JP3805243B2 - Image reading apparatus and elastic member used in image reading apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus using a contact image sensor, and an elastic member used in the image reading apparatus, and more particularly to a scanner, a facsimile machine, and a copying machine that can read an image formed on a sheet while conveying the sheet. It is suitable for application to the above.
[0002]
[Prior art]
The contact image sensor is configured as shown in FIG. As shown in the figure, a contact image sensor 100 includes a frame 101 that is a casing, an LED 102 that is a light source, a lens array 103, and an image sensor (light receiving element) 104. A contact glass 105 is installed on the upper surface.
[0003]
In the contact image sensor 100, when the sheet passes over the contact glass 105, light is emitted by the LED 102. The emitted light is irradiated onto the sheet at the image reading position A, and the reflected light is imaged on the image sensor (light receiving element) 104 via the lens array 103 and subjected to photoelectric conversion. Read as a signal.
[0004]
In the image reading apparatus using the contact image sensor 100 as described above, since the contact image sensor has a shallow depth of focus, the sheet is adhered to the surface of the contact glass 105 installed on the contact image sensor 100. Thus, it is necessary to read the image information formed on the sheet satisfactorily. For example, a platen roller or a pressure plate is provided on the side opposite to the reading position of the contact image sensor 100 so that the sheet is pressed against the contact glass 105 portion of the contact image sensor 100.
[0005]
FIG. 7 is a schematic configuration diagram of an image reading unit in a conventional image reading apparatus using the contact image sensor 100. The contact image sensor 100 is attached as a unit to a conveyance frame of an image reading apparatus.
[0006]
A sheet conveying roller 200 is disposed upstream of the contact image sensor 100 in the sheet conveying direction, and a sheet discharging roller 300 is disposed downstream of the sheet conveying direction. A platen roller 400 that presses the sheet against the contact glass 105 and conveys the sheet at a predetermined speed is disposed on the side opposite to the image reading position A of the contact image sensor 100.
[0007]
The contact image sensor 100 is pressed by a pressure spring 500 and pressed against the platen roller 400 with a predetermined load. It should be noted that the platen roller 400 is disposed with a predetermined minute gap with respect to the contact glass 105 of the contact image sensor 100 in order to prevent generation of a load due to contact between the contact glass 105 and the platen roller 400.
[0008]
[Problems to be solved by the invention]
In the conventional image reading apparatus, when the sheet is conveyed and passes through the image reading unit, the contact with the contact glass 105 of the contact image sensor 100 generates high voltage static electricity. On the other hand, the frame 101 of the contact image sensor 100 and the conveyance frame of the image reading apparatus that supports the frame 101 are often plastic molded products in order to reduce weight and improve the degree of freedom of shape, and are more easily charged. It has become. For this reason, the generated static electricity jumps from the gap between the contact glass 105 and the frame 101 to the LED 102 in the contact image sensor 100 or the circuit board on the image sensor (light receiving element) 104 and becomes noise of photoelectric conversion, and the read image There has been a problem in that the image quality is deteriorated, and in some cases, the electric circuit may malfunction or the image sensor (light receiving element) 104 may be destroyed.
[0009]
Another problem with the conventional image reading apparatus is that the contact image sensor 100 is supported on the conveyance frame of the image reading apparatus, and the contact glass 105 surface of the contact image sensor 100 covers a part of the sheet conveyance path. Therefore, it is difficult to completely match the contact glass 105 surface of the contact image sensor 100 with the sheet conveyance surface formed by the conveyance frame. In particular, as shown in FIG. 7, in the image reading apparatus in which the contact image sensor 100 is arranged on a bent sheet conveyance path or a curved sheet conveyance path, the contact glass 105 surface of the contact image sensor 100 is flat. Therefore, the sheet conveyance path including the contact glass 105 surface cannot be formed smoothly, hindering the smooth conveyance of the sheet in the sheet conveyance path, or the restriction of the sheet becomes difficult. Or a reduction in resolution occurs, causing a sheet conveyance failure or jamming.
[0010]
Further, as another problem in the conventional image reading apparatus, external light entering from the sheet feeding port on the upstream side of the sheet conveying path is caused by the conveying surface of the conveying frame, the contact glass 105 surface of the contact image sensor 100, or Reflected on the surface of the platen roller 400 disposed with a predetermined gap, the reflected light other than the regular light from the LED 102 in the contact image sensor 100 enters the image sensor (light receiving element) 104 as flare light. As a result, there is a problem that the image quality of the read image is deteriorated.
[0011]
The present invention has been made to solve the above-described problems, eliminates various effects due to static electricity without increasing the number of parts, and further facilitates image conveyance and sheet conveyance by smooth sheet conveyance. An object of the present invention is to suppress the occurrence of a jam and to prevent image quality deterioration of a read image due to external light.
[0012]
[Means for Solving the Problems]
An image reading apparatus according to the present invention includes an image reading unit that reads an image of a sheet conveyed along a sheet conveyance path, a sheet regulating unit that is provided to face the image reading unit, and the image reading unit that includes the sheet. An image reading apparatus including a pressing unit that presses in the direction of the regulating unit, wherein the pressing unit is a conductive elastic member that is detachably attached to the image reading unit and is electrically connected to a ground potential. Further, the elastic member is characterized in that a sheet conveyance guide for guiding a sheet conveyed along the sheet conveyance path to an image reading position of the image reading unit is integrally formed with the elastic member.
[0013]
Another feature of the image reading apparatus according to the present invention is that the sheet conveying guide is formed corresponding to the entire image reading width of the image reading means. The elastic member has a long plate-like bottom surface, a side surface standing on at least one long side of the bottom surface, and an upper surface functioning as the sheet conveyance guide formed by bending the upper end of the side surface. At the same time, the end of the bottom surface is formed with a bent portion for exerting an elastic force. Further, in the middle of the sheet conveyance path, there is provided a storage unit that detachably stores the image reading unit on which the elastic member is mounted.
[0014]
The elastic member of the present invention presses the image reading unit in the direction of the sheet regulating unit at the opposite position in a state where the image reading unit that reads an image of the sheet conveyed along the sheet conveying path is installed in the image reading apparatus. An elastic member that is made of a conductive material, has a long plate-like bottom surface, a side surface that stands on at least one long side of the bottom surface, and a top surface that is formed by bending the upper end of the side surface. And a bent portion for exhibiting elastic force is formed at the end of the bottom surface.
[0015]
Another feature of the elastic member of the present invention is that the upper surface functions as a sheet conveyance guide for guiding a sheet conveyed along the sheet conveyance path to an image reading position of the image reading unit. . The sheet conveying guide is formed corresponding to the entire image reading width of the image reading means.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an image reading apparatus and an elastic member used in the image reading apparatus of the invention will be described with reference to the drawings.
[0017]
(First embodiment)
FIG. 1 is a cross-sectional side view of a sheet conveying scanner that is an image reading apparatus according to a first embodiment. In the figure, a paper feed port 2 is provided at an upper portion of an image reading apparatus main body 1 (hereinafter referred to as an apparatus main body). The sheet stacking tray 3 is inclined and disposed above the sheet feeding port 2, and the document P, which is a sheet, is placed on the sheet stacking tray 3 with the image reading surface facing downward with the lower end portion inserted into the sheet feeding port 2. Set.
[0018]
The documents P set on the sheet stacking tray 3 are separated one by one from the lower sheet by the sheet feed roller 4 and the separation roller 5 one by one and fed to the conveyance roller 6. Then, the original P separated and fed one by one is conveyed by the conveying roller 6 at a constant speed to a position of a contact type image sensor 8 that is an image reading unit disposed on the conveying frame 7.
[0019]
On the opposite side of the image reading position A of the contact image sensor 8, a platen roller 10 that is a sheet regulating means for bringing the document P into close contact with the contact glass 9 and transporting the document P at a predetermined speed is installed in proximity. ing.
[0020]
The document P that has passed through the transport roller 6 is read at the image reading position A of the contact image sensor 8, and then the discharge roller 11 while changing the transport direction along the surface of the contact glass 9 by the platen roller 10. And is discharged out of the apparatus main body 1 through the discharge port 12.
[0021]
In this way, a bent sheet conveying path can be formed by conveying the platen roller 10 while changing the conveying direction. Therefore, in the image reading apparatus employing the vertical sheet conveying path, the sheet can be discharged smoothly. Can do. In addition, the entire sheet conveyance path can be made compact, whereby the apparatus main body 1 can be reduced in size.
[0022]
As shown in FIG. 2, the contact image sensor 8 includes an LED as a light source, a lens array, and an image sensor (light receiving element), which are not shown, in a frame 8 b formed of a long and narrow housing. The contact glass 9 is installed on the upper surface of the frame 8a. The contact image sensor 8 is provided with a leaf spring member 13 as a pressing means. FIG. 3 is a side view showing the mounting direction of the leaf spring member 13 to the contact image sensor 8 and the mounting state thereof.
[0023]
As shown in FIGS. 2 and 3, the leaf spring member 13 corresponding to the elastic member in the present invention includes a long plate-like bottom surface 13a, a side surface 13b erected on one long side of the bottom surface 13a, and a side surface 13b. It has a substantially U-shape having an upper surface 13c formed by bending the upper end. As shown in FIG. 3, the leaf spring member 13 thus configured is attached to the contact image sensor 8 so as to be sandwiched between the bottom surface 13a and the upper surface 13c from one side surface direction (arrow B direction) of the contact image sensor 8. The
[0024]
Bending portions 13d that are bent downward are formed on both sides of the bottom surface 13a of the leaf spring member 13, that is, the surface that contacts the bottom surface of the contact image sensor 8, and elastic force is exhibited by these bending portions 13d. Have been to.
[0025]
Further, the surface located on the upper surface (contact glass 9) side of the contact image sensor 8, that is, the upper surface 13c of the leaf spring member 13 is inclined downward. The tip of the upper surface 13 c is positioned on the contact glass 9 before the image reading position A with the leaf spring member 13 mounted on the contact image sensor 8.
[0026]
A dowel 8a is formed on the bottom surface of the frame 8b of the contact image sensor 8, and a hole 13e is formed on the bottom surface of the leaf spring member 13. The dowel 8a and the hole 13e are fitted together so that they are positioned at the time of mounting. The
[0027]
As shown in FIG. 4, the contact image sensor 8 is housed from the direction of arrow C in the sensor housing portion 14 formed integrally with the resin-made transport frame 7 with the leaf spring member 13 mounted.
[0028]
Here, hook portions 7 a and 7 b are formed integrally with the transport frame 7 on both sides of the sensor storage portion 14 formed on the transport frame 7. The hook portions 7a and 7b are plate-shaped only at the base ends and are continuous with the transport frame 7. A protrusion having an inclined surface 17a and a stopper surface 17b is integrally formed on the inner side of the tip end.
[0029]
When the contact type image sensor 8 with the leaf spring member 13 mounted thereon is stored in the sensor storage unit 14 from the direction of arrow C as described above, both ends of the contact type image sensor 8 press the inclined surfaces 17a of the hook portions 7a and 7b. To spread the hooks 7a and 7b. When the contact image sensor 8 is completely stored in the sensor storage portion 14, the hook portions 7 a and 7 b return to the original state, and the stopper surfaces 17 b are locked to both end portions of the upper surface of the contact image sensor 8. Thus, the contact image sensor 8 is fixed in the sensor housing portion 14.
[0030]
In this housed state, the bent portion 13d formed on the leaf spring member 13 contacts the bottom surface of the sensor housing portion 14, and the contact image sensor 8 is caused by the elastic force generated by the bent portion 13d formed on the leaf spring member 13. The state is always pressurized upward.
[0031]
In the present embodiment, the contact type image sensor 8 and the leaf spring member 13 can be easily attached and detached by the elastic force of the leaf spring member 13. Since the contact image sensor 8 is detachably mounted, the contact image sensor 8 can be used without being modified.
[0032]
In addition, the contact image sensor 8 with the leaf spring member 13 mounted therein can be easily stored and removed from the sensor storage portion 14 by the elasticity of the hooks 7a and 7b formed integrally with the resin transport frame 7. Thus, there are advantages that the assembling property is improved and the contact image sensor 8 can be easily replaced.
[0033]
Here, as shown in FIG. 1, the upper surface 13c of the leaf spring member 13 attached to the contact image sensor 8 functions as a sheet conveyance guide on the sheet conveyance path. In the present embodiment, the sheet conveyance path is formed to be bent in order to reduce the size of the apparatus main body 1, and the contact glass 9 surface of the contact image sensor 8 is not parallel to the sheet conveyance path. However, by using the upper surface 13 c formed on the leaf spring member 13 as a sheet conveyance guide, the conveyed sheet can be smoothly guided to the image reading position A of the contact image sensor 8.
[0034]
Further, the leaf spring member 13 is made of a metal such as phosphor bronze or stainless steel and has conductivity. A part of the leaf spring member 13 is directly or indirectly connected to the electrical ground member 15 of the apparatus main body 1 via another conductive member (see FIG. 1). Therefore, the static electricity generated by the sheet conveyance can be released to the ground member 15 via the leaf spring member 13 before flying into the contact image sensor 8, and the influence of the static electricity can be prevented beforehand.
[0035]
Furthermore, an upper surface 13c that functions as a sheet conveyance guide formed on the leaf spring member 13 is formed corresponding to the entire image reading width of the contact image sensor 8, as shown in FIG. Therefore, the close contact type image sensor detects the external light that enters the conveying surface from the gap other than the sheet feeding roller 4, the separation roller 5, and the conveying roller pair 6 along the sheet conveying path from the sheet feeding port 2 of the apparatus body 1. Since the light can be shielded before being reflected on the surface 8 of the contact glass 9, it is possible to prevent deterioration of the image quality of the read image due to the external light.
[0036]
(Second Embodiment)
FIG. 5 is a configuration diagram of a main part for explaining the second embodiment. The same components as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is provided. Is omitted. The present embodiment is an example in which the contact image sensor 8 serving as an image reading unit is arranged on a curved sheet conveyance path.
[0037]
As shown in FIG. 5A, the sheet passes through the U-turn guide formed on the conveyance frame 7 by the conveyance roller 6 and is discharged out of the apparatus main body by the discharge roller 11.
[0038]
The U-turn guide portion of the transport frame 7 is provided with a contact image sensor 8 having a leaf spring member 16 mounted thereon, and on the opposite surface of the image reading position A as in the first embodiment. A platen roller 10 is installed in proximity.
[0039]
Here, as shown in FIG. 5B, the leaf spring member 16 of the present embodiment has side surfaces 16b erected on both long sides of the bottom surface 16a, and the upper ends of these side surfaces 16b are bent downward. The upper surface 16c is inclined in the direction. These upper surfaces 16c function as a sheet conveyance guide along the U-turn guide portion of the conveyance frame 7 on the sheet conveyance path. In addition, it is the same as that of the leaf | plate spring member 13 of the said 1st Embodiment that the bending part 16d for exhibiting an elastic force is formed in the both ends of the bottom face 16a.
[0040]
Further, by making the leaf spring member 16 made of metal and connecting it to the electrical ground of the apparatus main body, the same effect as in the first embodiment can be obtained.
[0041]
In the present embodiment, by providing the upper surface 16c as the sheet conveyance guide before and after the image reading position A, the sheet can be smoothly conveyed in accordance with the U-turn guide portion, and at the same time, external light entering from the paper discharge port 12 In contrast, the light shielding effect is enhanced.
[0042]
It should be noted that the shapes and structures of the respective parts shown in the above embodiments are merely examples of implementation in carrying out the present invention, and these limit the technical scope of the present invention. It should not be interpreted. That is, the present invention can be implemented in various forms without departing from the spirit or the main features thereof.
[0043]
【The invention's effect】
As described above, according to the present invention, since the pressing means is an elastic member having conductivity, the static electricity generated near the image reading means is released to the ground by being electrically connected to the ground potential. Therefore, it is possible to prevent damage to electrical components due to static electricity and image quality deterioration of a read image.
[0044]
Further, since it is detachably attached to the image reading means, it can be used as it is without the need to modify the image reading means, and assembly and replacement work can be easily performed.
[0045]
Further, by integrally forming a sheet conveyance guide that guides the sheet to the image reading position of the image reading unit along the sheet conveyance path, even when the image reading unit is disposed on the bent or curved sheet conveyance path, the dedicated sheet conveyance guide is provided. It is possible to smoothly convey the sheet to the conveyance guide member and the image reading position without providing the guide member, and it is possible to stabilize the sheet conveyance at the time of image reading without increasing the cost.
[0046]
Furthermore, by forming the sheet conveyance guide corresponding to the entire image reading width of the image reading means, it is possible to shield external light (flare light) incident on the image reading means without providing a dedicated light shielding member, Deterioration of the read image can be prevented without increasing the cost.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an image reading apparatus according to a first embodiment.
FIG. 2 is a perspective view showing a contact image sensor 8 and a leaf spring member 13;
FIG. 3 is a side view showing a mounting direction of the leaf spring member 13 to the contact image sensor 8 and a mounting state thereof.
4 is a perspective view showing a state in which the contact image sensor 8 to which the leaf spring member 13 is mounted is housed in the sensor housing portion 14. FIG.
FIG. 5 is a diagram illustrating a main configuration of an image reading apparatus according to a second embodiment.
FIG. 6 is a cross-sectional view of a contact image sensor.
7 is a schematic configuration diagram of an image reading unit in a conventional image reading apparatus using a contact image sensor 100. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Image reading apparatus main body 2 Paper feed port 6 Conveyance roller 7 Conveyance frame 8 Contact type image sensor 8a Frame 9 Contact glass 10 Platen roller 11 Discharge roller 12 Discharge port 13, 16 Leaf spring member 13a, 16a Bottom surface 13b, 16b Side surface 13c, 16c Upper surface 13d, 16d Bending portion 15 Ground member P Document A Image reading position

Claims (7)

Image reading means for reading an image of a sheet conveyed along a sheet conveying path;
Sheet restricting means provided facing the image reading means;
An image reading apparatus comprising: a pressing unit that presses the image reading unit in the direction of the sheet regulating unit,
The pressing unit is a conductive elastic member that is detachably attached to the image reading unit, and is electrically connected to a ground potential. Further, the pressing unit is connected to the elastic member along the sheet conveyance path. An image reading apparatus, wherein a sheet conveyance guide for guiding a conveyed sheet to an image reading position of the image reading means is formed integrally.   2. The image reading apparatus according to claim 1, wherein the sheet conveying guide is formed corresponding to the entire image reading width of the image reading unit.   The elastic member has a long plate-like bottom surface, a side surface raised on at least one long side of the bottom surface, and an upper surface functioning as the sheet conveyance guide formed by bending the upper end of the side surface, The image reading apparatus according to claim 1, wherein a bent portion for exerting an elastic force is formed at an end portion of the bottom surface.   4. The storage unit according to claim 1, wherein a storage unit that detachably stores the image reading unit on which the elastic member is mounted is provided in the middle of the sheet conveyance path. Image reading device. This is an elastic member for pressing the image reading unit in the direction of the sheet regulating unit at the opposite position in the state where the image reading unit for reading the image of the sheet conveyed along the sheet conveying path is installed in the image reading apparatus. And
Made of conductive material,
It has a long plate-like bottom surface, a side surface standing on at least one long side of the bottom surface, and an upper surface formed by bending the upper end of the side surface, and exerts an elastic force at the end of the bottom surface. An elastic member characterized in that a bent portion is formed.   6. The elastic member according to claim 5, wherein the upper surface functions as a sheet conveyance guide for guiding a sheet conveyed along the sheet conveyance path to an image reading position of the image reading unit.   The elastic member according to claim 6, wherein the sheet conveyance guide is formed corresponding to the entire image reading width of the image reading unit.

Images