JPH1188594A - Image reader and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of a read image by avoiding partial expansion and contraction of a read image of an original in the carrying direction. SOLUTION: A sheet original 3a is carried by an original close contact roller 51 at a prescribed speed while being in close contact with an original platen glass 2a at a downstream in the original carrying direction in the vicinity of an original retainer roller 5d and a solenoid 55 is turned on/off based on a sensing signal of a sheet member sensor 5m and a beginning program search sensor 5n to allow a flapper 55a to be closely in contact or release of the original close contact roller 51 to/from the original platen glass 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image reading apparatus for reading image information of a document on a document supporting member, and more particularly to an image reading apparatus applied to an image forming apparatus such as a copying machine or a facsimile machine.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine or a facsimile apparatus performs recording based on image information read by an image reading apparatus.
It is configured as shown in FIG.

In the image reading apparatus shown in FIG. 8, reference numeral 101 denotes a pressure plate which is a first unit, which can be opened and closed by an operator with respect to the apparatus main body, and presses a document 103b placed on a platen glass 102a. Things. 102 is the second
An original (eg, a sheet-like original) 10 that is a flat head scanner serving as a unit and moves on the original platen glass 102a.
It reads an image of a document 3a or a document 103b (for example, a book-shaped document) that is stationary on the platen glass 102a.

Reference numeral 104 denotes a stationary / movable contact type image sensor for reading an image of the moving document 103a or the stationary document 103b, and an illuminating means 104a for irradiating the reading surface of the document with light, and a reflected light from the reading surface of the document. Selfoc lens through which
The image sensor 104 includes an image sensor 104c disposed directly below the lens 104b and forming an image of the reflected light. For example, a thick book-shaped document (stationary document 103b) such as a book placed on a document table glass 102a is moved by moving the contact image sensor 104 in the sub-scanning direction (the direction of arrow A in FIG. 8). Read (document still reading mode). The sheet-shaped document (moving document 103a) 103a is read while the contact image sensor 104 is stationary below the document pressing roller 105d (document moving reading mode).

On the upper surface of the pressure plate 101, there is provided a document table 101b configured to be able to stack a plurality of sheet-shaped documents. Then, the sheet-shaped document 103a is transported while being separated one by one by the transport / discharge unit 105, and information written on the document is read by the reading unit 106.
Thereafter, the document is discharged to the document discharge tray 107.

That is, the sheet document 103a is a document feed roller.
The document is conveyed to the reading unit 106 by the paper feed roller 105f and the paper feeding roller 105c, and is read by the image sensor 104 while being conveyed in close contact with the surface of the document pressing roller 105d. Then, at the position of the document pressing roller 105d, the sheet document 103a changes its conveying direction, and the downstream side of the reading unit 106 of the document table glass 102a becomes a conveying surface (guide surface). The document ejection tray 107 is moved by the document ejection roller 102c.
Is discharged.

As described above, the conveyance path of the sheet document 103a is bent at the position of the document pressing roller 105d, and the sheet document 103a is bent and conveyed in a substantially J-shape. I have.

The document transport / discharge unit 105 includes a pressure plate 10
1 part of the flat head scanner 10
2 is moved up and down as the pressure plate 101 opens and closes. That is, the paper feed roller 105c, the document discharge roller 105e
And the original pressing roller 105d is connected to the original conveying / ejecting unit 105.
The document transport / discharge unit 105 and the document feed roller 101f are provided on the pressure plate 101. Further, the original discharge roller 102c and the image sensor 104 are provided in the flat head scanner 102.

The document holding roller 105d has both ends supported by a swing arm 105g that can swing about a central axis 105l, receives a force in a clockwise direction by a pressing spring 105i, and floats from the document table glass 102a. It is held down. The document holding roller 105d is attached to the swing arm 105g.
A flange portion 105d1 slightly larger than the diameter of the flange portion 105d1 is provided. Therefore, when the swing arm 105g is pressed toward the platen glass 102a by the pressing spring 105i, the flange portion 105g1 comes into contact with the platen glass 102a, and the document pressing roller 105d faces the platen glass 102a with a small distance d. Become like

In the conventional example of the above construction, the original pressing roller
A transport speed and a transport force are set for each of the document feed roller 101f, the document pressing roller 105d, and the document discharge roller 105e so that the transport force of the sheet document 103a is applied to 105d.

That is, the tension of the conveyed sheet document 103a is generated due to the correlation between the conveyance speed and the conveyance force of the sheet document 103a by the document feed roller 101f and the document discharge roller 105e. Then, by applying the tension to the document pressing roller 105d at a position where the conveyance path of the sheet document 103a is bent, a frictional force is generated between the outer peripheral surface of the document pressing roller 105d and the sheet document 103a. As a result, a document conveying force is generated by the document pressing roller 105d.

The sheet document 103a in the reading unit 106
In order to prevent the image sensor 104 from reading the tip of the image and to reproduce the shadow as a shadow, the illuminating means 104a
It is arranged on the downstream side in the transport direction of the sheet document 103a. Therefore, a sufficient width (length in the transport direction) of the document table glass 102a to cover the image sensor 104 is required.
As a result, the document discharge roller 105e and the document discharge roller 102c are arranged at locations where they do not interfere with the end of the document table glass 102a.

[0013]

However, in the above conventional example, when the original pressing roller 105d has a conveying force,
That is, in the state where the tension of the sheet document 103a is applied to the document pressing roller 105d, the conveying speed of the sheet document 103a is kept constant, but in the state where the tension is not applied to the document pressing roller 105d, the sheet document 103a is There was a risk that the transport speed would change.

That is, the leading end of the sheet document 103a is
Until it reaches the document ejection roller 105e after passing through
Reading is performed by the reading unit 106 according to the transport speed of the document feed roller 101f. Further, after the rear end of the sheet document 103a has passed the document feed roller 101f, the document discharge roller 105e
The reading by the reading unit 106 is performed according to the transport speed of the image.

As a result, there is a possibility that the read image may have a difference in expansion and contraction when the tension of the sheet document 103a is applied to the document pressing roller 105d and when it is not applied.

That is, an area corresponding to the distance from the reading section 106 at the leading end of the read image to the document discharge roller 105e and an area corresponding to the distance from the document feeding roller 101f at the rear end of the read image to the reading section 106 are: There is a possibility that the read image in the transport direction shrinks as compared with the area other than the area (the front end and the rear end of the read image).

Further, when the tension of the sheet document 103a is not applied to the document pressing roller 105d, the sheet document 103a ramps up within the minute interval d between the document pressing roller 105d and the document glass 102a, and the reading unit 106 reads the sheet document 103a. The image may be distorted.

Furthermore, when the tension of the sheet document 103a is applied to the document pressing roller 105d and the sheet document 103a is conveyed, the minute distance d between the reading surface of the sheet document 103a and the document table glass 102a makes the distance smaller. A gap occurs and the reading unit
There is a possibility that the height of the focal position of the contact type image sensor 104 at 106 may be higher than the focal position of the book document 103b adhered on the platen glass 102a by the pressure plate 101.

As a result, there is a possibility that the density difference of the read image may occur between the original moving reading mode and the original stationary reading mode.

In view of the above, the length of the conveyable sheet document 103a should be longer than the distance from the document feed roller 101f to the document discharge roller 105e via the document pressing roller 105d. It will be limited.

An object of the present invention is to prevent a difference in expansion and contraction, a disorder, a density difference, and the like of a read image of a document and to stabilize the quality of the read image.

[0022]

A typical configuration of the present invention for achieving the above object is a document supporting member for supporting a document, and a transport for transporting a sheet-shaped document onto the document supporting member. Means, edge detecting means for detecting the leading edge and the trailing edge of the sheet-shaped document conveyed by the conveying means, and a conveying direction of the sheet-shaped document arranged at a small distance from the document supporting member surface A rotating member that rotates to
Reading for reading image information of a sheet-like document moving on the document support member at a position opposed to the rotating member or reading the image information while moving along the document stationary on the document support member And an ejection unit for ejecting the sheet-like original, wherein the sheet-like original is brought into close contact with the original-supporting member on the downstream side in the original-conveying direction near the rotating member so as to be conveyed. The image forming apparatus further includes a conveyance unit, and a contact release unit for bringing the contact conveyance unit into and out of contact with the document support member based on a detection signal of the end detection unit.

According to the above arrangement, the sheet-shaped original is supported on the downstream side in the conveying direction near the rotating member by the contact conveying means capable of adhering to and releasing from the original supporting member based on the detection signal of the end detecting means. Since the image may be read by the reading unit while the sheet is being conveyed at a constant speed while being in close contact with the member, it is possible to prevent a difference in expansion, contraction, disturbance, density difference, and the like of the read image of the sheet-shaped document.

Further, for the second unit provided with the document supporting member and the reading unit, the conveying unit, the end detecting unit, the rotating member, the discharging unit, the contact conveying unit, and the contact releasing unit. The first unit provided with the first unit is configured to be rotatable openable and closable, and when the first unit is closed with respect to the second unit, a conveyance path of the sheet-shaped document is formed.

Further, the invention is characterized in that the contact release means is operated by an operator's operation in addition to being operated based on the detection signal of the end detecting means.

According to the above arrangement, the close-contact releasing means is
In addition to the operation based on the detection signal of the end detection means, the first unit is also operated by the operation of the operator.
The sheet-shaped document conveyance path can be opened without opening the unit or opening the sheet-shaped document conveyance means / discharge means in the first unit with respect to the second unit. This can be easily performed.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an image reading apparatus to which the present invention is applied will be described with reference to the drawings.

[First Embodiment] An image reading apparatus according to a first embodiment will be described in detail with reference to the drawings. still,
In the present embodiment, an image reading apparatus used in a facsimile apparatus as an image forming apparatus will be described as an example.

FIGS. 1 to 7 show a first embodiment, FIG. 1 is an explanatory view of a configuration of an image reading apparatus, FIG. 2 is an explanatory view of a state in which a document transport / discharge unit is opened, and FIG. FIG. 4 is an explanatory diagram of a configuration of a sheet-shaped original conveying portion, FIG. 4 is an explanatory diagram of a facsimile device as an example of an image forming device provided with an image reading device, FIG. 5 is an external explanatory diagram of the image forming device, and FIG. FIG. 7 is an explanatory diagram of the operation of the document contact roller as the contact transport means, and FIG. 7 is a flowchart showing the flow of the reading operation.

Here, as the order of the description, first, the overall configuration of a facsimile apparatus which is an image forming apparatus having an image reading apparatus will be described, and then the configuration of the image reading apparatus will be described.

<< Overall Description of Facsimile Apparatus >> In FIGS. 4 and 5, reference numeral 1 denotes an opening / closing member, which is a pressure plate serving as a first unit, which can be opened and closed by an operator with respect to the apparatus main body. Platen glass 2 as a member
The document 3b is placed on the document 3a. Reference numeral 2 denotes a flat bed scanner serving as a second unit, and a document (for example, a sheet-shaped document) moving on the document table glass 2a.
It reads an image of a document 3a or a document 3b (for example, a thick book-like document such as a book) 3b resting on the platen glass 2a. Reference numeral 4 denotes a contact image sensor that reads an image.

On the upper surface of the pressure plate 1, there is provided a document table 1b configured to be able to stack a plurality of sheet-shaped documents 3a. Then, the sheet-shaped document 3a is transported while being separated one by one by a transport / discharge unit 5 constituting a document transport / discharge unit, and information written on the document is read by a reading unit 6. Here, the document transport / discharge unit 5 is provided in a part of the pressure plate 1, and moves up and down with opening and closing of the pressure plate 1. Further, the document 3 a read by the reading unit 6 is discharged to a document discharge tray 7. The configuration of the image reading apparatus that reads the written information by transporting the original will be described later in detail.

The information read by the reading section 6 or the information transmitted from another facsimile machine is recorded by an image forming means 8 comprising a laser beam printer.
The image forming unit 8 transfers and records the toner image on the recording paper, which is a recording medium supplied from the cassette paper feeding unit 9 or the manual paper feeding unit 10, by the image forming unit 11, and fixes and discharges the toner image by the fixing unit 12. The recording paper is discharged to a recording paper discharge tray 14 by a pair of paper rollers 13.

4 and 5, reference numeral 15 denotes a display unit.
An operation unit 16 includes an input unit a, an input unit, and the like, and a control unit 16 of the facsimile machine.

That is, the image forming means 8 is arranged on the apparatus main body side, separates the sheets P in the cassette 9a in which the general-purpose sheets P are stacked and accommodated one by one by the sheet feeding roller 9b, To correct the skew of the paper P,
The paper P is conveyed upward and fed to the image forming unit 11 in synchronization with a print signal from the control unit 16.

The surface of the photosensitive drum 11a, which is an electrophotographic photosensitive member, is uniformly charged by the charging member 11b, and the surface is exposed by the laser scanner 18 based on image information. As a result, an electrostatic latent image is formed on the photosensitive drum 11a, and the toner as a developer in the image forming section is transferred to the electrostatic latent image on the photosensitive drum 11a by the developing sleeve 11c as a developer carrier. Then, a toner image is formed on the photosensitive drum 11a. Then, the toner image is transferred onto a sheet P by a transfer roller 11d, and the sheet P is further conveyed to an upper fixing unit 12. In the fixing unit 12, the toner transferred on the sheet P is conveyed by a fixing roller 12 a and a pressure roller 12 b and is fixed on the sheet P by heat and pressure. The sheets are sequentially discharged to the paper tray 14.

On the other hand, the paper P stacked on the manual paper feed unit 10 is separated from the paper feed roller 10a by a separation pad.
10b, the sheet P is separated into one sheet, the skew of the sheet P is corrected by the registration roller pair 17, the sheet P is transported upward as described above, the toner image is transferred by the image forming unit 11, and the toner image is fixed by the fixing unit 12. Similarly, the paper P is sequentially discharged to the recording paper discharge tray 14.

{Image Reading Apparatus} Next, the configuration of the image reading apparatus will be described. The image reading apparatus according to the present embodiment is disposed above the image forming apparatus, and has a reading unit that reads image information of a document, a conveyance unit that conveys and discharges a sheet document, a discharge unit, and presses the sheet document to a reading position. And a document holding roller.

(Reading Means) As shown in FIGS. 1 and 4, a reading means for reading image information of a document reads both a sheet-like document and a thick document such as a book by a close contact type image sensor 4. It is designed to read.

The contact type image sensor 4 is provided with an illuminating means 4a for irradiating the reading surface of the original with light, a selfoc lens 4b through which the reflected light from the reading surface of the original passes, and is disposed immediately below the lens 4b. And an image sensor 4c for forming an image of the reflected light. Here, the selfoc lens 4b is of a long focus type, and the platen glass 2 having a thickness of 3 mm is used.
The focus is set on the upper surface side of a.

The flatbed scanner 2 scans a thick original such as a book (hereinafter referred to as a book original) in a stationary state (an original stationary reading mode). Is provided.

Reference numeral 1a denotes a pressing plate constituting a document pressing portion, which is fixed and supported on the pressure plate 1;
Is closed, the original on the original platen glass 2a is pressed.
In addition, reference numeral 2b shown in FIG. 4 denotes a frame serving as a structure of the flatbed scanner 2, which supports the original platen glass 2a.

As shown in FIG. 5, the pressure plate 1 is provided with a hinge 1h provided between the rotation center shaft 1g and the frame 2b so that the pressure plate 1 can be opened and closed by a predetermined angle with respect to the frame 2b. An operator opens the pressure plate 1 and places a document on the platen glass 2a. The hinge 1h has a built-in damper mechanism formed by a spring and a cam (not shown), and prevents the pressure plate 1 from falling and closing by its own weight. For this reason, the pressure plate 1
When the angle is about 10 degrees or more, the apparatus stops without falling due to its own weight, and is pressed by the flatbed scanner 2 at about 10 degrees or less.

The contact image sensor 4 is driven in the sub-scanning direction of the book document (the direction of arrow A in FIG. 1) by a drive mechanism (not shown) in the document stationary reading mode. The contact type image sensor 4 is urged against the lower surface of the platen glass 2a, and the distance between the contact type image sensor 4 and the platen glass 2a is always kept constant when moving in the sub-scanning direction by the above-described driving mechanism. As a result, the height of the focal position of the contact type image sensor 4 on the platen glass 2a becomes constant, and a good image without a deviation of the focal position can be obtained.

Document 3b stationary on platen glass 2a
Are read while moving the contact image sensor 4 in the sub-scanning direction (the direction of arrow A in FIG. 1).

In the original stationary reading mode, the original is placed at a predetermined position on the original platen glass 2a.
There is provided an index 19 serving as a placement instruction means when placing on the base. The index 19 has a white surface in contact with the platen glass 2a, and temporarily stops under the index 19 when the image sensor 4 moves in the sub-scanning direction. Read. Then, before reading the image information of the document, shading correction for setting a reference white level is performed.

(Sheet Conveying and Ejecting Means) When reading a sheet-shaped document (hereinafter referred to as a sheet document) 3a,
The sheet document is conveyed to the reading position by the sheet conveying means, and the sheet document 3a is prevented from floating from the platen glass 2a by the document pressing roller 5d as a rotating member. After the sheet document 3a is sandwiched between the glass 2a and reading is performed in this state, the document 3a is discharged to the document discharge tray 7 by a discharge unit.

The document transport / discharge unit 5 transports the sheet document 3a loaded on the document table 1b first to the preliminary transport rollers 1d.
The sheet is separated one by one by a separation roller 1e in contact with the separation piece 5b, and is further separated by an original feed roller 1f and a pressing spring (not shown) constituting the original conveying means.
The sheet is conveyed to the reading unit 6 by the paper feed roller 5c pressed by the button.

The sheet document 3a is read in a state where the contact image sensor 4 is stopped under the document pressing roller 5d (document moving reading mode). Here, the sheet document 3a is conveyed in close contact with the surface of the document pressing roller 5d, and is read by the image sensor 4. The document pressing roller 5d is prevented from floating from the document table glass 2a by the pressing means. It is designed to be held down.

At the position of the original pressing roller 5d, as shown in FIG. 1, the conveyed sheet original 3a changes the conveying direction, is held between the original contact roller 51 and the surface of the original table glass 2a, and is further discharged. Is discharged to the document discharge tray 7 by the document discharge roller 5e and the document discharge roller 2c.

As described above, the conveying path of the sheet original 3a is bent at the position of the original pressing roller 5d, so that the original 3a is bent in a substantially J-shape and conveyed. .

The paper feed roller 5c, the document discharge roller 5e, the document pressing roller 5d, and the document contact roller 51 are provided in the document transport / discharge unit 5, and the document transport / discharge unit 5 and the document feed The roller 1f is provided on the pressure plate 1. Further, the original discharge roller 2c and the image sensor 4
Is provided in the flatbed scanner 2.

As shown in FIG. 2, the document transport / discharge unit 5 can be opened and closed with respect to the pressure plate 1 excluding the document transport / discharge unit 5, and the document transport / discharge unit 5 is closed.
By closing the pressure plate 1 to the flatbed scanner 2, a document transport path is formed.

Accordingly, in the case of a jam clearance or the like, when the document transport / discharge unit 5 is opened with respect to the pressure plate 1, the document transport path is opened and the jam clearance or the like can be easily performed.

Further, the document transport / discharge unit 5 is provided on a part of the pressure plate 1 as described above, and when the pressure plate 1 is opened with respect to the flatbed scanner 2, the document transport / discharge unit 5 is also raised. There is a gap between the original pressing roller 5d and the original platen glass 2a (see FIG. 5A), and in the event of an original jam or the like, the original transport path is opened so that the jam can be easily cleared. .

Further, the sheet document 3a is placed on the document table 1b.
And a slider 1c slidable in a direction perpendicular to the conveying direction of the document (the width direction of the original 3a).
c, the sheet document 3 placed on the document table 1b
"a" can be aligned on both sides.

(Pressing Structure for Pressing Document Pressing Roller to Document Platen Glass) Next, a structure for pressing the document pressing roller 5d toward the document platen glass 2a will be described with reference to FIG.

In FIG. 3, reference numeral 5f denotes an original pressing roller 5;
Reference numeral 5g and 5h denote swinging arms which support both ends of the roller 5d in the rotation axis direction so as to swingably attach the document pressing roller 5d to the pressure plate 1. Reference numerals 5i and 5j denote pressing springs constituting pressing means for pressing the document pressing roller 5d against the document table glass 2a. Reference numeral 5k denotes a rotation center axis of the document pressing roller 5d.

The rotation center axis 1g of the pressure plate 1 and the rotation center axis 5k of the document pressing roller 5d are arranged orthogonal to each other, and the drive transmission means 5f is arranged on one side in the direction of the rotation center axis of the document pressing roller 5d. The pressure plate 1 is disposed on the side closer to the rotation center axis 1g.

The drive transmitting means 5f in the present embodiment comprises:
It comprises four drive gears 5f1, 5f2, 5f3, 5f4 and a timing belt 53. The drive is transmitted to the drive gear 5f1 by a drive source (not shown) and a drive transmission unit,
The drive is transmitted from the drive gear 5f1 to the original pressing roller 5d via the drive gear 5f2 via the drive gear 5f3. Further, the drive is transmitted to the original contact roller 51 by the timing belt 53 via the drive gear 5f2 and the drive gear 5f4.

The oscillating arms 5g and 5h are capable of oscillating about the rotation center shaft 51 of the driving gear 5f2, and receive a clockwise force by pressing springs 5i and 5j, respectively.
The original pressing roller 5d is pressed against the original table glass 2a. The urging force of the pressing springs 5i and 5j presses the original pressing roller 5d toward the original platen glass 2a, but is not so strong as to lift the pressing plate 1 when the pressing plate 1 is closed. .

Here, as shown in FIG. 1, the swing arms 5g and 5h are provided with a flange portion 5d1 slightly larger than the diameter of the original pressing roller 5d, and are swung by the pressing springs 5i and 5j. When the arms 5g and 5h are pressed toward the platen glass 2a, the flange portion 5d1 comes into contact with the platen glass 2a, and the document pressing roller 5d comes to face the platen glass 2a with a small distance d.

The minute interval d is set so that the minute interval d is slightly larger than the thickness t of the normally used sheet document 3a. For example, when t = 0.225 mm, d = 0.25 mm. It is appropriate to set the minute interval d to about 0.25 mm to 0.3 mm.

Next, the operation of the original contact roller 51 will be described with reference to FIG. In FIG. 6, reference numeral 52 denotes an original contact roller 51.
The upper and lower arms support both ends in the rotation axis direction of the roller 51 in order to swingably mount the roller 51 on the pressure plate 1 (one is not shown).

Reference numeral 54 denotes a pressing spring which constitutes a pressing means for pressing the original contact roller 51 against the original glass 2a (one is not shown). 5e1 is the rotation center axis of the document discharge roller 5e, and 51a is the rotation center axis of the document contact roller 51.

Also, a solenoid constituting the contact releasing means
55 is disposed at a position where the flapper 55a lifts the projection 52a of the upper and lower arms 52. As shown in FIG. 6A, when the solenoid 55 is turned off, the flapper 55a does not contact the protrusion 52a of the upper and lower arms 52. For this reason, the pressing spring 54 incorporated in the upper and lower arms 52
The outer peripheral surface of the original contact roller 51 is pressed (closely attached) to the original platen glass 2a by the urging force.

Accordingly, the sheet original 3a is placed on the original contact roller.
When it is located between the original platen 51 and the platen glass 2a, the drive gears 5f1, 5f2, 5f4 and the timing belt 53 rotate in the direction of the arrow in the drawing by a drive motor (not shown), and the original contact roller 51 The sheet is conveyed while being held between the base glass 2a (close contact conveyance).

As shown in FIG. 6B, when the solenoid 55 is turned on, the flapper 55a lifts the projection 52a of the upper and lower arms 52, so that the original contact roller 51
Is held at a position where the sheet document 3a is retracted from the platen glass 2a, and the conveying path of the sheet document 3a is released. That is, the original contact roller 51 is held at a position separated from the original table glass 2a as shown in FIG. 6B.

Incidentally, the solenoid 55 constituting the close contact releasing means
The roller having a sufficient suction force to hold the original contact roller 51 at the position shown in FIG. 6B is set.

(Original Conveyance Speed) As described above, when the original contact roller 51 closely transports the sheet original 3a between the original platen glass 2a and the original original feed roller 51 in this embodiment,
f, the original document conveying speeds of the original pressing roller 5d, the original contact roller 51, and the original discharging roller 5e are set as follows.

First, the sheet document conveying speed V1 by the document feed roller 1f and the sheet document conveying speed V2 by the document pressing roller 5d are set to have a relationship of V1> V2. As a result, the sheet document 3a becomes slack between the document feed roller 1f and the document press roller 5d, and the document press roller 5d is not affected by the load of the document feed roller 1f.

Further, the sheet original conveying speed V2 by the original pressing roller 5d and the sheet original conveying speed V3 by the original contact roller 51 are set to have a relationship of V2> V3. As a result, the sheet document 3a becomes loose between the document pressing roller 5d and the document contact roller 51, and the document contact roller 51 is not affected by the load of the document pressing roller 5d.

The sheet document conveying speed V4 of the document discharge roller 5e is set so as to have a relationship of V3> V4 with the sheet document conveying speed V3 of the document contact roller 51. As a result, the sheet document 3a becomes slack between the original contact roller 51 and the original discharge roller 5e, and the original close roller 51 is not affected by the load of the original discharge roller 5e.

Therefore, the rollers 1f, 5d, 51, 5
The sheet document conveying speed e is set to have a relationship of V1>V2>V3> V4.

(Reading Operation) Next, a reading operation of the facsimile apparatus using the image reading apparatus of the present embodiment will be described with reference to FIGS. 1 to 6 and a flowchart shown in FIG.

First, the operator turns on the power of the facsimile machine (step 11). At this time, it is checked whether or not the sheet material detection sensor 5m and the cueing sensor 5n have detected the presence of the sheet document 3a (steps 12 and 13), and at least one of them has detected that the sheet document 3a is present. For example, the process proceeds to step 34, which will be described later. If both of them detect that the sheet original 3a is not present, the process enters a standby state (step 14).

Next, the sheet document 3a is placed on the document table 1b (step 15). Further, the operator inputs the transmission destination of the sheet document 3a, the density at the time of reading, the resolution, and the like from the operation unit 15 (step 16), and instructs the start of reading by pressing the start switch 15b (step 17). Next, it is checked whether or not the sheet material detection sensor 5m detects the presence of the sheet document 3a (step 18). If the presence of the sheet document 3a is not detected, the sheet document 3a is placed on the document table 1b. The display unit 15a displays a message notifying that the
(Step 19), and after a predetermined time has passed, the display section
The display of 15a is canceled (step 20), and the process returns to the standby state of step 14.

If the sheet material detection sensor 5m detects that the sheet original 3a is present in step 18, a drive motor (not shown) is driven by a signal from the control unit 16 (step 21). Then, the solenoid 55 is turned on by a signal from the control unit 16 (step 22), and the flapper 55a lifts the original contact roller 51 as shown in FIG. 6B, and opens the sheet original transport path downstream of the reading unit. . Driving force from a drive motor (not shown) is transmitted to the preliminary transport roller 1d, and the upper peripheral surface of the preliminary transport roller 1d contacts the sheet document 3a to separate the sheet document 3a on the document table 1b from the separation roller 1e. To the lower sheet document 3
a to the nip of the separation roller 1e.

When a plurality of sheet documents 3a are conveyed to the nip portion of the separation roller 1e by the preliminary conveyance roller 1d, the separation roller 1e and the separation pad 5b
Separates the overlapped sheet document 3a, and separates only the lowest sheet document 3a from the document feed roller 1f and the sheet feed roller 5f.
The sheet is conveyed to the nip portion c (step 23). The separated sheet document 3a is conveyed toward the reading unit 6 by the document feed roller 1f and the feed roller 5c (step 24).

After the drive motor (not shown) rotates in step 21, the cueing sensor 5n monitors whether or not the leading edge of the sheet document 3a reaches within a predetermined time (step 2).
Five). In the process of separation in step 23 and conveyance in step 24, the sheet original 3a is not normally conveyed due to non-feeding or jamming, and the cueing sensor 5n does not detect the leading end of the sheet original 3a even after a predetermined time has elapsed. If so, the process proceeds to step 33 described later. When the cue sensor 5n detects the sheet document 3a, the image information is read from the leading edge of the sheet document 3a at the same timing (step 26).

Then, in step 25, a predetermined time has passed since the cueing sensor 5n has detected the leading edge of the sheet document 3a.
When the leading end of the sheet document 3a passes through the contact portion of the document contact roller 51 to the document table glass 2a (downstream near the document pressing roller 5d), the solenoid 55 is turned off by a signal from the control unit 16 (step 27). As a result, FIG.
As shown in (a), the flapper 55a is
Is released, and the sheet document 3a is conveyed (close contact conveyance) while being sandwiched between the outer peripheral surface of the document contact roller 51 and the platen glass 2a.

After the cueing sensor 5n detects the leading edge of the sheet document 3a in step 25, it is monitored whether or not the cueing sensor 5n detects the trailing edge of the sheet document 3a within a predetermined time (step 28). ). Then, during reading in step 26,
The sheet document 3a is not conveyed normally due to a jam or the like,
The cueing sensor 5n keeps the sheet original 3a even after a predetermined time has elapsed.
If the trailing end is not detected, the process proceeds to step 33 described later. When the cue sensor 5n detects the trailing edge of the sheet document 3a, the reading of the image information is terminated at the same timing from the trailing edge of the sheet document 3a.

Thereafter, the cueing sensor 5n detects the sheet document 3
When a predetermined time has passed since the detection of the trailing edge of the document a, and the trailing edge of the sheet document 3a has been conveyed to a position immediately before the document contact roller 51 comes into close contact with the platen glass 2a, a signal from the control unit 16 The solenoid 55 is turned on (step 29). This allows
As shown in FIG. 6B, the flapper 55a holds the original contact roller 51 and opens the sheet original transport path downstream of the reading unit.

Then, the sheet document 3a is discharged out of the apparatus by the document discharge rollers 5e and the document discharge rollers 2c (step).
30). Thereafter, it is confirmed by the sheet material detection sensor 5m whether or not the sheet original 3a is still detected (step
31).

Then, in step 31, the sheet material detection sensor 5m
If the sheet original 3a is still detected, the process returns to step 23 and the reading of image information is continuously repeated. When the sheet material detection sensor 5m stops detecting the sheet document 3a, it is determined that reading of all the sheet documents 3a has been completed, and the last sheet document 3a is scanned by the document discharge rollers 5e and the document discharge rollers 2c. Discharge outside (step 32).

When the discharge is completed, the solenoid 55 is turned off by a signal from the control unit 16 (step 38), and control is made to proceed to step 14, and the apparatus stands by in the standby state until the operator again sets the sheet document 3a.

In step 24, when the document feed roller 1f conveys the sheet document 3a, the peripheral speed V1 of the document feed roller 1f is set to be higher than the peripheral speed V5 of the separation roller 1e. The separation roller 1
e is rotated by the conveyed sheet document 3a.

Next, processing when an error occurs will be described.

First, in step 12 and step 13, when at least one of the sheet material detection sensor 5m and the cueing sensor 5n detects the sheet document 3a, the display unit
An error message is displayed at 15a (step 34), and after confirming that neither the sheet material detection sensor 5m nor the cueing sensor 5n has detected the sheet document 3a (step 35, step 36), the error message is released (step 35, step 36). step
37) Return to step 14.

In step 25, when the cueing sensor 5n does not detect the leading edge of the sheet document 3a even after the lapse of a predetermined time, or in step 28, the cueing sensor 5n does not detect the top of the sheet document 3a even after the lapse of the predetermined time. If the rear end is not detected, the drive motor (not shown) is stopped (step 33),
Thereafter, the flow shifts to step 34 described above.

If the sheet original 3a is not conveyed normally due to a jam or the like during reading in step 26, and the cueing sensor 5n does not detect the rear end of the sheet original 3a even after a predetermined time has elapsed in step 28, the drive is started. Stop the motor (step
33), an error display is performed (step 34), and the following reading operation may be performed as follows.

First, in the above-described error display, the operator is urged to press a jam release switch (not shown) on the operation unit 15.

When the operator turns on the jam release switch, the solenoid 55 is turned on as in step 22, and
As shown in FIG. 6B, the flapper 55a is
To open the sheet document conveying path on the downstream side of the reading unit 6.

Thereafter, the process proceeds to step 35 and step 36, where it is confirmed that neither the sheet material detecting sensor 5m nor the cueing sensor 5n has detected the sheet document 3a.
As in the case of 27, the solenoid 55 is turned off, and the flapper 55a releases the holding of the original contact roller 51 as shown in FIG.

That is, in addition to operating the solenoid 55 for bringing the original contact roller 51 into close contact with the original platen glass 2a and releasing it based on the detection signals of the sheet material detection sensor 5m and the cueing sensor 5n, the operation of the operator is also possible. It is also configured to work. Thus, the sheet document conveying path can be opened without the operation of opening the pressure plate 1 with respect to the flatbed scanner 2 and the operation of opening the transport / discharge unit 5 in the pressure plate 1 with respect to the flatbed scanner 2. Jam processing can be easily performed.

As described above, the sheet material detection sensor 5m
By bringing the original contact roller 51 into close contact with the original platen glass 2a via the sheet original 3a based on the detection signal of the cueing sensor 5n, the original 3a can be conveyed by the original original contact roller 51 alone. Since the transport speed V3 is constant, the sheet original 3a is
While being conveyed at 51, that is, while reading the image of the original, the read image is kept constant without expanding and contracting in the sub-scanning direction,
The quality of the read image is stabilized.

In the original moving reading mode, the sheet original 3a is closely transported by the original contact roller 51 on the original platen glass 2a on the downstream side in the vicinity of the reading unit 6, so that the original stationary reading mode for reading the book-shaped original is performed. A read image having the same density can be obtained, and it is not necessary to change the light amount of the illuminating means 4a in the contact image sensor 4 according to the document reading mode.

Further, a solenoid 55 as a contact release means is provided.
However, since the original contact roller 51 releases the close contact with the original table glass 2a, even when the drive is transmitted to the original close roller 51 at the time of releasing the close contact, the original table glass 2a does not rub on the surface of the original table glass 2a. The glass 2a surface and the like are not stained.

Further, by providing the original contact roller 51 between the original pressing roller 5d and the original discharging roller 5e, more specifically, on the downstream side near the original pressing roller 5d, the length of the sheet original 3a that can be conveyed is reduced. It is possible to shorten the distance by a distance corresponding to the distance from the original contact roller 51 to the original discharge roller 5e.

Further, by using an image reading apparatus having a stable reading accuracy as described above for the image forming apparatus, excellent image reproducibility can be obtained.

[Other Embodiments] In the above embodiment,
Although a facsimile apparatus is illustrated as an example of the image forming apparatus, the present invention is not limited to this. For example, another image forming apparatus such as a copying machine may be used, and an image reading apparatus used in the image forming apparatus may be used. A similar effect can be obtained by applying the present invention.

In the above-described embodiment, the electrophotographic method is exemplified as the recording method. However, the recording method is not limited to this, and another recording method such as an ink jet method may be used.

[0103]

As described above, according to the present invention,
At a constant speed, the sheet-shaped document is brought into close contact with the document support member on the downstream side in the document transport direction near the rotating member by the contact conveyance device capable of being brought into close contact with and released from the document support member based on the detection signal of the edge detection means. Since the image can be read by the reading unit while the sheet is being conveyed, the read image of the sheet-shaped document is kept constant without expanding and contracting in the document conveyance direction, and the quality of the read image is stabilized.

Further, in the original moving reading mode, the sheet original is closely transported by the close transport means on the original supporting member, so that a read image having the same density as that of the original stationary reading mode for reading the book original can be obtained. This makes it possible to eliminate the necessity of changing the light amount or the like of the reading means in accordance with the document reading mode, thereby stabilizing the quality of the read image.

Further, since the close-contact release unit performs close contact and release of the close-contact conveyance unit with the document supporting member based on the detection signal of the end detection unit, even when the drive is transmitted to the close-contact conveyance unit when the close contact is released. The surface of the document supporting member is not rubbed, and the surface of the document supporting member is not stained.

Further, since the close-contact conveying means is provided between the rotating member and the discharging means and on the downstream side in the document conveying direction near the rotating member, the length of the sheet-form document which can be conveyed can be increased by the close-contact conveying means. It is possible to shorten the distance by an amount corresponding to the distance to the discharging means.

Further, in addition to operating the close contact releasing means for performing close contact and release of the close contact conveying means with the document supporting member based on the detection signal of the end detecting means, it is also operated by the operation of the operator. With such a configuration, the first unit can be opened with respect to the second unit,
The sheet-shaped document conveying path can be opened without the operation of opening the sheet-shaped document conveying means and the discharging means in the first unit with respect to the second unit, and the paper jam can be easily performed. .

Also, by using an image reading apparatus having a stable reading accuracy as described above for the image forming apparatus, excellent image reproducibility can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the configuration of an image reading apparatus.

FIG. 2 is an explanatory diagram of a state where a document conveying / discharging unit is opened.

FIG. 3 is an explanatory diagram of a configuration of a sheet-shaped document conveying portion.

FIG. 4 is a configuration explanatory view of a facsimile apparatus which is an example of an image forming apparatus using the image reading apparatus.

FIG. 5 is a diagram illustrating the configuration of an image forming apparatus.

FIG. 6 is an explanatory diagram of an operation of a contact conveyance unit (document contact roller).

FIG. 7 is a flowchart illustrating the operation of the image forming apparatus.

FIG. 8 is a configuration explanatory view illustrating a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pressure plate 1a ... Holder plate 1b ... Document mounting table 1c ... Slider 1d ... Preliminary conveyance roller 1e ... Separation roller 1f ... Document feeding roller 1g ... Rotation center axis 1h ... Hinge 2 ... Flatbed scanner 2a ... Document table glass 2b ... Frame 2c. Original discharge roller 3a... Original 3b... Original 4... Contact image sensor 4a. ... Paper feed roller 5d... Original press roller 5d1... Flange 5e... Original discharge roller 5e1... Rotation center axis 5f... Drive transmission means 5f1, 5f2, 5f3, 5f4. Drive gear 5g, 5h. Pressing spring 5k ... rotation center axis 5l ... rotation center axis 5m ... sheet material detection sensor 5n ... cueing sensor 6 ... reading Reference numeral 7: Document discharge tray 8: Image forming means 9: Cassette feeding section 9a: Cassette 9b: Feeding roller 10: Manual feeding section 10a: Feeding roller 10b: Separating pad 11: Image forming section 11a: Photoconductor drum 11b ... charging member 11c ... developing sleeve 11d ... transfer roller 12 ... fixing unit 12a ... fixing roller 12b ... pressure roller 13 ... discharge roller pair 14 ... recording paper discharge tray 15 ... operation unit 15a ... display unit 15b ... start switch 16… Control unit 17… Registration roller pair 18… Laser scanner 19… Index 51… Document contact roller 51a… Rotation center axis 52… Up and down arm 52a… Protrusion 54… Pressing spring 55… Solenoid 55a… Flapper

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 1/04 106 H04N 1/04 106A

Claims (4)

[Claims] An original supporting member for supporting an original;
Conveying means for conveying the sheet-shaped document onto the document supporting member; edge detecting means for detecting the leading and trailing ends of the sheet-shaped document conveyed by the conveying means; A rotating member that is arranged at an interval and rotates in the sheet conveying direction, and reads image information of the sheet-shaped document that is stationary at a position facing the rotating member and moves on the document supporting member or reads the document. An image reading apparatus comprising: reading means for reading image information while moving along a document resting on a supporting member; and discharging means for discharging the sheet-shaped document. On the downstream side in the direction in which the sheet-shaped document is conveyed while being in close contact with the document support member; and Image reading apparatus for said an adhesion releasing means for performing the adhesion and release of the document support member, characterized in that the provided. A second unit provided with the document supporting member and the reading unit, the conveying unit, the end detecting unit, the rotating member, the discharging unit, the contact conveying unit, and the contact releasing unit; A first unit provided with the first unit is configured to be rotatable and capable of opening and closing, and when the first unit is closed with respect to the second unit, a transport path of the sheet-shaped document is formed. The image reading device according to claim 1. 3. An apparatus according to claim 1, wherein said contact release means is operated by an operation of an operator in addition to being operated based on a detection signal of said end detection means. The image reading device according to claim 1. 4. An image reading device for reading image information of a document, and image forming means for recording an image on a recording medium in accordance with the image information, wherein the image reading device is used as the image reading device. 3. An image forming apparatus using the image reading device according to any one of 2.