JP4077971B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a multifunction printer having an original moving type image reading device mechanism, and more particularly to light shielding of an image reading unit of an image reading device.
[0002]
[Prior art]
A conventional image reading apparatus will be described with reference to the drawings.
[0003]
FIG. 4 is a schematic configuration diagram of a conventional document moving type image reading device 51.
[0004]
In the image reading device 51, a separation roller 62, a conveyance roller 60, a contact image sensor 52 (hereinafter referred to as CIS) which is a means for reading a document image, a lower frame 64 including a paper discharge roller 58, a separation pad 63, a conveyance roller 61. An upper frame 56 having a document pressing plate 53 (hereinafter referred to as a white background plate) and a paper discharge roller 59 is opened in a crocodile shape.
[0005]
Conventionally, as shown in FIG. 4, the light-shielding means of the document moving type image reading device 51 is arranged on an upper frame 56 facing the CIS 52, and is a white for pressing the document P from the back side of the document P when reading the document image. A flat PET-shaped light shielding sheet 55 that blocks disturbance light is disposed on the upper frame 56 downstream of the ground plate 53.
[0006]
That is, the disturbance light from the paper discharge port does not affect the read image at the time of reading the CIS 52, so that the white base plate 53 enters the white background plate 53 so as to cover the reading downstream side of the CIS 52 with the flat light shielding sheet 55. The arrangement was affixed to the concave downstream side with double-sided tape.
[0007]
The document P is always conveyed between the upper frame 56 and the lower frame 64 so that the back surface of the document P is in contact with the end surface of the light shielding sheet 55 so as to be pressed in the direction of the CIS 52 by the light shielding sheet 55.
[0008]
The document P that has passed through the image reading device 51 is slightly charged with static electricity.
[0009]
The static elimination brush 65 is a static elimination means for removing static electricity from the original P, and is made of a soft string-like group of braided conductive fibers. The document P is arranged so as to be neutralized by touching it gently.
[0010]
[Problems to be solved by the invention]
However, when the light shielding sheet 55 is configured as in the prior art as described above, the document P is transported and discharged while the back surface of the document P is rubbed against the end surface of the light shielding sheet 55 when the document P is passed, resulting in the following problems. It was.
[0011]
When the document P is passed, the back surface of the document P is scraped by the end face of the light shielding sheet 55, and the back surface of the document P is rubbed and scratched. The foreign matter scraped off from the original P with foreign material such as toner, ink, pencil, etc. attached to the back side adheres to the end face of the light shielding sheet 55 and stains the back side and the rear end face of the original P passing through the original P. Caused scratches and dirt.
[0012]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide an image reading apparatus for preventing the influence of a read image due to disturbance shading while avoiding scratches and dirt on the original, and the image reading apparatus. An object of the present invention is to provide an image forming apparatus provided with an image reading device.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides:
A transport path through which the document is transported by the document transport means;
Image reading means for converting image information of a document conveyed on the conveyance path into an electrical signal read at a reading position ;
A pressing unit that presses the document conveyed on the conveyance path against the image reading unit at the reading position;
An abutting member disposed so as to block the conveying path downstream of the pressing unit with respect to the pressing unit, and bent by the abutting document being brought into contact and retracted from the conveying path;
In an image reading apparatus comprising:
The abutting member, in a state where the document is bent in contact to be sent transportable, the tip portion of the abutting member is a leading end side than the position where contact with the document conveyed, the curved portion to be separated from the conveying path It is characterized by providing.
[0015]
In addition, it is preferable that the contact member has conductivity.
[0016]
The contact member is preferably grounded.
[0017]
The pressing means has conductivity, is grounded ,
It is also preferable that the abutting member is provided in the pressing means and is grounded via the pressing member .
[0018]
In addition, it is preferable that the contact member has a characteristic with a light transmittance of 20% or less.
[0019]
In the image forming apparatus, the image reading apparatus described above, an exposure unit that exposes image information of a document read by the image reading apparatus to a photosensitive member, and an image that records the image information exposed to the photosensitive member on a recording material. Forming means.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.
[0021]
(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of a document movement type image reading apparatus 1 according to a first embodiment of the present invention.
[0022]
In the image reading apparatus 1, a separation roller 12, a conveyance roller 10, a contact image sensor 2 (hereinafter referred to as CIS) as an image reading unit for reading a conveyed original image, a lower frame 14 including a paper discharge roller 8, and a separation pad 13. An upper frame 6 having a white background plate 3 as a pressing means for pressing the document P from the back when reading the document roller 11 and the document P, and a sheet discharge roller 9 are opened in a crocodile shape.
[0023]
The document P is passed between the upper frame 6 and the conveyance guide 7 disposed upstream of the CIS 2, introduced into the CIS 2, and then attached to a pressing spring 4 as a pressing means fixed to the upper frame 6. The white background plate 3 is pressed against the image reading surface (reading position) of the CIS 2.
[0024]
The document P is read by the CIS 2 while being pressed against the image reading surface of the CIS 2 by the white background plate 3.
[0025]
The document P that has been passed is passed between the lower frame 14 and the upper frame 6, and is then discharged by the discharge roller 8 and the discharge roller 9, and is discharged from the discharge port.
[0026]
The document P that has passed through the image reading apparatus 1 is slightly charged with static electricity.
[0027]
The static eliminating brush 15 is a static eliminating means for removing static electricity from the original P, and is made of a soft string-like group of conductive fibers knitted. The document P is arranged so as to be neutralized by touching it gently.
[0028]
Here, the paper discharge roller 8 and the paper discharge roller 9 are arranged only at the center in the document width direction, and there is a gap between the upper frame 6 and the lower frame 14 so that disturbance light is generated. Get in. If disturbing light enters the CIS 2 when reading a document image, it causes a problem such as whiteness of the read image, which must be shielded from light.
[0029]
As the light shielding means, a light shielding sheet 5 as an abutting member made of an elastic material and bent in a direction that does not interfere with the passage of the original P is provided downstream of the white background plate 3 of the upper frame 6. Is provided on the downstream surface of the white base plate 3 of the concave portion of the upper frame 6 where it is arranged (by a method such as affixing with a double-sided tape or screwing) to solve the problems related to the image at the time of reading.
[0030]
At the time of passing the original, the original P is pressed against the CIS 2 side by the light shielding sheet 5 to pass the light to shield the CIS 2. However, the light shielding sheet 5 is bent by the curved portion when the conveyed original P is in contact and bent. The tip is separated from the transport path.
[0031]
In this way, the original P comes into contact with the smooth surface of the curved portion of the light shielding sheet 5, and it is possible to avoid scratches on the back side of the original P after passing the original and dirt on the rear end of the original P, which have been a concern. .
[0032]
Further, by using a material having a light transmittance of 20% or less for the light shielding sheet 5, disturbance light can be prevented more reliably.
[0033]
(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to FIG.
[0034]
FIG. 2 is a schematic cross-sectional view of a document movement type image reading apparatus 1A according to the second embodiment of the present invention. Components similar to those in the first embodiment are denoted by the same reference numerals. The description is omitted.
[0035]
The light-shielding sheet 5 to which bending is applied according to the present invention is grounded with electrical conductivity, and is adhered to the downstream side of the concave portion into which the white base plate 3 of the upper frame 6 enters with a double-sided tape.
[0036]
When the document is passed, the light shielding sheet 5 can obtain a neutralizing effect simultaneously with the light shielding to the CIS 2.
[0037]
Further, by using a material having a light transmittance of 20% or less for the light shielding sheet 5, it is possible to more reliably prevent disturbance light.
[0038]
(Embodiment 3)
Next, a third embodiment of the present invention will be described with reference to FIG.
[0039]
FIG. 3 is a schematic cross-sectional view of a document movement type image reading apparatus 1B according to the third embodiment of the present invention. Components similar to those in the first and second embodiments are denoted by the same reference numerals. A description thereof will be omitted.
[0040]
In order to prevent the original P from floating from the CIS 2 when the original is read, the white background plate 3 for pressing the original against the CIS 2 is arranged on the opposite side of the CIS 2, and the light-shielding sheet is bent in a direction that does not interfere with the passage of the original. 5 is arranged and configured downstream of the white base plate 3.
[0041]
The light shielding sheet 5 performs light shielding at a position closer to the CIS 2, thereby obtaining a higher light shielding effect.
[0042]
Further, by providing the light shielding sheet 5 with conductivity, the light shielding sheet 5 can obtain a neutralizing effect at the same time as the light shielding to the CIS 2 when the document is passed.
[0043]
Further, the material of the white background plate 3 is made of a conductive material, and is grounded via the white background pressing spring 4. By providing the light-shielding sheet 5 having conductivity on the grounded white plate 3, a more reliable neutralization effect can be obtained.
[0044]
Further, by using a material having a light transmittance of 20% or less for the light shielding sheet 5, it is possible to more reliably prevent disturbance light.
[0045]
【The invention's effect】
As described above, according to the present invention, when a document is passed, the document does not contact the end of the contact member and always contacts the curved portion of the contact member. The members come into contact smoothly, and it is possible to prevent scratches on the back side of the document when the document is passed and stains on the trailing edge of the document.
[0046]
In addition, by using a conductive material for the contact member and the pressing means and grounding it, it becomes possible to remove static electricity from the original, and it is possible to obtain a large electrostatic effect on the image reading means that is sensitive to static electricity. it can.
[0047]
In addition, it is possible to eliminate the need for a static eliminating unit that has been conventionally installed near the paper discharge port in order to remove static electricity from a document, and a simple configuration can be achieved.
[0048]
Further, by using a contact member having a light transmittance of 20% or less, it becomes possible to prevent disturbance light more reliably.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a document movement type image reading apparatus according to a first embodiment of the present invention.
FIG. 2 is a schematic sectional view of an original moving image reading apparatus according to a second embodiment of the present invention.
FIG. 3 is a schematic sectional view of an original moving image reading apparatus according to a third embodiment of the present invention.
FIG. 4 is a schematic cross-sectional view of a conventional image reading apparatus.
[Explanation of symbols]
1, 1A, 1B Image reading device 2 Contact image sensor (CIS, image reading means)
3 White board (pressing means)
4 White background pressing spring (pressing means)
5 Shading sheet (contact member)
6 Upper frame 7 Transport guide 8 Paper discharge roller 9 Paper discharge roller 10 Transport roller 11 Transport roller 12 Separation roller 13 Separation pad 14 Lower frame 15 Static elimination brush P Original

Claims (6)

A transport path through which the document is transported by the document transport means;
Image reading means for converting image information of a document conveyed on the conveyance path into an electrical signal read at a reading position ;
A pressing unit that presses the document conveyed on the conveyance path against the image reading unit at the reading position;
An abutting member that is disposed so as to block the conveying path downstream of the pressing unit with respect to the pressing unit , and that is bent when the conveyed document comes into contact and retracts from the conveying path;
In an image reading apparatus comprising:
The abutting member, in a state where the document is bent in contact to be sent transportable, the tip portion of the abutting member is a distal end side of a position abutting on the document conveyed, the curved portion to be separated from the conveying path An image reading apparatus comprising: The image reading apparatus according to claim 1 , wherein the contact member has conductivity. The image reading apparatus according to claim 2 , wherein the contact member is grounded. The pressing means has conductivity, is grounded ,
The image reading apparatus according to claim 3 , wherein the contact member is provided in the pressing unit and is grounded through the pressing member . Said abutment member, an image reading apparatus according to any one of claims 1 to 4, characterized in that a light transmittance of 20% or less of characteristics. An image reading apparatus according to any one of claims 1 to 5 ,
Exposure means for exposing image information of a document read by the image reading device to a photoconductor;
An image forming apparatus comprising: image forming means for recording image information exposed to the photosensitive member on a recording material.

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