JP3148039B2 - Document feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder incorporated in a copying apparatus or an image reading apparatus for sequentially feeding documents to be copied or read to a reading section.

[0002]

2. Description of the Related Art A copying apparatus or an image reading apparatus includes a document table on which a document is placed, a lighting device for illuminating the document placed on the document table, and reflected light from the document illuminated via the lighting device. It includes a reading unit for reading as image information.
Also, at one end of the platen, where the document to be read is placed as a reference, the leading (or trailing) edge of the document
A document stopper that defines the position of the document by contacting the document is disposed.

A document feeder includes a document holding unit for holding a document to be fed to a reading unit of a copying device or a reading device;
It is composed of a document transport section for transporting documents one by one to the reading section, a discharged document holding section for holding the read document, and the like. The document holding unit has a document tray on which a document is placed, a document sensor for detecting that the document is placed on the document tray, and the like.

The original transport section takes out the originals placed on the original tray one by one, and takes out the originals one by one, and transports the originals taken out via the take-out rollers along the original platen (of the reading section). A transport belt, a discharge roller for sending the read document toward the discharge document holding unit, a transport belt, a drive motor for urging the take-out roller and the discharge roller, and a drive motor. A control unit for controlling rotation is included.

[0005] The discharged document holding section has a stock tray for storing the documents sent out via the transport belt and the discharge roller, and a discharge sensor for checking that the documents have been discharged reliably.

In the document feeder, a document placed on a document tray is sequentially fed to a document table of a reading unit. The document taken out through the take-out roller is fed to a reading section via a transport belt. The document whose reading has been completed is again moved via the transport belt, and is discharged to a stock tray by a discharge roller. In this case, the drive motor that drives the transport belt is rotated so that the transport belt transports the document to a position (virtual position) beyond the position of the document stopper. That is, the inclination of the document which may occur during the conveyance by abutting the document against the document stopper is removed.

In the method of abutting a document against the document stopper, it is known that the leading edge of the document is shifted when the document is loaded on the document stopper. For this reason, a method of strengthening the document stopper has been proposed. However, if the document stopper is made strong, there is a new problem that the end of the document is damaged and the thin document is wrinkled. For this reason, a method has been proposed in which the drive motor is instructed to stop at a position just before the document stop position, that is, at a position separated by a predetermined distance from the document stopper, and the document is gently hit against the document stopper by inertia of the motor. ing. Furthermore, in order to keep the speed at which the document abuts against the document stopper, a method of detecting the size and thickness of the document and stopping the drive motor stepwise has been proposed.

[0008]

However, in any of the above methods of abutting the original against the original stopper, the individual error of the motor or the thickness (size and weight, that is, the inertial weight) of the original changes. There is a problem that a document is not stopped at a predetermined position. In addition, when the driving motor is stopped in a stepwise manner, not only does the control of the motor become complicated, but also there is a problem that the speed at which the original is replaced (processing speed) is reduced. SUMMARY OF THE INVENTION It is an object of the present invention to provide a document feeder capable of accurately feeding a document to a reading start position.

[0009]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above-mentioned problems, and has an original placing table for holding an original.
When the conveying means for conveying the original to a predetermined position of the document table, includes pulse generating means, a pulse motor for driving the conveying means, and biasing means for electrically biasing the pulse motor, Built in the above pulse motor, pulse
By reversing the polarity of the drive current supplied to the motor,
Braking means for forcibly stopping the rotation of the pulse motor ;
Detecting means for detecting that a document has been conveyed to the reading position of the document placing table via the conveying means; and energizing the urging means based on a document detection signal from the detecting means. after stopping, an original detection signal from the detection means
Is output via the pulse motor from the point when
The number of pulses generated by the
And control means for work moving said braking means at the timing,
Is provided. Also,
The invention relates to a conveying means for conveying a document, and a pulse generating means
Driving means for driving the conveying means, and
Braking means disposed on the means for stopping the driving means;
It is provided opposite to the original placing table, and is
Detecting means for detecting the position of the original being conveyed
And the original conveyed through this detecting means
It has been detected that the first position on the document table has been reached
When instructing the driving means to stop driving,
From the time when it is detected that the first position has been reached,
The pulse generated from the pulse generating means via the driving means
When the number of looses reaches a predetermined number, the braking means is controlled.
And control means for instructing a moving start, the document feeder including Hisage
To offer.

[0010] In addition, the present invention is a document that holds the manuscript
The loading table and the original are transported to a predetermined position on the document table.
Conveying means that includes a pulse generating means, said conveying means
The pulse motor to be driven and the pulse motor
Biasing means for biasing, incorporated in the pulse motor,
The polarity of the drive current supplied to the pulse motor is inverted.
And a braking means for forcibly stopping the rotation of the pulse motor and a document placed on the document table via the transport means .
Detecting means for detecting that the sheet has been transported to the reading position ;
Based on the original detection signal from the detecting means,
After the power supply to the step is stopped,
The polarity of the drive current supplied to the
The pulse motor is rotated in the reverse direction, and the original
When the detection signal is output again, the pulse motor
The number of pulses generated from the pulse generation means via
And <br/> control means for operating said braking means at the timing when reaching the number of fixed, Ru der <br/> provides a document feeder having a.

[0011]

According to the document feeder of the present invention, the transport means for transporting the original is driven via the driving means including the pulse generating means. When the drive unit detects that the document has passed through the detection unit that detects the position of the document placed at a predetermined position, the drive unit is instructed to stop driving and detects that the document has passed. From this point, braking is applied at a desired timing. This braking timing is defined based on a pulse generated from the driving means. Therefore, the original can be accurately fed to the reading start position regardless of the thickness and size of the original and without damaging the original.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, a document feeder 10 includes a reading document tray 20 on which a document D to be fed is placed, and a document take-out section for taking out the documents D placed on the document tray 20 one by one.
30, a document transport unit 40 for feeding a document D taken out through the document take-out unit 30 to a predetermined position on a document table 100 of a copying apparatus or an image reading apparatus, for example, and the read document D is discharged. Document discharge section 50, take-out section 30, and transport section 40
And a control unit 60 for controlling the discharge unit 50 independently or independently.
Contains.

The document feeder 10 is fixed to the document table 100 at the upper rear end of a copying machine or image reading device (not shown) so as to be openable and closable with respect to the document table 100. At one end of the document table 100 and on the side close to the document take-out section 30, a document stopper 101 indicating the reference of the leading end of the document D when the document D is placed is arranged. .

The document tray 20 has a gentle slope, for example, a tray body 22 formed so that about 50 documents D can be placed thereon, and the weight of the document D placed on the tray body 22. The auxiliary body 24 supports the tray body 22 so that the tray body 22 does not bend. The tray body 22 is provided with a document guide 24 that can move on the tray body 22, indicates a position where the document D is placed, and prevents the stacked documents D from shifting. .
Incidentally, the tray main body 22 is disposed on a main body cover 26 which covers a document transport section and a drive section described later.

The document take-out section 30 includes a shutter 31 for aligning the ends of the document D placed on the tray main body 22 of the document tray 20;
A document feed path 32 for guiding the document D fed from the tray body 22 to the end of the document table 100, and a pickup roller 33 disposed near the shutter 31 for taking out the document D placed on the tray body 22. The original D is disposed between the pickup roller 33 and the weight 34 for pressing the original toward the pickup roller 33 when the original D is placed. And an actuator 35a for operating the empty sensor 35.

The downstream side of the pickup roller 33,
At the entrance of the document feeding path 32, a separation roller 36 for limiting the number of documents D taken out via the pickup roller 33 to one sheet,
A separating pad 36a for pressing the document D against the separating roller 36 is disposed. The separating pad 36a is pressed against the roller 36 via a spring 36b disposed on the side opposite to the roller 36.

Downstream of the document feed path 32, a pair of aligning rollers 37 for correcting the inclination of the document D and adjusting the supply timing are arranged. On the upstream side and the downstream side of the aligning roller pair 37, an aligning sensor 37a for detecting the presence / absence of the document D and defining a timing for operating the aligning roller pair 37, and a size sensor for detecting the size of the document D 38 are located, respectively.

The document take-out section 30 is covered via a cover 39 so that the user does not touch the rotating portion. Further, the cover 39 is formed to be openable in order to remove an obstacle such as a document jam. For this reason, when the cover 39 is opened, a cover switch 39a for detecting that the cover 39 is opened is arranged near the opening so that a driving unit described later is not biased. ing.

The document transport section 40 has a transport belt 41 for covering the upper surface of the document table 100 and transporting the document D fed from the document take-out section 30 along the document table 100. The document conveying section 40 is covered so that a user does not touch the main body cover 26 via the cover 26 described above.

The transport belt 41 is a seamless wide belt having a white outer surface and formed in an annular shape, and supports a first belt roller 42 supporting an end portion adjacent to the document transport section 40 and other belt rollers. It is wrapped around a second belt roller 43 supporting the end portion, and is rotated in both forward and reverse directions via a drive roller described later. On the back side of the inner peripheral portion of the transport belt 41, a set switch for detecting whether or not a plurality of belt press rollers 44 # for bringing the belt surface into close contact with the document table 100 and a document D is set. 45 are located.

The document discharge unit 50 is placed on the document table 100 via the document transport unit 40, and the document D from which image information is read
Document tray 51, where the paper is stored
And a cover 53 that covers the original discharge path 52 and a driving unit described later.

A document discharge path 52 includes a transport roller 54 for propelling the document D, for which image information has already been read, in a direction away from the document transport section 40, and a plurality of documents D for bringing the document D into close contact with the outer peripheral surface of the transport roller 54. And a trailing edge detection sensor 56 for detecting the trailing edge of the document D sent toward the discharged document tray 51.

On the downstream side of the transport roller 54, a discharge roller 57 for further pushing the document D toward the discharge document tray 51.
Further, a spring 57a for bringing the original D into close contact with the paper discharge roller 57 is disposed.

Between the transport roller 54 and the discharge roller 57,
Document D whose front and back are inverted with the rotation of the transport roller 54
The flapper 58 is disposed to advance the sheet toward the transport belt 41 again or to push the sheet toward the discharged document tray 51. In the direction in which the document D directed to the conveyance belt 41 via the flapper 58 advances, a reversed document path 59 for allowing the document D, which has been turned upside down, to enter between the conveyance belt 41 and the document table 100. Is arranged.

Referring to FIG. 2, the document feeder 10 rotates the transport belt 41 in both the forward and reverse directions, and rotates many rollers disposed in the document take-out section 30 and the document discharge section 50. It has a mechanism 110.

The drive mechanism 110 is a first motor for rotating either one of the first and second belt rollers 42 and 43.
120, the rotation of the motor 120 is controlled by the belt roller of the document conveying section 40.
First power transmission mechanism for transmitting to either 42 or 43 12
2. The second power transmission mechanism 124 for transmitting the rotation of the motor 120 transmitted to the first power transmission mechanism 122 to the pair of aligning rollers 37 of the document take-out section 30 and the transport roller of the document discharge section 50. And a rotation of the motor 120 transmitted to the third power transmission mechanism 126, which is transmitted to the third power transmission mechanism 126.
The fourth power transmission mechanism 128 for transmitting the data to the
Second motor 13 for energizing 30 pickup rollers 33
0 and the rotation of the second motor is picked up by a pickup roller 33.
And a fifth power transmission mechanism 132 for transmitting the power to the motor.

The first motor 120 is a pulse motor which is energized at a given number of rotations (rotational speed) by a predetermined pulse. The first motor 120 outputs its own rotational speed to one end of a rotary shaft to the outside. Encoder 150 and a brake 152. The motor 120 is rotated by a drive pulse supplied from a motor drive circuit described later, and simultaneously generates a pulse corresponding to the rotation speed. The encoder 150 is
A pulse generating plate 150a which is arranged on the rotation axis of the motor 120 and is rotated with the rotation of the motor 120;
It is formed by a photointerrupter 150b in which a light emitting unit and a light receiving unit are integrally arranged with the 150a interposed therebetween.
The photo interrupter 150b is connected to a pulse counting circuit, which will be described later, and calculates the rotational speed of the motor 120 and the optimum braking position based on the output from the photo interrupter 150b. The brake 152 is an electromagnetic brake incorporated in the first motor 120, and is provided by reversing the polarity of a drive current supplied to the motor 120. Brake 1
Reference numeral 52 is turned on at a desired timing from the time when the document D is passed through the set switch 45 again when the document D is reversely fed, as shown in FIG. In addition, brake 152
May be a mechanical brake disposed outside the motor 120 or close to the conveyor belt 41.

The first power transmission mechanism 122 includes a pulley, a belt, a gear, and the like.
The first and second belt rollers 42 and 43 supporting the forty conveyor belts 41 are transmitted. The second power transmission mechanism 124 includes a belt, a pulley, a clutch 122a, and the like. The rotation of the motor 120 transmitted via the first power transmission mechanism 122 is controlled by the aligning roller of the document take-out unit 30.
It is transmitted intermittently at the desired timing to the pair 37. The third power transmission mechanism 126 includes a plurality of gears, and transmits the rotation of the motor 120 transmitted via the first power transmission mechanism 122 to the transport roller 54 of the document discharge section 50. The fourth power transmission mechanism 128 includes a belt and a pulley, and controls rotation of the motor 120 transmitted to the third power transmission mechanism 126 to a discharge roller 57.
To communicate.

The second motor 130 is a pulse motor that is energized at an arbitrary rotation speed (rotational speed) by a predetermined pulse, and is driven by a driving pulse supplied from a motor driving circuit described later. It is rotated and, at the same time, generates pulses according to the rotation speed.

The fifth power transmission mechanism 132 includes a pulley, a belt, and a plurality of gears, and transmits the rotation of the gear motor 130 to the pickup roller 33 of the document take-out section 30. The rotation of the motor 130 transmitted to the pickup roller 33 is
It is transmitted to the separating roller 36 via 134.

The drive mechanisms other than the rotation mechanism, that is, the shutter 31 and the weight 34 of the document take-out section 30 are provided with a shutter solenoid 136 and a weight solenoid 1 respectively.
Energized via 38. The flapper of the document discharge section 50
58 is driven by a flapper solenoid 140.

Referring to FIG. 3, the control unit 60 of the document feeder 10
Includes a main control unit, that is, a CPU 160, and is connected to an apparatus having the document table 100, that is, a copying apparatus or an image reading apparatus (not shown) via an interface 162 connected to the CPU 160.

The CPU 160 includes an empty sensor 35, an aligning sensor 37a, a size sensor 38, a cover switch 39, a set switch 45, and a photo interrupter 1.
50b are connected via input / output ports (not shown). CPU 160 also has a mode (not shown).
First and second motors 120 and 13 via a motor driving circuit.
0 is connected. The CPU 160 further includes a clutch 122a, a shutter solenoid 136, a weight solenoid 138, a flapper solenoid 140, and a brake 152.
Are connected via a connection circuit (not shown). next,
The operation of the document feeder will be described in detail.

When the document D to be copied (or read) is placed on the tray body 22 of the document tray 20, the empty sensor 35 is turned on, and it is detected that the document D is placed.

When a print (or start) key of a copying machine (or a reading device, not shown) is turned on,
When the first and second motors 120 and 130 are energized, the pickup roller 33 and the separating roller 36 are rotated, and the lowermost document D of the document D placed on the tray main body 22 is moved. Be taken out.

The extracted document D passes through a document feed path 32 and is conveyed to an aligning roller 37. The document D conveyed to the aligning roller 37 is temporarily stopped via the roller 37, and is sent out toward the conveyor belt 41 after the timing of the supply to the conveyor belt 41 is adjusted.
In this case, the size of the document D is detected via the size sensor 38.

The transport belt 41 covers all areas of the document D.
(Entire area) is urged until it passes document stopper 101,
The entire document area is set to the document stopper 101 via the set switch 45.
Is stopped when it is detected that the vehicle has passed. That is,
The entire area of the document D is opposed to the document table 100.

When the entire area of the document D is conveyed to the document table 100 via the set switch 45, the conveying belt 41 is rotated in the reverse direction by a desired number of pulses in order to align the leading edge of the document D with the document stopper. The first motor 120 is controlled as shown in FIG.
101 is exactly matched. Document D is the document stopper 101
Is set, the copying device (or reading device) not shown is sequentially energized, and the image of the document D is copied (read).

According to FIG. 4, when the document D is fed backward, the first motor 120 is stopped before the document D comes into contact with the document stopper 101. In this case, the first motor 1
The position where the document 20 is stopped is defined, for example, at the position where the set switch 45 detects the document D again. That is, the transport belt 41 does not push the original D until it comes into contact with the original stopper 101, and conveys the original D only by inertia in the vicinity of the original stopper 101.

Thereafter, a predetermined braking start position according to the number of pulses counted via the encoder 150
(That is, the timing at which the brake 152 is turned on), the brake 152 is turned on, and the inertia of the transport belt 41 is removed. Therefore, the leading end of the document D being conveyed by the inertia of the conveyance belt 41 is stopped at a position exactly coincident with the document stopper 101.

According to this method, the distance between the document stopper 101 and the set switch 45 is constant, and
From the time when the document D passes the set switch 45 again, the distance over which the transport belt 41 conveys the document D by inertia is defined as a distance corresponding to a fixed pulse amount with respect to the set switch 45, thereby Regardless of the individual error of the feeder 10, the distance at which the document D is fed backward is kept constant.

[0043]

As described above, according to the document feeder of the present invention, it is ensured that the document is fed to the document table.
Pulse motor is stopped after detecting
And then forcibly stop after counting a predetermined number of pulses.
Stops scanning so that the original is accurately positioned at the reading start position.
You can decide. Therefore, the thickness and size of the original
And regardless of the individual errors in the document feeder, moreover, a document
The original can be fed accurately to the reading start position without being damaged .

Thus, the document is accurately fed to the reading start position regardless of the thickness and size of the document and without damaging the document. In addition, the original exchange speed
(Processing speed) is not reduced.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a document feeder into which an embodiment of the present invention is incorporated.

FIG. 2 is a schematic perspective view showing a driving mechanism of the document feeder shown in FIG.

FIG. 3 is a block diagram schematically showing a control device incorporated in the document feeder shown in FIG.

FIG. 4 is a timing chart showing an example of control of the document feeder shown in FIGS. 1 to 3;

[Explanation of symbols]

10: Document feeder, 20: Document tray, 22: Tray body,
24 ... original guide, 26 ... body cover, 30 ... original removal section,
31 ... Shutter, 32 ... Document feed path, 33 ... Pickup row
LA, 34: weight, 35: empty sensor, 35a: actuator, 36: loosening roller, 36a: loosening pad, 36b ...
Spring, 37: Aligning roller pair, 37a: Aligning sensor, 38: Size sensor, 39: Cover, 39a: Cover
Switch, 40: Document transport section, 41: Transport belt, 42, 43 ...
Belt roller, 44: Belt press roller, 45: Set switch, 50: Document discharge section, 51: Document discharge tray, 52: Document discharge path, 53: Cover, 54: Transport roller, 55: Pinch roll −
56, rear end detection sensor, 57, discharge roller, 58, flapper, 59, reversing original path, 60, control unit, 100, original mounting table, 101, original stopper, 110, drive mechanism, 120, First
122, a first power transmission mechanism, 124, a second power transmission mechanism, 126, a third power transmission mechanism, 128, a fourth power transmission mechanism, 130, a second motor, 132: Fifth power transmission mechanism, 136: Shutter solenoid, 138: Weight solenoid, 140: Flapper solenoid, 150: Encoder, 150a: Pulse generating plate, 150b: Photo interrupter, 152: Brake, 160: CPU , 162 ... Inter
Face.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-88657 (JP, A) JP-A-2-147542 (JP, A) JP-A-59-84540 (JP, U) (58) Survey Field (Int.Cl. ⁷ , DB name) B65H 9/00 B65H 5/02

Claims (3)

(57) [Claims] Includes a document table for holding a 1. A document, conveying means for conveying the original to a predetermined position of the document table, the pulse generating means, pulse for driving the conveying means
A motor, a biasing means for electrically biasing the pulse motor, incorporated in the pulse motor, is supplied to the pulse motor
Braking means for forcibly stopping the rotation of the pulse motor by reversing the polarity of the driving current to be driven; and that the document has been conveyed to the reading position of the document mounting table via the conveying means. a detecting means for detecting that, after stopping the power supply to the biasing means on the basis of the document detection signal from the detecting means, the document from the detection means
From the point when the detection signal is output,
The number of pulses generated from the pulse generating means
Document feeder and a control means for work moving said braking means at the timing when reaching the number. A driving means for driving the conveying means, comprising conveying means for conveying the original, and pulse generating means;
A step and a brake hand arranged on the drive means for stopping the drive means
And a step, and are provided to face the document placing table, and
Detecting means for detecting the position of the original document being conveyed
And the original conveyed through the detecting means is
When it is detected that the first position on the manuscript table has been reached
Instruct the driving means to stop driving, and
From the time point when the first position is detected,
A pulse generated from the pulse generating means through the means
When the number reaches the specified number, the braking means is released
A document feeder including a control unit for instructing start of the document. And a pulse generating means for driving the transport means. The document mounting table holds an original, transport means for transporting the original to a predetermined position on the original mounting table, and pulse generating means.
A motor , biasing means for electrically biasing the pulse motor, and a motor incorporated in the pulse motor to supply the pulse motor.
The above-mentioned pulse motor
A document is read on the document table via a braking means for forcibly stopping the rotation of
Detecting means for detecting that the sheet has been conveyed to the position, and the urging means based on a document detection signal from the detecting means.
After the power supply to the step is stopped,
The polarity of the drive current supplied to the
The pulse motor is rotated in the reverse direction, and the original
When the detection signal is output again, the pulse motor
The number of pulses generated from the pulse generation means via
Control means for operating the braking means at a timing when a predetermined number is reached .