JP3555749B2 - Image reading device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading apparatus that reads an image of a document using an image sensor, and more particularly to an image reading apparatus that can prevent skew of a document when reading a document, on the premise that a platen roller is pressed. .
[0002]
[Prior art]
2. Description of the Related Art An image reading apparatus used for a facsimile apparatus or the like is provided with a contact image sensor (hereinafter, referred to as a CIS (Contact Image Sensor)). When an image of a document is read by the CIS, the platen roller is pressed from above the reading surface toward the reading surface of the CIS so that the document closely contacts the reading surface of the CIS. A configuration in which the CIS is pressed toward the platen roller is also conceivable. However, since the assembly method of the apparatus is completely different, a configuration in which the platen roller is pressed is assumed here. By pressing the platen roller, the document is brought into close contact with the reading surface of the CIS and an image is read, and the document is conveyed in a predetermined direction by rotating the platen roller. Conventionally, in an image reading apparatus of this type, elastic members for pressing the platen roller toward the reading surface of the CIS are attached to both sides of the platen roller, and a driving device for driving the platen roller is provided only on one side. Was.
[0003]
[Problems to be solved by the invention]
However, when an original is read (conveyed) by such a method, an extra pressing force is applied to the reading surface of the CIS by the driving device, so that the pressing force on both sides of the platen roller is not uniform, and the original is skewed. There was a problem that it was easy to cause such problems.
[0004]
SUMMARY An advantage of some aspects of the invention is to provide an image reading apparatus that can prevent skew of a document when reading the document.
[0005]
[Means for Solving the Problems]
In order to achieve this object, an image reading apparatus according to claim 1 includes an image sensor that reads an image of a document, and a platen roller that closely contacts a document to be read with the image sensor. A mounted reading member, provided on both sides of the platen roller, for driving the platen roller, and a driving urging unit for urging the platen roller to the reading member,The drive urging unit is interlocked with the platen roller, and is configured to rotate the platen roller in the direction of urging the platen roller toward the reading member, and to allow the platen roller to rotate outward along the outer periphery of the rotary member. An arm connecting the rotation axis of the rotation member and the rotation axis of the platen roller, the arm being in contact with the reading member, and the arm being moved from the rotation center axis of the platen roller. Is formed slightly larger than the radius of the platen roller, and when the edge of the arm contacts the surface of the reading member, the surface of the reading member and the platen roller Between the platen roller and the surface of the reading member to reduce the friction between the platen roller and the reading member, thereby reducing the rotational load of the platen roller. If the draft is conveyed, by the conveying while pressing to the reading member by the platen roller and the document, an image drawn on the document is configured to be read.
[0006]
According to the image reading apparatus of the first aspect, the platen roller is driven on both sides and the platen roller is urged toward the reading member by the drive urging portions provided on both sides of the platen roller.A direction in which the platen roller is urged toward the reading member by the rotating member while the platen roller is kept rotatable along the outer periphery of the rotating member by an arm connecting the rotating shaft of the rotating member and the rotating shaft of the platen roller. Is rotated. Furthermore, since the distance from the rotation center axis of the platen roller to the edge of the arm is formed slightly larger than the radius of the platen roller, when the edge of the arm comes into contact with the surface of the reading member, the reading member There is a slight gap between the surface of the platen and the platen roller.
[0007]
[0008]
[0009]
[0010]
[0011]
3. The image reading apparatus according to claim 2, further comprising: an image sensor for reading an image of the document; and a platen roller for bringing the document for reading into close contact with the image sensor; a reading member on which the image sensor is mounted; The platen roller is located on both sides of the roller. And a drive urging unit that urges the platen roller against the reading member.The drive urging unit is interlocked with the platen roller, and is configured to rotate the platen roller in the direction of urging the platen roller toward the reading member, and to allow the platen roller to rotate outward along the outer periphery of the rotary member. In order to maintain, the guide member is formed at an equal distance from the rotation center axis of the rotation member, and is configured by a guide groove into which the rotation axis of the platen roller is slidably fitted.The platen roller slidably fitted in the guide groove is formed with an outer diameter larger than the outer diameter thereof, and has a collar abutting on the reading member, and the color is the reading member. A small gap is created between the surface of the reading member and the surface of the platen roller, the friction between the platen roller and the surface of the reading member is reduced to reduce the friction between the platen roller and the platen roller. While the rotation load of the rollers is reduced, when the original is conveyed, the image drawn on the original is read by conveying the original while pressing the original against the reading member by the platen roller. Is configured.
[0012]
This claim2According to the described image reading device,The drive urging units disposed on both sides of the platen roller drive the platen roller on both sides and urge the platen roller toward the reading member. AndWhile being formed at an equal distance from the rotation center axis of the rotating member, the guide shaft into which the rotating shaft of the platen roller is slidably fitted, while maintaining the platen roller to be able to rotate over the outer periphery of the rotating member, The platen roller is rotated in a direction to urge the reading member by the rotating member.Furthermore, since the platen roller slidably fitted in the guide groove has a collar formed with an outer diameter larger than the outer diameter, when the collar comes into contact with the surface of the reading member, the reading is performed. There is a slight gap between the surface of the member and the platen roller.
[0013]
[0014]
[0015]
Claim3The image reading device described in the claims1 or 2Wherein the drive urging unit includes an elastic member that pulls or compresses in the urging direction of the platen roller.
[0016]
This claim3According to the image reading device described in the claims,1 or 2The platen roller operates in the same manner as the image reading device described above, and the elastic member applies a tensile force or a compressive force to the platen roller, thereby urging the platen roller toward the reading member.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The image reading apparatus according to the present embodiment is an apparatus that reads an image of a document using a contact image sensor (hereinafter, referred to as a CIS (Contact Image Sensor)), and is used, for example, in a facsimile apparatus.
[0018]
FIG. 1 is a side sectional view schematically showing an internal structure of an image reading apparatus 2 according to an embodiment of the present invention, which is disposed above a facsimile apparatus 1. In FIG. 3 shows a transport direction and a transport path of the document paper P.
[0019]
As shown in FIG. 1, on the upstream side (upper left side in FIG. 1) of the original sheet P in the transport direction, a sheet feed tray 3 formed in a substantially plate shape is disposed so as to be inclined downward toward the downstream side in the transport direction. Have been. On the downstream side in the transport direction of the paper feed tray 3, a paper feed slope 4 for guiding the stacked original sheets P placed on the paper feed tray 3 to the inside of the image reading device 2 is transported similarly to the paper feed tray 3. It is arranged to be inclined downward toward the downstream side in the direction.
[0020]
In the vicinity of the end of the paper feeding slope 4, a front actuator 5 having a substantially hook-shaped upper portion is rotatably supported about a fulcrum 5a. When the original paper P supplied from the paper feed tray 3 reaches the front actuator 5 via the paper feed slope 4, the front actuator 5 is tilted down by the original paper P and rotates around the fulcrum 5a. By rotating the front actuator 5 in this manner, a sensor (not shown) can detect that the sheet feeding has been completed.
[0021]
On the downstream side of the paper feeding slope 4 in the transport direction, a separation plate 6 formed in a substantially flat shape is disposed so as to be inclined upward toward the downstream side in the transport direction. The separation piece 6 is formed of a synthetic resin material such as silicone rubber having flexibility, and cooperates with a separation roller 10 described later to separate a plurality of original sheets P stacked on the sheet feeding slope 4. This is for separating each sheet. As described above, since the separation piece 6 is formed of a material having a large surface friction coefficient, such as silicon rubber, a plurality of original sheets P in contact with the surface can be hooked and separated one by one. It is.
[0022]
A substantially rectangular push-up member 7 that pushes up the separation piece 6 upward is disposed on the lower surface of the separation piece 6, and the push-up member 7 is rotatably attached to the main body of the image reading device 2 via a hinge 8. Is being worn. Further, a compression spring 9 is mounted on the lower surface of the push-up member 7. The pushing-up member 7 is urged toward the separation piece 6 by the force that the compression spring 9 tends to expand.
[0023]
Above the separation piece 6, a separation roller 10 that cooperates with the separation piece 6 to separate a plurality of original sheets P one by one and transports the separated original sheet P downstream in the transport direction. Are arranged. The separation roller 10 is rotatably mounted on the frame 11 by a separation roller shaft 10a. On the upstream side of the frame 11 in the transport direction (left side in FIG. 1), a pick roller 12 that transports the separated original paper P toward the downstream side in the transport direction similarly to the separation roller 10 is provided. The pick roller 12 is also rotatably mounted on the frame 11 by a pick roller shaft 12a, similarly to the separation roller 10. By the separation roller 10 and the pick roller 12, only one original sheet P stacked on the uppermost stage is transported to a first transport roller 13 and a first pressing roller 14, which will be described later.
[0024]
The frame 11 on which the separation roller 10 and the pick roller 12 are rotatably mounted is rotatably mounted on the main body of the image reading apparatus 2 with a fulcrum (not shown) as a fulcrum. When the manuscript paper P is inserted into the paper feeding slope 4, the pick roller 12 becomes an obstacle to paper feeding, so that the frame 11 rotates around the fulcrum in the direction in which the pick roller 12 rises. On the other hand, when the feeding of the original paper P is completed after the insertion of the original paper P into the paper feeding slope 4, the pick roller 12 must be brought into contact with the surface of the original paper P. As a center, the pick roller 12 rotates in a downward direction.
[0025]
A first transport roller 13 for transporting the separated document paper P downstream in the transport direction is provided downstream of the separation piece 6 in the transport direction. Below the first transport roller 13, a first transport roller 13 is provided. A first pressing roller 14 for pressing the document paper P against the first transport roller 13 is provided. The first transport roller 13 and the first pressing roller 14 are each rotatably mounted on the main body of the image reading device 2. A curved portion 15 is formed on the downstream side of the first transport roller 13 and the first pressing roller 14 in the transport direction. The original paper P passes through the curved portion 15 and the front and back of the original paper P are reversed. .
[0026]
A second transport roller 16 that transports the document sheet P downstream in the transport direction is disposed at the end of the curved portion 15. Below the second transport roller 16, a second transport roller 16 is provided. A second pressing roller 17 for pressing the original paper P is provided. The second transport roller 16 and the second pressing roller 17 are each rotatably mounted on the main body of the image reading device 2. The document sheets P separated one by one by the separating pieces 6 are nipped by a first transport roller 13, a first pressing roller 14, a second transport roller 16, and a second pressing roller 17. The sheet is conveyed at a predetermined speed with the rotation of the conveying roller 13 and the second conveying roller 16 and is sent to the image reading unit 18.
[0027]
An image reading unit 18 that reads an image of the document paper P is provided downstream of the second transport roller 16 and the second pressing roller 17 in the transport direction. The image reading unit 18 includes a CIS 19 serving as a sensor for reading an image on the document sheet P, a reading member 20 having the CIS 19 mounted thereon, a platen roller 21 for conveying the document sheet P while pressing the document sheet P against the reading member 20, and the like. I have. A white tape is wound around the surface of the platen roller 21 as a white reference when reading an image.
[0028]
The document paper P conveyed by the second conveyance roller 16 and the second pressing roller 17 is conveyed while being pressed by the platen roller 21 to the reading member 20 on which the CIS 19 is mounted, so that an image drawn on the back surface is formed. Read. The details of the image reading unit 18 will be described later.
[0029]
A discharge roller 22 for discharging the read original paper P from the image reading device 2 to the outside is disposed downstream of the image reading unit 18 in the transport direction. Is provided with a paper discharge pressing roller 23 for pressing the document paper P against the paper discharge roller 22. The paper discharge roller 22 and the paper discharge pressing roller 23 are rotatably mounted on the main body of the image reading device 2. The document paper P from which the image is read by the image reading unit 18 is nipped by the paper discharge roller 22 and the paper discharge pressing roller 23 and is conveyed at a predetermined speed with the rotation of the paper discharge roller 22. The paper is ejected outside the
[0030]
A substantially plate-shaped paper discharge tray 24 that stores the discharged read original paper P is disposed below the paper discharge roller 22 and the paper discharge pressing roller 23 in the forward direction in the transport direction. Further, a cover 25 for protecting each device is provided on the upper portion of the image reading device 2 from the paper feeding slope 4 to the paper discharge roller 22 via the curved portion 15.
[0031]
FIG. 2 is a side view showing details of the image reading unit 18 and the drive urging unit 30 of the first embodiment. Since both side surfaces of the image reading unit 18 and the drive urging unit 30 of the first embodiment have a symmetric structure, only one side will be described.
[0032]
A platen roller 21 is disposed above the reading member 20 on which the CIS 19 for reading the image of the document sheet P is mounted, for pressing and transporting the document sheet P to the reading member 20. As described above, the surface of the platen roller 21 is wound with a white tape that is used as a white reference when reading an image. Therefore, the white reference can be sequentially adjusted before reading the image.
[0033]
Platen gears 21a for transmitting a driving force for rotating the platen roller 21 are provided in the vicinity of both ends of the platen roller 21, respectively. The outer peripheral circle in the figure of the platen gear 21a indicates the tip circle of the gear, and the one-dot chain line inside the circle indicates the pitch circle of the gear. A platen shaft 21b extends from the center of the platen roller 21 and the platen gear 21a, and is rotatably mounted on an arm 33 described later.
[0034]
An urging gear 31 that can mesh with the platen gear 21a is disposed above the platen gear 21a. The outer circle in the figure of the urging gear 31 indicates the tip circle of the gear, the inner circle indicates the root circle of the gear, and the one-dot chain line between the outer circle and the inner circle indicates the gear. Is shown. An urging shaft 31a extends from the center of the urging gear 31, and is rotatably mounted on the side plate 32.
[0035]
Further, a platen shaft 21b, which is a rotation shaft of the platen roller 21 and the platen gear 21a, and a biasing shaft 31a, which is a rotation shaft of the biasing gear 31, are each formed by an arm 33 formed in a substantially oval plate shape. It is rotatably connected. By this arm 33, the platen gear 21a is maintained so as to be able to rotate over the outer periphery of the urging gear 31.
[0036]
A drive gear 34 that can mesh with the urging gear 31 is disposed above the urging gear 31. In the figure, the outer circle of the drive gear 34 indicates the tip circle of the gear, the inner circle indicates the root circle of the gear, and the one-dot chain line between the outer circle and the inner circle indicates the gear. The pitch circle is shown. A drive shaft 34a extends from the center of the drive gear 34, and is rotatably mounted on the side plate 32.
[0037]
Therefore, when the drive gear 34 is rotated in the direction of arrow R by the drive motor (not shown), the rotation is transmitted to the platen gear 21a by the urging gear 31, and the platen roller 21 is rotated in the direction of arrow R. . Thus, by rotating the platen gear 21 a by the urging gear 31, a pressing force is generated in a direction for urging the platen roller 21 toward the reading member 20. As described above, the direction in which the platen roller 21 is urged toward the reading member 20 by the urging gear 31 while the platen gear 21a is kept rotatable along the outer periphery of the urging gear 31 by the arm 33 (see FIG. 2). (In the direction of arrow R), the platen roller 21 can be urged toward the reading member 20 by the rotation of the urging gear 31.
[0038]
In addition, since the drive urging units 30 are disposed on both sides of the platen roller 21, the platen roller 21 can apply a uniform pressing force to the reading member 20. Therefore, it is possible to prevent the skew of the original sheet P when reading the original.
[0039]
A projection 33a for hooking the spring 35 is formed at a substantially intermediate portion of the arm 33, and a hook 32a for hooking the spring 35 is formed below the side plate 32. A spring 35 is stretched between the projection 33a and the hook 32a while applying a tensile force. The platen roller 21 pivotally attached to the arm 33 is urged toward the reading member 20 by the spring 35. Therefore, the platen roller 21 can be reliably pressed against the reading member 20.
[0040]
FIG. 3 is an enlarged sectional view of the platen roller 21 and the reading member 20 in the first embodiment. As shown in FIG. 3, the outer diameter of the circular portion of the arm 33 on the platen roller 21 side is slightly larger than the outer diameter of the platen roller 21. That is, when the platen roller 21 is urged against the reading member 20, the edge of the arm 33 comes into contact with the surface of the reading member 20, so that there is a slight gap between the platen roller 21 and the surface of the reading member 20. Gap t occurs. Therefore, the friction between the platen roller 21 and the surface of the reading member 20 can be reduced, and the rotational load of the platen roller 21 can be reduced.
[0041]
Although the outer diameter of the platen gear 21a is larger than the outer diameter of the circular portion of the arm 33 on the platen roller 21 side, the upper surface of the reading member 20 is provided to avoid interference between the platen gear 21a and the reading member 20. Since the concave portion (not shown) is formed, the platen gear 21a does not contact the reading member 20 and does not hinder the rotation.
[0042]
Next, a second embodiment will be described with reference to FIG. FIG. 4 is a side view showing details of the image reading unit 18 and the drive urging unit 40 of the second embodiment. In the second embodiment, the following points are changed from the first embodiment.
[0043]
In the first embodiment, the arm 33 connects the platen shaft 21 b and the urging shaft 31 a in order to maintain the platen gear 21 a so as to be able to rotate around the outer periphery of the urging gear 31. On the other hand, in the second embodiment, the guide groove 41a formed at a position equidistant from the center of the urging shaft 31a in order to maintain the platen gear 21a to be able to rotate around the outer periphery of the urging gear 31. The platen shaft 21b is slidably fitted on the shaft.
[0044]
Since the other parts are the same as those of the first embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Further, since both side surfaces of the image reading unit 18 and the drive urging unit 40 of the second embodiment have a symmetric structure as in the first embodiment, only one side will be described.
[0045]
A substantially elliptical guide groove 41a is formed in the side plate 41 on which the urging gear 31 and the drive gear 34 are axially mounted at a position equidistant from the center of the urging shaft 31a. The guide groove 41 a may be a hole penetrated through the side plate 41 as shown in FIG. 4 or a groove formed on the surface of the side plate 41. A platen shaft 21b, which is a rotation shaft of the platen roller 21 and the platen gear 21a, is slidably fitted in the guide groove 41a. As the platen shaft 21b slides along the guide groove 41a, the platen gear 21a is kept rotatable along the outer periphery of the urging gear 31. Therefore, the position and length of the guide groove 41a may be configured so that the platen roller 21 can be pressed against the reading member 20 when the platen shaft 21b slides.
[0046]
When the drive gear 34 is rotated in the direction of arrow R by a drive motor (not shown), the rotation is transmitted to the platen gear 21a by the urging gear 31, and the platen roller 21 is rotated in the direction of arrow R. Thus, by rotating the platen gear 21 a by the urging gear 31, a pressing force is generated in a direction for urging the platen roller 21 toward the reading member 20. As described above, the direction in which the platen roller 21 is urged toward the reading member 20 by the urging gear 31 while the platen gear 21a is kept rotatable along the outer periphery of the urging gear 31 by the guide groove 41a (see FIG. 2). (In the direction of arrow R), the platen roller 21 can be urged toward the reading member 20 by the rotation of the urging gear 31.
[0047]
Moreover, since the drive urging units 40 are disposed on both sides of the platen roller 21 as in the first embodiment, the platen roller 21 can apply a uniform pressing force to the reading member 20. Therefore, it is possible to prevent the skew of the original sheet P when reading the original.
[0048]
Further, a protrusion 21c for hooking the spring 42 is formed at a tip end of the platen shaft 21b, and a hook 41b for hooking the spring 42 is formed below the side plate 41. A spring 42 is stretched between the projection 21c and the hook 41b while applying a tensile force. Since the platen roller 21 is urged toward the reading member 20 by the spring 42, the platen roller 21 can be reliably pressed against the reading member 20.
[0049]
FIG. 5 is an enlarged sectional view of the platen roller 21 and the reading member 20 in the second embodiment. As shown in FIG. 5, near the both ends of the platen roller 21, a collar 21 d having an outer diameter slightly larger than the outer diameter of the platen roller 21 is provided. That is, when the platen roller 21 is urged against the reading member 20, the edge of the collar 21d abuts on the surface of the reading member 20, so that there is a slight gap between the platen roller 21 and the surface of the reading member 20. Gap t occurs. Therefore, similarly to the first embodiment, the friction between the platen roller 21 and the surface of the reading member 20 can be reduced, and the rotational load of the platen roller 21 can be reduced.
[0050]
Next, an operation of reading an image on the document sheet P by the image reading device 2 will be described with reference to FIG. First, a plurality of original sheets P on which an image is drawn are stacked on the sheet feed tray 3 such that the image surface faces upward. Then, when the original paper P is inserted into the paper feed slope 4 in a stacked state, the front actuator 5 falls forward in the transport direction and rotates about the fulcrum 5a. By the rotation of the front actuator 5, a sensor (not shown) detects the completion of sheet feeding. When the leading end of the document sheet P comes into contact with the lower surface of the separation roller 10 and the upper surface of the separation piece 6, the insertion of the plurality of document sheets P is completed.
[0051]
Subsequently, when an image reading switch (not shown) is turned on, the frame 11 rotates in a direction (counterclockwise) in which the pick roller 12 descends with the fulcrum (not shown) as a fulcrum. When the pick roller 12 comes into contact with the document paper P, the rotation of the frame 11 stops. When the rotation (counterclockwise) of the frame 11 stops, the separation roller 10 and the pick roller 12 start rotating in the transport direction of the document paper P. Then, the separation piece 6 hooks a plurality of original sheets P in contact with the surface thereof and separates them one by one. When the separation roller 10 and the pick roller 12 are further rotated, the uppermost document sheet P that comes into contact with the separation roller 10 is transported forward by one sheet.
[0052]
One original sheet P transported by the separation roller 10 is transported to the bending section 15 by the first transport roller 13 and the first pressing roller 14, and the original sheet P passing through the bending section 15 is transferred to the second transport roller 16. The sheet is conveyed to the image reading unit 18 at a predetermined speed by the second pressing roller 17.
[0053]
The document paper P conveyed to the image reading unit 18 is conveyed while being pressed by the platen roller 21 to the reading member 20 on which the CIS 19 is mounted, so that the image drawn on the back surface is read. The operation of the image reading unit 18 will be described later in detail. The document sheet P that has passed through the image reading unit 18 is nipped by a discharge roller 22 and a discharge pressing roller 23, conveyed at a predetermined speed with the rotation of the discharge roller 22, and discharged onto a discharge tray 24. Paper.
[0054]
Next, the operations of the image reading unit 18 and the driving urging units 30 and 40 will be described in detail with reference to FIGS. First, when an image reading switch (not shown) is turned on, a drive motor (not shown) starts rotating. The rotation of the drive motor is transmitted to the drive gear 34, and the drive gear 34 rotates in the direction of arrow R. This rotation is transmitted to the platen gear 21a by the urging gear 31, and the platen roller 21 rotates in the direction of arrow R.
[0055]
Thus, by rotating the platen gear 21 a by the urging gear 31, a pressing force is generated in a direction for urging the platen roller 21 toward the reading member 20. At that time, the platen gear 21a is maintained so as to be able to rotate around the outer periphery of the urging gear 31 by the arm 33 of the first embodiment or the guide groove 41a of the second embodiment. As described above, while the image drawn on the document sheet P is read by the CIS 19 mounted on the reading member 20, the document sheet P is conveyed toward the sheet discharge roller 22 by the rotation of the platen roller 21.
[0056]
As described above, the image reading apparatus 2 of the present embodiment is configured such that the platen gear 21a is rotatable around the outer periphery of the urging gear 31 by the arm 33 or the guide groove 41a while the platen gear is Since the roller 21 can be rotated in the direction of urging the reading member 20 (the direction of the arrow R in FIGS. 2 and 3), the rotation of the urging gear 31 urges the platen roller 21 toward the reading member 20. can do. Further, since the drive urging units 30 are disposed on both sides of the platen roller 21, the platen roller 21 can apply a uniform pressing force to the reading member 20. Therefore, it is possible to prevent the skew of the document sheet P during image reading.
[0057]
As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and it is easily understood that various improvements and modifications can be made without departing from the spirit of the present invention. It can be inferred.
[0058]
For example, the present invention may be applied to a copying machine in which a document is transported by a pick roller, or may be applied to an apparatus in which a facsimile and a copying machine are combined.
[0059]
【The invention's effect】
According to the image reading apparatus of the first aspect, the drive urging portions disposed on both sides of the platen roller drive the platen roller on both sides and urge the platen roller toward the reading member. Accordingly, since the platen roller can apply a uniform pressing force to the reading member, it is possible to prevent the skew of the original when reading the original.
[0060]
ChangeThe platen roller is urged to the reading member by the rotating member while the platen roller is kept rotatable around the outer periphery of the rotating member by an arm connecting the rotating shaft of the rotating member and the rotating shaft of the platen roller. Can be rotated in any direction. Therefore, there is an effect that the platen roller can be urged toward the reading member by the rotation of the rotating member.
[0061]
ChangeSince the distance from the rotation center axis of the platen roller to the edge of the arm is formed slightly larger than the radius of the platen roller, when the edge of the arm comes into contact with the surface of the reading member, the reading member There is a slight gap between the surface of the platen and the platen roller. Therefore, there is an effect that the friction between the platen roller and the surface of the reading member is reduced, and the rotational load of the platen roller can be reduced.
[0062]
Claim2According to the described image reading device,The drive urging units disposed on both sides of the platen roller drive the platen roller on both sides and urge the platen roller toward the reading member. Accordingly, since the platen roller can apply a uniform pressing force to the reading member, there is an effect that the skew of the document at the time of reading the document can be prevented.Furthermore, the platen roller is formed to be equidistant from the rotation center axis of the rotating member, and the platen roller is kept rotatable along the outer periphery of the rotating member by a guide groove into which the rotating shaft of the platen roller is slidably fitted. In addition, the platen roller can be rotated in a direction to urge the reading member by the rotating member. Therefore, there is an effect that the platen roller can be urged toward the reading member by the rotation of the rotating member.
[0063]
ChangeSince the platen roller slidably fitted in the guide groove has a collar formed with an outer diameter larger than the outer diameter of the platen roller, when the collar comes into contact with the surface of the reading member, the reading is performed. There is a slight gap between the surface of the member and the platen roller. Therefore, there is an effect that the friction between the platen roller and the surface of the reading member is reduced, and the rotational load of the platen roller can be reduced.
[0064]
Claim3According to the image reading device described in the claims,1 or 2In addition to the effects provided by the image reading device described in 1 above, the platen roller is urged toward the reading member by applying a tensile force or a compressive force to the platen roller by the elastic member. Therefore, there is an effect that the platen roller can be surely urged toward the reading member.
[Brief description of the drawings]
FIG. 1 is a side sectional view schematically showing an internal structure of an image reading apparatus according to an embodiment of the present invention.
FIG. 2 is a side view showing details of an image reading unit and a drive urging unit of the first embodiment.
FIG. 3 is an enlarged sectional view of a platen roller and a reading member according to the first embodiment.
FIG. 4 is a side view showing details of an image reading unit and a drive urging unit of a second embodiment.
FIG. 5 is an enlarged sectional view of a platen roller and a reading member according to a second embodiment.
[Explanation of symbols]
2 Image reading device
19 CIS (image sensor)
20 reading member
21 Platen roller
21d color
30, 40 drive urging unit
31 urging gear (rotating member)
33 arm
35, 42 Spring (elastic member)
41a Guide groove
P Manuscript paper (manuscript)

Claims (3)

In an image reading apparatus including an image sensor that reads an image of a document, and a platen roller that closely contacts the reading document with the image sensor,
A reading member equipped with the image sensor,
A drive urging unit disposed on both sides of the platen roller to drive the platen roller and urge the platen roller to the reading member;
The drive urging unit is interlocked with the platen roller, and is configured to rotate the platen roller in the direction of urging the platen roller toward the reading member, and to allow the platen roller to rotate outward along the outer periphery of the rotary member. In order to maintain, it is constituted by an arm connecting the rotation axis of the rotation member and the rotation axis of the platen roller,
The arm is in contact with the reading member, and a distance from a rotation center axis of the platen roller to an edge of the arm is formed to be slightly larger than a radius of the platen roller. Is contacted with the surface of the reading member, a slight gap is generated between the surface of the reading member and the platen roller, reducing the friction between the platen roller and the surface of the reading member. While the rotation load of the platen roller is reduced, when the document is conveyed, the document is conveyed while being pressed against the reading member by the platen roller, so that the image drawn on the document is read. An image reading apparatus characterized by being configured to be able to read. In an image reading apparatus including an image sensor that reads an image of a document, and a platen roller that closely contacts the reading document with the image sensor,
A reading member equipped with the image sensor,
A drive urging unit disposed on both sides of the platen roller to drive the platen roller and urge the platen roller to the reading member;
The drive urging unit is interlocked with the platen roller, and is configured to rotate the platen roller in the direction of urging the platen roller toward the reading member, and to allow the platen roller to rotate outward along the outer periphery of the rotary member. In order to maintain, the guide member is formed at an equal distance from the rotation center axis of the rotation member, and is configured by a guide groove into which the rotation axis of the platen roller is slidably fitted .
The platen roller slidably fitted in the guide groove is formed with an outer diameter larger than the outer diameter thereof, and has a collar abutting on the reading member, and the color is the reading member. A small gap is created between the surface of the reading member and the platen roller, and reduces the friction between the platen roller and the surface of the reading member to reduce the friction between the platen roller and the platen roller. On the other hand, when the original is conveyed while the rotation load of the original is reduced, the original is conveyed while being pressed against the reading member by the platen roller so that the image drawn on the original is read. image reading apparatus characterized by being configured. The drive biasing unit includes an image reading apparatus according to claim 1 or 2, characterized in that it comprises a resilient member for pulling or compressing the biasing direction of the platen roller.

Images