JP2001127949A - Image reader and image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader which obtains high quality read images by reliably separating an original pressing means from a reading surface with a simple configuration and an image forming device. SOLUTION: An original-pressing member 5b is fixed, while a downstream surface 5b1 imitates a regulation surface 6d of an upper original guide 6 and the original-carrying direction downstream side end part of a pressing surface 5a2 pressing the original S is separated from a read surface 4a. The deficiency of whiteness falling low, because a gap x is generated with respect to the face 4a and the surface 5a2 is stuck to the surface 4a at a reading position V.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus for reading image information of a document, and is applied to an image forming apparatus such as a facsimile apparatus.

[0002]

2. Description of the Related Art Conventionally, as this type of image reading apparatus,
There is one shown in FIG. As shown in FIG. 8, a document pressing unit 52 that presses a document against a contact image sensor 51 as an image reading unit is configured to be in close contact with the reading surface of the contact image sensor 51.

The original pressing means 52 includes a white sheet 52a.
And a white sheet metal 52b. The upper part of the white sheet 52a is fixed with screws. The white sheet metal 52b is fixed with the downstream side in the document transport direction hooked on the upper document guide inside the apparatus.

As shown in an enlarged view in FIG. 9, embosses 52c are provided at both ends in the longitudinal direction of the original pressing means 52 so that the original pressing means 52 is not brought into close contact with the reading surface of the contact type image sensor 51.

[0005]

However, in the case of the prior art described above, the document pressing means 52 may come into close contact with the reading surface of the contact image sensor 51, which is a reference for reading an image. There has been a problem that the output of whiteness is partially reduced and white streaks appear on the read image.

For this reason, it has been necessary to take measures such as providing a high-precision emboss in order to prevent the closeness of the document pressing means 52 and restricting the warpage of the white sheet metal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to reliably separate a document pressing means from a reading surface with a simple structure to obtain a high quality read image. An object of the present invention is to provide an image reading apparatus and an image forming apparatus which can be obtained.

[0008]

In order to achieve the above object, an image reading apparatus according to the present invention comprises: an image reading means for reading image information from a document conveyed on a reading surface at a reading position; A document pressing device for pressing a document on a pressing surface facing a reading surface of the reading device, wherein the document pressing device includes an upstream end of the pressing surface in the document conveying direction and A folded portion bent in the direction opposite to the reading surface is provided downstream of the pressing surface in the document transport direction while being brought into contact with the document transport direction upstream side of the reading position, and a downstream side surface of the folded portion in the document transport direction. By following the regulating surface provided in the apparatus, thereby positioning the downstream end of the pressing surface in the document conveying direction away from the reading surface, and positioning the pressing surface and the reading surface at the reading position. Gap between The is characterized in that provided.

Accordingly, a gap is provided between the document pressing means and the reading surface with a simple and low-cost configuration without increasing the number of parts, and the white and the document pressing means are always in a fixed white color without being in close contact with each other. So you can get the standard
An image defect does not occur in the read image, and a high-quality read image can be obtained.

The reading surface is inclined obliquely upward on the upstream side in the document transport direction and downward on the downstream side in the document transport direction, and the downstream surface of the bent portion in the document transport direction is brought into contact with the regulating surface by the weight of the document pressing means. It is preferable that they are copied.

With this arrangement, the positioning of the pressing surface on the downstream side in the document conveying direction can be performed by applying the weight of the document pressing means to the downstream surface of the bent portion in the document conveying direction, and following this surface to the regulating surface. .

It is preferable that the bent portion is bent at substantially 90 ° with respect to the pressing surface, and the regulating surface is provided at an acute angle with respect to the reading surface.

Thus, when the downstream surface of the bent portion in the document conveying direction is made to follow the regulating surface, a gap can be reliably provided between the document pressing means and the reading surface.

Preferably, the document pressing means has a white sheet adhered to the pressing surface.

It is preferable that the white sheet is adhered by a double-sided tape or an adhesive.

It is preferable that attachment portions for attachment inside the apparatus are provided at both ends in the longitudinal direction of the white sheet.

The document pressing means includes a document guide portion upstream of the pressing surface in the document transport direction and away from the reading surface toward the upstream of the document transport direction, and a back surface of the pressing surface and the document guide portion. And an elastic member pressed from above.

Thus, the document guide portion is pressed from the back by the elastic member, and the gap between the pressing surface and the reading surface can be more easily opened.

An image forming apparatus according to the present invention includes the image reading apparatus described above, and image forming means for forming image information read by the image reading apparatus on a sheet. .

Therefore, no image defect occurs in the read image, and a high quality read image can be obtained, so that the image formed on the sheet can also be made high quality.

[0021]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The materials, shapes, relative arrangements, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

An image reading apparatus and an image forming apparatus according to an embodiment will be described with reference to FIGS. still,
As a sequence of the description, first, a schematic configuration of a facsimile apparatus as an image forming apparatus will be described, and then a configuration and an operation of an image reading apparatus to which the present invention is applied will be described.

First, a schematic configuration of a facsimile apparatus will be described with reference to FIGS. 6 and 7, reference numeral 1 denotes an apparatus main body, which includes an image reading unit 2 that reads an image of a document S as a reading target, and an image forming unit 10 that forms an image on a recording sheet P as a recording target sheet. ,
It consists of.

The image reading unit 2 includes a top cover 8 having a document table 8a on which a plurality of documents S can be placed, a contact image sensor 4 as image reading means for reading image information of the document S, And a document pressing means 5 for pressing the document S against the mold image sensor 4.

Further, the image reading section 2 sequentially feeds the originals S placed on the original placing table 8 a one by one, and transports the originals via the contact type image sensor 4.
The upper document guide 6 and the lower document guide 7 which form the conveyance path of

The upper cover 8 having the document table 8a is
It is attached to the apparatus main body 1 so as to be openable and closable so that cartridge replacement and jam clearance described later can be easily performed.

The document table 8a is provided with a slider 8b slidable in a width direction orthogonal to the direction of conveyance of the document S. The slider 8b is used to move both ends of the width of the document S placed on the document table. They can be aligned.

The contact type image sensor 4 irradiates the image information surface of the original S with light from an LED array as a light source, and reflects the reflected light from the image information surface to a sensor element by a Selfoc lens (registered trademark). It forms an image and reads image information.

The image reading section 2 as an image reading apparatus to which the present invention is applied will be described later in detail.

The image forming section 10 is provided with a recording paper loading section 23 for loading the recording paper P, a recording paper feeding section 12 for sequentially feeding the recording paper P one by one from the recording paper loading section 23, and is fed. An image forming means 11 for forming an image on the recording paper P, and a laser scanner 13 for irradiating the image forming means 11 with laser light as image information.

The image forming section 10 includes a common discharge tray 19 for stacking and holding recording paper P discharged after image formation or a document S discharged after reading is completed, and a recording paper discharged U-turn after image formation. It has a recording paper discharge table 18 for stacking and holding P, and a transport guide 17 for guiding and supporting the recording paper P to be transported.

When the feeding is started, the recording paper feeding unit 12 separates the recording paper P pressed against the separation roller 12b one by one by the separation roller 12b and the separation pad 12a pressed against the separation roller 12b. The timing is such that the leading end of the image (toner image) formed on the photosensitive drum 11a of the image forming means 11 and the leading end of the recording paper P are coincident with each other by the conveying roller 12c and the conveying roller 12d which is pressed against and driven by the conveying roller 12c. And the photosensitive drum 11a of the image forming unit 11
And transfer means 11f.

The recording paper stacking section 23 can stack a plurality of recording papers P, and the number of recording papers that can be set is about 100.

Further, there are three types of recording paper that can be stacked and set: A4 size, letter size, and legal size. However, in the present invention, the number of sheets that can be set and the size of recording sheets that can be stacked and set are not limited to those described above, and may be appropriately configured as needed.

The cassette section 20 for the recording paper P is disposed at the bottom of the apparatus main body 1. The recording paper P loaded on the cassette 20a is pressed against the separation roller 14b by rotating the middle plate 20c upward by the pressing member 20b, and is separated one by one by the separation pad 14a (friction piece separation method). The sheet is conveyed along the separation pad guide 14e, and is further inverted by the conveying roller 14c, the cover-side U-turn guide 14f disposed on the rear cover, and the main-unit-side U-turn guide 14g disposed on the apparatus main body side. Reach.

Thereafter, the operation is the same as that of the above-described image forming section 10. The selection of the recording paper stacking unit 23 and the cassette paper feeding unit 20 can be arbitrarily selected.

In the image forming means 11, first, a laser beam as an image signal is emitted from a laser beam oscillator of the laser scanner 13 based on the image signal. The laser light is irradiated on the photosensitive drum 11a of the image forming unit 11 by the polygon mirror 13b, the lens 13a, and the return mirror 13c, and an image is formed on the surface of the photosensitive drum 11a.

In the image forming means 11, the photosensitive drum 11a is incorporated in a frame together with a charging means 11b, a developing means 11c and a cleaning means 11d as process means acting thereon, and a process cartridge 11e.
Is configured. The process cartridge 11e is configured to be detachable from the apparatus main body 1.

Therefore, the photosensitive drum 11a which is uniformly charged by the charging means 11b during the above-described image formation.
Is irradiated with laser light from the laser scanner 13 to form a latent image, and the latent image is visualized (toner image) by the toner supplied from the developing unit 11c.

In the image forming means 11, a transfer means 11f for transferring the toner image formed on the photosensitive drum surface to the recording paper P is provided around the photosensitive drum 11a.
Is further disposed on the recording paper transport path downstream of the photosensitive drum 11a.
Fixing means 14 for fixing the toner image to the toner image is provided. In FIG. 6, reference numerals 15 and 16 denote discharge roller pairs.

Accordingly, the recording paper P fed from the recording paper stacking section 23 to the image forming means 11 at a timed timing.
After the toner image formed on the surface of the photoconductor drum 11a is transferred by the transfer unit 11f, the toner image is conveyed along the conveyance guide 17, the toner image is fixed by the fixing unit 14, and the common discharge is performed by the discharge roller pair 15. The sheet is discharged to a recording sheet discharge table 18 by a discharge roller pair 16 via a tray 19 or a U-turn path.

If a jam occurs during image formation, the open / close bar of the upper cover 8 having the document placing table 8a is opened to easily remove the recording paper P staying inside the apparatus. it can.

Next, the configuration and operation of the image reading section 2 will be described with reference to FIGS.

FIG. 1 is a perspective view of a main part showing a connecting portion between the original pressing means 5 and the upper original guide 6. As shown in FIG. 2A and 2B are configuration diagrams of the document pressing means 5, in which FIG. 2A is a top view, FIG. 2B is a side view, FIG. 2C is a front view, and FIG. . FIG. 3 is a schematic sectional view of the image reading unit 2. FIG.
Reference numeral 5 is an enlarged view of a reading unit showing the document pressing means 5 and the contact image sensor 4 in an enlarged manner.

First, the configuration of the image reading section 2 will be described along the flow of the document S with reference to FIG. As shown in FIG. 3, in the image reading section 2, when the original S is stacked on the original placing table 8a (see FIG. 6), the leading end of the original S
a and the preliminary press-contact arm 3h pressed against the press-contact arm 3a.

After the original S is set in this way,
When the conveyance of the document S is started, the document S is
a and the pre-pressing arm 3h pressed against it to be fed to the friction piece 3b.

Then, the sheets are separated and fed one by one by the separation roller 3a and the friction piece 3b pressed against the separation roller 3a.

The separated original S is further conveyed to the close contact type image sensor 4 by a paper feed roller 3d pressed against a paper feed roller 3c pressed by a pressing spring 3i. While being pressed and brought into close contact with the contact type image sensor 4, the image information is read while the document is sequentially fed line by line.

Thereafter, the original S is discharged to the common discharge tray 19 (see FIG. 7) by the discharge roller 3f pressed against the discharge roller 3e pressed by the pressing spring 3i.

During this time, the document S is guided by the upper document guide 6 and the lower document guide 7 and is conveyed along the document conveyance path.

The upper original guide 6 is provided with a preliminary press-contact arm 3h, a friction piece 3b, a paper feed roller 3c, a paper discharge roller 3e, a pressing spring 3i, an original pressing means 5 and the like. On the side, a separation roller 3a, a paper feed roller 3d, a paper discharge roller 3f, a close contact image sensor 4, and the like are provided.

The upper document guide 6 can be opened and closed with respect to the lower document guide 7 in the direction of the arrow shown in FIG. Therefore, when a jam or the like occurs, the document conveying path is opened by opening the upper document guide 6 side, so that the jam processing can be easily performed.

Next, the document pressing means 5 will be described in detail. 1, 2, and 3, a document pressing unit 5 presses a document S against a contact image sensor 4.

The original pressing means 5 is provided with a white sheet 5a.
And a document pressing member 5b for pressing the document S onto the reading surface of the contact type image sensor 4 via the white background sheet 5a.

As shown in FIG. 2, the white background sheet 5a and the original pressing member 5b are joined by a double-sided tape. The method of joining the white sheet 5a and the original pressing member 5b is not limited to this, and it may be joined with another adhesive (acrylic or rubber adhesive) or adhesive other than the double-sided tape. Good.

As shown in FIGS. 1 and 2, the white sheet 5a has mounting holes 5a1 at both ends in the longitudinal direction (both ends in the width direction orthogonal to the document conveying direction) to serve as mounting portions for the upper document guide 6. are doing.

This white sheet 5a is deformed and self-contained.
Specifically, for example, it is formed of a material such as a polyester film, synthetic paper (Yupo), a polycarbonate sheet, and a vinyl chloride sheet.

The upper document guide 6 is provided with a triangular rib 6a as a hook for hooking and supporting the mounting hole 5a1 of the white background sheet 5a.

Further, the triangular rib 6a has a retaining portion 6b for retaining the mounting hole 5a1 of the white background sheet 5a, and a mounting hole 5a1 of the white background sheet 5a when the original pressing means 5 is mounted on the upper original guide 6. A slope 6c for guiding is provided.

Here, gaps t1 to t1 formed when the triangular rib 6a shown in FIG. 1 is hooked and supported by the mounting hole 5a1.
t4 is a gap opened so that the document pressing means 5 can move to a predetermined position.

Accordingly, when the original pressing means 5 combined as described above is attached to the upper original guide 6, the mounting hole 5a1 of the white background sheet 5a is pushed along the inclined surface 6c of the triangular rib 6a, and is bent inward in the longitudinal direction by the pushing. The mounting can be easily performed by opening the mounting holes 5al of the white background sheet 5a outward in the longitudinal direction and inserting the mounting holes 5al into the triangular rib 6a.

As described above, the original pressing member 5b is joined to the white sheet 5a by double-sided tape, and the deformable white sheet 5a to which the original pressing member 5b is joined is pushed into a predetermined position of the upper original guide 6. The mounting hole 5a
1 can be easily attached simply by inserting it into the triangular rib 6a of the upper document guide 6.

FIG. 4 shows a method of preventing sticking of the white sheet 5a according to the present invention. The document pressing member 5b has a downstream surface 5b1 at a bent portion bent approximately 90 ° on the downstream side in the document conveying direction, and the upper document guide 6 has an acute angle y with the reading surface 4a.
° regulating surface 6d. This time, y °
Is 88 °.

Since the reading surface 4a has an angle θ as shown in FIG. 3, the document pressing member 5b presses the document S in FIG. 4 by causing the downstream surface 5b1 to follow the regulating surface 6d of the upper document guide 6 due to gravity. The downstream end of the pressing surface 5a2 in the document conveying direction is fixed in a state separated from the reading surface 4a, and a gap x is generated with respect to the reading surface 4a. This gap x can be adjusted by the value of y.

According to this configuration, only the Z portion, which is the upstream end of the pressing surface 5a2 in the document conveying direction, is a close contact portion between the white sheet 5a and the reading surface 4a, and a minute gap can be opened at the reading position V portion. it can.

Thus, the reading surface 4a of the white sheet 5a
This prevents a decrease in whiteness at the time of prescan due to sticking to the image, and a constant output is always obtained.

Further, as shown in FIG. 5, a document pressing compression spring 5c as an elastic member is provided on the back side of the document pressing means 5 to increase the pressing of the document. At this time,
The original pressing compression spring 5c is moved to the pressing surface 5a of the original pressing member 5b.
2, the document is raised on the upstream slope 5b2 of the document guide portion provided on the upstream side in the document conveying direction, so that the force in the direction of the arrow f acts even when pressed by the document pressing and compression spring 5c, thereby ensuring the gap described above. I can do it.

In this case, three original pressing compression springs 5c are used, but it goes without saying that the present invention does not limit the number. In the above-described embodiment, one document pressing unit 5 has been exemplified, but the present invention is not limited to this, and it is needless to say that the present invention can be applied to the document pressing unit 5 using metal for the document pressing member 5b.

[0069]

As described above, according to the present invention, a gap is provided between the document pressing means and the reading surface, and the pressing surface and the reading surface come into close contact with each other at the reading position, and the whiteness is reduced. Can be easily and inexpensively eliminated, a stable white reference output is always obtained at the time of pre-scanning, no image defect occurs in the read image, and a high-quality read image is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a document pressing unit according to an embodiment of the present invention.

FIG. 2 is a three-sided view showing a document pressing unit according to the embodiment of the present invention.

FIG. 3 is a schematic sectional view showing an image reading unit according to the embodiment of the present invention.

FIG. 4 is an enlarged view showing a document pressing unit and a contact image sensor according to the embodiment of the present invention.

FIG. 5 is an enlarged view showing a document pressing unit and a contact type image sensor according to the embodiment of the present invention.

FIG. 6 is a schematic sectional view showing a facsimile apparatus according to the embodiment of the present invention.

FIG. 7 is a perspective view showing a facsimile apparatus according to the embodiment of the present invention.

FIG. 8 is a schematic sectional view showing a conventional image reading apparatus.

FIG. 9 is a side view showing a conventional document pressing unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device main body 2 Image reading part 3 Document conveyance part 3a Separation roller 3b Friction piece 3c Paper feed roller 3d Paper feed roller 3e Paper discharge roller 3f Paper discharge roller 3g Stopper 3h Preliminary pressure contact arm 4 Close contact type image sensor 4a Reading surface 5 Document pressing Means 5a White background sheet 5a1 Mounting hole 5a2 Pressing surface 5b Document pressing member 5b1 Downstream surface 5b2 Upstream slope 6 Upper document guide 6a Triangular rib 6b Retaining portion 6c Slope 6d Regulatory surface 7 Lower document guide 8 Top cover 8a Document mounting table 8b Slider DESCRIPTION OF SYMBOLS 10 Image forming part 11 Image forming means 11a Photoreceptor drum 11b Charging means 11c Developing means 11d Cleaning means 11e Process cartridge 11f Transfer means 12 Recording paper feeding part 12a Separation pad 12b Separation roller 12c Conveyance roller 12d Conveyance roller 13 Laser cutting Reference numeral 13a Lens 13b Polygon mirror 13c Folding mirror 14 Fixing means 15, 16 Discharge roller pair 17 Transport guide 18 Recording paper discharge stand 19 Common discharge tray 21 Slider 23 Recording paper stack

Claims (8)

[Claims] An image reading means for reading image information from a document conveyed on a reading surface at a reading position, and a document pressing means for pressing the document on a pressing surface facing the reading surface of the image reading means. In the image reading apparatus, the document pressing means causes an upstream end of the pressing surface in the document conveying direction to abut on the reading surface on the document conveying direction upstream of the reading position, and conveys the document on the pressing surface. A folding section bent in the direction opposite to the reading surface is provided on the downstream side in the direction, and the downstream side of the folding section in the document transport direction is made to follow a regulating surface provided in the apparatus, thereby conveying the document on the pressing surface. An image reading apparatus, comprising: positioning a downstream end in a direction away from the reading surface; and providing a gap between the pressing surface and the reading surface at the reading position. 2. The document reading apparatus according to claim 1, wherein the reading surface is inclined obliquely upward on the upstream side in the document conveying direction and downward on the downstream side in the document conveying direction, and the downstream side of the bent portion in the document conveying direction is regulated by the weight of the document pressing means. The image reading device according to claim 1, wherein the image reading device is imitated on a surface. 3. The device according to claim 2, wherein the bent portion is bent at substantially 90 ° with respect to the pressing surface, and the regulating surface is provided at an acute angle with respect to the reading surface. The image reading device according to claim 1. 4. The document pressing means according to claim 1, wherein a white background sheet is attached to said pressing surface.
Or the image reading device according to 3. 5. The image reading apparatus according to claim 4, wherein the white sheet is attached by a double-sided tape or an adhesive. 6. The image reading apparatus according to claim 4, wherein mounting portions for mounting inside the apparatus are provided at both ends in the longitudinal direction of the white background sheet. 7. The original document pressing means includes: an original guide portion that is located upstream of the pressing surface in the original document conveying direction and is separated from the reading surface toward an upstream side of the original document conveying direction; The image reading device according to any one of claims 1 to 6, further comprising: an elastic member that presses an image from a back surface. 8. An image reading apparatus according to claim 1, further comprising: an image forming unit configured to form image information on a sheet based on image information read by the image reading apparatus. Image forming apparatus.