JP2866979B2 - Document feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document feeder provided in an image forming apparatus such as a copying machine.

[Prior Art] Conventionally, a conveyance belt having a size to cover the entire surface of a platen of an image forming apparatus is provided, and a document is conveyed and set on a platen by driving the conveyance belt, or discharged from the platen after image formation. There is.

 However, this device has the following problems.

Although the size of the transport belt is adjusted to the maximum size document (for example, A3), the size of the document that is actually frequently used is often smaller than the maximum size (for example, A4). The frequently used small size document must be conveyed from one end to the other end of the large conveyance belt, and it takes time to set and feed the document.

Therefore, the following apparatus is disclosed in Japanese Patent Application Laid-Open No. Hei 2-13532 to solve the problem of the above apparatus.

In the apparatus disclosed in JP-A-2-13532, a paper feed tray 81 is provided at one end of the image forming apparatus as shown in FIG.
A transport belt 83 is provided in approximately half of the platen 82, and the platen 83
A platen cover 84 is provided on approximately the other half of the sheet, and a paper discharge tray 85 is provided above the transport belt 83. Conveyor belt 83
The document entrance and exit are located on the paper feed tray 81 side and the reading standard 87.
Located on the side. The discharge tray 85 includes a conveyor belt 83.
It is connected to the entrance side.

The frequently used small-sized document is sent out from the paper feed tray 87 toward the transport belt 83, and then is carried into the platen 82 by the forward rotation of the transport belt 83, and then the reverse rotation of the transport belt 82 is performed. And is set at the position of the reading reference 87 by being abutted against the stopper 86. After the image formation, the original is discharged toward the discharge tray 85 by the reverse rotation of the transport belt 83.

On the other hand, a large-sized document is set on the platen 82 by hand by lifting the transport belt 83 and the platen cover 84.

[Problems to be Solved by the Invention] However, in the apparatus disclosed in Japanese Patent Application Laid-Open No. Hei 2-13532, a large-sized document must be manually set after lifting up the transport belt 83 and the platen cover 84. I can't send it.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a document feeder capable of automatically feeding both a small-size document and a large-size document, and reducing the processing time of frequently used small-size documents.

[Means for Solving the Problems] In order to achieve the above object, there is provided a transport unit that is disposed so as to cover at least a part of the platen and transports a document fed to the platen to a reference position on the platen. In the document feeder, detecting means for detecting the length of the document fed onto the platen, and when the document detected by the detecting means is a small size smaller than a predetermined length, the document is moved to one end of the platen. Transported in the side direction and stopped at the reference position, in the case of a large size larger than a predetermined length,
Control means for controlling the transport means so that the document is transported in both directions of one end side and the other end side of the platen and stopped at the reference position.

[Operation] The present invention operates as follows.

The detecting unit detects the length of the document fed toward the transporting unit, and the drive control of the transporting unit is changed based on the result of the determination, and the document is set at the reading reference position by a different operation depending on the size of the document.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a longitudinal sectional view of the image forming apparatus of this embodiment, and FIG. 1B is a drive system thereof.

Referring to FIG. 1, reference numeral 1 denotes a main body of an image forming apparatus such as a copying machine, which incorporates an image forming system such as a copying optical system (not shown). Reference numeral 2 denotes a platen on which a document is set.

Reference numeral 3 denotes a document reading reference set at one end of the platen, and the document is set by aligning one end of the document with this position.

Conveying means 4 for feeding / discharging the document on the platen 2
In addition, a platen cover 5 for holding a document is arranged side by side so as to be freely opened and closed.

The transporting means 4 of this embodiment includes a pair of pulleys 6, 6,
It comprises a transport belt 7 stretched between the pulleys 6, 6 and a press roller 8. Then, the entrance 4a of the document of the conveying means 4 is located between the conveying means and the platen cover 5,
The outlet 4 b is placed so as to be located at the end of the platen 2.

Although a gap is always formed between the platen cover 5 and the platen 2, the platen cover 5 is pressed against the platen 2 by excitation of the cover solenoid 9.

The transporting means 4 and the platen cover 5 are connected to each other by an appropriate connecting mechanism, and can be opened and closed integrally with the platen by separating the connecting mechanism or individually.

The original conveyed by the conveying means 4 is read by the reference 3
A document stopper 10 that stops at the position is provided to be able to move forward and backward.

Above the platen cover 5, there are provided a paper feed tray 11 on which documents are stacked, and a document supply means 12 for feeding the documents on the paper feed tray 11 to the transport means 4 one by one. The detailed configuration of the document supply means 12 will be described later.

An auxiliary tray 11a used for automatically feeding a document of a predetermined size or more (large size) is rotatably attached to the paper feed tray 11.

In the vicinity of the discharge section of the conveying means, a discharge / reverse roller 13 is provided.
And a switching gate 14 for switching the original feeding direction of the discharge / reversal roller 13 toward the later-described paper discharge tray 21 or the platen 2, and a discharge roller 15.

The switching gate 14 performs a switching operation by a gate solenoid 16. When the switching gate 14 is rotated toward the discharge / reversal roller 13, a document discharge path toward the discharge tray 21 is formed. On the other hand, when the switching gate 14 is separated from the discharge / reversal roller 13, a reversal path is formed in which the document is reversed and returned to the platen 2.

17 is a pinch roller, and 18, 19 and 20 are guides. The motor M2 drives the conveying means 4, the discharging / reversing roller 13 and the discharging roller 15.

A paper discharge tray 21 is arranged above the transport means 4.

Next, the configuration of the document supply means 12 is shown in FIG.
(B) will be described with reference to FIG. FIG. 2 shows a drive system of the document supply means.

As shown in FIGS. 1 (a) and 1 (b), the document supply means 12 includes paper feed guides 22 and 23, a pickup roller 24 for feeding a document on the paper feed tray 11, and a paper supply rotating in the paper feed direction. A paper roller 25 and a separation roller 26 that rotates in a direction to retreat a document that follows the document fed by the paper feed roller 25
And a registration roller 27.

 M1 is a motor for driving this roller group.

The drive mechanism for this roller group is configured as shown in FIG.

Referring to FIG. 2, pulley 2 is
8, the pulley 30 is connected via the timing belt 29,
A gear is connected to a rotating shaft 31 of the pulley 30 via a spring clutch 32.
The gear 33 is engaged with the gears 34 and 35.

Gears 36 and 37 are meshed with the gear 35, and a separation roller 26 (not shown in FIG. 2) is connected to a rotation shaft 37a of the gear 37.

The feed roller 25 is connected to a rotation shaft 38 of the gear 35 via a one-way clutch (not shown).

Further, a pair of arms 40 that rotate via a spring clutch 39 is attached to the rotating shaft 38, and the pickup roller 24 is attached to the arm 40 via a rotating shaft 41, and the rotating shaft 38 and the gears 42, 43 , 44 to the pickup roller 24.

A gear 45 is attached to the rotating shaft 31 via a one-way clutch (not shown), and a gear 46 is meshed with the gear 45,
The registration roller 27 is supported on a rotation shaft 47 of the gear 46.

That is, at the time of forward rotation of the motor M1, the drive of the motor is transmitted to the pickup roller 24, the sheet feeding roller 25, and the separation roller 26 by the action of the one-way clutch at the gear 45. When the motor M1 rotates in the reverse direction, the drive of the motor is transmitted to the registration roller 27.

When the motor M1 rotates forward, the pickup roller 24 is lowered toward the document via the arm 40.However, when the pickup roller 24 comes into contact with the document, the spring clutch 39 idles due to the load, causing the pickup roller 24 to rotate. It is designed to be held at the lower position.

When the motor M1 rotates in the reverse direction, the pickup roller 24 is lifted from the original via the arm 40.
When the stopper 24 hits a stopper (not shown), the spring clutch 32 idles due to the load, and the pickup roller 24 is held at the upper position.

 Each sensor will be described with reference to FIG.

S1 is an empty sensor for detecting whether or not there is a document on the paper feed tray 11.

S2 is a registration sensor that detects the arrival of the leading edge of the original and stops the original after a predetermined feed amount has elapsed and corrects the registration, or detects the arrival of the leading edge of the original and the passage of the rear edge to detect the size of the original. Or, the passage of the trailing edge of a larger size document is detected, and after a predetermined feed amount (B pulse) has elapsed, the transport means 4 reversely feeds the document.

S3 is a discharge sensor that detects the passage of the rear end of the document to detect the completion of discharge of the document, or detects the passage of the front end of a large-sized document that has been reversely fed, and then detects a predetermined feed amount (C pulse).
After the elapse, the motor M2 is stopped to stop and set the original.

As shown in FIG. 5, an empty sensor S1, a registration sensor S2, a paper ejection sensor S3, a clock (pulse generating means)
48 is connected to the input side of a microcomputer 49 as control means. The motor M1, the motor M2, the cover solenoid 9, and the gate solenoid 16 are connected to the output side of the microcomputer 49.

A registration sensor that detects when the document reaches the leading edge and when the trailing edge passes
S2 and a microcomputer 49 which receives a signal from the registration sensor S2, calculates the length of the document and determines whether the document is a document of a predetermined size or more (large size) or less than a predetermined size (small size). A document size discriminating means is configured.

The microcomputer 49 changes the drive control of the conveying means 4 according to the result of the determination by the document size determining means as follows, and sets the document based on the reading operation according to the size of the document.

If the document is of a small size, the document is conveyed and set at the position of the reading reference 3 only by the forward feeding of the conveying means 4.

On the other hand, when the document is large, first, the front end of the document is moved out of the platen 2 by the forward feed of the conveying means 4 and conveyed until the rear end of the document reaches the platen 2. The original is reversely fed by the reverse feed of 4 and the rear end of the original is inserted into the gap between the platen cover 5 and the platen 2 to set the original at the reading reference 3 position.

The operation of the embodiment configured as described above will be described with reference to the state diagram showing the feeding of a small-size document in FIG. 4, the state diagram showing the feeding of a large-size document in FIG. 5, and the operation process in FIG. The flowchart shown will be described with reference to FIGS. 1 to 3.

Each step of the flowchart of FIG.
00, S101,...

<1> When a document is placed on the paper feed tray 11, the document is detected and displayed by the empty sensor S1 (FIG. 4A).
FIG. 5 (a)).

Next, in step S100, a start switch (not shown)
push.

Then, in step S101, the motor M1 rotates forward, the pickup roller 24 rotates and descends above the document while rotating, and the paper feed roller 25 and the separation roller 26 rotate.

Then, the pickup roller 24 feeds out the original on the paper feed tray 11. The fed original is separated into one sheet by a feed roller 25 and a separation roller 26. Then, the leading end of the document strikes the stopped registration roller 27 (FIG. 4 (b), FIG. 5 (b)).

<2> In step S102, a predetermined time has passed since the registration sensor S2 detected the leading edge of the document, and registration correction is performed.

Then, in step S103, the motor M1 rotates in the reverse direction and the motor M2 rotates in the normal direction.

The reverse rotation of the motor M1 causes the registration roller 27 to rotate and feed the document toward the conveyance means 4. The transport unit 4 that rotates forward by the motor M2 takes over the document and transports it on the platen 2.

In step S104, the registration sensor S2 detects the arrival of the leading edge of the document and the passage of the trailing edge, and inputs the signal to the microcomputer 49 to determine whether the document is a large document or a small document.

Then, in step S105, the original is transported by a different transport method depending on whether the original is small or large.

Subsequently, the case of the small size is described in the following <3-small>, and the case of the large size is described in the <3-large>.

<3-Small> When the document is of small size, the following operation is performed.

 In step S106, the motor M1 is stopped.

In step S107, the forward rotation of the motor M2 reaches the pulse A, and the conveying means 4 causes the leading end of the document to reach the reading reference 3.

Then, in step S108, the motor M2 is stopped and the document is set to the reading reference 3 (FIG. 4 (c)).

Next, in step S109, an image forming operation such as a copying operation is performed, and at the same time, the motor M2 is rotated forward to feed out the next original from the paper feed tray 11 (FIG. 4 (d)).

When the image forming operation is completed, in step S110, the motor M2 is rotated in the normal direction, and the conveying unit 4, the discharging / reversing roller 13, and the discharging roller 15 are rotated.
As a result, the document is discharged from the platen 2 toward the discharge tray 21.

In step S111, when a predetermined time elapses after the discharge sensor S3 detects the trailing end of the document, the discharge operation is completed (FIG. 4 (e)).

If both sides of the document are to be image-formed, the switching gate 14 is discharged by the gate solenoid 16 and the reversing roller is used.
13, the document is turned over by the discharge / reversal roller 13, and then set on the platen 2 again.

<3-Large> When the document is large, the following operation is performed.

 In step S112, the motor M1 is stopped.

Next, in step S113, the leading end of the document conveyed by the conveying unit 4 is moved beyond the platen 2, for example, a discharge / reversal roller.
When the registration sensor S2 comes out to the position 13 and the trailing edge of the original is detected, only the B pulse elapses (FIG. 5 (c)). At this time, the rear end of the document is introduced onto the platen 2.

Then, in step S114, the motor M2 is changed from normal rotation to reverse rotation. By the reverse rotation of the motor M2, the conveying means 4 reversely feeds the original.

After the discharge sensor S3 detects the passage of the leading edge of the original document that is reversely fed in step S115, the original document is reversely fed by C pulse.

Then, in step S116, the motor M2 is stopped, the rear end of the document is inserted under the platen cover 5 to stop the document, and the document is set at the position of the reading reference 3 (FIG. 5 (d)).

The cover solenoid 9 is turned on, and the original is pressed against the platen 2 by the platen cover 5.

Next, in step S117, an image forming operation such as a copying operation is performed, and the motor M1 is rotated forward to feed the next document to the sheet feeding tray.
Start from 11.

When the image forming operation is completed, in step S118, the cover solenoid 9 is turned off and the platen cover 9 is
Away from

Next, in step S119, the motor M2 is rotated forward and discharged to the paper discharge tray 21 (FIG. 5 (e) (f)).

It is also possible to lift the transport means 4 and the platen cover 5 and manually set the original on the open platen 2.

In this case, the transporting means 4 and the platen cover 5 can be lifted individually or can be lifted together.

 According to the above embodiment, the following effects can be obtained.

(1) In the case of a small-size document, after the image forming process is completed,
Since the original can be loaded and set only by sequentially feeding the original from the entrance 4a at one end thereof to the exit 4b at the other end by the transport means 4, the processing of a small-size original which is frequently used can be speeded up.

(2) The document is fed forward by the forward rotation of the conveying means 4, the leading edge of the document is brought out of the platen 2, and the trailing edge of the document is placed on the platen 2.
Then, the original is reversely fed by the reverse rotation of the conveying means 4 and inserted under the platen cover 5 and set, whereby even a large-sized original can be automatically fed.

(3) Since the document supply means 12 is disposed above the platen cover 5, the document supply means 12 and the paper feed tray 11 do not protrude from the image forming apparatus, and the apparatus can be downsized.

Note that the present invention is not limited to the above-described embodiment, and various other modifications are possible.

(1) In order to once take the leading end of a large-size document out of the platen, the leading end of the document is discharged into the document discharge path in the direction of the discharge tray in the above embodiment.

In addition, for example, as shown in FIG.
14 may be switched so that a double-sided image forming path in the direction of the platen 2 is formed, and the leading end side of the document may be discharged again toward the platen 2.

In addition, as shown in FIG. 8, a particularly provided document discharge gate 50 may be opened and the leading end side of the document may be discharged therefrom.

(2) In the above embodiment, the reading reference is set at one end of the platen (near the outlet of the transporting means). However, the reading reference is set at another position, for example, at the center of the platen (near the entrance of the transporting means). , The other end of the platen (position of the platen cover), or the like, or a plurality of places.

[Brief description of the drawings]

1 to 6 show an embodiment of the present invention. FIG. 1A is a longitudinal sectional view of the entire apparatus, and FIG. 1B is a view showing a drive system thereof. FIG. 2 is a plan view showing a drive system of the document supply means. FIG. 3 is a block diagram showing a control system. 4 (a) to 4 (e) are operation state diagrams showing the feeding of a small-size document. 5 (a) to 5 (f) are operation state diagrams showing the feeding of a large-size document. 6 (a) to 6 (c) are flowcharts showing the operation process of the device. 7 and 8 are partial views showing another embodiment. FIG. 9 shows a conventional example. 1: Image forming apparatus body, 2: Platen 3: Reading standard, 4: Transport means 4a: Inlet, 4b: Outlet 5: Platen cover, 9: Cover solenoid 11: Paper feed tray, 12: Document supply means 13: Ejection / reversal roller, 14: Switching gate 16: Gate solenoid M1, M: 2 motor 21: Ejection tray 50: Discharge gate

Claims (6)

(57) [Claims] 1. A document feeder disposed so as to cover at least a part of a platen and having a conveying means for conveying a document fed to the platen to a reference position on the platen, wherein the document is fed onto the platen. Detecting means for detecting the length of the original to be read, and when the original detected by the detecting means is a small size smaller than a predetermined length, the original is conveyed in the direction of one end of the platen to the reference position. Control means for controlling the transport means so as to stop the document and, in the case of a large size larger than a predetermined length, transport the document in both directions of one end and the other end of the platen and stop at the reference position. A document feeder comprising: 2. A platen cover, which is provided in parallel with said transport means and covers a portion other than a portion of said platen covered by said transport means, and feeds an original to said platen between said transport means and said platen cover. 2. The document feeder according to claim 1, wherein a document entrance for performing the document feeding is formed. 3. When the document is large, the control means conveys the document in the direction of one end of the platen, and then conveys the document in the direction of the other end of the platen. 3. The conveying means is controlled so that the sheet is introduced between the platen and the platen cover and stopped at the reference position. 4. The apparatus according to claim 1, wherein the control means conveys the document in the direction of one end of the platen until the leading end of the document reaches the reference position when the document is small, and at least feeds the document when the document is large. The document is conveyed in the direction of one end of the platen until the rear end in the feeding direction reaches on the platen, and then conveyed in the direction of the other end of the platen until the leading end of the document in the feeding direction reaches the reference position. 3. The document feeder according to claim 1, wherein the conveying unit is controlled. 5. The document feeder according to claim 3, wherein said reference position is set at one end of said platen. 6. The document conveying apparatus according to claim 1, wherein said conveying means has a conveying belt covering substantially half of one end of said platen.