JP2000136043A - Sheet material carrier device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet material carrier device which does not generate abnormal sound, even when any kind of paper is used. SOLUTION: A silicone rubber separating pad 35 is tightened with a machine screw at a base end part and is made in press-contact with a rubber separating roller 36. On a back face of the separating pad 35, a pad pushing down member 34 made of a plate spring is provided and the separating pad 35 is pushed down to the separating roller 36 side. A contact part with document paper of the separating pad 35 is formed into a gradually narrowing shape so that the contact width from a press-contact location toward a tip location may be from a full width W1 of the separating pad 35 to a width W2 of about 1/4 of W1. Further, the separating pad 35 performs support so as to be freely oscillatable in the directions of arrows A, B by making the base end part as a support point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading device for reading an image on an original sheet or an image forming apparatus for forming an image on a recording material. It belongs to the technical field of equipment.

[0002]

2. Description of the Related Art In recent years, as an image forming apparatus having a reading device, for example, a copy machine, a facsimile,
Multifunctional peripheral devices having various functions such as a printer function and a copy function have been developed. For multifunction peripherals,
For example, a contact image sensor (hereinafter referred to as CIS (Contac
t Image Sensor) and a laser printer as a printing device for forming an image on recording paper (printing paper). Then, printing is performed by the laser printer based on the image data of the document paper read by the reading device and the image data supplied from the host device such as the host computer. The laser printer of the multifunctional peripheral device has a mechanism for forming a toner image on a photosensitive drum by an electrophotographic process, and transferring and fixing the toner image on recording paper.

In the multifunctional peripheral device having such a configuration, it is important to smoothly transport the original paper and the recording paper in order to form a good image, and a plurality of original papers and the recording paper are continuously printed. It is indispensable to improve the ease of use of the apparatus by continuously transporting the image and continuously reading and recording the image.

For example, at the rear of the main body case of a multi-function peripheral device, that is, upstream of the main body case in the paper feeding direction, recording paper such as an ACF (Auto Cutsheet Feeder) is supplied to a laser printer. A paper feeding device is provided, a laser printer is provided downstream of the paper feeding device, and a reading device capable of continuously reading a plurality of original sheets is provided further downstream of the laser printer. Has been established.

In this reading apparatus, it is necessary to prevent a so-called double feed in which a plurality of original sheets or recording sheets are conveyed in an overlapping state. Therefore, the following sheet material conveying apparatus is provided. I have.

[0006] This conventional sheet conveying apparatus is composed of a paper feed roller for conveying paper such as recording paper and manuscript paper and silicon rubber of 3 x 2 cm square provided at a position facing the paper feed roller. A formed separation piece is provided, and the separation piece is urged by a pressure spring so as to sandwich the paper between the separation piece and the paper feed roller, and the frictional resistance between the separation piece and the paper is used.
It is configured to convey only the paper that has contacted the paper feed roller.

[0007]

However, according to the above-described conventional sheet conveying apparatus, depending on the type of paper used, self-excited vibration occurs due to friction between the separation piece and the paper at the leading end of the separation piece. Then, the vibration causes the housing of the laser printer to resonate, causing a problem that an abnormal sound is generated when the paper is conveyed.

Although the abnormal sound is not so loud in terms of sound volume, it may cause discomfort to the operator of the laser printer and those around him or may misunderstand that the laser printer has failed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a sheet conveying apparatus which does not generate an abnormal sound even when any kind of paper is used. I have.

[0010]

According to a first aspect of the present invention, there is provided a sheet conveying apparatus comprising: a conveying unit; and a separating piece urged toward the conveying unit by an urging unit. A sheet material transporting device that separates and transports only the sheet material that comes into contact with the transport means from a plurality of sheet materials, wherein the transport means has at least a front surface of the document sheet P that comes into contact with the sheet material. The separation piece is endlessly movable, and the separation piece is an elastic piece whose base end is supported such that its free end forms a contact part that makes elastic contact with the sheet material. The contact width with respect to the sheet material between the pressure contact position where the sheet material contacts the sheet material at a predetermined width and the sheet material is sandwiched between the surface portion of the conveying means and the leading end position of the separation piece, Gradually narrows toward the tip position Characterized in that it has a composed shape.

According to the first aspect of the present invention, when the driving of the conveying means is started, at least the surface of the conveying means which comes into contact with the sheet material moves endlessly, and conveys the sheet material. However, due to the separation pieces urged toward the conveyance means side by the urging means, sheet materials other than the sheet material contacting the conveyance means are prevented from being conveyed, and only the sheet material contacting the conveyance means is separated from the separation piece. It passes through a pressure contact portion between the conveying means. Therefore, this sheet material comes into sliding contact with the separation piece from the front end to the rear end of the sheet material. here,
Since the separation piece of the present invention has a shape in which the contact width with the sheet material gradually narrows toward the front end position between the position of the press contact portion and the front end position of the separation piece. The contact pressure on the sheet material at the front end position is significantly reduced as compared with a conventional separation piece having the same contact width at the front end position as the contact width at the press-contact position and having a corner formed at the front end. Therefore, conventionally, even when a sheet material that does not move smoothly due to frictional resistance between the separation piece and a large self-excited vibration is generated in the separation piece composed of the elastic piece is used, the present invention The contact of the separation piece with the sheet material becomes relatively smooth, and self-excited vibration is reduced. Moreover, the contact portion of the separation piece with the sheet material is
As described above, in order to gradually narrow the contact width from the pressure contact position toward the distal end position, compared to a conventional separation piece in which the pressure contact position and the distal end position substantially coincide with each other,
The contact portion from the press contact position to the tip position forms a sufficiently long free end, and even if self-excited vibration occurs as described above, the self-excited vibration is attenuated.
As described above, according to the present invention, occurrence of self-excited vibration of the separation piece is reliably suppressed, and abnormal noise is not generated through a frame or the like on which the separation piece is supported.

According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the sheet material transporting apparatus according to the first aspect, the contact portion of the separation piece has a rectangular shape in plan view. It is characterized in that it has a shape in which the tip corner is cut off with a straight line.

According to the second aspect of the present invention, in the contact portion of the separation piece, a rectangular tip corner is cut off in a straight line in a plan view, so that the contact pressure on the sheet material can be reduced. It is planned. Therefore, the contact of the separation piece with the sheet material becomes relatively smooth, and the above-described self-excited vibration is reduced.

According to a third aspect of the present invention, there is provided a sheet material conveying apparatus according to the first aspect, wherein the contact portion of the separation piece has a rectangular shape in plan view. It is characterized in that it has a shape in which a corner of the tip is cut off with a curve.

According to the third aspect of the present invention, the contact portion of the separation piece has a rectangular tip corner cut off in a curve in a plan view, so that the contact pressure on the sheet material can be reduced. It is planned. Therefore, the contact of the separation piece with the sheet material becomes relatively smooth, and the above-described self-excited vibration is reduced.

According to a fourth aspect of the present invention, there is provided a sheet material conveying apparatus according to any one of the first to third aspects, wherein the separation piece is made of silicone rubber. Characterized by being formed from

According to the fourth aspect of the present invention, since the separation piece is formed of silicon rubber, the separation piece comes into contact with the sheet material with an appropriate frictional force, so that a predetermined separation performance can be obtained. As well as exerting a suitable smoothness on the sheet material, the self-excited vibration is reduced as described above.

According to a fifth aspect of the present invention, there is provided a sheet material transporting apparatus as set forth in any one of the first to fourth aspects, wherein the contact of the separation piece is achieved. A film material is stuck on the surface other than the part.

According to a fifth aspect of the present invention, a film material is attached to a surface of the separation piece other than the contact portion, for example, a back surface opposite to a contact surface with the sheet material. So, without changing the thickness of the separation piece,
The rigidity of the entire separation piece can be changed. As a result, since the separating piece maintains a predetermined elastic force, the separating performance of the sheet material does not decrease, and the natural frequency of the entire separating piece changes, so that the above-described abnormal sound is not generated.

According to a sixth aspect of the present invention, in order to solve the above-mentioned problem, in the sheet material transporting apparatus according to the fifth aspect, the film material contacts the separation piece with the sheet material. It is characterized in that it is attached to the back surface opposite to the surface.

According to the sheet material conveying apparatus of the sixth aspect, the film material is attached to the back surface of the separation piece opposite to the contact surface with the sheet material. By avoiding the contact with the film material and preventing the separation performance of the separation piece from the sheet material from deteriorating, the natural frequency of the entire separation piece is changed to prevent the occurrence of the abnormal sound.

According to a seventh aspect of the present invention, in order to solve the above-mentioned problem, in the sheet material transporting apparatus according to the fifth or sixth aspect, the film material is made of PE.
T.

According to the sheet conveying apparatus of the seventh aspect, since the film material is PET, it can be formed extremely thin with respect to the thickness of the separation piece, and the entire separation piece can be formed without changing the thickness of the separation piece. Can change the rigidity. As a result, since the separating piece maintains a predetermined elastic force, the separating performance of the sheet material does not decrease, and the natural frequency of the entire separating piece changes, so that the above-described abnormal sound is not generated.

According to an eighth aspect of the present invention, there is provided a sheet material transporting apparatus according to any one of the first to seventh aspects, wherein the separation piece is formed of the material. The free end is mounted and supported so as to be swingable with the base end as a fulcrum.

According to the sheet conveying apparatus of the eighth aspect, the separation piece has the base end mounted and supported on a frame or the like, and the free end swings about the base end as a fulcrum. It is mounted and supported movably. As a result, the contact pressure of the contact portion of the separation piece is not uniform with respect to the sheet material due to a shift in the conveyance direction of the sheet material or a shift at the time of assembling the separation piece, and the frictional force on the contact portion is locally reduced. Even if the size increases, the separation piece is swingable as described above, so that the separation piece swings in a direction in which the force applied to the contact portion can be balanced, and the contact pressure on the sheet material is uniform. To Since the load from the sheet material on the separation piece is not concentrated in this way, the occurrence of self-excited vibration is suppressed.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a laser printer 1 with a reading device as a multifunctional peripheral device as an embodiment of an image forming apparatus provided with the reading device of the present invention.
FIG. 2 is a side sectional view schematically showing the internal structure of FIG. 1, wherein an arrow X in the figure indicates a feeding direction of a document sheet P, and an arrow Y indicates a feeding direction of a printing sheet (recording sheet) PP. I have.

The laser printer 1 with a reading device mainly includes a paper feeding device 2 for feeding a plurality of printing papers PP one by one, and a printing paper PP fed by the paper feeding device 2.
A recording device 3 for forming and transferring a toner image on the photosensitive drum 15 by an electrophotographic process, and the recording device 3
A laser beam scanning device 4 for performing exposure to form an electrostatic latent image on the surface of the photosensitive drum 15 and a fixing device 5 for fixing the toner image transferred by the recording device 3 to the printing paper PP. An image reading device 6 is provided for reading, from the original paper P, an image copied (copied) to the paper PP or an image transmitted to a host device such as a host computer.

The laser printer 1 with a reading device includes a main body case 1a formed of a synthetic resin in a box shape so as to enclose the outer periphery thereof, and a main frame 1b further housed inside the main body case 1a. The main body case 1a and the main frame 1b are integrally formed by injection molding or the like. On top of the main frame 1b of the main body case 1a, a top cover 1c made of synthetic resin that covers the upper part of the main frame 1b is covered. The top cover 1c is a lid of the main body case 1a which is opened when the recording device 3 is replaced or when the printing paper PP is jammed. It is rotatably attached to the front part (the right side in FIG. 1) of the main body case 1a in the clockwise direction. That is, the top cover 1
c is opened by being rotated clockwise via the rotating shaft 1d, and is closed by being rotated counterclockwise. A paper feeder 2 that feeds a plurality of printing papers PP stored one by one is provided behind the top cover 1c (left side in FIG. 1) and above the rear part of the main body case 1a.

The paper feeder 2 has a shallow box-shaped print paper holder 7 capable of stacking and storing a plurality of unused print papers PP. The print paper holder 7 is further rearward from the rear of the main body case 1a. (Left side in FIG. 1) Extends upward. The upper part of the print paper holder 7 is formed open, and a paper feed port cover 8 on which the image reading device 6 is mounted is openably and closably provided above the open part.
The details of the image reading device 6 mounted on the paper feed port cover 8 will be described later.

Inside the printing paper holder 7 covered by the paper feeding port cover 8, there is provided a substantially flat pressure plate 9 inclined from the rear of the main body case 1a toward the rear upper side. The pressure plate 9 is for supporting the printing paper PP from below, and sandwiches both sides of the printing paper PP in the paper width direction between both sides in the paper width direction (a direction substantially perpendicular to the paper surface of FIG. 1). In this manner, the pair of substantially flat side plates 9a are erected toward the lower surface of the paper feed port cover 8, respectively. The upper end of the side plate 9a is rotatably (swingably) attached to the printing paper holder 7 via a rotation shaft 9b, and the pressure plate 9 is connected to the printing paper holder 7 via the rotation shaft 9b and the side plate 9a. It is swingably mounted inside.

A spring member 10 composed of a coil spring is disposed on the lower end side of the pressure plate 9, that is, on the opposite side (right side in FIG. 1) of the pressure plate 9 from the side on which the rotary shaft 9b is mounted. The spring member 10 is for urging the pressure plate 9 upward, and the lower surface of the pressure plate 9 and the bottom plate 7 of the printing paper holder 7 are provided.
a. Therefore, the spring member 10
As a result, the pressure plate 9 is urged upward, and the printing paper PP supported by the pressure plate 9 is urged in a direction in which the printing paper PP comes into close contact with the paper feed roller 11. The paper feed roller 11 is a roller member for feeding the printing paper PP supported by the pressure plate 9, and is rotatably supported by the main body case 1a in a counterclockwise direction.

An operating plate 9c is integrally formed at the lower end of the side plate 9a of the pressure plate 9, and a bottom plate 7 of the printing paper holder 7 is formed on a lower surface of the paper feed port cover 8 adjacent to the operating plate 9c.
The pressing plate 8a extending toward "a" is integrally formed. Below the feed roller 11, the feed roller 1 described above is provided.
1, a separation pad 12 is provided for separating a plurality of printing papers PP one by one. The printing paper PP in the printing paper holder 7 is fed by the paper feed roller 11 and the separation pad 1.
2, the printing paper PP is sequentially sent out from the uppermost stacked printing paper PP. The printing paper PP sent out by the automatic paper feeding device is sent to the recording device 3 by a pair of upper and lower registration rollers 13 and 14. The printing paper P is fed by the feed roller 11 and the separation pad 12.
A paper feed port 2a for feeding P to the recording device 3 is configured.

The recording device 3 is a device for visualizing a print image based on image data on a print sheet PP. The recording device 3 includes a process cartridge 3a made of a synthetic resin detachably formed in the main frame 1b.
In the process cartridge 3a, the photosensitive drum 1 is provided.
5, transfer roller 16, developing roller 17, supply roller 1
8, a cleaning roller 19, a scorotron type charger 20, a toner cartridge 21 and the like are provided.
As described above, the recording device 3 is housed in the process cartridge 3a to be formed into a cartridge.
Can be replaced integrally, and maintenance work can be simplified. Further, since the toner cartridge 21 is detachably formed in the process cartridge 3a, when the toner in the toner cartridge 21 runs out, the process cartridge 3a can be taken out and only the toner cartridge 21 can be replaced. Therefore, even if the toner runs out before the end of the life of the recording device 3, it is sufficient to supply the toner to the toner cartridge 21, and it is not necessary to replace the entire recording device 3, so that the running cost of the laser printer 1 with the reading device is reduced. Can be reduced.

The photosensitive drum 15 provided in the process cartridge 3a is supported by the process cartridge 3a so as to be rotatable clockwise, and a charger 20 is arranged below the photosensitive drum 15. On one side of the photosensitive drum 15 and downstream of the charger 20 in the rotation direction of the photosensitive drum 15 (left side in FIG. 1), the developing roller 1
7 and a supply roller 18 are provided. Further, on one side of the supply roller 18 and opposite to the photosensitive drum 15 (left side in FIG. 1), a toner cartridge 21 containing toner as a developer is detachably mounted. Also,
A transfer roller 16 is arranged above the photosensitive drum 15 in contact with the photosensitive drum 15, and a cleaning roller 19 is arranged on one side of the photosensitive drum 15 and downstream of the transfer roller 16 in the rotation direction. Have been. still,
A discharge lamp 19a is disposed downstream of the cleaning roller 19 in the sheet feeding direction.

The developing roller 17 includes the toner cartridge 2
1 is supplied to the surface of the photosensitive drum 15 and the toner is adhered to the electrostatic latent image formed on the surface of the photosensitive drum 15 to visualize the electrostatic latent image. Things. The toner contained in the toner cartridge 21 is agitated by an agitator 21 a disposed in the toner cartridge 21, released from the toner cartridge 21, and carried on the outer peripheral surface of the developing roller 17 via the supply roller 18. . The thickness of the toner layer carried on the outer peripheral surface of the developing roller 17 is regulated by the blade 17a. The toner image developed on the surface of the photosensitive drum 15 is transferred between the transfer roller 16 and the photosensitive drum 15 by the transfer roller 16 to which a transfer bias having a potential opposite to that of the photosensitive drum 15 is applied. It is transferred to the paper PP. The toner remaining on the photosensitive drum 15 is held by the cleaning roller 19, and is returned to the photosensitive drum 15 by applying a bias having a polarity opposite to that of the toner to the cleaning roller 19 at a predetermined timing. Collected.

Below the recording device 3, a laser beam scanning device 4 is provided. The laser beam scanning device 4 performs exposure according to image data of a print image on the surface of the photosensitive drum 15 uniformly charged by the charger 20 to form an electrostatic latent image on the surface of the photosensitive drum 15. belongs to. An upper support plate 4a is provided above the laser beam scanning device 4, and the upper support plate 4a is fixed to a stay 1b2 integrally formed above the bottom plate 1b1 of the main frame 1b by screwing. . In the upper support plate 4a, a scanner hole 4b is formed in a lower portion of the developing roller 17 described above, and the scanner hole 4b extends in the rotation axis direction of the photosensitive drum 15, that is, in a direction substantially perpendicular to the paper surface of FIG. It is formed wide. The entire area of the scanner hole 4b is covered with a transparent glass plate 4c.

A toner sensor 4d projecting upward is provided on the upper surface of the upper support plate 4a. The toner sensor 4d includes a pair of a light emitting unit and a light receiving unit, and detects the presence or absence of toner in the toner cartridge 21. The toner sensor 4d is provided by mounting the recording device 3 in the main frame 1b.
The light emitting unit and the light receiving unit are respectively inserted into two concave portions 21 b provided on the lower surface of the toner cartridge 21. The toner sensor 4d pushed into the recess 21b is
When the light receiving unit does not receive the light emitted from the light emitting unit, it is determined that the toner remains in the toner cartridge 21. On the other hand, when the light emitting unit receives the light emitted from the light emitting unit, It is determined that no toner remains in the cartridge 21.

Below the upper support plate 4a, a laser diode (not shown) for emitting laser light and a polarizing device 2 are provided.
The polarizing device 22 includes a polygon mirror 22a, a scanner motor 22b for driving the polygon mirror 22a, and a drive circuit 22c for driving the scanner motor 22b. Further, a lens 23 is disposed on the downstream side (right side in FIG. 1) of the laser beam of the polarizing device 22.
, A reflection mirror 24 is disposed on the upstream side of the optical path L, and a reflection mirror 25 is disposed on the downstream side of the optical path L. A glass plate 4c that covers the above-described scanner hole 4b is disposed further downstream of the reflection mirror 25 disposed downstream of the lens 23 on the optical path L. In FIG. 1, the optical path L of the laser light is shown by a two-dot chain line.

Therefore, the laser light emitted from the laser diode is reflected by the polygon mirror 22a and the reflection mirror 24, enters the lens 23, and is reflected by the reflection mirror 25.
Then, the light passes through the glass plate 4c and is irradiated on the surface of the photosensitive drum 15. The photosensitive drum 15 is a charger 2
Since the photosensitive drum 15 is uniformly charged by 0, the surface of the photosensitive drum 15 is irradiated with a laser beam to form an electrostatic latent image on the surface.

The printing paper PP on which the toner image has been transferred is sent to a fixing device 5 provided downstream of the recording device 3.
The printing paper PP sent to the fixing device 5 is passed between the heating roller 26 and the pressure roller 27 of the fixing device 5. The toner image transferred onto the printing paper PP is heated and melted here and fixed on the printing paper PP. The heating roller 26 is constituted by an aluminum tube whose outer peripheral surface is coated with fluorine, and a fixing heater 26a constituted by a halogen lamp is provided inside the aluminum tube. The pressure roller 27 is a roller member made of rubber, and its surface is covered with a fluororesin.

The printing paper PP on which the toner image is fixed by the heating roller 26 and the pressure roller 27 is
The laser beam is discharged from a paper discharge port 30 to a paper discharge tray 31 extending to the outside of the laser printer 1 with a reading device by a paper discharge roller 28 and a pinch roller 29 disposed on the downstream side such as 6.
One end of the paper discharge tray 31 is rotatably attached to the main body case 1a via a rotary shaft 31a. When the paper discharge tray 31 is not used, it is rotated counterclockwise in FIG. 1c, it can be folded and stored while covering the top cover 1c.

Next, the image reading device 6 mounted on the above-described paper feed port cover 8 will be described in detail with reference to FIGS. 1, 2 and 3. As shown in FIG. 1, the image reading device 6 for reading an image written on the document paper P is mounted on an upper portion of a paper feed port cover 8, and a panel cover 32 is covered on the upper portion. The panel cover 32 has an operation panel provided with a plurality of buttons (not shown) on its surface (upper surface) and a liquid crystal display (not shown) for displaying the operation status of the laser printer 1 with a reader. The laser printer 1 with a reading device is operated by operating a button provided on the operation panel. In addition, the panel cover 32 is supplied in a state where the panel cover 32 is inclined downward from the upstream side (the left side in FIG. 1) of the original sheet P in the sheet feeding direction (the direction of the arrow X in FIG. It is attached to the paper mouth cover 8 so that it can be opened and closed freely. Therefore, for example, by opening the panel cover 32, it is possible to remove a paper jam of the document sheet P in the image reading device 6 and perform maintenance of the image reading device 6.

The rear end side (left side in FIG. 1) of the panel cover 32,
That is, on the upstream side in the transport direction of the document sheet P, a document sheet holder 33 that is a space in which a plurality of document sheets P can be inserted in a stacked state is formed. 2A to 2C using a synthetic resin material such as silicone rubber having flexibility on the lower surface of the panel cover 32 on the downstream side in the paper feeding direction of the original paper holder 33 (the right side in FIG. 1). 3), a separation pad 35 as a separation plate formed in a substantially flat plate shape is supported on the frame 32a by screws 50 as shown in FIG. 2A is a plan view showing the back surface of the separation pad 35 viewed from the Z direction in FIG. 3, FIG. 2B is a side view of the separation pad 35, and FIG. It is a bottom view. FIG. 3 is an enlarged view around the separation pad 35 in FIG.

The separation pad 35 is connected to a separation roller 3 described later.
6 to separate a plurality of original papers P one by one in cooperation with 6. Since it is formed of a synthetic resin material having a large surface friction coefficient such as silicon rubber, a plurality of original papers P contacting the surface thereof are formed. The document sheets P can be hooked and separated one by one. In the present embodiment, the separation rubber 35 is formed by injection molding the silicon rubber into a shape in which the rectangular tip corner of a flat plate as shown in FIGS. As shown in (B) and (C), the size was 20 mm × 30 mm and the thickness was 1.5 mm.

As shown in FIGS. 2A, 2B, and 3, a PET (polyet) as a film material is provided on the back surface of the separation pad 35 opposite to the contact surface with the manuscript paper P.
hylene terephthalate) 51 is attached by double-sided tape. The thickness of PET 51 was 100 μm.

On the back side of the separation pad 35, FIG.
As shown in FIG. 7, a substantially rectangular pad pressing member 34 as a biasing means is attached. This pad pressing member 34
This is for urging the separation pad 35 toward the separation roller 36 and pressing it down. The separation pad 35 is formed to a thickness of about 0.2 mm using an elastic metal material such as a thin stainless steel material. As shown in the figure, the frame 32a is screwed so as to be swingable in the vertical direction. In the present embodiment, the weight of the pad pressing member 34 is set to 200 gf. In addition, the pad pressing member 34, as shown in FIG.
It has a width substantially equal to the separation pad 35. FIG. 4 is a plan view of the periphery of the separation pad 35 from the Z direction shown in FIG.

As shown in FIGS. 3 and 4, a leaf spring 52 made of an elastic metal material such as a thin plate of stainless steel is attached below the separation pad 35. The document paper P is pressed together with 35. The plate panel 52 shown by a solid line in FIG. 3 shows a state in which the separation roller 36 is not in contact with the separation pad 35. In a case where the separation roller 36 is in contact with the separation pad 35, FIG. This is the position indicated by the dotted line.

The separation roller 36 as a conveying means cooperates with the separation pad 35 to separate a plurality of original sheets P one by one and to convey the original sheets P downstream in the conveying direction. And a 20 mm diameter EPDM (ethy
Lene-propylene terpolymer (ethylene-propylene trimer) is rotatably mounted on the paper feed port cover 8. On the downstream side of the separation roller 36, as shown in FIG.
Are provided on the paper feed port cover 8. A reading section 37a for reading an image is provided on the upper surface of the CIS 37. Above the reading section 37a, a white tape 38 serving as a white reference when reading an image is provided so as to face the reading section 37a. This white tape 38 is the panel cover 3
2 is attached to the lower surface of the original pressing member 39 disposed on the lower surface.
Is biased downward toward the reading section 37a.

Further, the separation pad 35 is set at a position approximately 6 mm away from the front end position as a pressure contact position by the separation roller 36.
And is positioned so as to form a press contact portion with the separation roller 36 at the press contact position. The contact position of the pad pressing member 34 against the separation pad 35 is also adjusted so as to coincide with the pressure contact position.

With such a configuration, the separation pad 35
In FIG. 2C, the area from the press contact position to the leading end position is a free end, and the bottom surface of the free end facing the separation roller 36 is in contact with the original paper P as shown in FIG. It is formed as.

Returning to FIG. 1 again, on the further downstream side of the CIS 37, the original sheet P on which the image has been read by the CIS 37 is located.
Discharge roller 41 rotatably mounted on the paper feed port cover 8 for discharging paper to the outside of the image reading device 6, and the lower surface of the panel cover 32 for pressing the original paper P against the discharge roller 41 And a pinch roller 42 which is rotatably mounted on the shaft. The document sheet P from which an image is read by the reading unit 37a of the CIS 37 is nipped by the discharge roller 41 and the pinch roller 42, and
After being conveyed at a predetermined speed with the rotation of 1, the sheet is discharged onto the upper surface of the top cover 1c of the main body case 1a. As described above, the image reading device 6 includes the panel cover 32 that accommodates the upper mechanism and the paper feed port cover 8 that constitutes the lower mechanism, with the transport path of the document paper P as a boundary.

Next, the operation of transporting the original sheet P in the image reading device 6 will be described. First, when a plurality of original sheets P are set in the original sheet holder 33, the leading end of the original sheet P is separated by the separation roller 36 and the separation pad 3.
Touch 5 Then, when the driving of the separation roller 36 is started by pressing a reading switch (not shown) or the like,
The document paper P contacting the separation roller 36 is
However, as described above, the other document paper P is prevented from being transported by the separation pad 35 pressed by the pad pressing member 34, and only the document paper P contacting the separation roller 36 is separated from the separation roller 36 by the separation roller 36. It passes through the pressure contact portion of the separation pad 35 and is conveyed to the CIS 37 side. The manuscript paper P is composed of white tape 38 and CIS 37.
An image is read by the reading unit 37a when passing through the reading unit 37a.

As described above, the image reading device 6 of the present embodiment is
According to the above, even when a plurality of original sheets P are set,
The original sheet P is satisfactorily conveyed without causing the empty or double feed of the original sheet P, and a good image is read.

In particular, the original paper P is conveyed while receiving frictional resistance at the pressure contact portion between the separation pad 35 and the separation roller 36. In the image reading apparatus 6 of the present embodiment, the pressure contact position of the separation pad 35 Since the contact portion from the contact point to the tip position is formed to be longer than before, and the rectangular tip corner is formed by cutting straight, it can be smoothly moved even when a special original paper P having a high frictional resistance is conveyed. The document paper P can be transported.

This is a major difference between the image reading device 6 of the present embodiment and the conventional image reading device. In a conventional image reading apparatus, as shown in FIGS. 11A and 11B, the separation pad 100 has a short length of about 2 mm from a press-contact position to a tip position. It has a shape having. Therefore, when a special original sheet P having a large frictional resistance is conveyed, the original sheet P
Receives strong resistance from the corner of the rectangular tip of the separation pad 100 and is not smoothly transported. As a result, the separation pad 1
00 vibrates every time the document paper P is transported, and may eventually self-excited at a constant frequency. If the frequency of the self-excited vibration matches the resonance frequency of the frame 32a supporting the separation pad 100 and the like, an abnormal sound may be generated in the image reading apparatus itself.

On the other hand, in the image reading apparatus 6 of the present embodiment, as described above, the original sheet P
As shown in FIG. 4, the contact width of the contact portion with the contact pad gradually decreases from W1 which is the entire width of the separation pad 35 to W2 at the tip end from the pressure contact position to the tip end position. Therefore, since there is no rectangular tip corner as in the related art, even when the special original paper P having a large frictional resistance is used as described above, the original original paper P is brought into smooth contact with the original original paper P and the separation pad as described above is used. 35 can be reduced.

In addition, the separation pad 3 in the present embodiment
The contact part from the press-contact position of No. 5 to the tip position is about 6 m
Since m is formed as a free end longer than the conventional one, even if self-excited vibration occurs, the vibration can be attenuated at the free end.

Further, the separation pad 3 in the present embodiment
Since the PET 51 is attached to the back surface of the separation pad 5 as described above, the rigidity of the entire separation pad 35 is adjusted without changing the thickness of the separation pad 35 itself. As a result, the separation pad 35 can be removed without deteriorating the separation performance of the original sheet P due to the elastic contact of the separation pad 35.
It is possible to change the whole natural frequency, and it is possible to reliably prevent the occurrence of abnormal sound due to the above-described self-excited vibration.

Further, as shown in FIG.
Is supported by a screw 50, and a washer 53 is provided on this support portion, so that a separation pad 35 is provided.
It is configured not to strongly tighten the base end portion. As a result, the separation pad 35 is swingable in the directions of arrows A and B with the base end as a fulcrum as shown in FIG. Therefore, when the document paper P is conveyed obliquely,
When assembling the separation pad 35, the separation pad 35
Are assembled diagonally, the contact pressure of the separation pad 35 against the document paper P is not uniform,
Even if the separation pad 35 may receive a large frictional force locally from the document paper P, the separation pad 35 swings in the direction in which the force can be balanced with the base end as a fulcrum, and the separation pad 35 contacts the document paper P. The pressure can be made uniform. As a result, the load on the separation pad 35 from the document sheet P is not concentrated, and the occurrence of the abnormal sound due to the self-excited vibration described above can be reliably prevented.

In a conventional image reading apparatus as shown in FIG. 11, when a special original sheet P having a large frictional resistance was conveyed, self-excited vibration of about 800 Hz was generated, and generation of an abnormal sound was confirmed. On the other hand, in the image reading device 6 of the present embodiment, when measured under the same conditions, about 110
Although the vibration of 0 Hz was measured, the amplitude was small,
No abnormal sound was generated.

As described above, according to the image reading apparatus 6 of the present embodiment, even when a plurality of original sheets P are set, good conveyance without empty or double feeding is performed, and good image reading is performed. In addition to the above, even when the original paper P having a large frictional resistance is conveyed, the self-excited vibration of the separation pad 35 is reduced, and the abnormal noise is not generated in the image reading device 6. Therefore, a quiet working environment can be provided.

In the above description, an example was given in which the contact width of the separation pad 35 at the pressure contact position was the entire width of the separation pad 35, but the present invention is not limited to such a configuration. As shown in FIG. 5, the pressure contact position may be set so that a width shorter than the entire width is set as the contact width.

In the above description, the contact portion has a trapezoidal shape in a plan view. However, the present invention is not limited to this, and as shown in FIG. A linear portion may be provided between them. Further, at this time, the shape of the tip may be formed in an acute angle as shown in FIG. Further, as shown in FIG. 8, it is also possible to form the shape of the distal end portion at an acute angle even when the straight portion is not provided.

Further, in the above description, the conventional rectangular tip corner is cut off with a straight line, but the present invention is not limited to such a configuration, and FIG.
As shown in FIG. 10 and FIG. 10, a conventional rectangular tip may be cut into a curved shape. FIG. 9 shows an example in which the contact portion is formed in a semicircular shape, and FIG.
In this example, a straight line portion in the longitudinal direction and a straight line portion at the tip end are connected by a curved line.

In the above description, an example was shown in which the washer 53 was used as shown in FIG. 3 to swingably support the separation pad 35, but the present invention is limited to such a configuration. Instead, for example, the boss portion 54 of the frame 32 a shown in FIG. 3 may be configured to be extended by an amount corresponding to the thickness of the washer 53.

Further, in the above description, an example is shown in which the sheet conveying apparatus of the present invention is applied to the original sheet conveying section in the image reading apparatus, but the present invention is not limited to this. It is also possible to apply the present invention to an automatic paper feeder including a paper feed roller 11 and a separation pad 12 shown in FIG. Further, the present invention can be applied to an ADF (auto document feeder) used in a copying apparatus.

Further, as an example of the conveying means, a separation roller 3
6, the present invention is not limited to this, and a conveying unit that conveys the sheet material by a belt may be used.

As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. Can easily be inferred.

[0069]

According to the sheet conveying apparatus of the first aspect, the free end of the separation piece supports the base end so as to form a contact portion which makes elastic contact with the sheet, and the contacting end is supported. A contact portion of the sheet member at a predetermined width to hold the sheet material between the pressing portion and a surface portion of the conveying means; Since the width has a shape that gradually narrows toward the front end position, the contact pressure on the sheet material at the front end position is changed to the front end where the contact width at the front end position is the same as the contact width at the press contact position. It can be significantly reduced as compared with the conventional separation piece having a corner.
Therefore, the contact of the separation piece with the sheet material can be made relatively smooth, and self-excited vibration can be reduced. In addition, since the contact portion gradually narrows the contact width from the pressure contact position to the tip position as described above, the contact portion is compared with a conventional separation piece in which the pressure contact position and the tip position substantially match. Thus, the contact portion from the press contact position to the tip position forms a sufficiently long free end, and self-excited vibration can be attenuated. As described above, according to the present invention, the occurrence of self-excited vibration of the separation piece can be reliably suppressed, and the occurrence of abnormal noise through a frame or the like on which the separation piece is supported can be reliably prevented.

According to the second aspect of the present invention, the shape of the contact portion of the separation piece in a plan view is a shape obtained by cutting off a rectangular tip corner with a straight line. , The contact of the separation piece with the sheet material can be made relatively smooth, and self-excited vibration can be reduced.

According to the third aspect of the present invention, the shape of the contact portion of the separation piece in a plan view is a shape obtained by cutting off a corner of a rectangular tip with a curved line. The pressure can be reduced, and the contact of the separation piece with the sheet material can be made relatively smooth to reduce self-excited vibration.

According to the sheet material transport device of the fourth aspect, since the separation piece is formed of silicon rubber, it can be brought into contact with the sheet material with an appropriate frictional force, and the predetermined separation can be performed. Performance can be demonstrated. In addition, since the sheet can be brought into contact with the sheet material with appropriate smoothness, self-excited vibration can be reduced.

According to a fifth aspect of the present invention, a film material is attached to a surface of the separation piece other than the contact portion, for example, a back surface opposite to a contact surface with the sheet material. Therefore, without changing the thickness of the separation piece, it is possible to change the rigidity of the entire separation piece, while maintaining the predetermined elastic force of the separation piece and reliably preventing the separation performance of the sheet material from decreasing,
The occurrence of abnormal noise can be prevented by changing the natural frequency of the entire separation piece.

According to the sheet material transporting device of the sixth aspect, the film material is attached to the back surface of the separation piece opposite to the contact surface with the sheet material, so that the sheet material and the sheet material are bonded together. By avoiding the contact with the film material and preventing the separation performance of the separation piece from the sheet material from deteriorating, it is possible to change the natural frequency of the entire separation piece to thereby prevent the occurrence of the abnormal sound.

According to the sheet conveying apparatus of the seventh aspect, since the film material is PET, it can be formed extremely thin with respect to the thickness of the separation piece, and the whole separation piece can be formed without changing the thickness of the separation piece. Can change the rigidity. As a result, it is possible to maintain the predetermined elastic force of the separation piece without deteriorating the separation performance of the sheet material, and change the natural frequency of the entire separation piece to reliably prevent the occurrence of abnormal noise.

According to the sheet conveying apparatus of the eighth aspect, the base end of the separation piece is mounted and supported on a frame or the like, and the free end is swingable about the base end. The contact pressure of the contact portion of the separation piece does not become uniform with respect to the sheet material due to a shift in the conveyance direction of the sheet material or a shift at the time of assembling the separation piece. Even if the frictional force locally increases, the contact pressure on the sheet material can be made uniform, and the load on the separation piece from the sheet material can be prevented, and the self-excited vibration can be prevented. Occurrence can be suppressed.

[Brief description of the drawings]

FIG. 1 is a side sectional view schematically showing an internal structure of a laser printer with a reading device as an embodiment of an image forming apparatus having a reading device of the present invention.

FIGS. 2A and 2B are diagrams showing a shape of a separation pad used in a sheet material conveying device in the reading device of FIG. 1, wherein FIG. 2A is a rear view, FIG. 2B is a side view, and FIG.

FIG. 3 is a side sectional view showing a schematic configuration of a sheet material conveying device in the reading device of FIG. 1;

FIG. 4 is a plan view of the sheet conveying apparatus as viewed from an arrow Z direction in FIG. 3;

FIG. 5 is a plan view showing a shape of a separation pad that can be used in a sheet conveying device in the reading device of FIG. 1 (part 1).

FIG. 6 is a plan view showing a shape of a separation pad that can be used in a sheet material conveying device in the reading device of FIG. 1 (part 2).

FIG. 7 is a plan view showing a shape of a separation pad that can be used in a sheet material conveying device in the reading device of FIG. 1 (part 3).

FIG. 8 is a plan view showing a shape of a separation pad that can be used in a sheet material conveying device in the reading device of FIG. 1 (part 4).

FIG. 9 is a plan view showing the shape of a separation pad that can be used in the sheet conveying device in the reading device of FIG. 1 (part 5).

FIG. 10 is a plan view showing a shape of a separation pad that can be used in a sheet material conveying device in the reading device of FIG. 1 (part 6).

11A and 11B are diagrams illustrating a schematic configuration of a conventional sheet material conveying device, in which FIG. 11A is a side sectional view, and FIG. 11B is a plan view viewed from a Z direction in FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 laser printer with reading device (image forming device with reading device) 2 paper feeding device 3 recording device (part of printing device) 6 image reading device (reading device) 32 a frame 34 pad pressing member 35 separation pad 36 separation roller 51 PET 52 Pressure panel 53 Screw 54 Washer P Original paper PP Printing paper (recording paper)

Claims (8)

[Claims] 1. A sheet, comprising: a conveying unit; and a separation piece urged by an urging unit on a side of the conveying unit, the sheet separating and conveying only a sheet material coming into contact with the conveying unit from a plurality of sheets. A material transporting device, wherein the transporting means has at least a surface portion in contact with the sheet material movable endlessly, and the separation piece forms a contact portion whose free end portion elastically contacts the sheet material. The contact portion is in contact with the sheet material at a predetermined width and presses the sheet material with the surface of the conveying means. A sheet material conveying device, wherein a contact width with respect to the sheet material is gradually narrowed toward the front end position between a position and a front end position of the separation piece. 2. The sheet conveying apparatus according to claim 1, wherein a shape of the contact portion of the separation piece in a plan view has a shape obtained by cutting a rectangular tip corner straight. 3. The sheet conveying apparatus according to claim 1, wherein a shape of the contact portion of the separation piece in a plan view has a shape in which a rectangular tip corner is cut off by a curve. 4. The sheet conveying apparatus according to claim 1, wherein the separation piece is formed of silicon rubber. 5. The sheet material conveying apparatus according to claim 1, wherein a film material is attached to a surface of the separation piece other than the contact portion. 6. The sheet material conveying apparatus according to claim 5, wherein the film material is attached to a back surface of the separation piece opposite to a contact surface with the sheet material. 7. The sheet conveying apparatus according to claim 5, wherein the film is PET. 8. The apparatus according to claim 1, wherein the separation piece is mounted and supported such that the free end can swing about the base end. The sheet material conveying device according to the item.