JP2002131989A - Double-sided image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the constitution of a carrying path, to reduce component parts such as an actuator for an ejection roller, and further to shorten the reading processing time in an image reader capable of reading both sides of an original. SOLUTION: This image reader is newly provided with a reversing path R2 for reversing the original from a front surface to a back surface before reading the 1st surface of the original, a 1st roller pair (rollers 32 and 33) for feeding the original reversed from the front surface to the back surface to a reading part, a 2nd roller pair (rollers 32 and 34) for feeding the original whose 1st surface has been read to the reading part again, and an ejection path R5 for ejecting the original whose 2nd surface has been read to the carrying path of the double-sided image reader. It is also provided with a switching member 39 at the upstream position of the 2nd roller pair so that the carrying direction of the original is switched by the switching member 39. Furthermore, the 1st roller pair and the 2nd roller pair are constituted of three rollers 32, 33 and 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique of an image reading apparatus capable of automatically feeding documents sequentially and reading both sides of the original.

[0002]

2. Description of the Related Art In a conventional image reading apparatus, when reading both sides of a document, the document is first fed to a reading section to read the front side, and is conveyed to a discharge port on a discharge tray by a discharge roller. The rotation direction of the discharge roller nipping the rear end of the document is reversed, the document is reversed and fed back to the reading unit while being reversed through the document return path, and then the back side is read and discharged to the discharge tray. Was. Further, as an improvement of the above technology, the original conveyed to the discharge port after reading both sides is switched back again, and is again conveyed to the reading unit through the original return path, at which time the reading unit performs reading. A technique has been invented in which the document is passed as it is, the document is discharged face down, and the documents are stacked one after another in the same page order.

[0003]

However, in the above-mentioned prior art, in order to rearrange the original pages after reading both sides of the original, the original is again switched back on the paper discharge tray and fed back to the original return path. The originals were turned over, and the originals were ejected to a paper output tray with the front side down, and the originals were sequentially stacked. As a result, the document passes through the reading unit three times, and in the third pass, the document is passed through the document reading unit even though the document is not read. Cannot be performed, which is an adverse effect of improving the document reading speed. Also, the return path is shorter than the document length, and the switch-reversed document is
While the leading end reaches the outlet through the return path, the end is still fed through the outlet, and the leading and trailing ends are in opposite directions, so that the discharging roller is moved. When the roller is separated, the leading end and the trailing end thereof pass each other due to the conveying force of another roller. In order to separate the discharge roller in this manner, an actuator using a solenoid or the like is required, which increases the number of parts, increases the manufacturing cost, and is disadvantageous in cost. In view of the above two points, the present invention simplifies the configuration of the transport path, and includes an actuator for the discharge roller and the like.
An object of the present invention is to provide a double-sided image reading apparatus in which the number of components is reduced and the reading processing time is reduced.

[Means for Solving the Problems]

[0004] In order to solve the problems described above, the present invention
The following means are used. That is, as described in claim 1, the original is fed to the reading unit, the first side is read, the original is turned over, and the original is fed back to the reading unit.
In a two-sided image reading apparatus for reading the second side, a reversing path for reversing the front and back surfaces of the original before reading the first side, and a first roller pair for feeding the document with the reversed front and back sides to the reading unit And a second roller pair for feeding the original after reading the first surface to the reading unit again, and a discharge path for discharging the original after reading the second surface.

Further, a switching means for switching a plurality of branch points is provided at a position upstream of the second roller pair.

According to a third aspect of the present invention, the first roller pair and the second roller pair are constituted by three rollers.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described with reference to the accompanying drawings. 1 is a perspective view of a facsimile employing a double-sided image reading apparatus, FIG. 2 is a side sectional view of the same, FIG. 3 is a side sectional view of an ADF of the double-sided image reading apparatus, and FIG. 4 is a perspective view showing another embodiment of a switching member. 5, FIG. 5 is a front view, FIG. 6 is a side sectional view, FIG. 7 is a block diagram showing a control configuration of the duplex image reading apparatus, and FIG. 8 is an ADF showing a flow of a document in a first process of the duplex image reading apparatus. FIG. 9 is a side cross-sectional view of the ADF showing the flow of the original in the second process, and FIG.
0 is a side sectional view of the ADF showing the flow of the original in the third process, FIG. 11 is a flowchart showing the first stage of the control configuration of the double-sided image reading apparatus, FIG. Is a flowchart showing the third stage, and FIG. 14 is a flowchart showing the final stage.

A double-sided document reading apparatus according to the present invention will be described first with reference to a facsimile apparatus as an example. The facsimile apparatus shown in FIGS.
The reading unit 1 is arranged above the image forming apparatus. Recorder 2
A recording device 3 and a paper feed cassette 4 are respectively provided in the upper and lower sides, and the paper deposited in the paper feed cassette 4 is fed to the recording device 3, and after recording, the paper is discharged to a recording paper discharge tray 5. It is configured to discharge.

The reading section 1 has a hinge 10b extending from a bottom surface of a reading case 10 which is a part of the reading section 1, and is pivotally supported on a hinge pin 1a provided in the recording section 2. With respect to the recording section 2, the recording section 2 can be turned up and down about the hinge pin 1a as a fulcrum.

In the reading section 1, a reading device 6 is housed in a reading case 10. On the upper surface of the reading case 10, a transparent stationary document placing bed 11 is provided.
When a document is placed on the stationary document placing bed 11, the reading device 6 moves from a solid line position to a virtual line position in FIG. 2 to perform scanning.

A document holding cover 7 is provided above the reading case 10 so as to be openable and closable about one side thereof. The document placed on the stationary document loading bed 11 is held by the document holding cover 7. Pressing from above.

An ADF 8 is attached to one end of the document holding cover 7.
Is attached. The appearance of ADF8 is as shown in FIG.
Side frames 7a and 7b are provided in parallel in a direction orthogonal to the scanning direction of the reading device 6, and an openable and closable ADF cover is provided between the side frames 7a and 7b so as to cover the entire document transport section of the ADF 8. 14 are arranged so as to be sandwiched therebetween. A of each side frame 7a, 7b
On the inner opening surface along the end of the DF cover 14, side plates made of sheet metal (not shown) are fixed in an upright manner. For example, among the feed rollers described below, for example, each shaft end of a roller shaft of a drive roller is provided. Is supported. Document holding cover 7
And one or both of the side frames 7a and 7b cover the drive source of the drive roller and its transmission system, and the inner surface thereof is covered by the side plate.

The document pressing cover 7 and the side frames 7a and 7b form an apparatus body of the ADF 8, and a document conveying section covered by the ADF cover 14 is disposed between the apparatus body and left and right. Make up the whole.

A document supply tray 9 is provided above the document holding cover 7 so as to be continuous with the paper feed port 8a of the ADF 8, and the document feeding tray of the ADF 8 A document discharge tray 7c is integrally formed so as to be continuous with a paper discharge port 8d disposed immediately below the port 8a. The ADF 8 includes a paper feed port 8a to a paper discharge port 8d.
A document transport path is configured up to this point.

Sheet documents stacked on the document supply tray 9 are picked up one by one and inserted downstream of the paper feed port 8a. Platen glass 12 fed by ADF 8
2 is read by the reading device 6 at the initial position indicated by the solid line in FIG. The read original is discharged onto the original discharge tray 7c.

As described above, the reading unit 1 is used as a flat bed type scanner that scans the reading device 6 to read a still original, and also reads the original while feeding the original to the ADF 8 with the reading device 6 fixed in position. It is configured to be able to be used as a sheet feed type scanner for performing the operation.

A key panel 13 is attached to one side of the reading case 10. By pressing various operation keys on the key panel 13, the contents of the document are read, the destination for facsimile transmission of the read contents is set, and the received contents and the read contents are recorded by the recording device 3. And various operations are performed.

Next, the internal structure of the ADF 8 will be described. In this description, in the side view shown in FIG. 3, the document transport direction is the front-rear direction (the paper feed path 8a / discharge port 8d side is forward in the document transport path, and the curved portion (transport direction folded portion) side is backward. The vertical direction in the horizontal direction is defined as the horizontal direction, and the vertical and vertical positions of each structure are described.

First, sheet document conveying paths R1 to R5
Will be described. A first reversing port 8b for feeding out the leading end of the sheet document and reversing the transport direction thereof is provided at an upper and lower intermediate position between the paper feeding port 8a and the paper discharging port 8d.
c are provided respectively. First, a main transport path R1 is formed from the sheet feeding port 8a to the second reversing port 8c, in a shape in which the letter "" is inverted left and right in a side view. Then, from the paper feeding port 8a to the first reversing port 8b, a side view,
An inverted path R2 in the shape of a “U” is laid down, and the vicinity of the paper feed port 8a of the two paths R1 and R2 is a common path and is branched at a branch point P. Then, the first reversing port 8
b, a return route R3 is formed toward the curved portion of the main transport route R1. Here, the first reversing ports 8b of both routes R2 and R3 are formed.
The vicinity is a common path, the path is branched at the branch point Q, the return path R3 is extended rearward as it is, and both paths R1 and R3 communicate with each other at a curved portion of the main transport path R1. Let the communication point be the junction S.

In the main transport route R1, a branch point U near the branch point Q is provided, a bypass route R4 is branched backward and upward from the branch point U, and communicates with the return route R3. Let it. Here, the communication point is defined as a merging point R, and the main transport route R1 below the merging point R is set.
Is further provided with a branch point T. The discharge path R5 is directed toward the discharge port 8d below and forward of the branch point T.
Branch. With such a configuration, the transport routes R1 to R5 are formed in the ADF 8, and the transport routes R1 and R5 are formed.
Along rollers 2, rollers 21 to 34 are arranged.

After the reversing ports 8b and 8c, the transport path R
An extra roller 32 that can be rotated forward and backward is disposed between 1 and R2, and a first press roller 33 and a second press roller 34 are arranged above and below it. The extra roller 32 and the first press roller 33 are in sliding contact with each other on a reversing path R2 in front of the branch point Q, and the extra roller 32 and the second press roller 34 are in a main transport path R1 in front of the branch point U. It is sliding on the top. Here, these sliding contact positions are referred to as a nip portion B for the former and a nip portion G for the latter. These three rollers 32, 33, and 34 discharge the sheet document or reverse the switchback.

A nip portion A between the separate roller 22 and the retard roller 23 is provided near the paper feed port 8a, and the arms 20 can swing forward from both ends of the separate roller 22. And the arm 2
A pickup roller 21 is pivotally supported at the front end of the pickup roller 0.20. Then, along the main transport path R1 from the sheet feeding port 8a to the second reversing port 8c, the nip portion A between the separate roller 22 and the retard roller 23, the registration roller 2
4 and resist follow roller 25, nip C, first
Nip portion D between master feed roller 26 and first slave feed roller 27, second master feed roller 2
8 and a nip portion E of the second slave feed roller 29, a nip portion F of the third master feed roller 30 and the third slave feed roller 31, and a nip portion G of the extra roller 32 and the second press roller 34. Have been.

Of the above-described rollers, the registration roller 2
4, a first master feed roller 26, a second master feed roller 28, a third master feed roller 30,
And the respective roller shafts 24a and 26a of the extra roller 32
28a, 30a and 32a have both shaft ends supported by the respective side plates of the main body of the above-mentioned ADF 8 apparatus, and are fixed in position. The rollers 22, 24, 26, 28 and 30 are fixed to the side frames 7a and 7b. , Or a drive source 41 such as a step motor provided in both of them, and a transmission mechanism thereof. That is,
The rollers 22, 23, 24, 26, 28, and 30 are drive rollers, and the rollers 25, 27 that come into contact with each other.
29, 31 and 32 are driven rollers that rotate with each drive roller.

In the vicinity of the branch point PQU of the transport paths R1 and R2, the following guide members 37.3 are provided.
8, a switching member 39 is provided. As shown in FIG. 3, immediately after the branch point P, a rotation fulcrum shaft 37a is provided between the main transport path R1 and the reversing path R2, and a first guide member 37 for switching the transport direction of the sheet document is provided. Has been established. The first guide member 37 electrically switches the path using an actuator 57 such as a solenoid, and guides the sheet document to the main transport path R1 or the reverse path R2. Normally, the position and orientation of the first guide member 37 are kept substantially horizontal, and the first guide member 37 cuts off the reversing path R2 to form the main transport path R1.
Is open. That is, this state is a path selection at the time of single-sided reading. Here, when the function key 18 is operated to set the double-sided reading mode, a control signal (switching signal) is output from the controller 40 shown in FIG. When the solenoid is energized, the actuator 57 is actuated and the first guide member 39 rotates counterclockwise, and is inclined obliquely upward, blocking the main transport path R1 and reversing the reverse path R2.
open.

A fulcrum shaft 38a is provided immediately after the branch point Q, between the inversion route R2 and the return route R3,
A second guide member 38 for distributing the routes R2 and R3 according to the sheet document conveyance direction is provided. The second
The guide member 38 uses a flexible member such as a film, and normally closes the reversing path R2 while maintaining a substantially horizontal position and orientation. The second guide member 38 is pushed down by the passage of the sheet document, opens the reversing path R2, and guides in the direction of the first reversing port 8b. After passing through the sheet document, the sheet document returns to its original position due to its elasticity, closes the reversing path R2 again, and the sheet document that has been switchback-reversed at the first reversing port 8b merges along the second guide member 38. Point R
You will be guided in the direction.

Further, a switching member 39 is provided near the branch point U, and the switching member 39 is provided with upper and lower guides 39.
a and 39b are configured to rotate in conjunction with each other.
For example, in the switching member 39 shown in FIG.
9a and 39b are juxtaposed in parallel and actuate an actuator 59 (see FIG. 7) such as a solenoid by a control signal (switching signal) from the controller 40, and rotate each of them via a gear (not shown). The fulcrum shafts 39d and 39d are both rotated by the same angle, and both guides 39a and 39b are rotated while maintaining the parallel state.

Alternatively, the switching member 39 may be configured as shown in FIGS. 4 to 6, in which case the switching member 39 is integrally formed by upper and lower guides 39a and 39b and both side plates. When viewed from the front, it is configured in the shape of a "mouth". When the structure is outlined, a plurality of ribs 39c are arranged on the upper and lower surfaces of both guides 39a and 39b with their longitudinal directions facing the front-rear direction.
39c, the sheet original and the guides 39a, 39
b reduces the contact area with the upper and lower surfaces, thereby reducing frictional resistance.

As shown in FIG. 6, the guides 39a and 3
The thickness of 9b is formed so that the rear side is thinner than the front side (the second reversing port 8c side), and the opening of the switching member 39 widens toward the front, so that the sheet document easily enters from the front. Like that. Rotation fulcrum shafts 39d and 39d are protruded from both side surfaces of the switching member 39, and an actuator 59 such as a solenoid (not shown) is attached to one of the rotation fulcrum shafts 39d. The switching member 39 is rotated by electrically switching the actuator 59 by a control signal (switching signal). The switching member 39 is not limited to the two examples described above, and is not particularly limited as long as it is capable of simultaneously switching a plurality of branch points TU.

Here, the switching control of the switching member 39 will be described. In the normal state, as shown in FIG. 8 or FIG. 9, the upper and lower guides 39a and 39b are maintained in a substantially horizontal position and orientation. The main path R1 and the return path R3 are opened by blocking the bypass path R4 and the discharge path R5, and both the paths R1 and R3 can pass. When the solenoid is energized, the actuator 59 is actuated, and as shown in FIG. 10, the switching member 39 is turned clockwise in a side view to move the upper and lower guides 39a and 39b respectively. The two routes R4 and R5 are opened along the bypass route R4 and the discharge route R5 to shut off the main transport route R1 and the return route R3. In this way, the sheet document is supplied to the bypass guide R4 by the upper guide 39.
a and the upper surface of the lower guide 39b,
The discharge path R5 is guided along the lower surface of the lower guide 39b.

Next, each sensor related to the conveyance of the sheet document will be described. First, a document set sensor (hereinafter, referred to as "DS sensor") 43 is provided near the paper feed port 8a. When the sheet original is set deep in the paper feed port 8a, the sheet is detected by the DS sensor 43, whereby the circuit between the start button 19 and the drive source 41 is connected, and the drive source 41 can be driven. In other words, when a document is not set, the drive source 41 does not start even if the start button 19 is pressed while the circuit is cut off, thereby preventing the document from being fed idly. .

A registration sensor 44 is disposed between the convergence point S and the nip C along the main transport path R1, and a branch point on a common path between the reverse path R2 and the return path R3. A first reversing sensor 45 is provided between Q and the nip portion B, and further, along the main transport route R1 near the second reversing port 8c, between the branch point U and the nip portion G. A second reversing sensor 46 is provided.

Each of the sensors 43, 44, 45 and 46 is constituted by an optical sensor or a limit switch in which a light emitting element is arranged on one side of the transport path and a light receiving element is arranged on the other side. The start and end of the passage of the sheet document passing through the sensor arrangement position are detected, and a control signal (detection signal) is output to the controller 40.

The controller 40 is further connected to the following control devices and control devices to control the transport pattern of the sheet document. The driving source 41 includes:
A control signal (drive signal) from the controller 40 is received and driven, and the respective rollers 22, 23, 24, 26, 28, 30, 32 are driven via a transmission mechanism (not shown). The drive source 41 uses a step motor or the like in which a pulse is sequentially applied to the multi-phase winding of the stator and the rotor rotates by a fixed angle for each pulse.
The step control is performed at 0. That is, a counter 42 is attached to the controller 40, and the counter 42 measures the number of rotation steps of the drive source 41,
Based on this, the transport distance of the sheet document is calculated.

Here, the rollers 22, 23, 24, 2
The rotation direction of 6.28.30 is interlocked with the rotation direction of the drive source 41, while the extra roller 32 is provided with a forward / reverse rotation switching mechanism 50 between the drive source 41 and the extra roller 32. Regardless, the rotation direction is appropriately switched. Thus, the extra roller 32 plays a role not only as a discharge roller for discharging the sheet document but also as a reversing roller for switching back the sheet document.

The forward / reverse rotation switching mechanism 50 includes a driving source 41
Drive shaft to which power from the motor is transmitted, and the extra roller 3
2 is provided with a same-direction transmission mechanism for transmitting rotation in the same direction as the drive shaft, and the other is provided with a reverse rotation transmission mechanism for transmitting the rotation in the reverse direction. axis,
Alternatively, the clutch such as an electromagnetic clutch spline-fitted to the output shaft is slid and disengaged, the connection with one transmission mechanism is released, and the other transmission mechanism is connected, and only one of the forward and reverse rotations is performed. It is taken out to the output shaft. When the control signal (switching signal) is output from the controller 40 to the forward / reverse rotation switching mechanism 50, the rotation direction of the extra roller 32 is switched.

The pickup roller 21 swings up and down by using an actuator 51 such as a solenoid, and receives a control signal (drive signal) from a controller 40, and a pulse is applied to the solenoid, whereby the actuator is driven. 51 acts to rotate the pickup roller 21 downward, thereby pressing down the sheet document.

Each of the separate roller 22 and the registration roller 24 has a clutch 52 or 54 such as an electromagnetic clutch between the drive source 41 and a control signal (disconnection / disconnection signal) from the controller 40. ), The clutch 52 (54) is connected or disconnected, and the roller 22 (24) is driven / stopped.

Also, on the key panel 13 shown in FIG.
A function key 18 for setting a reading mode such as a conversion of one-sided / two-sided reading, a start button 19 for starting an operation for taking in a sheet document, and a reading operation in the middle such as when reading a plurality of sheet documents continuously. A stop button 16 and the like for stopping are arranged, and when the function key 18, the start button 19, the stop button 16 and the like are operated, a control signal is output to the controller 40.

Here, the flow of double-sided reading of a sheet document according to the present invention will be briefly described. The sheet document set with its front side up in the document feed tray 9 is firstly shown in FIG. In the first step, the paper feed port 8a
→ Nip A → Branch P → Branch Q → Nip B → First
The sheet is conveyed to the reversing port 8b and reverses the front and back sides of the sheet document. At the first reversing port 8b, the back side of the document is on the top,
Next, as shown in FIG. 9, in the second step, the first reversing port 8b
→ Nip part B → Branch point Q → Merge point R → Merge point S → Nip part C → Nip part D → Nip part E → Nip part F → Branch point T
The document is conveyed to the branch point U, the nip portion G, and the second reversing port 8c, and the first side of the original is read. In this second process, the front and back sides of the sheet document are also inverted,
At the second reversing port 8c, the surface of the document faces upward. Then, as shown in FIG. 10, in the third step, the second reversing port 8c → the nip G → the junction U → the junction R → the junction S → the nip C →
The document is conveyed to the nip portion D → the nip portion E → the nip portion F → the branch point T → the sheet discharge port 8d, and the second surface of the document is read. Also in this third process, the front and back surfaces of the sheet document are reversed, and the surface of the sheet document discharged to the discharge tray 7c is down.

Next, two-sided reading of a sheet document according to the present invention will be described with reference to flowcharts shown in FIGS. First, as shown in FIG.
When the user sets the sheet document on the document feed tray 9 with the front side facing upward and inserts it deep into the sheet feed port 8a (step S1), the leading end of the sheet document is detected by the DS sensor 43 (step S2). Thus, the document can be taken in.

Next, the user operates the function keys 18 of the key panel 13 to select the original reading surface in the double-sided reading mode (step S3), whereby the actuator 57 is operated and the first guide member 37 is operated. Rotates and tilts its position and orientation forward and upward to form the main transport path R1.
Is shut off (step S4).

When the start button 19 is pressed (step S5), the drive source 41, the actuator 51,
And a control signal is output to the clutch 52, a positive pulse is applied to the solenoid of the actuator 51, and the solenoid is instantaneously excited. As a result, the pickup roller 21 rotates downward to hold down the sheet document, and its position and orientation is maintained until the loading of all sheet documents is completed (step S6). Then, the drive source 41 starts (step S7) and the clutch 52
Is connected and the separate roller 22 is driven (step S8), and only the uppermost sheet document is separated by the pickup roller 21, the separate roller 22, the retard roller 23 and the like, and is slowly taken in from the paper feed port 8a. (Step S9).

By the start of the driving of the driving source 41, the feed rollers 26, 28, and 30 are brought into a side view as shown in FIG.
Rotating counterclockwise, the extra roller 32 first
While rotating clockwise (forward rotation), the registrar roller 24 is in a state where the clutch 54 is disengaged and is stopped as it is.

The sheet document is guided to the reversing path R2 by the first guide member 37, pushes down the second guide member 38, passes the branch point Q, and when the leading end is detected by the first reversing sensor 45. (Step S10) After counting several steps by the counter 42, the clutch 52 is disengaged while the tip is completely nipped between the extra roller 32 and the first press roller 33, and the separation roller 22 The driving is stopped so that the next sheet document is not taken in (step S1).
1). Thereafter, the sheet document is fed in by the extra roller 32 and the first press roller 33, whereby the separate roller 22 and the retard roller 23 nipping the sheet document end side are rotated together, and the sheet document is fed in. .

As shown in FIG. 12, when the first reversing sensor 45 detects that the end of the sheet document has passed (step S12), the forward / reverse rotation switching mechanism 50 is activated at that moment. By switching, the extra roller 32 is rotated in the reverse direction (counterclockwise in the side view of FIG. 8) (step S13). As a result, the sheet document whose leading end is discharged from the first reversing port 8b and whose end is nipped by the extra roller 32 and the first press roller 33 is switched back and reversed (rearward). And the second is returning to the original position.
It is guided by the guide member 38 and carried along the return route R3.

When the leading edge of the sheet document is detected by the registration sensor 44 (step S14), the counter 42 counts several steps, and then the registration roller 24 and the registration follower whose leading edge is stopped are stopped. The sheet collides with the roller 25, where the skew of the sheet document is corrected (step S 15), and the leading end is nipped by the first registration roller 24 and the first registration follow roller 25. After a predetermined timing, the clutch 54 is engaged and the registration roller 24 starts rotating (step S16).

At this time, the drive source 41 corresponding to the distance by which the leading edge of the sheet document is transported from the position of the nip portion C to the rear end position of the platen glass 12 at the counter 42.
The number of rotation steps (first rotation step number) is measured, and after reaching the first rotation step number (step S1).
7) First, reading of the back side of the sheet document is started (step S18).

In this manner, the sheet original is formed by the rollers 24.
The sheet is conveyed by 25, 26, 27, 28, 29, 30 and 31, and as shown in FIG. 13, when the registration sensor 44 detects that the end of the sheet document has passed (step S19), From time to time, the counter 42 measures the number of rotation steps (second number of rotation steps) of the drive source 41 corresponding to the distance by which the end of the sheet document is conveyed from the position of the registration sensor 44 to the front end position of the platen glass 12. After reaching the second number of rotation steps (step S20), the reading of the back side of the sheet document is ended (step S21).

At this time, the clutch 54 is disengaged and the registration roller 24 is stopped (step S22), and the conveyance of the sheet document is passed on to the extra roller 32 and the second press roller 34, and the second reversal is performed. Sensor 46
When the passage of the trailing end of the sheet document is detected (step S23), the actuator 59 is actuated at that moment to rotate the switching member 39, and the position and posture thereof are tilted rearward and upward to move the main transport path R1. Cut off (Step S2
4) At the same time, the forward / reverse rotation switching mechanism 50 is switched to rotate the extra roller 32 in the forward rotation direction (clockwise in the side view of FIG. 9) (step S25). As a result, the leading end side is discharged from the second reversing port 8c, and the trailing end is located at the extra roller 32 and the second press roller 3c.
The sheet document in the state where the sheet document 4 is nipped at the position 4 is reversed in the switchback direction, moves in the opposite direction (rearward), and is guided along the switching member 39 to the bypass path R4.

Then, the sheet document is returned to the return path R3.
When the leading end is detected by the registration sensor 44 (step S26), the counter 42 counts several steps, and then the registration roller 24 and the registration follow roller whose leading ends are stopped. 25, the skew of the sheet document is corrected (step S27), and the leading end is nipped by the first registration roller 24 and the first registration follow roller 25. As shown in FIG. After a predetermined timing by the step control of the source 41, the clutch 54 is engaged and the registration roller 24 starts rotating (step S28).

At this time, the counter 42 measures the first number of rotation steps, and after reaching the first number of rotation steps (step S29), reading of the front side of the sheet document is started (step S29). S30).

Then, the sheet document is supplied to the rollers 24.2.
The sheet is conveyed by 5.26.27.28.29.30.31, and when the registration sensor 44 detects that the end of the sheet document has passed (step S31), the counter 42 starts counting from this time. After the number of rotation steps is measured and reaches the second number of rotation steps (step S32), the reading of the front side of the sheet document is terminated (step S33). Here, the clutch 52
Is cut off and the registration roller 22 stops (step S
34). Then, the sheet document is guided to the discharge path R5 along the lower surface of the guide 39b below the switching member 39, and is discharged from the paper discharge port 8c (step S3).
5).

When a plurality of sheet documents are set in the paper feed port 8a, the next sheet document is moved to the reversing path R2 at a predetermined timing before the previous sheet document is discharged. It is taken in and the processing time is shortened.

[0054]

As described above, the present invention has the following advantages. That is, claim 1
As shown in FIG.
A reversing path for reversing the front and back surfaces before reading the surface,
A first pair of rollers for feeding the original with the front and back reversed to the reading unit, a second pair of rollers for feeding the original after reading the first side to the reading unit again, and reading the second side. A new discharge path for discharging the completed document is newly provided. First, the front and back surfaces of the document are reversed by the reverse path, and the document is fed to the reading unit by the first roller pair, and the first surface is read. To
By feeding the document again to the reading unit by the second roller pair, reading the second surface, and discharging the document through the discharge path, the document can be passed through the reading unit twice, so that the previous document can be completed. During the reading process, the next document can be fetched at a predetermined timing, the processing time can be shortened, and the work efficiency can be improved.

Further, a switching means for switching a plurality of branch points is provided at an upstream position of the second roller pair, for example, as a structure for integrally rotating two guide members, The original before reading one surface is fed by the first roller pair, guided to the reading unit along the upper surface of one guide member, and the original after reading the first surface is passed between the two guide members. The document is guided to the second pair of rollers, and the switching means is switched to feed the original before reading the second surface by the second pair of rollers. The document is guided to the reading unit, and further, the document whose second surface has been read is guided to the discharge path along the lower surface of the other guide member, so that the document is not used without a mechanism for separating the rollers. Can be discharged. That is, this reduces the number of components such as a mechanism for separating the roller, thereby reducing manufacturing costs.

By forming the first roller pair and the second roller pair with three rollers, the number of parts can be reduced and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a facsimile employing a double-sided image reading device.

FIG. 2 is a side sectional view of the same.

FIG. 3 is a side sectional view of an ADF of the duplex image reading apparatus.

FIG. 4 is a perspective view showing another embodiment of the switching member.

FIG. 5 is a front view of the same.

FIG. 6 is a side sectional view of the same.

FIG. 7 is a block diagram illustrating a control configuration of the duplex image reading apparatus.

FIG. 8 is a side cross-sectional view of the ADF showing a flow of a document in a first process of the duplex image reading apparatus.

FIG. 9 is a side cross-sectional view of the ADF showing a flow of a document in a second process.

FIG. 10 is an ADF showing the flow of an original in the third process.
FIG.

FIG. 11 is a flowchart showing a first stage of a control configuration of the duplex image reading apparatus.

FIG. 12 is a flowchart showing a second stage.

FIG. 13 is a flowchart showing a third stage.

FIG. 14 is a flowchart showing the final stage.

[Explanation of symbols]

 8 ADF 8a Paper feed port 8b First reversing port 8c Second reversing port 8d Discharge port 12 Platen glass 32 Extra roller 33 First press roller 34 Second press roller 39 Switching member 39a Upper guide 39b Lower guide 39d Rotating fulcrum shaft 40 Controller 59 Actuator R1 Main transport route R2 Reverse route R3 Return route R4 Bypass route R5 Eject route

Continued on the front page (72) Inventor Ryuichi Onaka 136 Takeda Mukodaicho, Fushimi-ku, Kyoto Murata Machinery Co., Ltd. F-term (reference) 2H076 BA33 BA42 EA24 3F053 BA03 BA12 BA19 LA01 LB02 3F100 AA03 CA12 5C062 AA05 AB17 AB29 AC09 AC11 AC15 AC66 AC68 AD01 AD06 BA01 BA04 5C072 AA01 BA02 BA03 NA01 NA07 RA04 WA02 XA01

Claims (3)

[Claims] 1. A document is fed to a reading unit, the first side of the document is read, and the document is turned over and fed again to the reading unit.
In a two-sided image reading apparatus for reading the second side, a reversing path for reversing the front and back surfaces of the original before reading the first side, and a first roller pair for feeding the document with the reversed front and back sides to the reading unit And a second pair of rollers for feeding the original after reading the first side to the reading unit again, and a discharge path for discharging the original after reading the second side. Image reading device. 2. A double-sided image reading apparatus according to claim 1, wherein a switching means for switching a plurality of branch points is provided at an upstream position of said second roller pair. 3. The device according to claim 1, wherein the first roller pair and the second roller pair comprise three rollers.
Or a double-sided image reading device according to claim 2.