JPH1179453A - Sheet separating and feeding device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a sheet from being damaged and prevent the trace of a roller as a feeding means from being marked on the rear surface of the sheet in a sheet separating and feeding part of an image forming device. SOLUTION: A sheet separating and feeding device is provided with a sheet separating and feeding device comprising a feeding means 832 to feed sheets, a frictional means 837 disposed on the feeding means opposedly to each other, and a first energizing means 903 to energize the frictional means and a preliminary feeding means comprising a preliminary feeding member 906 disposed opposedly to the feeding means and a second energizing means 904 to energize the preliminary feeding member, and separates the stacked sheets frictionally one by one before feeding. Also it is provided with a friction reset means 841 to separate the frictional means and feeding means. When the frictional means is separated by the friction reset means in thick sheet feeding, the preliminary feeding member keeps the state pressed by the feeding means so as to facilitate the positioning of the top end of the sheets.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a facsimile and a printer, and more particularly to an image forming apparatus having an improved automatic sheet separating and conveying mechanism.

[0002]

2. Description of the Related Art A document reading section of a conventional image forming apparatus, for example, a document reading section of a facsimile apparatus, automatically transmits one document at a time when a plurality of sheets are set on a document table and the document is transmitted. And an automatic document separation and transport mechanism for separating and returning the document. As the document separation and transport mechanism, there are many apparatuses having a mechanism in which a separation piece is brought into contact with a separation roller and the separation piece is pressed by an elastic body such as a spring.

The separation / conveyance mechanism rotates a separation roller in the direction of conveyance of a document to generate a frictional force between sheets of paper (hereinafter, often referred to as an example of paper) and a frictional force between the paper and the separation piece. By utilizing the difference in force and frictional force between the paper and the separation roller, only one sheet of the plurality of papers that is in contact with the separation roller is separated and conveyed.

[0004] In a facsimile machine, it is expected that various types of paper such as thick paper, thin paper, or paper with weak stiffness will be used as originals. Paper and paper or separation roller and paper,
The frictional force between the separation piece and the paper greatly changes depending on the temperature, humidity and paper type.

Therefore, in order to reliably carry out the separation and conveyance of the original even when these conditions change,
A mechanism for adjusting the frictional force by changing the length of the elastic member that presses the separation piece according to the paper type (Japanese Utility Model Laid-Open No. 2-28842).
Has been proposed. Further, a mechanism for releasing a separation piece from a separation roller (Japanese Patent Laid-Open No. 59-13256) has been proposed.

[0006]

SUMMARY OF THE INVENTION In addition to a facsimile transmission and reception function, a facsimile (multifunction facsimile) having a function of performing color copying or a function as a scanner connected to a computer and taking a color image into the computer is provided. In this case, paper different from the paper at the time of facsimile transmission is used as the original.

For example, newspaper clippings, color photographs, magazine color pages, business cards, and the like can be considered. Newspaper and magazine clippings are thin and weak paper types, and often have printing on the reverse side. When transporting these, it is essential that the document is not damaged and that the back surface as well as the front surface is not stained.

In the conventional sheet conveyance of a facsimile apparatus, the emphasis has been placed on the function of reliably separating a bundle of documents. Therefore, a rubber material having a high coefficient of friction is used for the separation piece. Even if the pressing force is weakened as in the conventional example, the document may be scratched or damaged due to the high friction coefficient of the separation piece. Rubbing of the original material with the rubber material used for the separation piece causes traces of rubber on the back side (rubber residue)
Adheres. When thick hard paper such as a business card is used as a document, it is difficult to convey the paper only by reducing the pressing force.

In view of the above, in order to transport thick paper (such as a business card) and transport the original such as a photograph or a newspaper without damaging the original and leaving no trace of the rubber on the back surface, the separation piece is completely released from the separation roller. A mechanism is needed.

[0010] The purpose of the prior art for releasing a separation piece was to remove a document that was damaged during transportation. Therefore, in this configuration, the preliminary transport unit is separated at the same time as the separation piece is released. Therefore, when this mechanism is applied to document transport, the leading edge of the document must be inserted to the reading position (back of the apparatus).

One of the characteristics of business cards is that the paper is not only thick but also small in size. It is difficult to set without bending when inserting a business card. Further, in the above case, since the conveyance from the sheet insertion port is performed only by the separation roller, stable conveyance is difficult (the leading end is liable to be skewed).

[0012]

In order to solve the above problems, a sheet separating and conveying apparatus according to the present invention comprises a conveying means for conveying a sheet, a friction means arranged opposite to the conveying means, A sheet separating / conveying means comprising a first urging means for urging the means, a preliminary conveying member disposed opposite to the conveying means, and a backup comprising a second urging means for urging the preliminary conveying member A sheet separating and conveying device that has a conveying unit and frictionally separates the stacked sheets one by one, and conveys the friction unit with the friction unit by separating the friction unit from the conveying unit; When the means is separated, the preliminary conveying member keeps being pressed by the conveying means.

A roller is used as the conveying means, an elastic spring is used as the first and second urging means, and a high friction coefficient member such as rubber is used as the friction means, and a holder for holding the high friction coefficient member. And an arm member can be used as the preliminary transport member.

The holder includes a main body that supports the high friction coefficient member on one surface and receives the bias of the first elastic spring on the opposite surface, and an upstream portion of the main body in the sheet conveying direction with respect to the conveying direction. A protruding shaft that protrudes in the vertical direction, and is rotatable around the protruding shaft.

The preliminary transport arm is rotatably supported around the projecting shaft, extends on both sides of the high friction coefficient member, and is provided upstream of an opposing portion between the high friction coefficient member and the transport roller. The sheet separation unit can be downsized, facing the transport roller.

The friction releasing means has an operation lever having an operation section exposed to the outside of the apparatus, so that the operation can be facilitated.

The operating lever is rotatable about an axis perpendicular to the sheet conveying surface, has a leading end as the operating portion, and has an inclined portion and a flat portion for operating the holder. The holder is operated in a direction away from the transport roller by the inclined portion, and the separated state can be maintained by the flat portion.

The operating lever is composed of one member, and the number of parts can be reduced.

The distance from the opposing position of the preliminary conveying member and the conveying means to the sheet insertion port and the distance from the opposing position of the preliminary conveying member and the conveying means to the feeding means downstream in the sheet conveying direction are respectively set to a thick sheet. , And the sheet can be reliably conveyed.

An image forming apparatus according to the present invention includes any one of the above-described sheet separating and conveying devices, a reading unit for reading an image of a sheet conveyed by the sheet separating and conveying device, a recording sheet feeding unit, and an image on the sheet. Recording means for recording the information.

The above image forming apparatus can be used as a facsimile machine.

The image recording means may include an ink jet recording means for discharging ink in response to a signal and recording on a recording sheet.

[0023]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an external perspective view of a facsimile apparatus as an example of an image forming apparatus.

In FIG. 1, a color reading facsimile apparatus 1000, which is a reading and recording apparatus, includes a color scanner apparatus 800, which is a document conveying type color reading apparatus, inside a casing which forms front, rear, left and right side walls as shown in FIG. A serial recording type recording apparatus, a color control board, and a power supply are built therein. Each of these components is individually configured so that it can be easily replaced and detached.

The housing is a lower cover 100, which is a first housing on the lower side, an upper cover 200, which is an upper second housing, and a third housing described later for guiding a recording sheet and covering a power supply. And a rear cover.

The upper cover 200 has a slider 3 which can be adjusted in width to guide the document in the width direction. The slider 3 which is moved around only a central portion by moving only one of the sliders 3 is provided. The provided document table 2 is rotatably supported by the upper cover 200 as described later, and allows access to the ink head.

A detachable document stacking tray 4 is provided at the rear of the document table 2. For example, when a document of A4 size is conveyed forward toward the color scanner unit 800, the rear end may hang down. I try not to.

The original conveyed forward with the original surface facing downward is sent to the apparatus 10 from below the color scanner unit 800.
00 and is placed on the document discharge tray 6. The document ejection tray 6 is connected to the
0 can be moved in the front-back direction.

On the other hand, after the recording sheet conveyed to the recording apparatus is regulated in the width direction by the movement of the width adjusting plate 9 provided on the recording sheet table 401 disposed on the back side of the apparatus 1000, After serial recording in a printer unit to be described later, the sheet is discharged to a recording sheet table 8 below the color scanner unit 800.

When the recording sheet is conveyed such that its longitudinal direction is in the front-rear direction of the apparatus, the rear recording sheet support table 5 and the front recording sheet support bar 7 for preventing drooping are attached. Is provided. The support table 5 is built in the recording sheet table 401 and is configured to be brought to the position shown in the drawing by pulling it out as appropriate. On the other hand, the recording sheet support rod 7 on the front side is moved in the front-rear direction similarly to the above-mentioned document support rod. It is provided so that it can be pulled out.

The upper cover 200 is shaped so as to surround the color scanner section 800 as shown in the figure, and is detached from the lower cover 100 along the edge 202 of the upper cover 200 so that the color scanner can be removed. Part 80
0 can be left as it is on the lower cover 100.

The color scanner 800 has a scanner main body and a panel connected to each other so as to open and close about a hinge (not shown). A liquid crystal display unit 811 and a dial key 810 and other operation units are provided on the panel unit as shown in the figure.

FIG. 2 is a three-dimensional exploded view of the apparatus 1000, in which the upper cover 200 is omitted. In this drawing, the same components as those already described are denoted by the same reference numerals, and description thereof is omitted. A color scanner unit 800 which is a document transport type reading device that reads a document while transporting the document inside a lower cover 100 integrally formed with a base serving as a bottom surface, a side wall serving as an external surface, and an opening surface surrounded by the sidewall; A printer 400, which is a serial recording paper type recording apparatus that performs serial recording while transporting, a color control board and a power supply 600 that are connected to these printers to perform predetermined control, and ink absorption that absorbs ink that is unnecessary at initial ejection. Body 13 and rear cover 15
In this configuration, the recording sheet table 8 and the entire speaker 16 can be fixed to the lower cover 100 without using any tools.

Next, the configuration of each part will be described in detail with reference to FIGS. First, the color scanner unit 800 will be described.

The color scanner unit 800 irradiates the original G with light and converts the reflected light into an electric signal, and transmits the signal to another machine according to the operation mode, or transmits the signal to its own printer unit 400. Is what you do. The document G is stacked on the document table 2.

In the color scanner main body 800, 83
1 is a frame of the color scanner unit 800, and
A scanner base that guides the lower side of the document G is fixed to the lower cover 100. The scanner base 831 includes a separation roller 832 for feeding out the original, a feed roller 833 for conveying the original, a discharge roller 834 for discharging the original onto the original discharge tray, a color contact sensor 835 for reading image information of the original, and the like. Is provided.

The panel portion is rotatably attached to the scanner base 831 by a fulcrum (not shown), and an upper document guide 836 for guiding the upper side of the document, a separation piece 837 opposed to the separation roller 832 and pressed, Feeding roller 8 pressed against roller 833 and paper discharge roller 834
38, paper ejection roller 839, color contact sensor 835
And a release lever 841 for releasing the pressing of the separation piece 837 for conveying a thick original.

Reference numeral 842 denotes a panel frame which forms a part of an exterior and is attached to an upper document guide. The panel frame 842 is provided with operation keys 843, a display portion 844 such as an LCD, a panel substrate 845 on which these are mounted, and the like.

Here, the original conveying and reading operations of the color scanner unit 800 are performed by a motor and a sensor driving circuit (not shown), and these controls and the display control of the panel unit 801 are controlled by color control. Controlled by the substrate.

Next, the printer 400 will be described.
The printer 400 has a tray 4 as a stacking unit of a paper feeding unit.
Numeral 02 is provided on a base 401, and the tray has a middle plate supported by a fulcrum (not shown), and the middle plate is pressed by a spring. The base 401 is fixed to the printer body 400 by screws or the like.

The recording paper S1 is stacked on the middle plate, its back surface is supported by a paper feed tray provided on the paper supply base so as to be stretchable, and the position in the width direction is movably provided on the middle plate. It is regulated by the side guide 9. The paper feed roller 403 feeds out the recording paper one by one,
Send out to 00. S2 indicates a manual recording sheet supplied from the rear cover unit 15.

The printer main unit 400 is provided with, for example, an ink jet recording unit. The ink head 417 moves the sheet S transported by the transport roller 412 and the pinch roller.
This is for recording an ink image. As a recording means in this apparatus, an ink jet recording method of discharging ink from an ink head for recording is used. That is, the ink head has a fine liquid discharge port (orifice), a liquid path, and an energy action section provided in a part of the liquid path, and energy generation for generating droplet forming energy to act on the liquid in the action section. Means.

As an energy generating means for generating such energy, a recording method using an electromechanical transducer such as a piezo element or the like, an electromagnetic wave such as a laser is irradiated to generate heat, and droplets are discharged by the action of the generated heat. There are a recording method using an energy generating means, and a recording method using an energy generating means for discharging a liquid by heating a liquid by an electrothermal converter such as a heating element having a heating resistor.

Among them, an ink head used in an ink jet recording method for discharging a liquid by thermal energy has a high density of liquid discharge ports (orifices) for discharging a recording liquid droplet to form a discharge solution droplet. Therefore, high-resolution recording can be performed. Among them, an ink head using an electrothermal converter as an energy generating means is easy to make compact,
In addition, it is possible to fully utilize the advantages of IC technology and micro-machining technology, which are remarkable in recent advances in technology in the field of semiconductors and improvement in reliability, and it is advantageous because high-density mounting is easy and the manufacturing cost is low. .

Reference numeral 411 denotes a printer chassis serving as a frame of the printer main body 400, which is fixed to the lower cover 100. Reference numeral 412 denotes a paper feed roller, and the recording paper S sent from the paper feed unit is pressed by a pinch roller disposed opposite thereto.
To the printing section further downstream.

Reference numeral 414 denotes a platen that supports the back surface of the recording paper in the printing section. On the front surface of the recording paper, a recorded image is formed by an ink head 417 attached to a reciprocating carriage 416 supported by a guide shaft 415. It is formed.

Thereafter, the recording paper S is discharged from the printer unit 400 by the recording paper discharge roller pair 418, and
The sheet is conveyed and stacked on a recording sheet table 8 provided on the lower cover 100.

Here, recording paper conveyance, recording operation, and the like of the printer unit 400 are performed by a motor, a sensor, a head drive circuit, and the like (not shown), and these controls are controlled by a control board unit. The board 421 is a recording interrupt board that relays signals from these motors, sensors, head drive circuits, and the like and transfers the signals to the control board unit. In addition, an absorber 13 that absorbs waste ink generated during operations such as ink clogging prevention in the printer unit 400 is attached to the lower cover 100.

Next, the flow of the document sheet G will be described. FIG. 3 is an enlarged sectional view of the color scanner section 800. The document transport path is as shown by arrow F. In FIG. 2, a document G is loaded on a document loading tray 4 with the image side facing down. The originals G stacked on the original stacking tray 4 are positioned by the slider 3 movable in the width direction.

Reference numeral 906 denotes a preliminary transport arm, which is a separation roller 83.
2 is located at the opposite part. The preliminary transport arm is pressed against the separation roller 832 by a preliminary transport spring 904 described later. The set document sheet is preliminarily conveyed by being cut by the cooperation of the preliminary conveyance arm and the separation roller.

Reference numeral 837 denotes a separating piece, which is pressed from above by the ADF spring 903 to the separating roller 832 and cooperates with the separating piece 837 and the separating roller 832 to copy the pre-conveyed document G from the bottom one sheet. Separately conveyed.
Further, the separation roller 832 has a role of conveying the document G to the feeding roller 833.

The original G conveyed by the separation roller is conveyed by the feed roller 833 to the reading position of the contact color sensor 835. Color contact sensor 8
Reference numeral 35 reads an image of the document G conveyed by the feed roller. Reference numeral 840 denotes a white sheet metal, which is urged from above by a white background spring 907 along the reading line of the color contact sensor 835 to bring the image of the separated and conveyed document G into close contact with the reading line.

The document G transported and read by the color contact sensor is discharged by a discharge roller 834. The discharged document G is discharged and stacked on a document discharge tray 6 which is detachable from the main body.

Next, the sheet separating / conveying section D will be described. FIG. 4 is an enlarged perspective view of a sheet separating and conveying unit, which is a portion D in FIG. In this embodiment, a separation piece releasing mechanism for releasing and holding the pressing of the separation piece will be described in detail.

In FIG. 4, reference numeral 836 denotes an upper document guide;
Reference numeral 1 denotes a lower document guide. A document sheet is set in a document insertion opening formed between the upper document guide 836 and the lower document guide 901.

In FIGS. 3 and 4, reference numeral 837 denotes a separation piece formed of a friction member such as a rubber piece.
05. Reference numeral 906 denotes a preliminary transfer arm, which is made of a plastic, metal plate, or rubber member having a relatively small friction coefficient. A projection shaft 905a extends to the ADF holder 905.

The preliminary transport arm is provided with a concave portion 906a, and a projection shaft 905a of the holder is attached to a concave portion of the concave portion 906a. The preliminary transport arm is rotatable about the projection shaft 905a.

Reference numeral 904 denotes a pressing spring as a preliminary transfer arm urging means, which is a tension coil spring. Of both ends of the preliminary transport pressing spring 904, one side is a preliminary transport arm and the other is A
It is attached to the projection of the DF holder.

A concave portion (not shown) is provided on the upper document guide 836, and a projection shaft 905a of the holder is attached to a concave portion of the concave portion. The holder 905 is rotatable around the axis 905a. The ADF holder 905 is located at a position facing the separation roller, and is arranged such that the preliminary transport arm 906 and the separation piece 837 are in contact with the separation roller 832.

One end of an ADF spring 903 as a holder urging means is engaged with the receiving surface 905b of the holder 905, and the other end is engaged with the operation panel 842. AD
The F spring 903 is a compression coil spring. The separation piece 837 on the holder 905 is separated from the separation roller 832 by this elastic force.
Is pressed.

Since the pressing force of the ADF spring 905 is larger than the tensile force of the preliminary transport spring 904, the ADF spring 903
By the action of the preliminary transport spring 904 and the preliminary transport pressing arm 9
06 is pressed by the separation roller 823.

Reference numeral 841 denotes a separation piece release lever. 841
Is a member that provides a gap between the above-described separation piece and the separation roller and maintains that state. In FIG. 4, an inclined portion 841 is provided at the tip of the separation piece release lever 841.
a and a flat portion 841b.

FIG. 5A is a view showing a state in which the ADF holder member and the separation piece releasing lever are assembled on the upper document guide. The separation piece release lever 841 is attached to a shaft 902a on the upper document guide. By operating the separation piece release lever 841 operating in the rotation direction about this axis in the rotation direction, the separation piece release lever described above is operated. The inclined portion 841a at the tip pushes up a protrusion 905c as an engaged portion of the ADF holder. The inclined portion may be formed on the protrusion 905a side.

Operation of Separation Piece Release Mechanism FIGS. 5 and 6
This will be described with reference to FIG. When the separation piece release lever 841 is operated in the direction of arrow I in FIG. 5A, the inclined portion 841a at the tip of the separation piece release lever is turned into the ADF holder projection 90.
5c. When the operation is further continued in the direction of arrow I, the ADF holder projection 905c is pushed up by the inclined portion 841a at the tip of the separation piece release lever, and the holder rotates upward about the shaft 905a. Further, the protruding portion 905c has a flat portion 841b at the tip of the separation piece releasing lever.
At this point, the ADF holder is held in a state where the protrusion is lifted. This state is shown in FIG.

FIG. 6 shows that the separation piece release lever 841 is operated.
FIG. 4 is a cross-sectional view when the tip of the ADF holder is lifted and held. H is a gap generated between the separation piece and the separation roller by operating the separation piece release lever in the direction of the arrow in FIG.

When the protrusion 905c of the ADF holder is raised, the extension of the ADF holder 905 and the preliminary transport pressing spring (elastic tension spring) attached to the preliminary transport arm is reduced, but the force of the ADF spring pressing the ADF holder is reduced. , The preliminary transport arm is pressed against the separation roller by the elastic force of the preliminary transport spring. Therefore, even when the separation piece release lever is operated, the preliminary conveyance arm is kept pressed by the separation roller. The pressing position of the preliminary transfer arm 906 is determined by the separation piece 837.
Are the same as when they are not separated.

The flow of a document when the release lever is operated to release the separation piece 837 from the separation roller 832 will be described. The document sheet G is set on a document stacking tray. The leading end of the document sheet G is set at a position where the preliminary conveyance arm 906 and the separation roller 832 are in contact with each other. This position is the same as when the separation piece 837 is not released. Therefore, there is no need for the user to change the position where the document is set. The stacked original sheets are conveyed to the position of the feed roller by the rotation of the separation roller.

Since no frictional force acts between the separating piece 837 and the original sheet, the function of separating a plurality of sheets is reduced, but one sheet of thick paper can be fed. In addition, no rubber mark of the separation piece 837 adheres to the back surface of the document, and no scratch is caused by friction with the separation piece. The leading edge of the document is the feed roller 83
Until the sheet 3 is sandwiched between the feeding rollers 838, the original sheet is stably conveyed while being pressed by the separation roller 832 by the preliminary conveying arm 906. If the spare transfer arm 90
When the document is conveyed by rotation of the separation roller without pressing 6, the conveyance is performed only by the frictional force between the separation rollers 832 generated by the original weight of the document, the conveyance force is small, and the conveyance of the document becomes unstable. The tip becomes easy to skew.

Next, the positional relationship between the separation roller, the feeding roller, the separation piece, and the preliminary transport arm will be described. In FIG. 6, L2 is the distance from the position where the feed roller 833 and the feed roller 838 are in contact to the position where the separation roller 832 and the preliminary conveyance arm 906 are in contact, and L1 is the contact position between the separation roller 832 and the preliminary conveyance pressing arm 906. This is the distance from to the sheet insertion slot.

M is a sheet insertion opening formed by the upper document guide and the lower document guide. Here, the position of the sheet insertion port is a position that can be visually observed by a user from outside the apparatus. L
In this embodiment, both 1 and L2 are assumed to be 3
It is set to 0 mm or less.

When the original is set, the leading end thereof is brought into contact with the contact position between the preliminary transport arm 906 and the separation roller 832. The size of the business card is approximately 80 mm × 40 mm. When the separation piece 837 is released and a business card is set, L
Since 1 is 40 mm, the rear end of the business card about 10 mm protrudes from the sheet insertion slot (a user can see it from the outside). Therefore, even when the business card is set diagonally by mistake, it is possible to arrange that the user does not skew the business card by holding the rear end.

Further, since the distance L2 from when the feeding roller 833 and the feeding roller 838 sandwich the document to start feeding is smaller than the size of the business card, the business card is kept in a standby state until the leading end is sandwiched by the feeding roller. The sheet is conveyed while being pressed by the transfer arm 906. Therefore, the business card can be stably transported.

According to the above-described embodiment, the separation piece 837 and the holder as the friction means disposed so as to contact the separation roller 832 as the conveyance means and the lever 841 as the friction releasing means are provided. By operating, the separation / release is performed, and at this time, the preliminary transfer arm 906 as the preliminary transfer member can be kept pressed by the separation roller, and the operating portion of the lever is connected to the panel frame 842 or the like. Since it is exposed outside the apparatus, the user can easily operate the lever.

Therefore, if the sheet is conveyed in a state in which the release lever is operated to release the separation piece, the original can be conveyed without attaching rubber scum or dirt on the rear surface and without damaging the sheet. It becomes possible to use a cutout of a photograph or a magazine as a manuscript. Further, by releasing the separation piece, it becomes possible to use thick paper as a document.

Further, since the preliminary transport arm is not released from the separation roller, the setting position of the leading end of the original at the time of releasing the separation piece is the same as the normal setting position. When it is set, the rear end protrudes from the sheet insertion slot so that it can be confirmed from the outside of the apparatus, and it is possible to reset the user so that the user does not skew holding the rear end. In addition, during the transport, the business card is pressed by the preliminary transport member until it is sandwiched between the feeding roller and the feeding roller, so that the business card is transported in a stable state. Stable transport becomes possible. The above effects are remarkable when the sheet separating and conveying device is used for facsimile.

[0077]

As described above, according to the present invention,
The friction releasing means separates the friction means from the sheet conveying means when necessary, and at this time, the preliminary conveying member maintains a state pressed by the conveying means. The skew is prevented by being restricted by the member, and the pressing force is reduced by separating the friction means as described above, thereby preventing separation pieces and dirt from the friction means from adhering to the back surface of the sheet. can do.

[Brief description of the drawings]

FIG. 1 is a perspective view of a facsimile apparatus as an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a side sectional view of the image forming apparatus shown in FIG.

FIG. 3 is an enlarged side sectional view of a sheet conveying unit in the image forming apparatus shown in FIG.

FIG. 4 is a perspective view of a separation piece releasing mechanism in the image forming apparatus shown in FIG. 1;

FIGS. 5A and 5B are plan views showing the arrangement of the separation piece releasing mechanism on the upper guide, where FIG. 5A shows a normal state and FIG.

FIG. 6 is an enlarged sectional side view of the sheet conveying unit when a separation piece is released.

[Explanation of symbols]

 1000 facsimile apparatus 3 slider 4 document stack tray 6 document discharge tray 100 lower cover 200 upper cover 800 color scanner section 831 scanner base 832 separation roller 833 feed roller 834 discharge roller 835 ... Color contact sensor 836 Upper document guide 837 Separation piece 838 Feed roller 839 Discharge roller 840 Reading white background 841 Release lever 842 Panel frame 843 Operation keys 844 LCD display section 845 Panel board 901 Lower document guide 903: Spring 904: Preliminary transport spring 905 ... Holder 906: Preliminary transport arm 907: White background spring D: Sheet separation transport section F: Original transport path G: Original document M: Sheet insertion port

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Atsushi Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (11)

[Claims] A sheet conveying means for conveying a sheet; a friction means arranged opposite to the conveying means; a sheet urging means for urging the friction means; A pre-conveying member comprising a pre-conveying member disposed opposite to the means and a second urging means for urging the pre-conveying member, wherein the stacked sheets are conveyed by frictionally separating the loaded sheets one by one In the separation / conveyance device, it has friction releasing means for separating the friction means and the transportation means, and when the friction means is separated by the friction releasing means, the preliminary transportation member is pressed by the transportation means. A sheet separating and conveying device characterized by keeping. 2. A member according to claim 1, wherein a roller is used as said conveying means, an elastic spring is used as said first and second urging means, and a high coefficient of friction member such as rubber is used as said friction means. A sheet separation / conveyance device using a holder for holding a friction coefficient member, and using an arm member as the preliminary conveyance member. 3. The body according to claim 2, wherein the holder supports the high coefficient of friction member on one surface, and receives a bias of the first elastic spring on an opposite surface, and a sheet conveying direction of the body. And a projecting shaft projecting in a direction perpendicular to the conveying direction at an upstream portion, wherein the projecting shaft is rotatable about the projecting shaft. 4. The pre-transfer arm according to claim 2,
The high friction coefficient member is rotatably supported around the protruding shaft, and extends on both sides of the high friction coefficient member. The high friction coefficient member and the conveyance roller are opposed to the conveyance roller upstream of a facing portion of the conveyance roller. Sheet separation and conveyance device. 5. The sheet separating and conveying apparatus according to claim 2, wherein the friction releasing unit has an operation lever having an operation unit exposed to the outside of the apparatus. 6. The operation lever according to claim 4, wherein the operation lever is rotatable around an axis perpendicular to a sheet conveyance surface, and a leading end portion is the operation portion to operate the holder. Wherein the holder is actuated in a direction away from the conveyance roller by the inclined portion, and the separated state is maintained by the flat portion. 7. The sheet separating and conveying apparatus according to claim 5, wherein the operation lever is formed of one member. 8. The sheet feeding device according to claim 1, wherein a distance from a position where the preliminary conveying member faces the conveying means to a sheet insertion port, and a distance downstream from the position where the preliminary conveying member faces the conveying means in a sheet conveying direction. A sheet separating and conveying apparatus, wherein the distances to the feeding means are each smaller than the dimension of the thick sheet in the conveying direction. 9. A sheet separating / conveying device according to claim 1, reading means for reading an image of a sheet conveyed by said sheet separating / conveying device, recording sheet feeding means, and printing an image on said sheet. An image forming apparatus comprising a recording unit for recording. 10. The image forming apparatus according to claim 9, wherein said image forming apparatus is a facsimile machine. 11. An image forming apparatus according to claim 9, wherein said image recording means has an ink jet recording means for ejecting ink in response to a signal and performing recording on a recording sheet.