JP2010260679A - Document feeder and image reading device equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a document feeder including an inversion mechanism for aligning double face document sheets arranged on a paper delivery tray page by page to improve efficiency of processing and miniaturize the paper delivery tray at the same time. <P>SOLUTION: This document feeder is constituted by arranging a paper feeding tray above on an image reading part and the paper delivery tray below in parallel and providing a paper feed supporting face for loading the document sheet on the paper feeding tray and a paper delivery guide face for guiding the document sheet from a paper delivery port onto the paper delivery tray. A predetermined storage space is formed between the paper feed supporting face and the paper delivery guide face, and an inversion guide means for inverting a distal end of the sheet conveyed onto the paper delivery tray through the paper delivery port between its surface and its rear surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a document feeding device that is mounted on an image reading device that optically reads a document image and converts it into electronic data, and feeds a document sheet to a predetermined image reading position. The present invention relates to an improvement in a paper discharge mechanism that discharges originals in the same page order.

  Generally, this type of document feeder supplies, for example, document sheets placed and set on a sheet feed tray one by one to a platen such as a copying machine or a facsimile machine, and after reading the image, this document sheet is placed on a sheet discharge tray. Devices for storing are widely known. In such an apparatus, a double-sided image reading apparatus is also known that reads one side and then reverses the original sheet and resends it to the platen, and reads the image on the opposite side.

  For example, in Patent Document 1, a paper feed tray and a paper discharge tray are arranged side by side vertically to feed a document from the paper feed tray to the platen and store it in the paper discharge tray, and from the paper discharge port to the platen side. An apparatus having a circulation path for reversing a document sheet and retransmitting it is disclosed. In order to arrange the page order of the original sheets stored in the paper discharge tray, the apparatus of Document 1 resends the original sheet from which the double-sided image is read to the circulation path and reverses the front and back, and then stores them in the paper discharge tray. During document circulation for this page alignment, the platen is fed in an idle state without image reading.

  On the other hand, a paper discharge device that reverses a sheet on a paper discharge tray is disclosed in, for example, Japanese Patent Application Laid-Open No. 06-080297. In Patent Document 2, when a sheet is dropped and stored in a tray from a paper discharge port, the front end of the sheet is abutted against the curved guide and reversed, and the rear end of the sheet is fed out while the front end is locked to the tray wall. It is reversed upside down. The bending guide for bending the leading end of the sheet is configured to shift between an operating position located in the sheet carry-out track and a retracted position retracted upward.

  Similarly, in Patent Document 3, a curved guide is provided on a tray disposed below the sheet discharge port, and the front end of the sheet is turned upside down with the curved guide, and then the front end of the sheet is locked to the nip member to be on the rear end side of the sheet. A mechanism is disclosed for delivering. A mechanism is disclosed in which the leading end of the sheet bent by the bending guide is locked and its posture is captured to adjust the posture of the carry-out sheet. Patent Document 4 also discloses a similar device.

  Next, in Patent Document 4, two trays are provided at the paper discharge port, and one of the trays accommodates the sheet from the paper discharge port without being inverted, and the other tray stores the sheet from the paper discharge port. An apparatus for reversing and storing the front and back is disclosed. For this reason, a mechanism is disclosed in which a curved guide is provided at the sheet discharge port, and the sheet is distributed to the first tray and the second tray by changing the posture of the curved guide.

  Similarly, Patent Document 5 discloses an apparatus similar to Patent Document 2, and Patent Document 6 discloses an apparatus similar to Patent Document 3.

JP 2004-175460 A Japanese Patent Laid-Open No. 06-080297 Japanese Patent Laid-Open No. 08-282900 JP-A-11-130314 JP 05-244323 A JP 09-323854 A

  As described above, in a device that feeds an original sheet from a paper feed tray to a predetermined reading position, reads an image, and stores the image in a paper discharge tray, the sheet is turned upside down and re-fed to the reading position to form a double-sided image. A feeding device for reading is known. In such an apparatus, it is required to store in the paper discharge tray in the same order as the page order of the original sheets set on the paper feed tray. For this reason, for example, in the apparatus of the above-mentioned Patent Document 1, a sheet whose front screen is read by the platen is retransmitted to the platen via a circulation path having a switchback path, and the rear screen is read. When the sheet that has read this back screen is stored in that position in the paper discharge tray, the page order is out of order. Therefore, the apparatus of Patent Document 1 sends this sheet to the circulation path again, reverses the front and back, and stores it in the paper discharge tray. Yes. For this reason, the document sheet feed path from the paper feed tray to the paper discharge tray requires a circular conveyance in which images are not read for page alignment.

  Therefore, in the conventional document feeding apparatus, when the duplex reading mode is executed, the feeding timing of the subsequent sheet requires an interval time for page alignment of the preceding sheet, and the processing efficiency is significantly reduced as compared with the single-sided scanning. There's a problem.

  Therefore, it is suggested in Patent Documents 2 to 6 that the storage page order of sheets is reversed and aligned on the discharge tray. When such a mechanism is employed in a double-sided reading device, if a reversing guide mechanism is provided above the paper discharge tray, when the document sheet is switched back for double-sided reading above the paper discharge tray, or for single-sided image reading This hinders the progress of the sheet to be discharged. When sheet jam occurs in the switchback path or the front / back reversal path, the treatment becomes complicated. As described above, when the discharge path for the single-sided reading sheet and the switchback path for the double-sided reading sheet are arranged above the paper discharge tray, and the reverse guide member for the double-sided reading sheet is simultaneously arranged above the tray, the sheet jam of each other This causes a cause and increases the size of the device.

Therefore, the present inventor arranges a paper discharge tray below the paper feed tray and provides a guide surface for guiding the sheet from the paper discharge port at the bottom of the paper feed tray to form a switchback or single-sided reading sheet carry-out path. The idea was to provide a space for storing a reversing guide member for reversing the front end of the double-sided reading sheet between the guide surface and the tray surface. As a result, the upper portion of the paper discharge tray can be configured simply and compactly, and the cause of the sheet jam can be eliminated.

  According to the present invention, it is possible to improve the processing efficiency by arranging a reversing mechanism on the discharge tray for aligning pages of a document sheet read from a double-sided image, and at the same time, the discharge tray is compact and causes sheet jamming. The main problem is to provide a document feeding apparatus with a small amount of document.

  In order to achieve the above object, according to the present invention, a paper feed tray is arranged above the image reading unit and a paper discharge tray is arranged below, and a paper feed support surface on which a document sheet is placed on the paper feed tray and a paper discharge. A paper discharge guide surface for guiding the original sheet from the paper discharge port is provided on the tray. A predetermined storage space is formed between the paper feed support surface and the paper discharge guide surface, and reversing guide means for reversing the front end of the sheet conveyed from the paper discharge port to the paper discharge tray is stored in this space. It is characterized by doing. As a result, the reversing guide means arranged at the paper discharge port guides the document sheet entering from the paper discharge port for switchback reversal to the paper discharge guide surface and stands by in the storage space inside the guide surface. Will not cause sheet jams.

  Further, the configuration will be described in detail. A document feeding device for reversing a document sheet, which has been scanned on both sides by an image reading unit, and storing it in a sheet discharge tray (34), a sheet feeding tray on which a document sheet is set (1), a paper discharge tray (34) disposed below the paper feed tray, and a paper feed path (35) for feeding a document sheet sent from the paper feed tray to the paper discharge tray. And an image reading section (33) arranged in the sheet feeding path, and a circulation path (inverted from the original sheet passing through the image reading section connected to the sheet feeding path) and transported to the image reading section again. 40) and reversing guide means (45) for reversing the original sheet placed on the paper discharge tray and carried out from the paper discharge port (39), the paper feed tray placing the original sheet thereon A paper feed support surface (1a) and a paper discharge outlet on the paper discharge tray A predetermined storage space (48) is formed between the paper discharge guide surface (1b) for guiding the original sheet and the reversing guide means is disposed on the discharge tray in the storage space. It is configured to retract from the operating position and stand by.

  In the present invention, a paper feed tray is disposed above the paper discharge tray, a paper feed support surface on which the document sheet is placed and set on the paper feed tray, and a paper discharge tray for guiding the document sheet from the paper discharge port to the paper discharge tray. A predetermined storage space is provided between the paper guide surface and a reversing guide means for reversing the front end of the sheet conveyed from the paper discharge port to the paper discharge tray. The following effects are achieved.

  The reversing guide means for aligning the pages of the original sheet from which the double-sided image has been read is stored inside the discharge guide surface for guiding the original sheet to the discharge tray. When a double-sided read original is switched back and reversed at the paper discharge port, these sheets enter the paper discharge tray along the paper discharge guide surface, so that they are not obstructed by the reverse guide means and cause sheet jamming.

  Further, the reversing guide means is provided in a storage space between the paper feed support surface on which the document sheet is placed and set and the paper discharge guide surface, and the apparatus can be configured in a compact and compact manner. In particular, the space between the paper feed tray and the paper discharge tray can be saved.

  As described above, according to the present invention, when feeding the original sheet from the paper feed tray to the reading position, in the double-sided reading mode, the reversing guide means is positioned at the operating position above the discharge tray in the single-sided reading mode. Sometimes, when the sheet is unloaded, the reversing guide means is retracted to the space above the sheet discharge guide surface that guides the sheet to the tray, thereby achieving high-speed processing when the surface reading mode is executed, and at the same time on the sheet discharge tray when the one side reading mode is executed. Such a sheet jam can be reduced, and thus a remarkable effect can be obtained.

1 is an explanatory diagram of the overall configuration of an image reading apparatus according to the present invention. FIG. 2 is an explanatory diagram of a path configuration for guiding a document sheet to the image reading unit in the apparatus of FIG. 1. FIG. 2 is an explanatory diagram of a structure of a paper discharge tray that stores document sheets in the apparatus of FIG. 1. FIG. 4 is an explanatory diagram of an overall configuration of a reversing guide mechanism having a paper discharge tray structure in FIG. 3. Explanatory drawing of the conveyor mechanism in the inversion guide mechanism of FIG. Explanatory drawing of the front-end | tip locking mechanism in the inversion guide mechanism of FIG. FIGS. 4A and 4B are explanatory diagrams of a document sheet discharging operation in the apparatus of FIG. 3, in which FIG. 4A illustrates a state where the sheet is discharged, and FIG. 4B illustrates a state where the sheet hits a reversing guide. FIGS. 4A and 4B are explanatory diagrams of a document sheet discharge operation in the apparatus of FIG. 3, in which FIG. 3C shows a state in which the leading end of the sheet is locked, and FIG. The block diagram which shows the control structure in the apparatus of FIG. 10 is a flowchart of a document feeding operation in the control configuration of FIG.

  The present invention will be described in detail below based on the preferred embodiments shown in the drawings. FIG. 1 shows an image reading apparatus according to the present invention, which includes a document feeder (feeder unit) A, an image reading apparatus (scanner unit) B, and an image forming apparatus (printer unit) C. Then, the original sheets set on the original feeding apparatus A are fed one by one to the image reading unit (second platen) 33 of the image reading apparatus B, and the image forming apparatus C according to the image data read by the image reading apparatus B. In this case, the image is formed.

  The image forming apparatus C employs a structure in which a sheet supplied from the paper feeding unit (paper feeding tray) 1 is printed by an image forming unit based on image data and stored in a paper discharge tray 34. In this case, since various methods such as an electrostatic printing method, an ink jet printing method, and an offset printing method are already known as the image forming unit, the description thereof is omitted. Hereinafter, the document feeding device A and the image reading device B will be described in this order.

[Original Feeder]
The document feeder A includes a paper feed tray 1 on which a document sheet (hereinafter referred to as “sheet”) is placed and set, a paper discharge tray 34, a paper feed path 35, and a circulation path 40. The paper feed tray 1 and the paper discharge tray 34 are arranged above the second platen 33 (image reading unit; hereinafter the same), with the paper feed tray 1 on the top and the paper discharge tray 34 on the bottom. The paper feed path 35 has a substantially U-shaped path configuration so as to guide the sheet from the paper feed tray 1 to the paper discharge tray 34 via the second platen 33. The circulation path 40 is connected to the paper feed path 35 so that the sheet unloaded from the paper feed path 35 is switched back and conveyed to the paper feed path 35 through the paper discharge port 39.

  The paper feed tray 1 is provided with a paper feed support surface 1a for placing and setting sheets and a side guide 11a (11b) for regulating the position of the side edges of the sheets placed on the support surface. A pickup roller means 2 that sequentially feeds the sheets on the paper feed support surface 1a to the front end of the paper feed tray 1 and a paper feed that separates and feeds the sheets fed by the pickup roller means 2 one by one. Roller means 3 are provided. In addition, an empty sensor Se1 for detecting the presence or absence of a sheet and a size sensor (not shown) for detecting the size of the sheet are arranged on the sheet feeding support surface 1a.

  The pickup roller means 2 shown in the drawing moves up and down between an operating position that engages with the uppermost sheet above the sheet feeding tray 1 and a retracted position that is spaced upward from the sheet. This is because when the sheet is set on the sheet feeding support surface 1a, the sheet is retracted to the upper retracted position, and when the sheet is fed out after being set, it is positioned at the operating position. For this reason, the pick-up roller means 2 comprises a roller 21, a support arm 23 that supports the roller 21, and a rotating shaft 5. A drive motor M1 (paper feed motor; see FIG. 2) is connected to the rotary shaft 5, and the support arm 23 is fitted and supported on the rotary shaft 5 via a spring clutch (not shown).

  The rotation of the rotary shaft 5 is transmitted to the roller 21 by a transmission mechanism (not shown). When the rotating shaft 5 is rotated in one direction (counterclockwise in FIG. 2) with such a configuration, the spring clutch of the support arm 23 is loosened and the roller 21 is lowered from the standby position shown in the drawing onto the uppermost sheet on the tray. ing. When the rotary shaft 5 is rotated in the opposite direction (clockwise in FIG. 2), the roller 21 rotates in the sheet feeding direction, and the paper feed roller (paper feed roller means; hereinafter the same) 3 attached to the rotary shaft 5 is also used for the sheet. It is configured to rotate in the feeding direction.

  A retard roller 13 is pressed against the paper feed roller 3, and the retard roller 13 is a fixed (stationary) roller or rotates in a direction opposite to the paper feed direction so as to prevent double feeding of the sheet fed by the paper feed roller 3. It is made up of rollers. 22 is a gate stopper, which locks the leading end when setting a sheet on the sheet feeding support surface 1a, and then retracts upward from the sheet feeding tray.

  A registration roller unit 4 is disposed on the downstream side of the sheet feeding tray 1, and the sheet is fed out to the sheet feeding path 35 on the downstream side after the leading edge of the sheet from the sheet feeding tray 1 is bent to correct the registration (alignment of the leading edge). It is like that. The registration roller means 4 is composed of a pair of rollers in pressure contact with each other and a registration path 15 arranged on the upstream side thereof, and a registration sensor Se3 is arranged in the registration path 15.

  On the downstream side of the registration roller means 4, a sheet feeding path 35 is constituted by a U-shaped path guide that reaches a sheet discharge tray 34 via an image reading unit (platen) 33 through a sheet correction. A pair of pressure rollers 36 and a lead Se4 are disposed in the paper feed path 35 on the upstream side of the second platen 33. Although the configuration of the second platen 33 will be described later, a backup roller 37 that backs up the sheet fed by the read roller 36 toward the second platen 33 is disposed opposite to the second platen 33, and this second platen 33 is further arranged. An unloading roller 38 is disposed on the downstream side of 33.

  In such a configuration, an image on the lower surface of the sheet is read while the sheet sent to the sheet feeding path 35 is passed through the second platen 33 by the read roller 36, the backup roller 37, and the carry-out roller 38. Therefore, the rollers 36, 37 and 38 are connected to the same drive motor (reading motor; see FIG. 2) M2 so that the peripheral speed is constant.

  The paper feed path 35 is provided with a paper discharge port 39, and the paper discharge tray 34 is disposed in the paper discharge port 39. The paper discharge port 39 is provided with a pair of pressure-contact paper discharge rollers 43a and 43b. The paper discharge rollers 43a and 43b connect the illustrated roller 43a to a drive motor (reading motor) M2 in the first embodiment to be described later. The roller 43b is drivingly connected so as to be driven and rotated. In the second embodiment to be described later, the illustrated roller 43b is connected to a drive motor, and the roller 43a is driven to rotate.

  A circulation path 40 is connected to the paper feed path 35 through the paper discharge port 39, and the circulation path 40 is configured to return the sheet to the registration roller means 4 described above. A path switching means (flapper) 42 is provided at a branch portion between the paper feed path 35 and the circulation path 40. When the sheet discharge rollers 43a and 43b are rotated reversely after the trailing edge of the sheet sent from the sheet supply path 35 to the sheet discharge outlet 39 passes through the flapper 42 with such a configuration, the sheet is guided to the circulation path 40, and the registration rollers. It will be returned to the means 4.

  A sheet sensor for detecting the leading edge and the trailing edge of the sheet is disposed at the position shown in FIG. The illustrated sheet sensor Se2 is disposed in the vicinity of the downstream side of the sheet feed roller 3, and is a sensor (jam sensor) for determining a separation jam when the sheet leading edge does not reach the predetermined time after the sheet feed motor M1 is activated. The illustrated sheet sensor Se3 is a registration sensor that stops the sheet feeding motor M1 after a predetermined time (after forming a registration loop) when the leading edge of the sheet reaches the registration position. Further, the sheet feeding motor M1 is activated and rotated in order to feed the succeeding sheet from the sheet feeding tray 1 with a signal that the registration sensor Se3 detects the passage of the trailing edge of the sheet.

  The illustrated sheet sensor Se4 is a lead sensor that detects the arrival of the leading edge of the sheet immediately before the second platen 33, and sets the reading start position of the sheet by the detection signal. The illustrated sheet sensor Se5 is a timing sensor that detects the front and rear ends of the sheet that is transported to the sheet discharge port 39, and switches back by separating the sheet discharge rollers 43a and 43b with a signal that the sheet sensor has detected the trailing end of the sheet. Measure transport timing. The illustrated sheet sensor Se <b> 6 is a paper discharge sensor that detects the front and rear ends of the sheet that has reached the paper discharge port 39.

[Image reading device]
Next, the image reading apparatus B shown in FIG. 1 will be described. The image reading apparatus B includes a first platen 30 for setting a document sheet, a carriage 31 for scanning and reading the document sheet on the first platen, and a reading unit having a photoelectric conversion unit 32 built in the carriage 31. Composed. The illustrated one is provided with a second platen 33 for reading an image in the process of moving the original sheet. A document feeder A for feeding a document is mounted on the second platen.

  A light source lamp is mounted on the carriage 31 to irradiate the original sheet prepared on the first platen 30 and the second platen 33 with reading light. Then, the reflected light from the original is condensed by a mirror and a lens and imaged on a photoelectric conversion element (for example, a CCD substrate). The carriage 31 thus configured is supported so as to reciprocate for a predetermined stroke along the guide rail, and is connected to a carriage motor (not shown) that reciprocates the carriage 31.

  Therefore, the first platen 30 is formed of a glass plate corresponding to the sheet size so as to manually set the original sheet, and the carriage 31 moves on the sheet in the process of reciprocating left and right (scanning operation) along the first platen 30. Are read and output as electronic data. The document sheet is transferred to the second platen 33 by the document feeder A at a predetermined speed, and the image is read by the carriage 31 (solid line state in FIG. 1) positioned and stationary at this position. Reference numeral 41 denotes a platen cover that covers the platen 30.

[Sheet reversing mechanism in the output tray]
The present invention is characterized in that the following sheet reversing mechanism is provided on the paper discharge tray 34 in the above-described document feeder A. As described above, the paper discharge tray 34 is disposed below the paper feed tray 1 and includes a placement surface 34a for stacking and storing sheets and a vertical surface 34b for regulating the trailing edge of the sheet. The pair of paper discharge rollers 43a and 43b are disposed in the paper discharge port 39 (see FIG. 3).

  The pair of paper discharge rollers 43a and 43b are supported by the apparatus frame so as to be capable of being pressed and separated, and are pressed and separated by an operating means 44 such as a solenoid. That is, one of the pair of paper discharge rollers 43a and 43b (preferably the driven side) is supported in the apparatus frame by a long hole so that it can be pressed and separated from the other, and is pressed against the other roller by a pressure spring (not shown). ing.

  The movable roller (the illustrated roller 43a) is engaged and supported by the operating arm 44a, and a solenoid 44L is connected to the operating arm 44a. 44b shown is a return spring. Accordingly, when the solenoid 44L is energized, the operating arm 44a swings counterclockwise in FIG. 3, and the movable roller 43a is separated from the fixed roller 43b.

  Therefore, a sheet discharge guide surface 1b, a reverse guide unit 45, a locking unit 46, and a conveyor unit 47 are provided above the sheet discharge tray 34 as shown in FIG. Is turned upside down on the placement surface 34a of the paper discharge tray 34 (more precisely, the uppermost sheet stacked on the placement surface). The sheet discharge guide surface 1b is integrally formed at the bottom of the sheet feed tray 1, and guides a sheet carried into the sheet discharge tray 34 from the sheet discharge port 39 in the sheet discharge direction (right direction in FIG. 3). The illustrated paper feed tray 1 is formed by resin molding, and a paper feed support surface 1a is formed on the surface thereof, and a paper discharge guide surface 1b is formed on the bottom surface thereof by integral molding. The other discharge guide surface 1b may be formed of a flexible sheet material (mylar material) and a separate member separated from the sheet feed tray 1, and from the discharge port 39 to the front end side of the discharge tray (the right end in FIG. 3). As long as it is a member that guides the sheet, various structures can be adopted.

  A storage space 48 for storing a reverse guide member 45 described later is provided between the paper feed support surface 1a and the paper discharge guide surface 1b. Then, the reversing guide means 45 is accommodated in the storage space 48. As shown in FIG. 4, the reversing guide means 45 is provided with a half-cylindrical curved guide surface 45a, and the curved guide surface 45a is formed into a shape that inverts the front and back by curving the leading edge of the sheet that has entered from the sheet discharge port 39. Yes. The reversing guide means 45 is axially supported by a storage space 48 provided in the paper feed tray 1 by a rotating shaft 45b, and is accommodated in the storage space 48 by an urging spring 45c. The rotary shaft 45b is configured to move to an operating position that protrudes from the storage space 48 toward the placement surface 34a by an operating solenoid (shift means) 45d.

  Particularly, in the illustrated apparatus, the paper discharge guide surface 1b and the reverse guide means 45 are arranged in the paper discharge direction of the paper discharge tray 34 in the order of the paper discharge port 39, the paper discharge guide surface 1b, and the curved guide surface 45a. The sheet that has entered from the opening 39 is guided downstream by the sheet discharge guide surface 1b, and then the leading end of the sheet is bent by the curved guide surface 45a so that the sheet is reversed on the placement surface 34a of the sheet discharge tray 34. Yes.

  The locking means 46 is composed of a lever member that temporarily locks the leading end of the sheet curved by the curved guide surface 45a. The configuration is shown in FIG. 6, and a paper pressure piece 46 b that engages and holds a sheet is integrally formed at the tip of an arm member 46 a that protrudes into and out of the discharge tray 34 from the outside of the elevation surface 34 b of the discharge tray 34. The arm member 46a is supported by the apparatus frame by a support shaft 46c.

  Then, by swinging and rotating about the support shaft 46c, the paper pressure piece 46b moves to a standby position (solid line position in FIG. 3) outside the paper discharge tray and an operation position (broken line position) in the paper discharge tray. For this reason, the support shaft 46c is equipped with an urging spring 46d and an actuating solenoid 46e that always urges to the standby position side. An adjuster spring 46f is provided between the support shaft 46c and the actuating solenoid 46e in order to engage the paper pressure piece 46b with the uppermost sheet stacked on the placement surface 34a.

  As shown in FIG. 8, the conveyor means 47 has one or a plurality of belts 47c laid between a pair of pulleys 47a and 47b, and a gripper 47d for locking the rear end of the sheet is provided on the belt 47c. is there. A belt motor Mv is connected to one of the pulleys 47a (47b). 47S shown is a position sensor for detecting the position of the gripper 47d.

  As shown in FIG. 3, the conveyor means 47 configured in this manner is arranged in the paper discharge direction along the paper discharge guide surface 1 b of the paper feed tray 1, and the gripper 47 d is the trailing edge of the sheet from the paper discharge port 39. And the sheet is transferred in the paper discharge direction. At this time, the belt motor Mv uses the position sensor 47S and the timing sensor Se5 that has detected the trailing edge of the sheet as a reference, and the gripper 47d detects the trailing edge of the sheet in accordance with the expected time for the trailing edge of the sheet to reach the discharge port 39. The timing is controlled so as to capture.

[Control configuration]
A control configuration in the system of FIG. 1 will be described with reference to FIG. The image forming apparatus C includes a control unit 60, and the control unit 60 includes a reading mode setting unit 61 and an image reading condition setting unit (not shown). Then, reading conditions such as “monochrome / color” and “reading resolution” are set from the control panel 62, and at the same time, a reading mode is set to read a single-sided image or a double-sided image. Information relating to the image reading is transmitted to the image reading apparatus B and the document feeding apparatus A attached thereto.

  The document feeding apparatus A is prepared by a control unit 65 image, for example, a control CPU 65, a program for executing sheet feeding operation is stored in the ROM 63, and data required for sheet feeding is stored in the RAM 64. ing. The control CPU 65 is provided with 65a, a reading / conveying operation execution unit 65b, and a paper discharge operation execution unit 65c.

  The sheet feeding operation execution unit 65a performs an operation of separating the sheet set on the sheet feeding tray and waiting at the registration position. The sheet at the registration position is fed downstream, and a signal (registration register) is detected. The subsequent sheet is fed out from the sheet feeding tray 1 by the sensor Se3).

  Further, the reading / conveying operation execution unit 65b controls the reading motor M2 to feed the sheet at the position of the lead roller 36 toward the second platen 33, and carries out the sheet on the discharge tray 34 in the single-sided reading mode. In the double-sided reading mode, the sheet is switched back and conveyed to the circulation path 40 by reversing the reading motor M2 when the trailing edge of the sheet passes the path switching flapper 42.

  In the single-sided reading mode, the paper discharge operation execution unit 65c places the above-described reversing guide unit 45, the locking unit 46, and the conveyor unit 47 in the standby state so that the sheet from the paper discharge port 39 is loaded on the paper discharge tray 34. The paper discharge rollers 43a and 43b are controlled so as to be stored in the placement surface 34a. Further, the sheet discharge operation execution unit 65c controls the position of the reversing guide unit 45, the locking unit 46, and the conveyor unit 47 in the operation state in the double-sided reading mode so that the sheet from the sheet discharge port 39 is placed on the front and back sides of the tray. Invert.

  For this reason, the control CPU 65 is wired so that the detection signals of the sensors Se1 to Se6 are transmitted, and the paper feed operation execution unit 65a and the read conveyance operation execution unit 65b send commands to the driver circuits of the paper feed motor M1 and the read motor M2. Wired to transmit signals. Further, the paper discharge operation execution unit 65c is connected to the operation solenoid 45d of the reverse guide means 45, the operation solenoid 46e of the locking means 46, and the belt motor Mv of the conveyor means 47.

[Image reading operation]
Details of the control structure operation will be described with reference to the flowchart of FIG. When the apparatus power supply is turned “ON”, the control means (control CPU) 65 of the document feeder A executes an initialization operation. On the other hand, the operator sets a reading mode and a reading condition from the control panel 62 of the image forming apparatus B (St01). In accordance with the setting of the reading mode, the control CPU 65 executes a “single-sided reading mode” and a “double-sided reading mode”.

"Single-sided scanning mode"
In this mode, when a sheet is set on the paper feed tray 1, the control CPU 65 executes a paper feed operation control 65a. In this control, in response to the “ON” signal of the empty sensor Se1, the paper feed motor M1 is rotated in the forward direction (the rotating shaft 5 is rotated in the clockwise direction in FIG. 2; the same applies hereinafter) (St02). Then, the pickup roller 21 descends to an operating position in contact with the uppermost sheet on the sheet feeding tray, and transfers the uppermost sheet to the sheet feeding roller side. At the same time, the sheet feeding roller 3 also rotates in the sheet feeding direction (clockwise in FIG. 2), and cooperates with the retard roller 13 to separate the sheets into one sheet. When the jam sensor Se2 is in the “OFF” state for a predetermined time, it is determined as a paper feed jam (St03).

  Next, the control CPU 65 receives the “ON” signal from the jam sensor Se2 and activates the registration timer, and waits for a predetermined time (St04). When the set time elapses, the paper feed motor M1 rotates in the reverse direction (rotation of the rotary shaft 5 counterclockwise in FIG. 2) (St05). Then, the pickup roller 21 and the paper feed roller 3 stop, and the registration roller 4 rotates in the paper feed direction. With the rotation of the sheet feeding motor M1, the sheet is transferred from the registration roller 4 to the position of the lead roller 36 on the downstream side. When the read sensor Se4 is “ON”, the paper feed motor M1 is stopped and a paper feed instruction signal is awaited.

  Next, when receiving a paper feed instruction signal from the image forming apparatus, the control CPU 65 rotates the paper feed motor M1 in the reverse direction and rotates the reading motor M2 in the forward direction (rotation in the arrow direction of the read roller 36 in FIG. 2; ) (St06). By the rotation of the reading motor M2, the read roller 36, the backup roller 37, the carry-out roller 38, and the paper discharge roller 43 are rotated in the direction in which the sheet is transferred to the downstream side. The rotation of the lead roller 36 moves the sheet toward the second platen 33, and image reading is executed at this position (St07).

  Next, the leading edge of the sheet that has passed through the second platen 33 is detected by the timing sensor Se5, and with the “ON” signal, the control CPU 65 correctly positions the reverse guide means 45, the locking means 46, and the conveyor means 47 at the standby position. In order to continue the paper discharge operation when it is normal, the paper discharge rollers 43a and 43b are brought into a pressure contact state. Further, when an abnormality is detected in this determination, the apparatus is stopped. Next, when the sheet reaches the paper discharge sensor Se6, the control CPU 65 determines a jam by the detection signal (St09), and carries the sheet toward the paper discharge tray 34 from the paper discharge port 39.

  With such an operation, the sheet whose image has been read by the second platen 33 is stacked and stored on the placement surface 34 a of the paper discharge tray 34. Therefore, when the signal from the empty sensor Se <b> 1 is “ON”, the control CPU 65 returns to step St <b> 06 and transfers the subsequent sheet to the second platen 33. The succeeding sheet is an “OFF” signal that the registration sensor Se3 detects the trailing edge of the sheet, and the sheet feeding motor M1 is switched from the reverse rotation to the normal rotation to wait for the subsequent sheet at the registration roller position.

"Double-sided scanning mode"
In this mode, an original sheet is sent from the paper feed tray 01 to the platen 33 to read the front image, and this sheet is turned upside down through the circulation path 40 and retransmitted to the platen to read the back image. Then, the sheet on which the double-sided image is read is sent again to the circulation path 40 and turned upside down, and then carried out and stored in the paper discharge tray. The reverse “second paper discharge operation” is selectively executed. The procedure will be described below.

  Similar to the above-described single-sided reading mode, an original sheet is fed from the paper feed tray 01 to the platen 33 and the surface image thereof is read (St12). That is, the above-described steps St01 to St07 are executed. Next, the control CPU 65 detects the trailing edge of the sheet that has passed through the platen by the sensor Se4, and reverses the read motor M2 after the expected time that the trailing edge of the sheet has passed the path switching flapper 42 from the “OFF” signal (St13) of this sensor. Rotate. With the reverse rotation of the motor, the paper discharge rollers 43 a and 43 b rotate in the direction opposite to the paper discharge direction, and convey the sheet toward the circulation path 40.

  The leading edge of the sheet sent to the circulation path 40 is detected by the registration sensor Se2 (St15), and after correcting the registration based on the “ON” signal, the sheet feeding motor M1 is rotated in the reverse direction (St16). Then, the registration roller 04 rotates in the sheet feeding direction, and the sheet is fed toward the lead roller 36. At this time, the control CPU 65 separates the paper discharge roller 43 and releases the engagement with the sheet (St17). Next, the control CPU 65 rotates the read motor M2 in the forward direction in response to an “ON” signal (St18) when the leading edge of the sheet reaches the read sensor Se3 (St19).

The sheet is sent to the platen 33 by the forward rotation of the read motor M2, and the back side image is read (St20). Therefore, although not shown, the control CPU 65 selects whether to execute the first paper discharge operation or the second paper discharge operation. In this selection, for example, the first and second operations are selected based on the sheet size information detected on the paper feed tray or the paper thickness information input from the control panel 62. In the illustrated apparatus, a reference value for the length in the sheet conveyance direction is stored in the RAM 64. This reference value indicates that the first discharge operation is performed when the conveyance direction length is equal to or greater than the reference value, and the second discharge operation is performed when the reference value is less than the reference value. It comes to choose. That is, for example, the first paper discharge operation is set when the sheet size is JIS standard A4 vertical or larger, and the second paper discharge operation is executed when the sheet size is smaller than that. Similarly, it is possible to set so that the first paper discharge operation is executed when the paper thickness is equal to or greater than a predetermined value (thick paper sheet), and the second paper discharge operation is executed when the paper thickness is less than the predetermined value.

"First discharge operation"
When the first paper discharge operation is set, the control CPU 65 presses the paper discharge roller 43 with an ON signal when the leading edge of the sheet reaches the sensor Se4 (not shown). Then, the lead motor M2 is rotated in the reverse direction by the OFF signal that the rear end of the sheet has passed the sensor Se4 (St14). With this motor rotation, the paper discharge roller rotates in the reverse direction and is sent from the circulation path 40 toward the registration roller 04. After that, the same operation as the above-mentioned steps St14 to St20 is executed (St21 to St28). By this operation, the sheet is transferred to the platen 33 via the circulation path 40, and the front and back are reversed. The control CPU 65 presses the sheet discharge roller 43 with a signal that the leading edge of the sheet that has passed through the platen 33 is detected by the sensor Se4, and the sheet is conveyed to the sheet discharge tray 34 and accommodated on the placement surface 34a (St29).

"Second paper discharge operation"
When the first paper discharge operation is set, the control CPU 65 starts a timer with an ON signal (St30) when the leading edge of the sheet reaches the sensor Se4 (St31). Simultaneously with the start of the timer, the control CPU 65 moves the reverse guide means 45 from the standby position (solid line position in FIG. 3) to the operating position (broken line position) (St32). This state is shown in FIG.

  Next, the control CPU 65 presses the paper discharge roller 43 into the state shown in FIG. 7B after a predetermined timer time elapses. Thereafter, the control CPU 65 moves the locking means 46 from the standby position (solid line position in FIG. 3) to the operating position (broken line position) (St33). This timer time is set so that the leading edge of the sheet is curved by the curved guide surface 45a of the reversing guide means 45 and reaches the vertical surface 45b of the sheet. This state is shown in FIG. At the same time, the control CPU 65 returns the reversing guide means 45 to the standby position before and after the movement of the locking means 46 to the operating position.

  After the above operation, the control CPU 65 starts to rotate the belt motor Mv of the conveyor means 47 based on the signal (OFF signal) detected by the paper discharge sensor Se5 at the trailing edge of the sheet (St34). Then, the gripper 47d provided on the belt engages with the rear end of the sheet and moves in the belt traveling direction. This state is shown in FIG. 8 (b). The leading end of the sheet reversed by the reversing guide means 45 is restrained by the locking means 46. In this state, the trailing end of the sheet is transferred to the leading end of the tray by the conveyor means 47. Stored on top.

  After such a paper discharge operation, the control CPU 65 moves the reverse guide means 45, the locking means 46, and the conveyor means 47 to the initial standby positions after the lapse of the operation end time set in the timer (St35). The control CPU 65 transfers the succeeding sheet toward the platen 33 before and after such a paper discharge operation. For the transfer of the succeeding sheet, after the sheet trailing edge has passed through the platen 33, for example, the lead sensor Se3 conveys the succeeding sheet from the registration roller 04 position toward the platen 33 downstream from the position of the registration roller 04. This enables high-speed reading.

[Discharge roller control]
In the second paper discharge operation described above, there is a case where the sheet rear end portion that switches back the sheet from the paper discharge port 39 to the circulation path 40 and the sheet front end portion that is transferred toward the paper discharge tray 34 are conveyed so as to rub against each other. . This is a case where when the paper feed path 25 is formed compactly, the loop formed by the path 25 and the circulation path 40 is set to be shorter than the length of the original sheet in the conveyance direction. It will be sent in the opposite direction. Therefore, the present invention can adopt the first embodiment in which the paper discharge rollers 43a and 43b are separated and conveyed while being separated from each other and the second embodiment in which the paper discharge rollers 43a and 43b are frictionally conveyed while being in pressure contact with each other.

“First Embodiment”
In this embodiment, the roller 43a that engages the rear end of the sheet that moves toward the circulation path 40 is driven and rotated in the sheet discharge direction (clockwise in FIG. 3) and is directed toward the sheet discharge tray 34. A roller 43b that engages with the leading end of the sheet to be transferred is driven and connected so as to be driven to rotate. With such a configuration, the control CPU 65 separates the pair of paper discharge rollers by a signal that the leading edge of the sheet that has passed through the platen 33 reaches the sensor Se4. In this state, the leading end of the sheet reaches the discharge roller 43b. At this time, the discharge roller 34b that engages with the leading end of the sheet is driven to rotate, and the other discharge roller 43a is driven in the opposite direction while being separated from this. Rotate. Therefore, the leading end of the sheet is carried out from the paper discharge port toward the reverse guide unit 45 by the conveying force of the upstream carry-out roller 38. Therefore, the sheet is guided to the reversing guide means 45 without hindering the circulation and conveyance of the sheet. Next, the control CPU 65 presses the discharge rollers 43a and 43b before or after the leading edge of the sheet reaches the curved guide surface 45a of the reversing guide means 45, and simultaneously rotates the read motor M2 in the forward direction.

“Second Embodiment”
In this embodiment, the roller 43 b that engages with the leading end of the sheet transported toward the sheet discharge tray 34 is rotated by driving the roller 43 b and the sheet rear end that moves toward the circulation path 40. 43a is driven and connected to rotate. With such a configuration, the control CPU 65 turns the read motor M2 in the forward direction by pressing the pair of paper discharge rollers with a signal that the rear end of the sheet has passed the sensor Se4. Then, the sheet leading side toward the sheet discharge tray 34 is sent to the reverse guide means 45 by the driving rotation of the sheet discharge roller 43b, and the sheet trailing end toward the circulation path is nipped by the conveying force of the upstream registration roller 04. It will be pulled out from.

  In either case, the leading edge of the sheet carried out to the discharge port enters the tray along the discharge guide surface 1b, and the curved guide of the reversing guide means 45 disposed on the downstream side of the guide surface 1b. It will face the surface 45a and be turned upside down.

A Document feeder (feeder unit)
B Image reading device (scanner unit)
C Image forming device (printer unit)
Se1 Empty sensor Se2 Jam sensor Se3 Registration sensor Se4 Read sensor Se5 Timing sensor Se6 Paper discharge sensor M1 Drive motor (paper feed motor)
M2 drive motor (reading motor)
Mv belt motor 1 Paper feed unit (paper feed tray)
1a Paper feed support surface 1b Paper discharge guide surface 33 Second platen (image reading unit)
34 Paper discharge tray 34a Placement surface 34b Elevation surface 35 Paper feed path 39 Paper discharge port 40 Circulation path 43a Paper discharge roller (movable side)
43b Paper discharge roller (driven side)
44 Actuating means 44a Actuating arm 44b Return spring 44L Solenoid 45 Reverse guide means 45a Curved guide surface 45b Rotating shaft 45c Energizing spring 45d Actuating solenoid (shift means)
46 Locking means 46a Arm member 46b Paper pressure piece 46c Support shaft 46d Biasing spring 46e Actuation solenoid 46f Adjuster spring 47 Conveyor means 47a, 47b Pulley 47c Belt 47d Gripper 47S Position sensor 48 Storage space

Claims (8)

A document feeder that reverses the front and back of a document sheet that has been scanned on both sides by an image reading unit and stores it in a paper discharge tray.
A paper tray for loading original sheets,
A paper discharge tray located below the paper feed tray,
A paper feed path for feeding a document sheet sent from the paper feed tray to the paper discharge tray;
An image reading unit disposed in the paper feed path;
A circulation path that is provided continuously with the paper feed path and that passes through the image reading unit and reverses the original sheet and transfers it to the image reading unit again;
A reversing guide means for reversing the original sheet placed on the paper discharge tray and carried out from the paper discharge port;
With
In the paper feed tray,
A predetermined storage space is provided between a paper feed support surface on which the document sheet is placed and a paper discharge guide surface that guides the document sheet from the paper discharge port to the paper discharge tray.
The document feeding device is characterized in that the reversing guide means is retracted from the operating position on the paper discharge tray and stands by in the storage space.   The paper discharge guide surface and the reverse guide means provided in the paper feed tray are arranged in the paper discharge direction of the paper discharge tray in the order of the paper discharge port, the paper discharge guide surface, and the reverse guide means. The document feeder according to claim 1. 2. The document feeding according to claim 1, wherein the sheet feeding tray includes a tray body integrally including the sheet feeding support surface, the sheet discharge guide surface, and the storage space. apparatus. 2. The document feeding device according to claim 1, wherein the reversing guide unit has a curved guide surface having a half-cylindrical shape for reversing the leading edge of the document sheet from the paper discharge port. Locking means for temporarily locking the leading edge of the document sheet reversed by the reversing guide means is disposed on the paper discharge tray,
2. The document feeding apparatus according to claim 1, wherein the locking means is configured to be movable between an operating position on the paper discharge tray and a standby position retracted from the paper discharge tray. apparatus. The discharge tray is provided with conveyor means for transferring the rear end of the sheet in the discharge direction above the discharge port.
6. The document feeding device according to claim 5, wherein the conveyor means is configured to transfer a rear end portion of a document sheet whose front end portion is locked to the locking means in a paper discharge direction. . The reversing guide means includes a shifting means for moving the reversing guide means from the standby position to the operating position when a document sheet having been scanned on both sides by the image reading section is carried into the paper discharge tray. The document feeder according to claim 1, wherein the document feeder is provided. An image reading means arranged in the image reading unit;
A document feeder for transporting a document sheet to the image reading unit;
And consists of
An image reading apparatus having the configuration according to claim 1 to 7.

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