JPH0649564Y2 - Automatic document feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic document feeder that can convey a document by document conveying means such as a so-called document conveying belt and stop the conveyed document at a predetermined position. This type of automatic document feeder is attached to an image forming apparatus such as a copying machine, a facsimile, a printer or the like.

2. Description of the Related Art In the above-described automatic document feeder, the document is stopped at a predetermined position by stopping the document transport belt, and the document is stopped at a predetermined position by a document stop member that can project into or retract from the document transport path. It is known that it is stopped at a position.

However, in the former belt stop type device, there is a drawback that a stop position is deviated between a thick document and a thin document. On the other hand, in the latter apparatus using the document stopping member, when a particularly thin document collides with the document stopping member, the leading end of the document may be broken or crushed, and the document may be damaged or misaligned. .

An object of the present invention is to provide an automatic document feeder capable of reliably stopping a thick document or a thin document at a predetermined position.

The present invention is an automatic document feeder for stopping a document transported by a document transporting unit at a predetermined position, and a document identifying unit for determining the thickness of the document and thinning the document at the predetermined position. And a document stop member that is movable to a projecting position projecting from the contact glass upper surface of the image forming apparatus to which the automatic document feeder is mounted and a retracted position retracted from the contact glass upper surface. The document is stopped at the predetermined position by stopping the document conveying means in a state where the document stop member is moved to the retracted position according to the result of the document thickness identification by the document identifying means. Automatic document conveyance, characterized by selecting whether the document is stopped or the document is stopped at the predetermined position by the document stop member moved to the protruding position. It is a device.

Hereinafter, the present invention will be described based on examples.

FIG. 1 is a side sectional view of an embodiment. The automatic document feeder according to this embodiment is attached to an upper part of the copying machine 1 and conveys a document to a predetermined position on a document placing glass, which is a contact glass 2 provided on the upper surface of the copying machine 1. ,
At a predetermined position, the original document is temporarily stopped and subjected to a predetermined copying process (image exposure process), and then a series of original document carrying processes such as further carrying the original document to the outside are performed.

The originals 4 to be conveyed are stacked on the original table 3 and inserted until their tips are detected by the set sensor 8. A calling roller 7 and a calling roller 5 are arranged on the right side of the set sensor 8. Manuscript table 3
A separation roller 25 and a pull-out roller 10 which are coaxially attached to each other are arranged at the left end of the. The calling roller 5 and the separation roller 25 (pull-out roller 10) are connected to a drive source (not shown) via a sheet feeding solenoid 125, and rotate when the sheet feeding solenoid 125 is in the ON state, respectively, in the counterclockwise direction in the figure. The calling roller 7 is connected to an elevating mechanism (not shown) via a calling solenoid 107, and is positioned apart from the calling roller 5 as indicated by a solid line when the calling solenoid 107 is in the OFF state, while the calling solenoid 10 is connected.
When 7 is in the ON state, it contacts the calling roller 5 as shown by the broken line.
As described above, when the document stack 4 is inserted up to the set sensor 8, the calling roller 7 is placed at the solid line position.

Above the separation roller 25 and the calling roller 5, a separation belt holder 30 is detachably attached to the cover 6 of the automatic document feeder. One end of the separation belt 29 is connected to the right end of the separation belt holder 30 via a spring 28, and the other end of the separation belt 29 is fixed to the left end of the separation belt holder 30. The lower surface of the separation belt 29 contacts the peripheral surface of the separation roller 25, and a pressing roller 31 is provided on the back surface (upper surface) of the separation belt 29.
The separating belt 29 is pressed downward by. By the separation roller 25 and the separation belt 29 that contacts the separation roller 25, only the lowest one of the document bundle 4 is further folded forward (to the left in the drawing). At this time, the document is guided by the guide ribs 11. The guide rib 11 is divided into two parts on the right and left sides (the back side and the front side in the drawing) with respect to the document conveying direction with the separation belt 29 interposed therebetween, and each is fixed by a screw (not shown). The position of these guide ribs can be adjusted within a certain range by adjusting the screw fixing.

One original sent out from the separation roller 25 is conveyed downward while being reversed by the pull alt roller 10 and the driven roller 12 that abuts on it, and is guided along the guide plate 18 to the original conveying belt 22 as original conveying means. Is sent. A registration sensor 20 is arranged on the way.

The document conveying belt 22 includes a driving roller 21 and a belt fixing roller.
41, a plurality of (four in the figure) belt pressure rollers 42, auxiliary rollers 55, and tension rollers 43. The drive roller 21 is rotationally driven in the clockwise and counterclockwise directions by the motor M1. Depending on the rotation of the drive roller 21,
The document conveying belt 22 rotates in the direction of arrow C or E while being pressed against the contact glass 2 by the belt pressure roller 42. Due to this circumferential movement, the document is conveyed on the contact glass 2 in the left-right direction in the drawing. Tension roller
A pressure spring (not shown) is attached to 43, and is biased in the direction of arrow D. This allows the document transport belt
Tension is applied to 22. The motor M1 generates an encoder pulse P for controlling document conveyance.

On the right side of the contact glass 2, a stopper claw 44 as a document stopping member rotatable about a support shaft 54 is provided. A stop solenoid 144 is connected to the stopper claw 44, and when the stop solenoid 144 is in the OFF state, the left end thereof projects above the contact glass 2, that is, the original conveying path as shown by the solid line, while the stop solenoid 144 is on the other hand. When 144 is in the ON state, the left end thereof is below the contact glass 2, that is, retracted from the document conveying path as indicated by the chain line.

When the stop claw 44 is in the protruding position (solid line), the document conveyed in the C direction (right direction) by the document conveying belt 22 stops at its leading end (right end) hitting the left end of the stop claw 44. As a result, the contact glass 2 is placed at a predetermined position. Predetermined copy processing by the copying machine 1 on the original document in this state (in particular, original document proof processing for image exposure)
Is performed. Since various kinds of equipment necessary for the copying process such as document illumination which should be provided in the copying machine 1 can be conventionally known ones, description thereof will be omitted. When the stop claw 44 is at the retracted position (chain line), the document conveyed in the C direction by the document conveying belt 22 passes between the stop claw 44 and the branch guide plate 45 and is further conveyed to the right.

A pull-out roller 46 that rotates counterclockwise, a conventional roller 47 that contacts the pull-out roller 46, and a guide plate 49 that guides the document are provided on the upper right side of the stop claw 44. To the left of the pull-out roller 46, the deflection solenoid 150
Deflection claws 50 are provided whose positions are switched by the FF between a chain line position and a solid line position. By rotating the deflection claw 50 about the support shaft 51, the position is switched between the above two positions.

When the deflecting claw 50 is at the retracted position (solid line), the document fed by the pull-out roller 46 passes over the deflecting claw 50, and is discharged by the sheet discharge roller 52 and the sheet discharge roller 53 that abuts the arrow F. As described above, the sheet is discharged to the original stack portion formed on the upper surface of the cover 6. When the deflecting claw 50 is in the projecting position (chain line), the document sent by the pull-out roller 46 passes between the lower side of the deflecting claw 50 and the branch guide plate 45 and is again sent to the document conveying belt 22. To be By being conveyed around the pull-out roller 46, the original re-fed to the original conveying belt 22 is turned upside down.

FIG. 2 shows a block diagram of a control system of the automatic document feeder of FIG. The main control board 200 arranged at a predetermined position in the automatic document feeder includes a CPU, an IC around the CPU, an input circuit for I / O, and a drive circuit. The main control board 200 is connected to the copying machine 1 via a serial line 201, and signals are exchanged with the copying machine 1 via this. Original detection signals from the set sensor 8, the registration sensor 20, the paper discharge sensor 48, etc. are input to the main control plate 200. The operation display panel (not shown) of the automatic document feeder of FIG. 1 is provided with a document thickness selection switch and a mode selection switch in advance, and the document thickness information and the document transportation mode from these switches are provided. Information is entered into the main control board 200. Reference numeral 202 in FIG.
Reference numeral 203 denotes a document thickness selection switch, and reference numeral 203 denotes a mode selection switch. In the case of the embodiment, the operator can select either the thick original or the thin original by the original thickness selection switch. When the original on the original table 3 is thick, the thick original and the original are selected. If is thin, select the thinner one. Main control board 20
0 is the calling solenoid 107, the paper feeding solenoid 125,
The output devices such as the stop solenoid 144, the reversing solenoid 150, the belt drive motor M1, and the paper discharge motor M2 that drives and rotates the pullout roller 46 are driven. The encoder pulse P from the belt drive motor M1 is the main control board 200.
Entered in.

The CPU in the main control board 200 conveys a document according to four types of document conveyance modes, which are a single-sided document abutting mode, a single-sided document non-abutting mode, a double-sided document abutting mode, and a double-sided document non-abutting mode.

Single-sided original abutment mode This is a mode in which an original having an image on one side is abutted against the stop claw 44 and stopped at a predetermined position. In this mode, the single-sided original mode is selected by the mode selection switch 203 (FIG. 2), and the original thickness selection switch 202
This is executed when "thick original" is selected by (FIG. 2).

The document conveying process in this mode will be described below with reference to the flowchart shown in FIG. 3 and the timing chart shown in FIG.

(1) In FIG. 1, first, the document stack 4 is placed on the document table 3 with the image surface facing upward, and is inserted until the leading end of the document stack 3 is detected by the set sensor 8.

(2) A print key (not shown) provided at a predetermined position of the copying machine 1 is turned on by the operator.

(3) The call solenoid 107 is turned on, whereby the call roller 7 is lowered to the position of the broken line and presses the leading end of the document stack 4.

(4) The paper feeding solenoid 125 is turned on, and the calling roller 5
The pull-out roller 10 and the separation roller 25 rotate counterclockwise. As a result, the lower several sheets of the document stack 4 (only the lowermost sheet in some cases) are fed in the direction of the arrow A, and only the lowermost sheet of them is separated by the separation roller 25 and the separation belt 29.
Separated from other documents by the pull-out roller
It is sent in the direction of arrow B by 10 and driven roller 12.

At this time, the motor M1 is started and the document conveying belt 22 is rotated in the C direction.

(5) When the set sensor 20 detects the leading edge of the document, the call solenoid 107 is turned off and the call roller 7 is lifted to the solid line position. Further, the paper feeding solenoid 125 is turned off, and the calling roller 5, the separation roller 25, and the pullout roller
10 rotations stop.

At this time, a timer provided in the main control board 200 counts time, and counting of pulses from the motor M1 is started.

(6) The original that has reached the original conveying belt 22 is conveyed rightward on the contact glass 2 by the belt 22 that rotates in the C direction.

(7) At this time, the document is conveyed with the leading edge of the document slightly exceeding the reference position X as a target. This conveyance amount is determined by the number of pulses after the registration sensor 20 detects the leading edge of the document. This carry amount can be adjusted by the volume.

(8) The one-sided original abutting mode is being performed now, and since the original thickness selection switch 202 (FIG. 2) is set to "thick original", the stop solenoid 144
Remains in the OFF state, so that the stop claw 44 is in the protruding position (solid line). Therefore, the document transported on the contact glass 2 by the document transport belt 22 should be stopped by the stop claw.
It hits the left end of 44 and stops in place.

(9) After the image exposure operation by the copying machine 1 is completed, the document is returned by the document transport belt 22 in the direction of arrow E by a predetermined amount.

(10) The stop solenoid 144 is turned on, and the stop claw 44 rotates to the retracted position (chain line).

(11) The document transport belt 22 starts to rotate in the C direction again, and the document is transported again in the C direction. The document thus conveyed is guided to the stop claw 44 and the reversing guide 49, and then conveyed to the deflecting claw 50 by the pull-out roller 46 and the driven roller 47 contacting the pull-out roller 46. Output sensor 48
When the leading edge of the conveyed document is detected, the stop solenoid 144 is turned off and the stop claw 44 moves to the projecting position (solid line).

(12) In the single-sided original mode, the deflection solenoid 150 is in the OFF state, and the deflection claw 50 is in the solid line position in the figure. Therefore, the document is guided by the deflecting claw 50, and the discharge roller 52 and the discharge roller are
It is discharged by 53 as shown by arrow F.

(13) The above operation is repeated for the predetermined number of copies, and the operation ends.

Single-sided original non-abutting mode This is a mode in which an original having an image on one side is stopped at a predetermined position without abutting against the stop pawl 44.
This mode is executed when the single-sided original mode is selected by the mode selection switch 203 (Fig. 2) and "thin original" is selected by the original thickness selection switch 202 (Fig. 2).

(1) First, (1) in the above-mentioned single-sided document abutting mode
The processes (6) to (6) are executed.

(2) After that, the document is conveyed with the aim that the leading edge of the document exactly matches the reference position X. The original conveyance amount at this time is also determined by the number of pulses after the registration sensor 20 detects the front end of the original. Between the time when the registration sensor 20 detects the leading edge of the document and the time when the document is conveyed to the reference position X, the stop solenoid 144 is turned on and the stop claw 44 moves to the retracted position (chain line).

(3) The document is transported by the document transport belt 22 by a predetermined amount, and is stopped when the leading end of the document reaches the reference position X. After the document is stopped, the stop claw 44 moves to the protruding position (solid line).

(4) After that, the processes (9) to (13) in the single-sided original abutting mode are executed.

Double-sided original contact mode This is a mode in which an original having images on both sides is abutted against the stop claw 44 and stopped at a predetermined position. In this mode, the double-sided original mode is selected by the mode selection switch 203 (FIG. 2), and the original thickness selection switch 202
This is executed when "thick original" is selected by (FIG. 2).

(1) First, (1) in the above-mentioned single-sided document abutting mode
The processes (6) to (6) are executed.

(2) The stop claw 44 is provided between when the registration sensor 20 detects the leading edge of the document and when it is conveyed to the reference position X.
Moves to the retracted position (chain line). Therefore, the document conveyed to the contact glass 2 is not stopped and is conveyed in the direction C as it is to the discharge unit (pullout roller 46, discharge roller 52,
It is led to the paper discharge roller 53).

(3) The document is guided to the stop claw 44 and the guide plate 49, and is conveyed to the deflecting claw 50 by the pull-out roller 46 and the driven roller 47. When the discharge sensor 48 detects the leading edge of the document, the stop claw 44 moves to the protruding position (solid line).

(4) In the double-sided original mode, the deflection solenoid 150 is turned on.
In this state, the deflecting claw 50 has moved to the deflecting position (chain line). Therefore, the document is guided in the direction of arrow H by being guided by the deflecting claw 50 and the branch guide 45. After a lapse of a predetermined time after the document passes, the deflecting claw 50 moves to the retracted position (solid line) again.

(5) After a lapse of a predetermined time after the paper ejection sensor 48 detects the leading edge of the document, the circumferential direction of the document transport belt 22 is switched from the C direction to the E direction. Therefore, the original that has passed through the branch guide 45 is gripped by the original conveying belt 22 with its front and back reversed and conveyed in the E direction.

(6) After that, the document is conveyed with its rear end (the right end in FIG. 1) slightly exceeding the reference position X as a target. The original conveyance amount at this time is determined by the number of pulses after the discharge sensor 48 detects the rear end of the original.

(7) When the trailing edge of the original document exceeds the reference position X by a predetermined amount, the circumferential direction of the original document transport belt 22 is switched from the E direction to the C direction, and accordingly, the original document is fed backward in the C direction. Then, the document hits the stop claw 44 and stops at a predetermined position where the tip of the document matches the reference position X. At this time, the rotation of the document transport belt 22 also stops.

(8) After that, the same processes as (9) to (11) in the single-sided original abutting mode are executed.

(9) After that, the same processes as (4) to (8) in the double-sided document abutting mode are repeated.

(10) The deflecting claw 50 is moved to the retracted position (solid line) at an appropriate timing during the process of (9), and the document on which the front and back surfaces have undergone the image exposure process is discharged to the outside as indicated by arrow F.

(11) The above operation is repeated for a predetermined number of copies to complete the operation.

Double-sided document non-abutting mode This is a mode in which a document having images on both sides is stopped at a predetermined position without hitting the stop claw 44.
This mode is executed when the double-sided original mode is selected by the mode selection switch 203 (Fig. 2) and "thin original" is selected by the original thickness selection switch 202 (Fig. 2).

(1) First, (1) in the double-sided document abutting mode described above.
The processes (6) to (6) are executed.

(2) After that, the document is conveyed with the target that the rear end of the document matches the reference position X. The original conveyance amount at this time is also determined by the number of pulses after the discharge sensor 48 detects the rear end of the original. As a result, when the document transport belt 22 stops, the document stops at a predetermined position (the position where the trailing edge of the document matches the reference position X).

(3) After that, the processes (9) to (11) in the single-sided document abutting mode are executed.

(4) After that, (4) in the double-sided collision mode described above.
And the processes of (5) are executed.

(5) After that, the process of (2) in the double-sided non-abutting mode is repeated.

(6) After that, the processes (9) to (11) in the single-sided original abutting mode are repeated.

(7) The deflecting claw 50 is moved to the retracted position (solid line) at an appropriate timing during the process of (6) above, and the document subjected to the image exposure processing on both front and back surfaces is discharged to the outside as shown by arrow F.

(8) The above operation is repeated for a predetermined number of copies to complete the operation.

As can be understood from the above description, in the present embodiment, the stop pawl 44 is used to reliably stop the original for thick originals, while the original conveying belt 22 is stopped for the thin original without using the stop pawl 44. Stops the document without damaging it.

In the above description, the abutting mode and the non-abutting mode are selectively used between the thick original and the thin original even in the reverse conveyance mode for the double-sided original. However, the present invention is not limited to this, and the non-abutting mode may not be adopted in the reverse conveyance mode for a double-sided original, and the abutting mode may be programmed to be always selected. This is because a double-sided document is generally thick paper and is rarely thin paper. If it is thin paper, the images on the front and back will be seen through each other, and there is a strong possibility that it will be meaningless as a double-sided original.

Advantageous Effects According to the present invention, it is possible to reliably stop a thick document or a thin document at a predetermined position.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment, FIG. 2 is a control block diagram, FIG. 3 is a control flowchart, and FIG. 4 is a timing chart. 22 ... Original conveying means, 4 ... Original, 202,200 ... Original identifying means, 44 ... Original stop member

Front page continued (72) Inventor Takashi Taruki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Koichi Tsunoda 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Goro Mori 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (56) Reference JP 60-232355 (JP, A) JP 60-55332 (JP, A) )

Claims (1)

[Scope of utility model registration request] 1. An automatic document feeder for stopping a document transported by a document transporting device at a predetermined position, and a document identifying device for determining the thickness of the document and stopping the document at the predetermined position. And a document stop member that is movable to a protruding position protruding from the contact glass upper surface of the image forming apparatus to which the automatic document feeder is mounted and a retracted position retracted from the contact glass upper surface. Whether the document is stopped at the predetermined position by stopping the document conveying means in a state where the document stop member is moved to the retracted position according to the result of the document thickness identification by the document identifying means. Alternatively, it is selected whether the document is stopped at the predetermined position by the document stop member moved to the projecting position. Location.