JP2002111964A - Image reading device and image forming device - Google Patents

Abstract

(57) [Problem] To provide an image reading apparatus and an image forming apparatus capable of obtaining a stable color reference at the time of pre-scan and performing high-precision reading. A document pressing member (5b) is provided with a concave portion (5b4) that retreats from a reading glass surface (4a) in a concave shape at a position facing a reading position (4) (dot-dash line) of a contact image sensor (4) in an image reading section (2). . By doing this,
The weight of the original pressing member 5b does not add to the reading position 4b, the sticking of the reading glass surface 4a and the white sheet 5a at the reading position 4b is prevented, and the disadvantage that the whiteness at the time of pre-scanning is reduced is reduced simply and at low cost. And a stable white reference output is always obtained.

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, and more particularly, to an image reading apparatus applied to an image forming apparatus having an image forming section such as a copying machine or a facsimile machine.

[0002]

2. Description of the Related Art Conventionally, there is an image reading apparatus mounted on a facsimile apparatus as shown in FIG. In the image reading apparatus, the conveyed original is brought into close contact with a reading glass surface as a reading surface of the contact type image sensor 51 by the original pressing means 52, and the image of the pressed original is contacted with the contact type image sensor 51.
It was configured to read in.

In FIG. 6, a document pressing means 52 is composed of a white sheet 52a and a white sheet metal 52b which are color reference members used as a reading reference (color reference). The white sheet 52a is screwed to the upper part of the upper document guide 53. The white sheet metal 52b is hooked and fixed to the upper document guide 53 at a position downstream of the document conveying direction from the position where the white sheet 52a is fixed by screws.

[0004] As shown in FIG.
In order to prevent the image sensor 2 itself from being in close contact with the contact image sensor 51, embosses 52c and the like are provided outside the document transport area at both ends in the longitudinal direction (width direction orthogonal to the document transport direction) of the document pressing means 52. Was.

The document pressing means 52 provided with the emboss has no function of pressing the document against the reading surface, and has a function of guiding the document at the reading position so that the document does not move.

Then, for example, at the time of pre-scanning before the image reading operation is started, the amount of reflected light from the white background sheet is detected to determine the white level (color reference), and the output level of the information read by the contact image sensor ( The operation for determining the light / dark level is performed.

[0007]

However, in the case of the prior art as described above, the provision of the embossing 52c in FIG. This only prevents the white sheet 52a pressed by the white sheet metal 52b at a part such as the center in the width direction and may stick to the reading glass surface.

If the white sheet 52a sticks to the reading glass surface at the reading position of the close contact type image sensor 51, the state of reflection of light changes on the close contact surface, causing a phenomenon of a decrease in whiteness and a white color. During pre-scan for adjusting the degree, the white reference becomes unstable. Then, in the unstable portion, there may be a problem that a white streak appears in the image of the subsequently read document.

Therefore, in order to further prevent the original pressing means 52 from sticking to the reading glass surface of the white background sheet 52a, measures such as increasing the accuracy of the emboss 52c and restricting the warpage of the white background sheet metal 52b are taken. Is required, the configuration becomes complicated, and the cost increases.

An object of the present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an image reading apparatus capable of obtaining a stable color reference at the time of prescan and capable of reading with high accuracy. An object of the present invention is to provide an image forming apparatus.

[0011]

In order to achieve the above object, an image reading apparatus according to the present invention comprises: reading means for reading an image at a reading position from an image surface of a document conveyed on a reading surface; An image reading apparatus comprising: a document pressing unit that presses a document against a reading surface of a reading unit to adhere the document to the reading surface; wherein the document pressing unit includes a color reference member, and a document pressing member that presses the color reference member against the reading surface. And the document pressing member is provided in a shape to be retracted without pressing the color reference member at the reading position.

Therefore, since the color reference member is not pressed by the document pressing member at the reading position, it is possible to prevent the color reference member from sticking to the reading surface of the reading means. For this reason,
During the pre-scan for adjusting the chromaticity, the output of the chromaticity as the reading reference is stabilized, and the color reference is stabilized. Then, the image of the document read thereafter does not have the disadvantage that white streaks appear as in the related art, and accurate reading can be performed.

Further, since the document pressing member has a simple configuration in which the document pressing member is retracted, there is no need to add another member, the configuration becomes simple, and the cost is reduced.

It is preferable that the document pressing member is provided in a concave shape withdrawn from the color reference member at a position facing a reading position.

It is preferable that the document pressing means connects the color reference member and the document pressing member with an adhesive or an adhesive.

It is preferable that a document guide for forming a document conveying path is provided, and the document pressing means is fixed to the document guide by hooking the color reference member and the document pressing member on the document guide.

Thus, the original pressing means can be attached even with a deformable white background sheet, and assemblability is improved.

Further, by attaching the document pressing member and the color reference member to the document guide so as to prevent them from falling off, the document pressing means can be attached to the document guide with a very simple configuration. The shape of the mounting portion for mounting the document pressing means of the document guide can also be simplified.

An image forming apparatus according to the present invention includes the above-described image reading apparatus and image forming means for forming an image on a recording medium.

[0020]

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. Here, as an order of 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 unit as an image reading apparatus according to the present embodiment mounted on the facsimile apparatus will be described. Will be described.

First, a schematic configuration of the facsimile apparatus will be described with reference to FIG. In FIG. 4, reference numeral 1 denotes an apparatus main body, an image reading unit 2 for reading an image of a document S as a reading target, and an image recording unit for recording an image on a recording paper P as a recording medium such as a sheet as a recording target. 10
, And is constituted.

The image reading section 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 reading means for reading image information of the document S, and a contact image sensor 4. A document pressing unit 5 for pressing the document S against the image sensor 4, a document transport unit 3 for sequentially feeding the documents S placed on the document mounting table 8 a one by one, and discharging the document S via the contact image sensor 4. And an upper document guide 6 and a lower document guide 7 that form a transport path for the document S.

The top cover 8 having the document table 8a is
The ink cartridge 11e is openably and closably attached to the apparatus main body 1 so that the ink recording cartridge 11e can be easily replaced or jammed.

The document table 8a is provided with a slider 8b slidable in a width direction orthogonal to the direction in which the document S is conveyed. The slider 8b is used to move the document S placed on the document table 8a. Both ends in the width direction can be aligned.

The contact type image sensor 4 as a reading means irradiates light from an LED array as a light source to an image information surface as an image surface of the document S, and reflects reflected light reflected from the image information surface of the document S. Selfoc lens (registered trademark)
To form an image on the sensor element and read image information.

On the other hand, the image recording unit 10 includes a recording paper loading unit 23 for loading the recording paper P as a recording target, and a recording paper feeding unit for sequentially feeding the recording paper P one by one from the recording paper loading unit 23. 12, an image forming unit 11 for forming an image on the fed recording paper P with the ink supplied from the ink recording cartridge 11e, and stacking and holding the recording paper P discharged after the end of recording by the image forming unit 11. Recording paper discharge tray 18
And

The image forming unit 11 according to the present embodiment
Adopts an ink jet recording system in which an image is formed by discharging ink onto a recording paper P. The image forming unit 1
Reference numeral 1 denotes an image forming unit that forms an image.

Next, the configuration of the image reading section 2 will be described along the flow of the document S with reference to FIG. FIG. 3 is a front sectional view of the image reading unit 2.
The document S is stacked on the document a. At the time of loading, the leading end of the original S is separated from the separation roller 3a and the preliminary pressing arm 3 pressed against the separation roller 3a.
h.

After the original S is set in this way,
When the transport of the document S is started, the document S is transferred to the document transport unit 3.
Separation roller 3a and preliminary pressure contact arm 3h pressed against the same.
As a result, it is sent to a position where the tip abuts on the friction piece 3b.

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

The separated original S is read by the close contact type image sensor 4 in the original transporting unit 3 by the paper feed roller 3d pressed against the paper feed roller 3c pressed by the pressing spring 3i. The document is conveyed to a position where the reading is performed, and the surface thereof is brought into close contact with a reading glass surface 4a as a reading surface of the contact type image sensor 4 by a document pressing means 5 described later. The image information is read by the sensor 4.

Thereafter, the document S is discharged onto a document discharge tray 19 (see FIG. 4) by a discharge roller 3f pressed against a discharge roller 3e pressed by a 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 of the image reading section 2 can be opened and closed in the direction of arrow A in FIG. For this reason, when a jam of the document S during conveyance or the like occurs, the document conveyance path is opened by lifting and opening the upper document guide 6 side of the image reading unit 2, and the jam clearance can be easily performed.

Next, the original pressing means 5 will be described with reference to FIGS.
This will be described in detail with reference to FIG. FIG. 1 is a perspective view of the document pressing means 5, and FIG. 2 is an enlarged main cross-sectional view of the document pressing means 5 and its peripheral portion as viewed from the direction of the arrow in FIG.

An original pressing means 5 for pressing the original S against the contact image sensor 4 includes a white sheet 5a as a color reference member and the reading glass surface of the contact image sensor 4 via the white sheet 5a. And a document pressing member 5b that presses on the document 4a.

As shown in FIG. 2, a white background sheet 5a, which is a color reference member, and a document pressing member 5b are connected 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 FIG. 1, the white sheet 5a has a substantially vertical wall surface of the upper document guide 6 at both ends in the width direction (hereinafter, width direction) perpendicular to the document conveyance direction and upstream of the document conveyance direction. Is provided, and the flat portion has a mounting hole 5a1 serving as a mounting portion to the upper document guide 6.

The white background sheet 5a is deformable, and is specifically made of a material such as a polyester film, synthetic paper (Yupo), a polycarbonate sheet, a vinyl chloride sheet, and the like.

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.

The triangular rib 6a has a retaining portion 6b for retaining the white sheet 5a from the mounting hole 5a1.
And a slope 6c for guiding the mounting hole 5a1 of the white sheet 5a to the depth of the triangular rib 6a when the document pressing means 5 is mounted on the upper document guide 6.

Here, t1 to t4 are gaps opened so that the original pressing means 5 can move to a predetermined position.

The document pressing member 5b has protrusions 5b3 which are attached to the upper document guide 6 at both ends in the width direction and downstream in the document conveying direction. The protruding portion 5b3 is provided by vertically lifting the downstream side in the document conveying direction of the position where the document pressing member 5b presses the document S via the white background sheet 5a, and then extending its tip to the downstream side in the document conveying direction. .

The upper document guide 6 is provided with a mounting hole 6d for hooking and supporting the projection 5b3 of the document pressing member 5b on a wall surface which is substantially vertically raised.

Here, t1 'to t4' are the document pressing members 5
b is a gap opened so that it can move to a predetermined position.

The original pressing means 5 connected as described above to the upper original guide 6 is attached to the original pressing member 5b.
Is inserted into the mounting hole 6d of the upper document guide 6, and then the mounting hole 5a1 of the white sheet 5a is pushed along the inclined surface 6c of the triangular rib 6a, and the white sheet 5a is pressed.
By inserting the mounting hole 5a1 into the triangular rib 6a as far as it will go, it can be easily mounted.

That is, the original pressing means 5 is connected to the upper original guide 6
It is mounted in a concave shape that is recessed above between the two wall surfaces.

FIG. 2 shows a white sheet 5a which is a feature of the present invention.
The configuration for preventing the contact type image sensor 4 from sticking to the reading glass surface 4a will be described.

The original pressing member 5b is located at the reading position 4b of the contact type image sensor 4 in the image reading section 2 (dotted line).
A concave portion 5b4 that retreats from the reading glass surface 4a in a concave shape is provided at a position opposed to. By doing so, the original weight of the document pressing member 5b does not add to the reading position 4b.

Therefore, the white sheet 5a is placed at the reading position 4
In b, since no pressure is applied from the document pressing member 5b, sticking to the reading glass surface 4a can be prevented, and a decrease in whiteness at the time of prescan due to the sticking can be prevented. can get.

In this embodiment, the original pressing member 5
As for b, a steel plate is used, and the gap between the concave portion 5b4 and the reading glass surface 4a is 0.7 m by bead drawing in the width direction.
m. Of course, the original pressing member 5b may be an integrally molded part using a resin material.

Further, as shown in FIG.
Adopts a configuration in which the original S is securely brought into close contact with the reading glass surface 4a by urging the original pressing member 5b against the reading glass surface 4a using the original pressing compression spring 5c.

Also at this time, the white sheet 5a is prevented from sticking to the reading glass surface 4a at the reading position 4b, the degree of light reflection at the time of pre-scanning is changed, and the phenomenon that whiteness is reduced is prevented. Output is obtained and a stable white reference is obtained.

In the present embodiment, the original pressing compression spring 5c
Are arranged in three places, but it goes without saying that the present invention does not depend on the number of springs.

FIG. 5 shows another example of the present embodiment.
As shown in the figure, the original pressing member 5b using a steel plate is bent in a rectangular shape near the reading position 4b to form a large recess 5b4, and the original pressing member 5b is completely retracted from the reading glass surface 4a at the reading position 4b. It may be configured as follows.

The reading glass surface 4 of the original pressing member 5b
The retraction from the reading position 4b may be any structure that does not press the white background sheet 5a at the reading position 4b. 5b can be provided separately.

Further, with respect to the width direction of the document pressing member 5b, the portion pressing the white background sheet 5a on the upstream and downstream sides in the document feeding direction is retracted at intervals in the width direction unless the white background sheet 5a is not loosened. Is also good.

In the above-described embodiment, one document pressing unit 5 has been described as an example. However, the present invention is not limited to this, and it is needless to say that the present invention can be applied to a document pressing unit using metal.

Further, in the embodiment, the image forming apparatus is an example of a facsimile apparatus, but the apparatus may be a single image reading apparatus.

The image forming method applied to the image forming section of the image forming apparatus employs an ink jet method in the present embodiment, but adopts a known technique such as an electrophotographic method or an electrostatic method. You may.

[0062]

As described above, the present invention prevents the reading surface of the reading means from sticking to the color reference member at the reading position, and reduces the chromaticity at the time of prescan easily and at low cost. And a stable color reference output is always obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a document pressing unit according to an embodiment.

FIG. 2 is an enlarged cross-sectional view illustrating a document pressing unit and a peripheral portion thereof according to the embodiment;

FIG. 3 is a front sectional view showing an image reading unit according to the embodiment.

FIG. 4 is a front sectional view showing the facsimile apparatus according to the embodiment.

FIG. 5 is an enlarged cross-sectional view showing a document pressing unit and a peripheral portion thereof according to another example of the embodiment.

FIG. 6 is a front sectional view showing a conventional image reading unit.

FIG. 7 is a front sectional view showing a document pressing member of the related art.

[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 3h Preliminary pressure contact arm 3i Press spring 4 Contact image sensor 4a Reading glass surface 4b Reading position 5 Document pressing means 5a White background sheet 5a1 hole 5b Document pressing member 5b3 Projection 5b4 recess 6 Upper document guide 6a Triangular rib 6b Retaining portion 6c Slope 6d hole 7 Lower document guide 8 Top cover 8a Document table 8b Slider 10 Image Recording unit 11 Image forming unit 11e Ink recording cartridge 12 Recording paper feeding unit 18 Recording paper discharge tray 19 Document discharge tray 23 Recording paper stacking unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/19 H04N 1/04 103E F-term (Reference) 2H076 AA43 AA65 BA07 BA24 BA47 BA48 DA21 2H108 AA14 CB01 GA01 JA00 5C062 AA02 AB32 AB33 AD00 AD06 BA00 5C072 AA01 BA07 DA25 EA07 LA07 LA15 RA16 WA04

Claims (5)

[Claims] An image reading means for reading an image at a reading position from an image surface of a document conveyed on a reading surface; and a document pressing means for pressing the document against the reading surface of the reading means to bring the document into close contact therewith. In the reading apparatus, the document pressing unit is configured by combining a color reference member and a document pressing member that presses the color reference member against a reading surface, and the document pressing member is configured to read the color reference member at a reading position. An image reading device provided in a shape to retract without pressing. 2. The image reading apparatus according to claim 1, wherein the document pressing member is provided in a concave shape retracted from the color reference member at a position facing a reading position. 3. The image reading apparatus according to claim 1, wherein the document pressing unit connects the color reference member and the document pressing member with an adhesive or an adhesive. 4. A document guide for forming a document conveying path, wherein the document pressing means is secured by hooking the color reference member and the document pressing member on the document guide. Item 4. The image reading device according to item 1, 2, or 3. 5. An image forming apparatus, comprising: the image reading apparatus according to claim 1; and image forming means for forming an image on a recording medium.