部Ｄへと排出される。(3) In the copying machine as shown in FIG. 3C, in the case of the single-sided copy mode, the sheet is discharged to the discharge section D in the same manner as in the above (1), and in the case of the double-sided copy mode. As in the case of the above single-sided copying mode, the sheet is stored in the re-feeding section E which is also used as the discharging section D and is outside the machine. In the case of the multiple copy mode, the flapper a is switched to the chain line state, the sheet passes through the conveying path I, and is further conveyed in the direction of the conveying path II by the pair of rollers R'in the normal rotation state, and then the sensor X is used. When the trailing edge of the sheet is detected, the sheet is accommodated in the re-feeding unit E outside the apparatus via the conveyance path III by the reverse rotation of the roller pair R ′ and with the image side facing down. Then (1) above
In the same manner as described above, the sheet on which both sides or the multiple image is formed is discharged to the discharge section D.

【０００７】[0007]

【発明が解決しようとする課題】しかしながら、上記
（１）の複写機の場合、、定着部Ｃから再給紙部Ｅまで
のシートの搬送経路が非常に長くなり、そのため、装置
の大きさ、特にその高さ寸法が大きくなってしまう欠点
があり、また、同じく搬送経路が長いため、ジャムが発
生した際にジャム処理を行う箇所が多くなり、ジャム処
理操作に手間が掛る欠点があった。However, in the case of the copying machine of the above (1), the sheet conveying path from the fixing section C to the sheet re-feeding section E becomes very long, so that the size of the apparatus, In particular, there is a drawback that the height dimension becomes large, and also, since the conveyance path is also long, there are many places where jam processing is performed when a jam occurs, and there is a drawback that the jam processing operation is troublesome.

【０００８】また、上記（２）の複写機においては、排
出ローラ対Ｒが正逆転ローラとなっている構造上、両面
複写モ−ドに際して、反転されるシートが一旦機外に露
出するため、ユーザーが誤ってそのシートを無理に引き
出してしまう危険があり、万一引き出された場合ジャム
を生ずる結果となる不都合があった。また、同じくシー
トが機外に露出することに起因して、排紙部Ｄの位置に
ソーターや綴じ装置あるいは折り装置等のフィニッシャ
ーの装着が困難となる欠点があった。Further, in the copying machine of the above (2), since the discharge roller pair R is a forward / reverse rotation roller, the sheet to be reversed is once exposed to the outside in the double-sided copying mode. There is a risk that the user will accidentally pull out the sheet, and if it is pulled out, a jam will result. Further, there is also a drawback that it becomes difficult to mount a finisher such as a sorter, a binding device, or a folding device at the position of the paper discharge section D due to the sheet being exposed to the outside of the machine.

【０００９】更に、上記（３）の複写機では、機外に再
給紙部Ｅが配置されているため、装置の横幅が大きくな
り、また（２）の複写機と同様に、ソーターやフィニッ
シャーの装着が困難となる欠点があった。Further, in the copying machine of the above (3), since the re-feeding section E is arranged outside the machine, the lateral width of the apparatus becomes large, and, similarly to the copying machine of the above (2), a sorter and a finisher. There was a drawback that it was difficult to install.

【００１０】以上のように、従来の複写機では、装置が
大型化したり、ジャム処理が大変であったり、更にはソ
ーター、フィニッシャー等のアプリケーションの装着が
困難となる欠点があった。As described above, the conventional copying machine has the drawbacks that the apparatus becomes large, the jam processing is difficult, and it is difficult to install applications such as a sorter and a finisher.

【００１１】[0011]

【課題を解決するための手段】本発明は、上述問題点を
解消することを目的とするものであって、画像形成部を
経由する経路を形成し、該経路の下流に排出経路と垂直
経路とを夫々分岐配設し、該垂直経路の下流で上記経路
の下方に上下に夫々略水平に中間排出経路と反転経路と
を分岐して設け、上記中間排出経路と反転経路との間に
上記中間排出経路から排出されるシート材を集積する中
間トレイ部を略水平に配設し、該中間トレイ部の下流に
シート材を再び上記経路に向けて搬送する垂直返送経路
を設け、更に、上記経路と排出経路および垂直経路との
間に上記経路からのシート材を排出経路又は垂直経路に
切換える第１の切換手段を配設し、上記垂直経路と中間
排出経路および反転経路との間に垂直経路からのシート
材を中間排出経路又は反転経路に切換え、反転経路から
のシート材を中間排出経路に切換える第２の切換手段を
配設し、上記垂直返送経路と上記経路との間に垂直返送
経路からのシート材を上記経路に向けて搬送する合流手
段を設けたことを特徴としている。SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned problems, and to form a route passing through an image forming unit, and a discharge route and a vertical route downstream of the route. And branching respectively, and an intermediate discharge path and a reversal path are provided substantially vertically below the path downstream of the vertical path, respectively, and the intermediate discharge path and the reversal path are branched and provided between the intermediate discharge path and the reversal path. An intermediate tray part for accumulating the sheet material discharged from the intermediate discharge path is disposed substantially horizontally, and a vertical return path for conveying the sheet material toward the path again is provided downstream of the intermediate tray part, and further, First switching means for switching the sheet material from the above-mentioned path to the discharge path or the vertical path is provided between the path and the discharge path and the vertical path, and is vertically provided between the vertical path and the intermediate discharge path and the reversal path. Intermediate discharge route for sheet material from the route Is provided with a second switching means for switching to the reversing path and switching the sheet material from the reversing path to the intermediate discharge path, and the sheet material from the vertical returning path to the above path between the vertical returning path and the above path. It is characterized in that a merging means for carrying toward is provided.

【００１２】[0012]

【作用】上述構成に基づき、画像形成部を経由する経路
を搬送されることにより画像形成部にて一面に画像形成
がなされたシート材は、片面モ−ドの場合、第１の切換
手段の第２の切換状態により排出経路を経てそのまま排
紙部へと排出される。In the single-sided mode, the sheet material on one side of which the image is formed by being conveyed through the path passing through the image forming section based on the above-mentioned construction is the first switching means of the first switching means. In the second switching state, the sheet is discharged as it is to the sheet discharge unit via the discharge path.

【００１３】そして、両面又は多重モ−ドの場合は、第
１の切換手段の第１の切換状態によりシート材は画像形
成装置の外部に露出されることなく垂直経路に向けて搬
送される。In the case of the double-sided or multi-mode, the sheet material is conveyed to the vertical path without being exposed to the outside of the image forming apparatus by the first switching state of the first switching means.

【００１４】ここで、両面モ−ドが選択されている場
合、第２の切換手段の第１の切換状態により、シート材
は垂直経路から一旦、反転経路に搬送された後、該反転
経路から同じく第１の切換状態の第２の切換手段により
中間排出経路を経て、画像面を上にした状態で画像形成
装置内部の中間トレイ部に集積される。Here, when the double-sided mode is selected, the sheet material is once conveyed from the vertical path to the reversing path and then from the reversing path due to the first switching state of the second switching means. Similarly, the second switching means in the first switching state passes through the intermediate discharge path, and the sheets are accumulated in the intermediate tray section inside the image forming apparatus with the image surface facing upward.

【００１５】また、多重モ−ドが選択されている場合、
シート材は第２の切換手段の第２の切換状態により垂直
経路から直接中間排出経路を経て、画像面を下にした状
態で中間トレイ部に集積される。When the multiple mode is selected,
The sheet material is accumulated in the intermediate tray portion with the image surface facing downward through the vertical path, the intermediate discharge path, and the second switching state of the second switching means.

【００１６】その後、両面又は多重モ−ド何れかの場合
も、シート材は順次中間トレイ部から垂直返送経路を経
て合流手段に向けて搬送され、該合流手段により再びシ
ート材の他面又は同一面に画像形成がなされるべく上記
画像形成部を経由する経路へと合流される。Thereafter, in either of the double-sided or multi-mode, the sheet material is sequentially conveyed from the intermediate tray portion through the vertical return path toward the merging means, and again by the merging means, the other surface of the sheet material or the same. The surface is merged into a path that passes through the image forming unit so that an image is formed on the surface.

【００１７】[0017]

【実施例】以下、図面に沿って、本発明の実施例につい
て説明する。Embodiments of the present invention will be described below with reference to the drawings.

【００１８】図１は一実施例装置の概略構成を示す縦断
正面図である。本例の装置は、循環式自動原稿送り装置
（ＲＤＦ装置）Ｂを具備し、両面・多重複写処理可能な
電子複写機Ａである。FIG. 1 is a vertical cross-sectional front view showing the schematic construction of the apparatus of one embodiment. The apparatus of this example is an electronic copying machine A equipped with a circulating automatic document feeder (RDF device) B and capable of double-sided / multiple copying.

【００１９】Ｉ 複写機Ａ １は複写機本機の外装筐、２はその外装筐の上面板面に
大きく形成した開口に不動に嵌めつけた原稿台で、ガラ
ス板等の透明板である。この原稿台上に後述するＲＤＦ
装置Ｂによりシート原稿Ｏが自動的に給送・排送され
る。I Copier A 1 is an exterior casing of the main body of the copier, and 2 is a document stand immovably fitted in an opening formed large in the upper surface of the exterior casing, and is a transparent plate such as a glass plate. The RDF, which will be described later, is placed on this document table.
The sheet original O is automatically fed and discharged by the device B.

【００２０】３は、原稿台上面の所定位置に位置決めセ
ット状態の原稿の下向き画像面を一端辺側から他端辺側
に順次に光学走査して回転感光体４の周面に原稿画像を
投影露光する移動型光学系であり、移動照明ランプ３ａ
・移動ミラー群３ｂ・結像レンズ３ｃ・固定ミラー群３
ｄ等からなる。Reference numeral 3 denotes a document image projected on the peripheral surface of the rotary photoconductor 4 by sequentially optically scanning the downward image surface of the document positioned and set at a predetermined position on the upper surface of the document table from one end side to the other end side. It is a moving optical system for exposing, and a moving illumination lamp 3a
-Movable mirror group 3b-imaging lens 3c-fixed mirror group 3
d etc.

【００２１】感光体４は軸５を中心に矢示方向に所定の
周速度で回転駆動されるドラム型感光体であり、帯電器
６により正又は負の一様な帯電処理を受け、露光部７に
て上記光学系３による原稿画像投影露光を受けることに
より、周面に露光原稿画像パターンに対応した静電潜像
が順次に形成されていく。その潜像は次いで第１現像器
８又は第２現像器９のうちの予め選定された現像器でト
ナー像として順次に現像される。感光体の現像面は帯電
器１０により転写前に電位均一安定化処理を受け、転写
帯電器１１部にて該帯電器と感光体４との間に感光体４
の回転と同期どりされて第１〜第３の給紙部１５〜１７
の何れかから給送された転写材の面に感光体４面側のト
ナー像が順次に転写されていく。The photosensitive member 4 is a drum type photosensitive member which is rotationally driven around the shaft 5 in a direction indicated by an arrow at a predetermined peripheral speed. The photosensitive member 4 receives a uniform positive or negative charging process by the charger 6 and is exposed. By receiving the original image projection exposure by the optical system 3 at 7, electrostatic latent images corresponding to the exposed original image pattern are sequentially formed on the peripheral surface. The latent image is then sequentially developed as a toner image by a preselected one of the first developing device 8 and the second developing device 9. The developing surface of the photoconductor is subjected to uniform potential stabilization treatment by the charging device 10 before transfer, and the transfer charger 11 part is provided between the photoconductor 4 and the charging device.
1 to 3 sheet feeding units 15 to 17 being synchronized with the rotation of
The toner image on the surface of the photoconductor 4 is sequentially transferred to the surface of the transfer material fed from any one of the above.

【００２２】像転写を受けた転写材は帯電器１２で感光
体４面から順次に剥離され、搬送ベルト２２で定着ロー
ラ対２３のニップ部へ搬送され、定着ローラ対２３を通
過することにより像定着処理される。像転写後の感光体
４面は帯電器１３で転写残りトナーの感光体面への付着
力が弱められ、次いでクリーナ１４で転写残りトナーの
除去処理を受け、繰り返して像形成に供される。The transfer material which has received the image transfer is sequentially peeled off from the surface of the photosensitive member 4 by the charging device 12, is conveyed to the nip portion of the fixing roller pair 23 by the conveying belt 22, and passes through the fixing roller pair 23 to form an image. It is fixed. After the image is transferred, the surface of the photosensitive member 4 is weakened by the charger 13 to reduce the adhesion of the transfer residual toner to the photosensitive member surface, and then the cleaner 14 removes the transfer residual toner, and is repeatedly used for image formation.

【００２３】給紙は、第１給紙部１５が選定された場合
は該給紙部の転写材が給紙ローラ１５ａの回転により１
枚宛繰り出され、補助搬送ローラ１８→シートパス１５
ｂ→シートパス２０→レジストローラ２１の経路で転写
部１１へ給送される。第２給紙部１６の場合は、該給紙
部の転写材が給紙ローラ１６ａの回転により１枚宛繰り
出され、シートパス１６ｂ→シートパス２０→レジスト
ローラ２１の経路で転写部１１へ給送される。第３給紙
部１７の場合は該給紙部の転写材が給紙ローラ１７ａの
回転により１枚宛繰り出され、シートパス１７ｂ→シー
トパス２０→補助ローラ１９→レジストローラ２１の経
路で転写部１１へ給送される。When the first paper feeding unit 15 is selected, the transfer material of the paper feeding unit is set to 1 by the rotation of the paper feeding roller 15a.
Sheets are delivered to the auxiliary conveyance roller 18 → sheet path 15
The sheet is fed to the transfer unit 11 through the path of b → sheet path 20 → registration roller 21. In the case of the second paper feed unit 16, the transfer material of the paper feed unit is fed out one by one by the rotation of the paper feed roller 16a, and is fed to the transfer unit 11 through the path of sheet path 16b → sheet path 20 → registration roller 21. Will be sent. In the case of the third sheet feeding unit 17, the transfer material of the sheet feeding unit is fed out by one sheet by the rotation of the sheet feeding roller 17a, and the transfer unit is routed through the path of sheet path 17b → sheet path 20 → auxiliary roller 19 → registration roller 21. Delivered to 11.

【００２４】而して、定着ローラ対２３を通った第１回
目複写済み転写材は予め指定されている複写モ−ド、即
ち片面複写モ−ド、両面複写モ−ド、多重複写モ−ドの
各場合によって夫々以後の搬送経路が異なる。Thus, the transfer material which has passed through the fixing roller pair 23 and has been copied for the first time is a copy mode designated in advance, that is, a single-sided copy mode, a double-sided copy mode, and a multiplex copy mode. In each of the cases, the subsequent conveyance route is different.

【００２５】（１）片面複写モ−ドの場合 定着ローラ対２３の次位の第１デフレクタ２４につい
て、これが２点鎖線示の第１切換え姿勢に保持される。
これにより定着ローラ対２３を出た第１回目複写済み転
写材は該第１デフレクタ２４の上側を通りシートパス２
５→排紙ローラ対２６→排紙口２７の経路で機外のコピ
ートレイ２８に片面複写物として順次に排出され積載し
ていく。(1) Single-sided copying mode With respect to the first deflector 24, which is the next position of the fixing roller pair 23, this is held in the first switching posture indicated by the chain double-dashed line.
As a result, the first-transferred transfer material exiting the fixing roller pair 23 passes above the first deflector 24 and passes through the sheet path 2
A single-sided copy is sequentially discharged and stacked on the copy tray 28 outside the apparatus through a path of 5 → paper discharge roller pair 26 → paper discharge port 27.

【００２６】（２）両面複写モ−ドの場合 第１デフレクタ２４は実線示の第２切換え姿勢に保持さ
れる。これにより定着ローラ対２３を出た第１回目複写
済みの転写材は該第１デフレクタ２４の下側ガイドに沿
ってシートパス２９へ案内され、中継ぎ搬送ローラ対３
０→実線示の第１切換え姿勢に保持されている第２デフ
レクタ３１の垂直ガイド面→正転駆動状態の正逆転ロー
ラ対３２の経路でスイッチバック通路３３内へ導かれ
る。その転写材後端辺の第１デフレクタ３１位置通過が
センサＳ１により検知されると、その信号により正逆転
ローラ対３２が逆転駆動状態に切換えられ、上記スイッ
チバック通路３３内へ導入された転写材が逆搬送されて
第２デフレクタ３１の下側ガイド面に沿うシートパス３
４から中継ぎ搬送ローラ対３６へ搬送される。３７は該
中継ぎ搬送ローラ対３６の次位に配設した第３デフレク
タであり、搬送転写材が大サイズのものであるときは実
線示の第１切換え姿勢に保持されており、中継ぎローラ
対３６を通った転写材は該第３デフレクタ３７の下側を
通って中間トレイ３８に第１回目複写画像面上向きで導
入される。又搬送転写材が小サイズのものであるときは
第３デフレクタ３７は２点鎖線示の略水平の第２切換え
姿勢に保持されており、中継ぎ搬送ローラ対３６を通っ
た転写材は該第３デフレクタ３７の上面に沿って該デフ
レクタ３７の次位の中継ぎ搬送ローラ対３９へ導入さ
れ、該ローラ対３９から中間トレイ３８に第１回目複写
画像面上向きで導入される。(2) Double-sided copying mode The first deflector 24 is held in the second switching posture shown by the solid line. As a result, the transfer material that has exited the fixing roller pair 23 and has been copied for the first time is guided to the sheet path 29 along the lower guide of the first deflector 24, and the intermediate transfer roller pair 3
0 → vertical guide surface of the second deflector 31 which is held in the first switching posture shown by the solid line → the path of the forward / reverse roller pair 32 in the forward drive state is guided into the switchback passage 33. When the sensor S1 detects the passage of the first deflector 31 on the trailing edge of the transfer material, the signal causes the forward / reverse rotation roller pair 32 to be switched to the reverse rotation driving state, and the transfer material introduced into the switchback passage 33. Is conveyed in the reverse direction, and the sheet path 3 along the lower guide surface of the second deflector 31 is conveyed.
4 is conveyed to the relay transfer roller pair 36. A third deflector 37 is arranged next to the intermediate transfer roller pair 36, and is held in the first switching posture shown by the solid line when the transfer transfer material is of a large size. The transfer material that has passed through is passed through the lower side of the third deflector 37 and is introduced into the intermediate tray 38 with the first copy image surface facing upward. When the transport transfer material is of a small size, the third deflector 37 is held in the substantially horizontal second switching posture indicated by the chain double-dashed line, and the transfer material passing through the intermediate transfer roller pair 36 has the third transfer position. It is introduced along the upper surface of the deflector 37 to the next intermediate transfer roller pair 39 of the deflector 37, and is introduced from the roller pair 39 to the intermediate tray 38 in the upward direction of the first copy image surface.

【００２７】マルチコピーの場合には上記の経路で中間
トレイ３８に対して第１回目複写済み転写材が夫々画像
面上向きで次々と導入され積載していく。In the case of multi-copying, the transfer material which has been first copied is sequentially introduced and stacked on the intermediate tray 38 in the above-mentioned path one by one with the image surface facing upward.

【００２８】而して、中間トレイ３８に一旦導入収納さ
れた第１回目複写済み転写材は、１枚分離給送ローラ対
４０により下のものから１枚づつシートパス２０へ導入
され、該シートパス２０内をローラ対４１・同１９・レ
ジストローラ対２１で順次に中継ぎ搬送されて転写部１
１へ再給送され、該転写部で第１回目複写済みの面とは
反対側の転写材面に第２回目の複写（像転写）を受け、
感光体４面から分離され、ベルト２２で定着ローラ対２
３へ再搬送されることにより第２回目複写画像の定着処
理を受ける。第１デフレクタ２４は２点鎖線示の第１切
換え姿勢に切換え保持されていく、定着ローラ対２３を
出た転写材即ち両面複写済み転写材はシートパス２５→
排紙ローラ対２６→排紙口２７の経路を通って機外の排
紙トレイ２８上に順次に排出される。Then, the first-time copied transfer material once introduced and stored in the intermediate tray 38 is introduced into the sheet path 20 one by one from the lower one by the pair of separating and feeding rollers 40, and the sheet is transferred. In the path 20, the roller pair 41, the roller pair 19, and the registration roller pair 21 are sequentially intermediately conveyed to transfer unit 1.
1 is re-fed, and a second copy (image transfer) is received on the transfer material surface on the side opposite to the surface on which the first copy has been completed at the transfer section,
It is separated from the surface of the photosensitive member 4 and the fixing roller pair 2 is separated by the belt 22.
By being transported again to No. 3, the fixing process of the second copy image is performed. The first deflector 24 is switched and held in the first switching posture indicated by the chain double-dashed line.
The sheets are sequentially ejected onto a sheet ejection tray 28 outside the machine through a path from the sheet ejection roller pair 26 to the sheet ejection port 27.

【００２９】（３）多重複写モ−ドの場合 第１デフレクタ２４は実線示の第２切換え姿勢に保持さ
れる。第２デフレクタ３１は２点鎖線示の第２切換え姿
勢に保持される。これにより定着ローラ対２３を出た第
１回目複写済みの転写材は第１デフレクタ２４の下側ガ
イド面に沿ってシートパス２９へ案内され、中継ぎ搬送
ローラ対３０→第２デフレクタ３１の上側ガイド面に沿
うシートパス３５→中継ぎ搬送ローラ対３６の経路を通
り、搬送転写材が大サイズの場合はローラ対３６から、
小サイズの場合はローラ対３６→２点鎖線示の第２切換
え姿勢に切換え保持されている第３デフレクタ３７の上
側を通ってローラ対３９から、夫々中間トレイ３８上に
第１回目複写画像面下向きで導入される。(3) In the case of multiple copy mode The first deflector 24 is held in the second switching posture shown by the solid line. The second deflector 31 is held in the second switching posture shown by the chain double-dashed line. As a result, the transfer material that has exited the fixing roller pair 23 and has been copied for the first time is guided to the sheet path 29 along the lower guide surface of the first deflector 24, and the intermediate transfer roller pair 30 → the upper guide of the second deflector 31. The sheet path 35 along the surface is passed through the path of the intermediate transfer roller pair 36, and from the roller pair 36 when the transfer transfer material has a large size,
In the case of a small size, the roller pair 36 is passed from the roller pair 39 through the upper side of the third deflector 37, which is switched and held in the second switching posture indicated by the chain double-dashed line, to the intermediate tray 38 and the first copy image surface, respectively. Introduced downward.

【００３０】マルチコピーの場合には上記の経路で中間
トレイ３８に対して第１回目複写済み転写材が夫々画像
面下向きで次々と導入されて積載していく。In the case of multi-copy, the transfer material which has been copied for the first time is successively introduced and stacked downward on the image surface on the intermediate tray 38 through the above-mentioned path.

【００３１】而して、中間トレイ３８に一旦導入収納さ
れた第１回目複写済み転写材は上記（２）の両面複写の
場合と同様に１枚分離給送ローラ対４０により下のもの
から１枚宛シートパス２０を介して転写部１１へ再給送
され、該転写部で第１回目複写済みの面と同じ面に対し
て第２回目の複写（像転写）を受け、感光体４面から分
離され、ベルト２２で定着ローラ対２３へ再搬送される
ことにより第２回目複写画像の定着処理を受ける。第１
デフレクタ２４は２点鎖線示の第１切換え姿勢に切換え
保持されていて、定着ローラ対２３を出た転写材即ち多
重複写済み転写材はシートパス２５→排紙ローラ対２６
→排紙口２７の経路を通って機外の排紙トレイ２８上に
順次に排出される。Then, the first-time copied transfer material once introduced and stored in the intermediate tray 38 is transferred from the lower one by the one-sheet separating / feeding roller pair 40 as in the case of the above-mentioned two-sided copying. The sheet is re-fed to the transfer unit 11 via the sheet-to-sheet sheet path 20, and the transfer unit receives the second copy (image transfer) on the same surface as the surface that has already been copied for the first time. And is conveyed again by the belt 22 to the fixing roller pair 23 to undergo the fixing process of the second copy image. First
The deflector 24 is switched and held in the first switching posture shown by the chain double-dashed line, and the transfer material exiting the fixing roller pair 23, that is, the transfer material after multiple copying, is the sheet path 25 → the discharge roller pair 26.
→ The paper is sequentially discharged onto the paper discharge tray 28 outside the machine through the path of the paper discharge port 27.

【００３２】ＩＩ ＲＤＦ装置Ｂ ５０は原稿トレイであり、このトレイ上にシート原稿Ｏ
が積載セットされる。５１は原稿分離給送機構、５２は
複写機本機Ａの原稿台２上に原稿を給送・排送する正逆
転ベルトである。The II RDF device B 50 is a document tray, and the sheet document O is placed on this tray.
Are loaded and set. Reference numeral 51 is a document separating / feeding mechanism, and 52 is a forward / reverse belt for feeding / discharging a document on the document table 2 of the copying machine A.

【００３３】（１）第１給送モ−ド これは原稿Ｏが片面画像原稿である場合の給送モ−ドで
あり、原稿Ｏは画像面を上向きにしてトレイ５０上に積
載セットされる。(1) First feeding mode This is a feeding mode when the original O is a single-sided image original, and the original O is stacked and set on the tray 50 with the image surface facing upward. .

【００３４】トレイ５０上の原稿は分離給送機構５１
で下のものから１枚宛分離されてシートパス５３→ロー
ラ対５４・５５→シートパス５７の経路で原稿台２の左
端へ送られ、正回動ａの状態のベルト５２により原稿台
２上を画像面下向きで右方へ摺動搬送され、原稿台２上
の所定の位置まで搬送された時点でベルト５２の回動が
停止することによりその位置に保持される。次いで複写
機本機Ａ側において上記原稿台２上の原稿の下向き画像
面についての所定枚数分の片面複写処理、或は両面又は
多重複写の第１回目の複写処理が実行される。Documents on the tray 50 are separated and fed by a separating / feeding mechanism 51.
Is separated from the lower one by one and is sent to the left end of the document table 2 through a path of sheet path 53 → roller pair 54/55 → sheet path 57, and on the document table 2 by the belt 52 in the state of forward rotation a. Is slid to the right with the image surface facing downward, and when the belt 52 is conveyed to a predetermined position on the document table 2, the rotation of the belt 52 is stopped and the belt is held at that position. Next, on the side of the copying machine A, a predetermined number of single-sided copying processes for the downward image surface of the document on the document table 2, or a first copying process of double-sided or multiplex copying is executed.

【００３５】所定枚数分の光学走査が終了すると、ベ
ルト５２が逆回動駆動ｂされる。これにより原稿は原稿
台２上を左方へ摺動搬送され、実線示の第１切換え姿勢
に保持されているデフレクタ５８の上面→ローラ対５５
・５６→シートパス６０→同６１→排出ローラ対６２の
経路で原稿トレイ５０側へ戻し搬送され、トレイ５０上
の原稿の上に画像面上向きで排出される。When the optical scanning for the predetermined number of sheets is completed, the belt 52 is driven in the reverse rotation b. As a result, the original is slid and conveyed to the left on the original table 2, and the upper surface of the deflector 58 held in the first switching posture shown by the solid line → the roller pair 55.
56, the sheet path 60, the same 61, and the discharge roller pair 62 are returned to the original tray 50 side and conveyed, and discharged onto the original on the tray 50 with the image surface facing upward.

【００３６】このようにしてトレイ５０上の片面画像
原稿が下のものから順次に自動的に原稿台２に対して給
送・排送されることにより、複写機本機Ａ側において片
面画像原稿を元とする所定枚数の片面複写処理、或は両
面又は多重複写処理が自動的に実行される。In this manner, the single-sided image originals on the tray 50 are automatically fed and ejected from the lower one in order from the lower one, so that the single-sided image originals on the copying machine main unit A side. Based on the above, a predetermined number of single-sided copying processes, or double-sided or multiple copying processes are automatically executed.

【００３７】（２）第２給送モ−ド これは原稿Ｏが両面画像原稿である場合の給送モ−ドで
あり、原稿の表裏反転動作が入る。(2) Second feeding mode This is a feeding mode in the case where the original O is a double-sided image original, and an operation of reversing the front and back of the original is entered.

【００３８】前記第１給送モ−ドのと同じ。Same as the first feeding mode.

【００３９】所定枚数分の光学走査が終了すると、ベ
ルト５２が逆回動駆動ｂされる。デフレクタ５８は２点
鎖線示の第２切換え姿勢に保持される。これにより原稿
は原稿台２上を左方へ摺動搬送され、デフレクタ５８の
下側のシートパス６３→正転状態の正逆転ローラ対６４
の経路でスイッチバック通路６５内へ導かれる。その原
稿後端辺のシートパス６３からの抜け切りがセンサＳ２
で検知されると、その信号により正逆転ローラ対６４が
逆転駆動状態に切換えられ、上記スイッチバック通路６
５内へ導入された原稿が逆搬送されてシートパス６１側
へ導入される。原稿はシートパス６１内を通り、排出ロ
ーラ対６２で中継ぎされて原稿トレイ５０上に出てくる
が、途中、その原稿後端辺がシートパス６１と同６０の
分岐部を通過したことがセンサＳ３で検知されると排出
ローラ対６２が逆転駆動に切換えられる。これにより原
稿はシートパス６１→逆転駆動状態のローラ対５５・５
６→シートパス５９→第１切換え姿勢状態のデフレクタ
５８の上面側の経路で原稿台２の左端へ送られ、正回動
ａ状態のベルト５２により原稿台２上の右方へ摺動搬送
される。この原稿台２上の搬送原稿は上記の経路通過に
より表裏反転処置されたもので、原稿台２上の所定の位
置まで搬送された時点でベルト５２の回動が停止するこ
とによりその位置に保持される。次いで複写機本機Ａ側
において、上記表裏反転処理されている原稿台２上の原
稿の下向き画像面についての所定枚数分の片面複写処
理、或は両面又は多重複写の第２回目複写処理が実行さ
れる。When the optical scanning for a predetermined number of sheets is completed, the belt 52 is driven in the reverse rotation b. The deflector 58 is held in the second switching posture shown by the chain double-dashed line. As a result, the original is slid and conveyed to the left on the original table 2, and the sheet path 63 below the deflector 58 → the forward / reverse roller pair 64 in the forward rotation state.
Is introduced into the switchback passage 65. The sensor S2 indicates that the trailing edge of the document is completely cut off from the sheet path 63.
When it is detected by, the forward / reverse rotation roller pair 64 is switched to the reverse rotation driving state by the signal, and the switchback passage 6
The document introduced into the sheet 5 is conveyed backward and introduced to the sheet path 61 side. The document passes through the sheet path 61, is spliced by the discharge roller pair 62, and comes out onto the document tray 50. However, it is detected that the trailing edge of the document has passed the branch portion of the sheet path 61 and the branch portion of the document path 60 on the way. When detected in S3, the discharge roller pair 62 is switched to the reverse drive. As a result, the document is moved from the sheet path 61 to the roller pair 55.5 in the reverse rotation drive state.
6 → Sheet path 59 → Sent to the left end of the document table 2 via the path on the upper surface side of the deflector 58 in the first switching posture, and is slid and conveyed to the right on the document table 2 by the belt 52 in the normal rotation a state. It The conveyed original document on the original table 2 has been turned upside down by passing through the above path, and is held at that position by stopping the rotation of the belt 52 at the time of being conveyed to a predetermined position on the original table 2. To be done. Next, on the side of the copying machine A, a predetermined number of one-sided copying processes for the downward image surface of the document on the document table 2 that has been subjected to the above-mentioned front-back reversal process or a second copying process of two-sided or multiple copying is executed. To be done.

【００４０】所定枚数分の光学走査が終了すると、ベ
ルト５２が逆回動駆動ｂされて原稿は原稿台２の左方へ
摺動搬送される。そしてその原稿は、第１切換え姿勢状
態のデフレクタ５８の上面→シートパス５９→同６０→
同６１→排出ローラ対６２の経路で再反転処置なしに原
稿トレイ５０上に排出されるか、第２切換え姿勢状態の
デフレクタ５８の下側のシートパス６３→スイッチバッ
ク通路６５→シートパス６１→排出ローラ対６２の経路
を通させることにより再反転処置されて原稿トレイ５０
上に排出される。When a predetermined number of optical scans are completed, the belt 52 is driven to rotate in the reverse direction, and the document is slid and conveyed to the left of the document table 2. Then, the original is placed on the upper surface of the deflector 58 in the first switching posture → sheet path 59 → the same 60 →
Same as 61 → discharge roller pair 62 is discharged onto the document tray 50 without re-inversion treatment, or the lower sheet path 63 of the deflector 58 in the second switching posture → switchback path 65 → sheet path 61 → By passing the path of the discharge roller pair 62, re-inversion processing is performed and the document tray 50
Discharged on top.

【００４１】このようにしてトレイ５０上の両面画像
原稿が下のものから順次に自動的に原稿台２に対して給
送・反転再給送・排送されることにより、複写機本機Ａ
側において両面画像原稿を元とする所定枚数の片面複写
処理、或は両面又は多重複写処理が自動的に実行され
る。In this way, the double-sided image originals on the tray 50 are automatically fed, reversed, re-fed, and ejected to the original table 2 sequentially from the bottom, so that the copying machine main unit A
On the side, a predetermined number of single-sided copy processes based on a double-sided image original, or double-sided or multiplex copy processes are automatically executed.

【００４２】６６は原稿一循検知手段であり、原稿Ｏ上
の最上位にのせた検出レバー６６ａとレバーの位置検出
センサ６６ｂからなり、トレイ５０上の原稿Ｏが最下部
から送り出されるとレバー６６ａはそれにともなって下
降して行き、当初最上位にあった原稿が送り出される
と、レバーは下降してセンサ６６ｂの位置に達して原稿
の一循を検知することが出来るものである。レバー６６
ａは原稿一循後再び最上位の原稿の上に戻し手段（モー
タ等）で自動的にのせられる。Reference numeral 66 denotes an original circulation detecting means, which comprises a detection lever 66a placed on the uppermost position on the original O and a position detection sensor 66b for the lever, and when the original O on the tray 50 is sent out from the lowermost position, the lever 66a. Then, when the original document, which was initially at the highest position, is sent out, the lever descends to reach the position of the sensor 66b, and the circulation of the original document can be detected. Lever 66
After the original is circulated, a is automatically placed on the uppermost original again by the returning means (motor or the like).

【００４３】本実施例は以上のような構成よりなるの
で、以下図１における必要部分のみを概略的に示した図
２を用いてその作動について説明すると、略水平な転写
経路イを搬送されることにより画像形成部４において第
一面に複写がなされた転写紙は、片面複写モ−ドが選択
されている場合、点線で示す切換状態の第１の切換手段
２４により排出経路ハを経て直接ソーターあるいはフィ
ニッシャー等のアプリケーションを採用し得る排紙部２
８へと排出される。そして、両面又は多重複写モ−ドが
選択されている場合には、実線で示す切換状態の第１の
切換手段２４の案内作用により、転写紙は垂直経路ロに
向けて搬送され、両面複写モ−ドの場合、該垂直経路ロ
から実線切換状態の第２の切換手段３１により一旦反転
経路ホに搬送された後正逆転ローラ３２の反転作動によ
り同じく実線切換状態の第２の切換手段の案内作用によ
り中間排出経路ニを経て、複写がなされている第１面を
上にした状態で中間トレイ部ヘに集積される。また、多
重複写モ−ドの場合、転写紙は、点線切換状態の第２の
切換手段３１により直接垂直経路ロから中間排出経路ニ
を経て、複写面を下にした状態で中間トレイ部ヘ上に集
積される。そして、次で両面あるいは多重複写が指令さ
れると、中間トレイ部ヘ上に集積された転写紙は再給紙
ローラ４０により下のものから順次垂直返送経路トそし
て合流部を経て、再び転写紙の他面又は同一面に複写が
なされるべく転写経路イに合流される。Since the present embodiment has the above-described structure, its operation will be described below with reference to FIG. 2 which schematically shows only the necessary parts in FIG. As a result, when the single-sided copy mode is selected, the transfer sheet copied on the first side in the image forming section 4 is directly passed through the discharge path C by the first switching means 24 in the switching state shown by the dotted line. Paper output unit 2 that can adopt applications such as sorter or finisher
It is discharged to 8. When the double-sided or multi-copy mode is selected, the transfer sheet is conveyed toward the vertical path B by the guiding action of the first switching means 24 in the switching state shown by the solid line, and the double-sided copy mode is selected. In the case of the negative mode, the second switching means 31 in the solid line switching state guides the second switching means also in the solid line switching state by the reversing operation of the forward / reverse rotation roller 32 after being conveyed to the reversing path E by the second switching means 31 in the solid line switching state. By the action, the sheets are accumulated on the intermediate tray portion with the first surface on which the copy is being made facing up through the intermediate discharge path d. In the case of the multiple copy mode, the transfer sheet is directly moved to the intermediate tray section with the copy surface facing downward by the second switching means 31 in the dotted line switching state from the vertical path B through the intermediate discharge path D. Accumulated in. Then, when double-sided or multiple copying is instructed next, the transfer sheets accumulated on the intermediate tray section are sequentially transferred from the lower one by the sheet re-feeding roller 40 from the lower one to the vertical return path and the merging section, and then the transfer sheet is again transferred. It is joined to the transfer path B so that a copy is made on the other surface or the same surface.

【００４４】[0044]

【発明の効果】以上説明したように画像形成装置を構成
したので、装置本体内に再給紙部である中間トレイ部を
設けることができ、しかも略水平な各経路（中間排出経
路、中間トレイ部、反転経路）を近接して平行に配設す
ることができ、それにより画像形成装置の装置本体の横
幅及び高さを小さくでき、また、各経路（経路、中間排
出経路、中間トレイ部、反転経路）が多層に近接して配
設されていることにより、ジャム処理に際して広範囲に
亘る点検作業が不要となり、更に、両面画像形成に際し
て装置本体の内部でシート材の反転を行いシート材が外
部に一時的にも露出しないため、オペレータが両面画像
形成すべきシート材を片面画像形成の状態で誤って引き
出してしまう危険性が全くなくなり、加えて、排紙部に
ソーターあるいはフィニッシャー等の各種アプリケーシ
ョンの装着が自由となる。Since the image forming apparatus is constructed as described above, it is possible to provide an intermediate tray section which is a sheet re-feeding section in the main body of the apparatus, and each substantially horizontal path (intermediate discharge path, intermediate tray). Sections, inversion paths) can be arranged in close proximity to each other, thereby reducing the lateral width and height of the main body of the image forming apparatus, and each path (path, intermediate discharge path, intermediate tray section, By arranging the reversal path in close proximity to multiple layers, a wide range of inspection work is not required during jam processing.Furthermore, when double-sided image formation is performed, the sheet material is reversed inside the apparatus body and the sheet material is external. Since it is not exposed even temporarily, there is no risk of the operator accidentally pulling out the sheet material for double-sided image formation in the state of single-sided image formation. Mounting of the various applications is free of such Inissha.

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

【図１】本発明を複写機に適用した一実施例を示す側断
面図。FIG. 1 is a side sectional view showing an embodiment in which the present invention is applied to a copying machine.

【図２】作動説明のために図１を簡略化して示す概略側
断面図。FIG. 2 is a schematic side sectional view showing, in a simplified manner, FIG. 1 for explaining the operation.

【図３】（ａ）〜（ｃ）は夫々従来の複写機を示す概略
構成図である。3A to 3C are schematic configuration diagrams showing a conventional copying machine, respectively.

【符号の説明】[Explanation of symbols]

１ 画像形成装置（複写機） ４ 画像形成部 ２４ 第１の切換手段 ３１ 第２の切換手段 イ 画像形成部を経由する経路（転写経路） ロ 垂直経路 ハ 排出経路 ニ 中間排出経路 ホ 反転経路 ヘ 中間トレイ部 ト 垂直返送経路 1 image forming apparatus (copier) 4 image forming unit 24 first switching unit 31 second switching unit a route passing through image forming unit (transfer route) b vertical route c discharge route d intermediate discharge route e reversal route f Intermediate tray part Vertical return path

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 画像形成部にて一面に画像が形成された
シート材を、一旦中間トレイ部に集積した後、再び画像
形成部へと搬送し、上記シート材の他面又は同一面に再
び画像形成を行うように構成された画像形成装置におい
て、 画像形成部を経由する経路を形成し、 該経路の下流に排出経路と垂直経路とを夫々分岐配設
し、 該垂直経路の下流で上記経路の下方に上下に夫々略水平
に中間排出経路と反転経路とを分岐して設け、 上記中間排出経路と反転経路との間に上記中間排出経路
から排出されるシート材を集積する中間トレイ部を略水
平に配設し、 該中間トレイ部の下流にシート材を再び上記経路に向け
て搬送する垂直返送経路を設け、 更に、上記経路と排出経路および垂直経路との間に上記
経路からのシート材を排出経路又は垂直経路に切換える
第１の切換手段を配設し、 上記垂直経路と中間排出経路および反転経路との間に垂
直経路からのシート材を中間排出経路又は反転経路に切
換え、反転経路からのシート材を中間排出経路に切換え
る第２の切換手段を配設し、 上記垂直返送経路と上記経路との間に垂直返送経路から
のシート材を上記経路に向けて搬送する合流手段を設け
たことを特徴とする画像形成装置。1. A sheet material having an image formed on one surface thereof in the image forming section is once accumulated on an intermediate tray section, and then conveyed again to the image forming section, and again on the other surface or the same surface of the sheet material. In an image forming apparatus configured to perform image formation, a path that passes through an image forming unit is formed, and a discharge path and a vertical path are branched and arranged downstream of the path, and the discharge path and the vertical path are provided downstream of the vertical path. An intermediate tray section is provided below the path, and the intermediate discharge path and the reversal path are branched substantially vertically, respectively, and the sheet material discharged from the intermediate discharge path is accumulated between the intermediate discharge path and the reversal path. Is provided substantially horizontally, and a vertical return path for transporting the sheet material toward the above path again is provided downstream of the intermediate tray portion. Further, a vertical return path is provided between the above path and the discharge path and the vertical path. Sheet material discharge route or vertical route A first switching means for switching the sheet material from the vertical path to the intermediate discharge path or the reverse path between the vertical path and the intermediate discharge path and the reverse path, and the sheet material from the reverse path to the intermediate position. Second switching means for switching to the discharge path is provided, and a merging means for transporting the sheet material from the vertical return path toward the path is provided between the vertical return path and the path. Image forming apparatus.