JPH1169077A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve read accuracy and to reduce defects in the conveyance of originals by locating the turning center of a supporting member, with which a read sensor is freely turnably fitted to the image reader body, on the side of the image reader on the tangent of the read sensor and an abutting member. SOLUTION: Images are read by conveying an original sheet while biasing it to a read sensor 10. In this case, the read sensor 10 is freely turnably fitted through a link 11 of the supporting member to a supporting point 11a, and the supporting point 11a is arranged on the tangent of the read sensor 10 and a scan roller 13. Besides, an elastic body 14 is fitted to the upper part of the read sensor 10 and biased to the scan roller 13. The biasing direction is set while being inclined to the downstream side of conveyance rather than a perpendicular to the tangent of the read sensor 10 and the scan roller 13, and the backlash of the link 11 is previously made eccentric to the downstream side. When the scan roller 13 is rotated and frictional force in the conveying direction is generated on the read sensor 10, the read sensor 10 does not move so that read accuracy is improved and defects in the conveyance of originals can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus for conveying an original sheet and reading an image on the original sheet, and more particularly to a technique for smoothly conveying an original sheet.

[0002]

2. Description of the Related Art A conventional image reading apparatus will be described with reference to FIGS. 8 is a side view schematically showing an image reading apparatus according to a conventional example, FIG. 9 is a schematic side view showing a state in which a rotating unit is opened, FIG. 10 is a front view of a feeding unit, and FIG. FIG. 12 is an enlarged view of the vicinity of a reading sensor, and FIG. 13 is a view showing a state of conveying a document sheet.

As shown in FIGS. 8 and 9, an image reading apparatus
100 comprises a lower body 101 and an upper rotating part 102,
It is configured to be rotatable around a rotation support portion 103 provided on the main body 101. A transport path for the document sheet P is formed between the main body 101 and the rotating section 102.

[0004] At the rear (left side in FIG. 8) of the main body 101, there are provided an exterior 104 as a stacking means and an original sheet stacking section 105, and can stack a bundle of original sheets P for reading an image. The bundle of original sheets P is blocked at a contact point between a feeding roller 106 serving as feeding means provided on the main body 101 and a separation pad 107 serving as separating means.

[0005] The separation pad 107 has a separation surface 107 a having a high surface frictional resistance at a contact point with the feeding roller 106.
On the other hand, since the feed roller 106 transmits the driving force to the uppermost original sheet P stacked, only the uppermost original sheet P is sent out to the transport path, and the other original sheets P It remains blocked by the separation pad 107.

As shown in FIG. 10, the feed roller 106 and the separation pad 107 have a width of about 30 mm, and are disposed substantially at the center of the main body 101. At least one set of rollers 106a having a smaller diameter than the feed roller 106 is mounted on both sides and coaxially of the feed roller 106. Hold out,
It is configured to improve loadability and transportability.

A leading end detection lever 108 as detection means rotatably attached to the main body 101 protrudes from the conveyance path of the document sheet P. When the conveyed document sheet P is rotated while contacting the leading edge detection lever 108, the light shielding portion 108a that has blocked the photo interrupter 109 is retracted, and the leading edge position of the document sheet P is detected. After a predetermined period of time, reading is started on the assumption that the document sheet P passes through the reading sensor 110.

The reading sensor 110 is arranged in a direction perpendicular to the conveying direction of the original sheet P, and has a width at least wider than the original sheet P. A scan roller 113 is provided at a position facing the reading sensor 110 via the conveyance path.
Is provided. The scan roller 113 is a contact member and a transport unit, and is formed to have a width wider than the original sheet P, and transports the original sheet P that has reached a contact portion with the reading sensor 110. A guide 120 is mounted on the upstream side of the reading sensor 110 in the conveying direction, and the conveyed original sheet P is read by the reading sensor 110 and the scan roller 113.
It is configured to guide between.

The reading sensor 110 has a link 11 as a support member.
1 and is rotatably attached to a fulcrum 111a of the rotating portion 102 via a lever 1, and is urged against the scan roller 113 by an elastic body 114 as urging means. At this time, the fulcrum 111a
Is provided at a position distant from the transport path.
The direction in which the reading sensor 110 is urged is parallel to the perpendicular to the tangent line between the reading sensor 110 and the scan roller 113.

The scan roller 113 is driven to rotate at a speed v4 higher than the rotation speed v3 of the feed roller 106. Here, as shown in FIG. 11, the feeding roller 106 is configured to transmit the driving force only in the transport direction by the one-way clutch gear 124. Therefore, when the original sheet P is conveyed to both the feed roller 106 and the scan roller 113, the original sheet P is conveyed by the faster rotation speed v4 of the scan roller 113, and the feed roller 106 is driven to rotate at a higher speed. Rotate at v4.

When the trailing end of the original sheet P comes off the feed roller 106, the feed roller 106 is again driven to rotate at the speed v3 by the driving force transmitted from the one-way clutch gear 124. Then, the next stacked original sheet P is fed, but due to the speed difference between the rotation speed v3 of the feed roller 106 and the rotation speed v4 of the scan roller 113,
The distance between the preceding document sheet P and the subsequent document sheet P is increased.

[0012]

The image reading apparatus constructed as described above has the following problems.

(1) As described above, the fulcrum 111a, which is the center of rotation of the reading sensor 110, is provided away from the conveyance path, that is, the tangent line between the reading sensor 110 and the scan roller 113. However, when the scan roller 113 is rotated, a frictional force F is generated in the reading sensor 110 toward the downstream side in the transport direction by the scan roller 113 or via the document sheet P as shown in FIG. Then link 111
May cause the reading sensor 110 to move due to the moment M1.

(2) The direction in which the elastic body 114 urges the reading sensor 110 toward the scan roller 113 depends on the direction of the reading sensor 110.
And the scanning roller 113 is parallel to a perpendicular line drawn to the tangent line. For this reason, the reading sensor 110 does not have a load in the transport direction, and the scan roller 113 may move to the downstream side in the transport direction by the play behind the link 111 or the like due to the frictional force F due to the rotation.

(3) The leading edge detecting lever 108 for detecting the leading edge of the document sheet P is provided on the opposite side of the main body 101, that is, the reading sensor 110, on the side opposite to the conveying path. Here the manuscript sheet P
If the tip is thin or the tip is rounded,
There is a risk that the leading end will be lifted by 108 and be caught between the reading sensor 110 and the guide 120.

(4) As shown in FIG. 13, when the original sheets P are stacked on the original sheet stacking section 105 while being inclined, the original sheets P are separated and conveyed by the feeding roller 106 while being inclined. When the leading end of the inclined original sheet P reaches the contact portion between the reading sensor 110 and the scan roller 113, the original sheet P is conveyed at a rotation speed v4 higher than the rotation speed v3 of the feeding roller 106. That is, the feed roller 106 is driven by this. Then, only one side of the original sheet P receives the conveying force F4 of the scan roller 113, and the resistive force F
Since 3 occurs, a moment M2 about the feed roller 106 is generated. This moment M
Due to 2, the original sheet P is further inclined.

(5) When an original sheet P having a rounded tip is stacked on the original sheet stacking section 105, the original sheet P first comes into contact with the roller 106a coaxially mounted with the feed roller 106. Therefore, there is a possibility that the leading edge of the document sheet P may be turned.

(6) When a stack of original sheets P is stacked on the original sheet stacking section 105, the uppermost original sheet P is caught on the separation surface 107a of the separation pad 107, and the original sheet P is fed by the feeding roller. There is a possibility that the sheet may not be transported because it does not press against the sheet 106.

[0019]

In order to solve the above-mentioned problems, an image reading apparatus according to the present invention comprises a feeding means for feeding a document sheet one by one, and a feeding path opposite to the feeding path of the feeding means. An elastic member provided on the upstream side in the direction to urge the document sheet toward the supply means, and formed continuously with a different curvature in a direction away from the document sheet bundle on the upstream side of the feeding means, and On the downstream side from the feeding means, a feed guide member formed in a shape along the conveyance path of the document sheet, a leading end detection member having a rotation support shaft on the same side as the reading sensor, and a conveyance direction of the document sheet. A reading sensor arranged in a direction perpendicular to the original sheet and wider than the document sheet; a supporting member having the reading sensor rotatably mounted on the image reading apparatus main body and having a rotation center on a conveyance path; A contact member that forms a conveyance path for the document sheet between the sensor and a reading sensor and is formed to have a width equal to or smaller than the width of the feeding unit, and biases the reading sensor toward the downstream side in the conveyance direction of the document sheet. And a biasing means for performing the operation.

An object of the present invention is to provide a sheet feeding type image reading apparatus for preventing a position change of a reading sensor, preventing a conveyance failure inside the apparatus, improving a stacking property, preventing a feeding failure, and preventing a skew during conveyance. With the goal.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image reading apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a side view schematically showing an image reading apparatus, FIG. 2 is a schematic side view showing a state in which a rotating unit is opened, FIGS. 3 and 4 are enlarged views near a feeding unit, and FIG. 6 is an enlarged view, FIG. 6 is a perspective view of a feeding unit and a conveying unit, and FIG. 7 is a diagram illustrating a conveying state of a document sheet.

As shown in FIGS. 1 and 2, the image reading apparatus 1 according to the present embodiment comprises a lower main body 2 and an upper turning section 3, and a rotation supporting section 4 provided on the main body 2 is mainly used. It is configured to be rotatable. A transport path for the document sheet P is formed between the main body 2 and the rotating unit 3.

An original sheet stacking section 5 and an exterior 12 as stacking means are provided behind the main body 2 (left side in FIG. 1), and can stack a stack of original sheets P for reading an image. The bundle of document sheets P is blocked at a contact point between a feeding roller 6 serving as feeding means provided on the main body 2 and a separation pad 7 serving as separating means.

The feed roller 6 and the separation pad 7 are formed to have a width of about 30 mm, and are disposed substantially at the center of the main body 2. As shown in FIGS. 3 and 4, a feeding guide 20 is provided so as to surround the feeding roller 6. The feeding guide 20 is formed to have the same width as the document sheet P, and forms a conveying path from the upstream side to the downstream side of the feeding roller 6.
The surface of the feed guide 20 with respect to the transport path on the upstream side of the feed roller 6 is formed so that different curvatures are continuously formed and gradually curved away from the transport path. The downstream side of the feed roller 6 is formed as a plane along the transport path.

That is, the entrance of the transport path of the document sheet P is wide and narrows smoothly toward the contact point between the feed roller 6 and the separation pad 7. Therefore, when the bundle of the original sheets P is stacked on the original sheet stacking section 5, even if the leading end of the original sheet P is rounded, there is no possibility that the original sheet P is turned up. In addition, since the downstream side of the feeding roller 6 of the feeding guide 20 is made flat, it is possible to suppress flapping and waving of a portion of the document sheet P that is out of the width of the feeding roller 6.

An elastic member 21 such as a mylar sheet is provided on the side opposite to the conveyance path of the feeding roller 6 and on the upstream side in the conveyance direction. The elastic member 21 is supported with one end fixed to the main body 2 and the other end protruding above the separation pad 7.

Therefore, the original sheet P is placed on the original sheet stacking section 5.
When the bundle is stacked, the elastic member 21 is bent and positioned closer to the separation pad 7 than the lowermost sheet of the bundle of the original sheets P, and urges the bundle toward the feed roller 6. As a result, the bundle of document sheets P always comes into contact with the feed roller 6, and the sheet can be fed reliably.

The separation pad 7 is rotatably attached to the main body 2 and is urged against the feed roller 6 by an elastic member 7c. The separation pad 7 has a separation surface 7a having a high surface frictional resistance at the point of contact with the feeding roller 6, and the uppermost original sheet P on which the feeding roller 6 is stacked
, Only the uppermost original sheet P is sent out to the transport path, and the other original sheets P
Remain blocked by the separation pad 7.

A lever 7b provided at one end of the separation pad projects out of the exterior from the opening 12a of the exterior 12. By rotating the lever 7b against the urging force of the elastic member 7c, the pressure between the feed roller 6 and the separation pad 7 can be released, and the original sheet stopped during the conveyance can be removed.

A tip detecting lever 8 serving as a detecting means is rotatably attached to the rotating portion 3 and has one end protruding into the conveying path of the document sheet P and the photo interrupter 9 blocked by the light shielding portion 8a at the other end. ing. When the conveyed document sheet P is rotated by contacting the leading edge detection lever 8, the light shielding portion 8a also pivots, and the photo interrupter 9 becomes transparent so that the leading edge of the document sheet P is detected. Assuming that the original sheet P passes the reading sensor 10 after a predetermined time from this, reading is started by the reading sensor 10.

As shown in FIG. 5, the rotated tip detecting lever 8 is moved to a position that closes a step or a gap between a reading sensor 10 described later and a transport guide 22 upstream of the reading sensor 10. Have been. Accordingly, even when the original sheet P is thin or the tip is rounded, it is possible to prevent the original sheet P from being caught on a step between the reading sensor 10 and the transport guide 22 or the like.

The reading sensor 10 is rotatably attached to a fulcrum 11a of the rotating portion 3 via a link 11 as a support member. A fulcrum 11a of the link 11 is disposed on a tangent line between the reading sensor 10 and the scan roller 13 as a transport unit.
Therefore, even when the scan roller 13 rotates and a frictional force is generated in the reading sensor 10 in the transport direction, there is no possibility that the link 11 will move due to a moment.

A projection 10a is provided above the reading sensor 10. The projection 10a is urged by the scan roller 13 by attaching an elastic body 14 to the projection 10a. At this time the elastic body
The biasing direction of the scanning sensor 14 and the scanning roller 13
Is set so as to be inclined to the downstream side in the transport direction with respect to the perpendicular to the tangent line to. Thereby, the play of the attachment of the link 11 can be brought to the downstream side in advance, and the reading sensor 10 does not move even when the scan roller 13 is driven to rotate.

As shown in FIG. 6, the width of the scan roller 13 is equal to or narrower than that of the feed roller 6, and a plate-like elastic pressing member 23 such as a mylar sheet is attached to both sides thereof. That is, the scanning roller 13 and the elastic pressing member 23 constitute a contact member that presses the original sheet P against the reading sensor 10, whereby the original sheet P is conveyed to read an image on the front surface.

The scan roller 13 is driven to rotate at a speed v2 higher than the rotation speed v1 of the feeding roller 6. Here, the feed roller 6 is configured to transmit driving force only in the transport direction by a one-way clutch gear 24 as shown in FIG. Accordingly, when the original sheet P is conveyed to both the feed roller 6 and the scan roller 13, the original sheet P is conveyed by the faster rotation speed v2 of the scan roller 13, and the feed roller 6 is driven to rotate at a higher speed. Rotate at v2.

Here, as described above, the scan roller 13
Is equal to or narrower than the width of the feeding roller 6. Accordingly, as shown in FIG. 7, the direction of the conveying force applied to the original sheet P by the scan roller 13 and the direction of the resultant force of the resistance applied to the original sheet P by the feed roller 6 substantially match the conveying direction. As a result, no moment is generated in the original sheet P, and even if the original sheet P stacked with inclination is conveyed as it is, there is no possibility that the inclination is increased.

When the trailing end of the original sheet P comes off the feed roller 6, the feed roller 6 is again moved to the one-way clutch gear 24.
Is driven at a speed v3 by the driving force transmitted from the motor. Then, the next stacked original sheet P is fed. The speed difference between the rotation speed v1 of the feed roller 6 and the rotation speed v2 of the scan roller 13 causes the preceding original sheet P and the subsequent original sheet P to be fed. The distance from P is increased.

The original document sheet P loses the conveying force when it comes out of the contact portion between the reading sensor 10 and the scan roller 13, and falls out of the apparatus by its own weight, or is pushed out by the original sheet P conveyed later. .

[0039]

With the above configuration, the image reading apparatus according to the present invention has the following effects.

(1) The center of rotation of the support member for rotatably attaching the reading sensor to the main body of the image reading apparatus is positioned on the tangent line between the reading sensor and the contact member. Thus, even when the scan roller rotates, no moment due to the frictional force is generated, and there is no possibility that the reading sensor moves.

(2) The reading sensor is configured such that the biasing direction of the biasing means for biasing the reading sensor to the contact member or the contact member to the reading sensor is inclined toward the downstream side in the document sheet conveyance direction. Can be brought to the downstream side in advance. Therefore, even when the scan roller rotates, the reading sensor does not move, and reading accuracy can be improved.

(3) A detecting means for detecting the leading end of the document sheet is provided on the same side of the transport path as the reading sensor, and the rotated detecting means is located at a step or a gap between the reading sensor and the guide. . As a result, the original sheet P
When the original sheet P is thin or the tip is rounded,
Even if the leading end of the sheet is lifted by the detecting means, there is no possibility that the conveyance error occurs due to being caught between the reading sensor and the guide in the step or gap.

(4) Since the width of the conveying means, which is located downstream of the feeding means and performs high-speed conveyance, is equal to or narrower than the width of the feeding means, when the original sheet is conveyed at an inclination. However, there is no possibility that the inclination is increased.

(5) By providing a feed guide member on the upstream side of the feed roller in the direction of conveyance in which the surfaces having different curvatures are smoothly continuous in the direction away from the original sheet bundle, the original sheet having a rounded leading end is provided. Can be easily led to the contact portion between the feeding roller and the separation pad, and there is no possibility that the leading end of the document sheet P is turned up.

(6) An elastic member is provided on the side opposite to the conveying path of the feeding means and on the upstream side in the conveying direction to bias the bundle of original sheets toward the supplying means, so that the original sheets are caught by the separating means. There is no danger of transport failure, such as inability to feed.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing an image reading apparatus.

FIG. 2 is a schematic side view showing a state where a rotating unit is opened.

FIG. 3 is an enlarged view near a feeding unit.

FIG. 4 is an enlarged view near the feeding means.

FIG. 5 is an enlarged view near a reading sensor.

FIG. 6 is a perspective view of a feeding unit and a conveying unit.

FIG. 7 is a diagram illustrating a conveyance state of a document sheet.

FIG. 8 is a side view schematically showing an image reading apparatus according to a conventional example.

FIG. 9 is a schematic side view showing a state in which a conventional rotating unit is opened.

FIG. 10 is a front view of the feeding means.

FIG. 11 is a perspective view of a feeding unit and a conveying unit.

FIG. 12 is an enlarged view near a reading sensor.

FIG. 13 is a diagram illustrating a state of conveying a document sheet.

[Explanation of symbols] [Explanation of symbols]

 P ... original sheet v1 ... rotational speed v2 ... rotational speed 1 ... image reading device 2 ... body 3 ... rotating part 4 ... rotating support part 5 ... original sheet stacking part 6 ... feeding roller 7 ... separating pad 7a ... separating surface 7b ... lever 7c ... elastic member 8 ... tip detection lever 8a ... light shielding part 9 ... photo interrupter 10 ... reading sensor 10a ... convex part 11 ... link 11a ... fulcrum 12 ... exterior 12a ... opening 13 ... scan roller 14 ... elastic body 20 … Feeding guide 21… Elastic member 22… Transport guide 23… Elastic pressing member 24… One-way clutch gear

Claims (7)

[Claims] A feeder configured to feed the original sheets one by one; a reading sensor arranged in a direction perpendicular to a conveying direction of the original sheets and having a width wider than the original sheets; A support member rotatably attached to the main body, a contact member that forms a conveyance path of the document sheet between the reading sensor, and a biasing member that urges the reading sensor to the contact member via the document sheet. An image reading apparatus comprising: an urging unit, wherein an image on the document sheet is read by a reading sensor while passing the document sheet through a contact portion between the reading sensor and the contact member. An image reading device, wherein a rotation center on a reading device side is arranged on a tangent line between the reading sensor and the contact member. 2. A feeding means for feeding a document sheet one by one, a reading sensor arranged in a direction perpendicular to a conveying direction of the document sheet and wider than the document sheet, and a reading sensor. An image reading device that has an abutting member that forms a transport path for the original sheet, and reads an image on the original sheet with a reading sensor while passing the original sheet through a contact portion between the reading sensor and the abutting member. And wherein a biasing direction of a biasing means for biasing the reading sensor to the contact member or the biasing member to the reading sensor is inclined to a downstream side in a conveying direction of the document sheet. An image reading apparatus characterized by the above-mentioned. 3. A feeding means for feeding the original sheets one by one, a reading sensor arranged in a direction perpendicular to the conveying direction of the original sheets and having a width wider than the original sheets, and A contact member that forms a transport path for the document sheet; a transport guide member that is provided upstream of the reading sensor in the transport direction; and a document guide that is provided upstream of the image reading sensor in the transport direction and detects the document sheet. An image reading apparatus which starts image reading by the reading sensor a predetermined time after the detecting means detects the document sheet, wherein the detecting means reads the document with respect to a document conveying path. A lever-shaped member having a rotation support shaft on the same side as a sensor, which is rotated by being pushed by the conveyed document sheet, and is provided with a gap between the reading sensor and the conveyance guide member; Image reading apparatus characterized by being configured to be positioned as cover the step. 4. A feeding means for feeding the original sheets one by one, a reading sensor arranged in a direction perpendicular to the conveying direction of the original sheets and wider than the original sheets, and arranged near the reading sensors. An image reading apparatus having a conveying means for conveying the original sheet faster than the feeding means, wherein the width of the conveying means is equal to or smaller than the width of the feeding means. Reader. 5. The transport means forms a transport path for the original sheet between the read sensor and the read sensor, and forms a transport path for the original sheet between the transport means and the read sensor on both sides of the transport means. The image reading device according to claim 4, further comprising a contact member. 6. A stacking means for stacking a bundle of original sheets, a feeding means for transporting the original sheets by rotating, a separating means for contacting the feeding means and restricting the passage of the original sheets. An image reading apparatus having a feeding device comprising: a feeding guide member extending from an upstream side to a downstream side of the feeding unit; and the stacking unit provided upstream of the feeding unit of the feeding guide member. An image reading apparatus formed continuously with different curvatures in a direction away from the sheet feeding means, and formed in a shape along the conveyance path of the document sheet downstream of the feeding means. 7. A stacking unit for stacking a bundle of original sheets, a feeding unit that conveys the original sheets by being driven to rotate, and a separating unit that abuts on the feeding units and regulates passage of the original sheets. An image reading device having a feeding device comprising: a resilient member provided upstream of the feeding device in a conveying direction, and configured to urge the document sheet stacked on the stacking device toward the feeding device. An image reading apparatus, comprising: