JP2002265075A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of skewing when a document is delivered by a pickup roller due to contact of the pickup roller to the document caused by obliquely lowering in an automatic document reader. SOLUTION: Drive transmitting mechanisms 48, 49, 50 for driving the pickup roller 26 to rotate are disposed in the center in the axial direction of a separate roller 27, and a pair of pickup arms 45b, 45b supporting the pickup roller 26 are provided axially symmetrical about the drive transmitting mechanisms 48, 49, 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the configuration of a sheet feeding device provided in a facsimile, a copying machine, or the like.

[0002]

2. Description of the Related Art As a general configuration of a paper feeding unit of a conventionally known automatic document feeder (auto document feeder, abbreviated as "ADF") is generally used.
There is a type in which a separate roller is disposed on a drive shaft, a pickup arm is rotatably provided around the drive shaft, and a pickup roller is supported at the tip of the pickup arm. In this configuration, a gear provided on the drive shaft or a gear disposed on one side of the pickup arm and transmitting the drive from the gear to the pickup roller includes a friction member such as felt between the gear and the pickup arm. By interposing the friction member, frictional resistance can be given to the gear by the friction member.
In this configuration, when the sheet feeding operation is started, the drive shaft rotates. However, the gear provided with the friction member does not rotate until the load exceeds a predetermined load torque determined by the frictional resistance. The other gears revolve around, and the pickup arm rotates downward. As a result, the pickup roller is lowered so as to come into contact with the upper surface of the document bundle set in advance. Here, in the conventional sheet feeding device, the force for lowering the pickup roller is input from one side of the pickup arm.

[0003]

However, if a force for lowering the pickup roller is input from one side of the separate roller as in the prior art, the force for lowering the pickup roller is applied to the pickup roller. It is difficult to make it uniform in the axial direction of the roller. As a result, the axis of the pickup roller to be maintained parallel to the surface of the original is lowered while the axis of the pickup roller is inclined. Was gone. In addition, the force with which the pickup roller contacts and presses the document is unbalanced in which one side in the axial direction of the pickup roller is large and the other side is small. Such imbalance in the pressing force has caused skew when the document is fed.

[0004]

The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

That is, in the first aspect, a drive transmission mechanism for rotating and driving the pickup roller is disposed at the center in the axial direction of the separate roller, and a pair of pickup arms supporting the pickup roller are provided with the drive transmission mechanism. It is provided so as to be axially symmetric with respect to the center.

According to a second aspect of the present invention, each of the pair of pickup arms is provided with a spring for urging the pickup roller to move down.

In a third aspect, the pair of pickup arms are integrally formed.

[0008]

Next, embodiments of the present invention will be described. FIG. 1 is a perspective view showing a facsimile apparatus to which the sheet feeding device of the present invention is applied, and FIG. 2 is a front sectional view of the same. FIG. 3 is an enlarged front sectional view showing the configuration of the sheet feeding device and the reading device.

First, a schematic configuration of a facsimile apparatus to which the sheet feeding apparatus of the present invention is applied will be described with reference to FIGS. The facsimile apparatus F is configured by arranging a recording device 1, a reading device 2, and a transport device 30 in this order from the lower side to the upper side. As shown in FIG. 2, the recording device 1 is provided with a rotation fulcrum 20, and the reading device 2 is vertically rotatable about the rotation fulcrum 20 with respect to the recording device 1. The recording apparatus 1 has an image forming apparatus 3 and a paper feed cassette 4 which are respectively housed in the upper and lower sides. After the paper deposited in the paper feed cassette 4 is fed to the image forming apparatus 3 for recording, the recording paper is discharged. It is configured to discharge to the tray 5. In the following description, the arrow A shown in FIG. 1 and the like will be described as the front side (front side) of the facsimile machine F.

The reading device 2 comprises a document reading section 6 shown in FIG. 2 and a reading case 13 in which the document reading section 6 is housed. A transparent original mounting surface 14 is provided on the upper surface of the reading case 13 so that the original placed on the original mounting surface 14 can be seen through the original from below the original mounting surface 14. I have.

As shown in FIG. 3, the document reading section 6 includes an illumination device 35, a plurality of mirrors 36, 37, 38, 39, and an image receiving device 41. At the time of reading the original, the original reading unit 6 is moved in the left and right direction, and the original placed on the original placing surface 14 is irradiated with light from the illumination device 35 to reflect the reflected light from the original to the plurality of mirrors. 36 ・ 37
The light is reflected at 38 and 39 and is read by the image receiving device 41 via the image forming body 40. Above the reading case 13, a document holding cover 7 that can be opened and closed with one side thereof as a center is disposed, and the document holding cover 7 presses the document placed on the document placing surface 14 from above. I have to.

As shown in FIG. 1, a key panel 15 is attached to a front portion of the reading case 13, and by operating various operation keys of the key panel 15, the contents of the document are read or read. A destination for facsimile transmission of the content can be set, and the received content and the read content can be recorded by the image forming apparatus 3.

A document feeder 8 which is an automatic document feeder (ADF device) for automatically feeding a document is attached to one end of the document pressing cover 7, and a document is placed above the document pressing cover 7. A supply tray 9 is provided. The document holding cover 7, the sheet feeding device 8, and the document supply tray 9 constitute the transport device 30.

As shown in FIG. 1, left and right side frames 32 and 33 are provided at the inner and lower portions of the sheet feeding device 8, and a platen cover 34 for covering the sheet feeding device 8 is provided on both side frames. It is arranged between 32 and 33.
On the inner opening surfaces of the side frames 32 and 33 along the platen cover 34 side end, sheet metal side plates (not shown) are fixed in an upright state, respectively, and drive rollers (for example, drive rollers 23 described later) are fixed. A shaft end such as a drive shaft is supported. One or both of the document holding cover 7 and the side frames 32 and 33 cover the drive source of the drive roller and its transmission system, and the inner surface thereof is covered with the sheet metal side plate.

A paper feed port 8a is opened in the upper part on the right side of the paper feed device 8, and the document placed on the document feed tray 9 is supplied into the paper feed device 8 from the paper feed port 8a. Like that. A document discharge tray 7c is formed on the upper surface of the document pressing cover 7 so as to be continuous with a paper discharge port 8c disposed immediately below the paper feed port 8a. And paper feeder 8
A document transport path R is configured inside the paper feed port 8a to the paper discharge port 8c, and the document to be transported is read in the document reading section 6 in the middle of the transport path R as described later. It is made to be done by.

Sheet documents stacked on the document supply tray 9 are picked up one by one and supplied to a paper feed port 8a. An ADF reading surface 17 is provided on the upper surface of the reading case 13 to the left of the document placing surface 14. The reading is performed by the unit 6. At this time, the original reading unit 6 is configured to operate the original placing surface 1 described above.
Unlike the case where the original on the document 4 is read, the document is stationary at the standby position indicated by the solid line in FIG. The read document is discharged from the paper discharge port 8c onto the document discharge tray 7c.

The transport path R is substantially "U" as shown in FIG.
Rollers are arranged on both sides of the inside of the transport path R to enable the original to be transported. Document feed path R
Constitutes a document transport guide 42, on which a retard roller 21 and drive rollers 22, 23, 24 are arranged along a transport path R, and a press roller 25 is disposed near the paper discharge port 8c. ing. Outside the transport path R, a pickup roller 26 is located near the paper feed port 8a.
Is provided, and a separate roller 27 is provided so as to be in pressure contact with the retard roller 21.
· Press rollers 28, 29, 43 and drive roller 3 so as to contact with 23, 24 and the press roller 25.
1 is provided. The rollers described above are arranged in the order described above from upstream to downstream along the transport path R.

As will be described in detail later, the pickup roller 26 is configured to be driven in conjunction with the separate roller 27. The pickup roller 26 picks up the documents placed on the document supply tray 9 one by one.
The transfer is performed between the separate roller 27 and the retard roller 21. When a plurality of originals are conveyed by the pickup roller 26, the lower originals in contact with the retard roller 21 are reversely fed, and the plurality of originals are simultaneously transferred to the original reading unit 6. , And only the uppermost document is sent to the document reading unit 6. The effect of this separation is realized by making the friction coefficient between the retard roller 21 and the document larger than the friction coefficient between the documents.

Next, a description will be given of a structure for feeding a document by a pickup roller. FIG. 4 is a plan view showing the arrangement of the pickup roller and the separate roller in the sheet feeding device. FIG. FIG. 6 is a diagram showing a state in which the pickup roller is lowered from the state shown in FIG.

As shown in FIGS. 4 and 5, the separate roller 27 is fixed to a drive shaft 44, and the power of a motor (not shown) serving as a drive source is transmitted to the drive shaft 44. As shown in FIG. 4 which is a plan view, the separate roller 27 has a two-part configuration including a rear roller 27a and a front roller 27b, and the arm member 45 is positioned at a position between the two rollers 27a and 27b. The base 45a is connected to the drive shaft 4
4 is rotatably fitted to the outside. The arm member 4
5 is the base 45a and two pickup arms 45
The pickup arms 45b and 45b are integrally formed, and one of the pickup arms 45b and 45b is disposed on the back side and the other is disposed on the front side, and extends in the same direction toward the paper feed port 8a. A common pickup roller shaft 46 is disposed so as to penetrate the tip portions of the two pickup arms 45b. The pickup roller shaft 46 is rotatable. The center of the pickup roller shaft 46 is, as described above, the two pickup arms 45b and 45b.
b. The pickup roller 26 is, similarly to the separate roller 27, a rear roller 26.
a and a front roller 26b.
It is non-rotatably fixed to both ends of the pickup roller shaft 46, respectively.

A recess 45 is formed in the base 45a of the arm member 45 at the central position in the axial direction. A drive gear 48 is disposed inside the recess, and the drive gear 4
Numeral 8 is fixed to the drive shaft 44 so as not to rotate relatively.
An idle gear 49 is supported between the two pickup arms 45b. The idle gear 49 meshes with the drive gear 48. On the other hand, at a position sandwiched between the tip ends of the two pickup arms 45b and 45b, the driven gear 50 is fixed to the pickup roller shaft 46 so as not to rotate relatively, and the driven gear 50 meshes with the idle gear 49. Is done. These drive gears 48
The idle gear 49 and the driven gear 50 form a gear train as a drive transmission mechanism for transmitting a driving force to the pickup roller. However, the present invention is not limited to the configuration of the present embodiment in which the gear train is used. For example, a drive transmission mechanism using a belt may be provided instead.

As shown in FIG. 4, the gear trains 48, 49, and 50 are separate rollers 2 having a two-part structure.
7a and 27b, and separate roller 27a
27b is disposed at the axial center position.
Further, the two pickup arms 45b, 45b
Are arranged axially symmetrically about the gear trains 48, 49, 50. Further, the pickup rollers 26a and 26b having the two-part configuration are also provided with the gear trains 48 and 49
A pair is arranged so as to be axially symmetric with respect to 50. Thereby, the pickup arms 45b, 45b,
And pickup rollers 26a and 26 supported thereon
b moves straight up and down, and in particular, the pickup rollers 26a and 26b descend while keeping surely parallel to the surface of the document 55. Therefore, the pressure at which the pickup rollers 26a and 26b press the document 55 is uneven. Then, the pickup roller 26 is driven to drive the original 55
Skewing of the original 55 can be avoided when the repetition is performed. As described above, the pair of pickup arms 45b and 45b
Is integrally formed, the number of parts is reduced, and the manufacturing cost can be reduced.

The two pickup arms 45b and 4
In each of 5b, a concave portion 51 that releases upward is formed along the longitudinal direction. Each recess 51.5
1, biasing springs 52 are disposed, one end of which is engaged with an upper edge of a base 45 a of the arm member 45 (the base of the corresponding pickup arm 45 b), and the other end is fixed to the frame member 53 on the fixed side. Is locked to a locking portion 53a formed by bending. The biasing spring 52 constantly pulls the edge of the base 45a to rotate the arm member 45 downward and apply a biasing force in a direction to lower the pickup roller 26. Thus, the pair of pickup arms 45b / 4
5b, the urging springs 52, 52 are provided so that the urging springs 52, 52
, The force for lowering the pickup roller 26 is more reliably uniformized by the biasing spring 52, and the unevenness of the force by which the pickup roller 26 presses the document 55 is eliminated. It is possible to more reliably prevent the skew of the original when the document is fed by the pickup roller 26.

As shown in FIGS. 4 and 5, the tip of the push-up arm 57 is inserted between the tips of the two pickup arms 45b. As shown in FIG.
The push-up arm 57 is formed integrally with one end of a support shaft 58, and the support shaft 58 is rotatably supported by a side plate of the frame member 53. An input arm 59 projects downward from the other end of the support shaft 58, and the tip of the input arm 59 is connected to a movable portion of the solenoid 60. In this configuration, when the solenoid 60 is driven, the input arm 59 is pushed or stretched and the support shaft 58 is pushed.
Rotates, and the push-up arm 57 moves up or down.

On the other hand, as shown in FIGS. 4 and 5, a thin pressing piece 61 is bridged between the tip ends of the two pickup arms 45b so as to straddle the tip of the push-up arm 57. It is formed. In this configuration, at the time of starting document feeding, when the solenoid 60 is driven to lower the push-up arm 57, the arm member 45 to which the urging force of the urging springs 52 acts acts downward, and As shown in FIG. 6, the pickup roller 26 descends and comes into contact with the document 55. In this state, the drive shaft 4
When the drive roller 4 is driven, the driving force is transmitted to the drive gear 48 → the idle gear 49 → the pickup roller shaft 46, and the pickup roller 26 is rotationally driven to feed in the uppermost document 55, and between the separate roller 27 and the retard roller 21. Send to On the other hand, when the feeding of the original is completed, the solenoid 60 is driven to raise the push-up arm 57, and the tip of the push-up arm 57 contacts the lower surface of the pressing piece 61, and the urging springs 52. The arm member 45 is rotated upward against the urging force of
6 rises and returns to the state of FIG. Thus, a new document can be set.

As shown in FIG. 4, a shutter shaft 63 is rotatably supported in parallel with the support shaft 58.
A shutter 62 is formed integrally with the shutter 3. The shutter 62 is configured to move up and down in synchronization with the elevation of the push-up arm 57. Thereby, when the pickup roller 26 is raised, the shutter 6 is moved as shown in FIG.
2 descends to shut off the paper feed port 8a,
, And the leading ends of a plurality of originals 55 can be aligned and set. On the other hand, the pickup roller 2
When the shutter 6 is lowered, the shutter 62 rises and retracts, and as shown in FIG. 6, the sheet feeding port 8a is opened so that the original can be fed between the separate roller 27 and the retard roller 21.

As shown in FIG. 4, the space between the pickup roller 26a and the separation roller 27a provided on the back side and the space between the pickup roller 26b and the separation roller 27b provided on the front side are provided. And a guide member 54 are provided. The guide members 54 are formed of a smooth film and have a rectangular shape in a plan view, and are attached to the side portions of the pickup arms 45b so as to protrude. As shown in FIG. 5, the guide member 54 substantially covers the lower surface of the space, and has one end edge substantially along the lower surface of the circumferential surface of the separate roller 27.

With this configuration, even when the original 55 whose front end is curled upward is fed in, the front end 56 is guided by the guide member 54 so as not to enter the space between the pickup roller 26 and the separate roller 27. However, it is surely fed between the separate roller 27 and the retard roller 21. As described above, since the leading end 56 of the document is prevented from entering the space between the pickup roller 26 and the separate roller 27, the frequency of occurrence of a jam is reduced, and the stability of the sheet feeding operation is improved.

[0029]

The present invention is configured as described above.
The following effects are obtained.

That is, as set forth in claim 1, a drive transmission mechanism for rotationally driving the pickup roller is disposed at the center in the axial direction of the separate roller, and a pair of pickup arms supporting the pickup roller are connected to the drive transmission mechanism. Is provided so as to be axially symmetrical with respect to the center, so that the pickup roller descends straight while keeping parallel to the original, and can press and send the original with a uniform force. Therefore, skewing of the document can be prevented.

According to a second aspect of the present invention, the pair of pickup arms are provided with springs for urging the pickup roller to move down, respectively. , The pickup roller descends straight while keeping the original in parallel with the original, so that the original can be pressed and sent out with a uniform force. Therefore, skewing of the document can be prevented.

According to a third aspect of the present invention, since the pair of pickup arms are integrally formed, in addition to the effects of the first and second aspects, the number of parts is reduced, and manufacturing is simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a facsimile apparatus to which a sheet feeding device of the present invention is applied.

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

FIG. 3 is an enlarged front sectional view showing a configuration of a sheet feeding device and a reading device.

FIG. 4 is a plan view showing an arrangement configuration of a pickup roller and a separate roller in the sheet feeding device.

FIG. 5 is a partial sectional view of the same front view.

FIG. 6 shows a state in which the pickup roller descends from the state shown in FIG. 5,
FIG. 3 is a diagram illustrating a state where a document is fed.

[Explanation of symbols]

 26a / 26b Pickup roller 27a / 26b Separate roller 45b / 45b Pickup arm 48/49/50 Drive transmission mechanism 52 Bias spring

Claims (3)

[Claims] 1. A drive transmission mechanism for rotating and driving a pickup roller is disposed at an axial center of a separate roller, and a pair of pickup arms for supporting the pickup roller are axially symmetric about the drive transmission mechanism. A sheet feeding device characterized by being provided as described above. 2. The sheet feeding device according to claim 1, wherein the pair of pickup arms are provided with springs for urging the pickup roller to move down. 3. The sheet feeding device according to claim 1, wherein the pair of pickup arms are formed integrally.