JP7201111B2 - Image reader - Google Patents

Description

The present invention relates to a medium feeding device for feeding a medium, and an image reading device having the medium feeding device.

2. Description of the Related Art In a scanner, which is an example of an image reading apparatus, drive sources for various drive systems are provided inside the apparatus main body.
For example, in Patent Document 1, a stepping motor is used as a drive source for moving the optical system of a copier.

By the way, a scanner is provided with a medium feeder (also called an ADF (Auto Document Feeder)) for automatically feeding a document as a medium, and automatically feeds a plurality of documents to an image reading unit fixed in the device. , and reading (for example, Patent Document 2).
A medium feeding device provided in such a scanner includes a feeding roller for feeding a document placed on a document tray, a feeding roller for feeding the document fed by the feeding roller to the image reading section, and the like. is driven by a drive source such as a motor.

Here, if a stepping motor as disclosed in Patent Document 1 is used as a drive source for a medium feeding device that feeds a document to the image reading unit fixed in the apparatus, the load on the drive source during scanning in the image reading unit is reduced. If there is a change, the transport of the document is disturbed, which may disturb the read image. For this reason, some medium feeding devices use a DC motor as a drive source (for example, Patent Documents 3 and 4).
By providing an encoder, the DC motor can perform feedback control in response to load fluctuations of the motor, and can easily suppress disturbance of the read image due to load fluctuations of the motor.

JP-A-4-242234 JP 2014-60494 A JP-A-6-54132 JP 2006-10855 A

In a scanner equipped with such a medium feeding device, there is a need for further miniaturization of the device as a user's need, but there is a limit to the space for arranging a drive source such as a motor, which is relatively heavy and large. There are also restrictions on the layout of the components.
In particular, in a small scanner, as in the scanner described in Patent Document 2, the housing constituting the scanner is divided into an upper unit (cover portion 11b) and a lower unit (main body portion 11a), and a medium feeding device. When the upper unit can be opened and closed with respect to the lower unit for maintenance or the like, the weight balance when the upper unit is opened is also important.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a medium feeding device that can be stably installed and an image reading device having the same. Another object of the present invention is to provide a medium feeding device or an image reading device capable of stably feeding a medium.

In order to solve the above problems, a medium feeding device according to a first aspect of the present invention includes a feeding roller for feeding a medium placed on a medium stacking section, and a feeding roller provided downstream of the feeding roller. a transport roller, a first drive source that drives at least the feed roller, a second drive source that drives at least the transport roller, the feed roller, the transport roller, the first drive source, and a housing including the second drive source therein, wherein the housing includes a lower unit that forms a lower portion of the housing, and an upper unit that opens and closes with respect to the lower unit. , wherein the first drive source and the second drive source are provided on both sides of the central portion of the lower unit in a width direction that intersects the medium conveying direction.

According to this aspect, the first drive source and the second drive source are used as drive sources in the medium feeding device, and the first drive source and the second drive source are Since they are provided on both sides of the central portion of the lower unit in the direction intersecting the medium conveying direction, the weight balance of the medium feeding device can be improved.
Further, since both the first drive source and the second drive source are provided in the lower unit, the stability of the housing can be maintained even when the upper unit is opened with respect to the lower unit. can be maintained. As described above, the medium feeding device can be stably installed.

A medium feeding device according to a second aspect of the present invention is, in the first aspect, provided on the downstream side of a separation roller that nips and separates the medium from the feeding roller, and the transport roller. and a downstream transport roller, which is provided so as to be able to move forward and backward with respect to the feeding roller, and which advances relative to the feeding roller to press the medium placed on the medium stacking portion toward the feeding roller. a unit, and a regulating portion capable of switching between a regulating state for regulating advancement of the pressing unit with respect to the feeding roller and a permitting state for permitting advancement of the pressing unit with respect to the feeding roller; The downstream transport roller and the restricting section are driven by the second drive source.

According to this aspect, the separation roller, the downstream transport roller, and the regulation section can be driven using a drive source (second drive source) common to the transport roller.

A medium feeding device according to a third aspect of the present invention is the first aspect or the second aspect, wherein the first drive source and the second drive source are DC motors, and the first drive source is a DC motor. a first encoder that detects the amount of rotation of a scale that rotates in response to driving of the second drive source; a second encoder that detects the amount of rotation of the scale that rotates in response to driving of the second drive source; or a controller for controlling driving of the corresponding drive source based on the information detected by the second encoder.

According to this aspect, the controller controls the drive of the corresponding drive source based on the information detected by the first encoder or the second encoder, thereby adjusting the rotation state of the driven object. The feed rollers or the transport rollers can be driven accordingly.
Therefore, it is possible to suppress disturbance in transportation when the medium is fed by the first drive source or the second drive source.

In the medium feeding device according to a fourth aspect of the present invention, in the third aspect, the first drive source has a direction along the width direction as an axial direction of a motor output shaft of the first drive source. A first transmission mechanism portion arranged and connected to the motor output shaft extending from the motor main body of the first drive source to transmit power of the motor is positioned outside the motor main body in the width direction. and the first encoder is provided inside the motor body of the first drive source in the width direction.

According to this aspect, the first drive source is arranged with the direction along the width direction as the axial direction of the motor output shaft, and is connected to the motor output shaft extending from the motor main body to drive the motor. A first transmission mechanism for transmission is attached so as to be positioned outside the motor body in the width direction, and the first encoder is located outside the motor body of the first drive source in the width direction. Since it is provided on the inner side of the direction, the first encoder can be arranged in a space-saving way in the width direction. Therefore, the size of the device in the width direction can be made compact.

In the medium feeding device according to a fifth aspect of the present invention, in the third aspect or the fourth aspect, the second drive source is configured to rotate the direction along the width direction as the motor output of the second drive source. A second transmission mechanism unit arranged in the axial direction of the shaft and connected to the motor output shaft of the second drive source extending from the motor main body of the second drive source to transmit the power of the motor, A rotary shaft provided with the transport roller, and the second drive source at one end in the axial direction of the rotary shaft. a one-side holder that is attached to the arrangement side of the second drive source and has a drive gear that receives power from the second drive source via the second transmission mechanism to rotate the rotating shaft; A D-cut portion having a shape obtained by cutting a part of a circular cross section is formed at the one-side end portion of the rotating shaft, and the one-side holder has a shape corresponding to the D-cut portion and the A D-cut hole into which a D-cut portion is press-fitted is formed, and the scale of the second encoder is provided other than the one-side holder and is configured to rotate integrally with the rotating shaft.

In order to realize highly accurate transportation by the transportation roller, it is desirable that the scale of the second encoder be provided so as to rotate integrally with the rotary shaft.
On the other hand, the engagement between the rotating shaft and the one-side holder provided with a drive gear for rotating the rotating shaft is such that the one-side end portion having a D-cut shape with a circular cross section with a part cut is If it is made by press-fitting into the D-cut hole of the side holder, there is a risk that the drive gear of the one-side holder will become eccentric due to the press-fitting. Therefore, if the scale of the second encoder is provided on the one-side holder, the scale will become eccentric together with the drive gear, which may make it impossible to accurately detect the rotation of the rotary shaft.

According to this aspect, the scale of the second encoder is provided outside the one-side holder and is configured to rotate integrally with the rotating shaft. can be detected, and the conveying roller can be controlled with high accuracy.

A medium feeding device according to a sixth aspect of the present invention is characterized in that, in the fifth aspect, the scale of the second encoder is a circular press-fitting device in which the rotating shaft is press-fitted into a circular hole and integrally attached to the rotating shaft. It is characterized by being attached to a holder.

According to this aspect, the scale of the second encoder is attached to the round press-fit holder that is integrally attached to the rotating shaft with the rotating shaft press-fitted into the circular hole. By reducing the influence of the eccentricity in the one-side holder that is press-fitted, the scale of the second encoder can be attached so as to rotate integrally with the rotating shaft.

In the medium feeding device according to a seventh aspect of the present invention, in the sixth aspect, the round press-fit holder is provided on the other side of the rotating shaft in the axial direction with respect to the one side end of the rotating shaft. characterized in that

According to this aspect, the round press-fit holder to which the scale of the second encoder is attached is provided on the other side of the rotating shaft in the axial direction with respect to the one side end of the rotating shaft. Since the side holder and the round press-fit holder are provided on both sides of the rotating shaft, the width of the device is smaller than that of a configuration in which both the one-side holder and the round press-fitting holder are provided on the same side of the rotating shaft. can be suppressed.

A medium feeding device according to an eighth aspect of the present invention is any one of the first to seventh aspects, wherein a timing belt is used in the first transmission mechanism or the second transmission mechanism. , characterized in that

According to this aspect, it is possible to reduce the influence of the vibration of the first drive source or the second drive source and transmit the power from each drive source.

An image reading device according to a ninth aspect of the present invention is the medium feeding device according to any one of the first to eighth aspects, comprising a reading section for reading a medium, and feeding the medium toward the reading section. and.

According to this aspect, in the image reading apparatus including the reading unit for reading a medium and the medium feeding device for feeding the medium toward the reading unit, the image reading apparatus is the same as any of the first to eighth aspects A working effect is obtained.

1 is a perspective view showing a scanner according to the present invention; FIG. FIG. 4 is a perspective view showing a feeding state in the scanner according to the present invention; 3 is a rear perspective view of the scanner shown in FIG. 2; FIG. FIG. 2 is a side cross-sectional view showing a feeding path in the scanner according to the present invention; FIG. 2 is a rear view of the main body of the scanner according to the present invention; FIG. 4 is a rear perspective view of the side of the device main body where the second drive source is arranged; FIG. 2 is a rear perspective view of the side of the device main body where the first drive source is arranged; The side view of a device main body. FIG. 2 is a perspective view showing drive system components in the device main body; FIG. 4 is a perspective view showing a driving mechanism of a feeding roller; FIG. 4 is a perspective view showing a drive mechanism for a separation roller; The perspective view at the time of making an upper unit an open state with respect to a lower unit. The perspective view which shows the B section in FIG. 12 from another angle. The figure explaining operation|movement of a control part. The perspective view of an 8th transmission gear. The top view of an 8th transmission gear. 1 is a block diagram of a scanner according to the present invention; FIG. FIG. 11 is a perspective view showing a state in which the seventeenth transmission gear is removed on the side of the device main body where the second drive source is arranged;

[Example 1]
First, an outline of an image reading apparatus according to an embodiment of the present invention will be described. As an example of the image reading apparatus of this embodiment, a document scanner (hereinafter simply referred to as scanner 1) capable of reading at least one of the front and back sides of a document as an example of a medium will be taken.
FIG. 1 is a perspective view showing a scanner according to the invention. FIG. 2 is a perspective view showing the feeding state of the scanner according to the present invention. 3 is a rear perspective view of the scanner shown in FIG. 2; FIG. FIG. 4 is a side sectional view showing a feeding path in the scanner according to the invention. FIG. 5 is a rear view of the main body of the scanner according to the present invention. FIG. 6 is a rear perspective view of the side of the device main body where the second drive source is arranged. FIG. 7 is a rear perspective view of the side of the device main body where the first drive source is arranged. FIG. 8 is a side view of the device main body.

FIG. 9 is a perspective view showing drive system components in the apparatus main body. FIG. 10 is a perspective view showing the driving mechanism of the feeding roller. FIG. 11 is a perspective view showing the driving mechanism of the separation roller. FIG. 12 is a perspective view when the upper unit is opened with respect to the lower unit. FIG. 13 is a perspective view showing part B in FIG. 12 from another angle. 14A and 14B are diagrams for explaining the operation of the regulating unit. FIG. FIG. 15 is a perspective view of an eighth transmission gear; FIG. 16 is a plan view of the eighth transmission gear. FIG. 17 is a block diagram of a scanner according to the invention.

<Overview of the scanner>
A scanner 1 (FIG. 1) as an image reading apparatus according to the present invention includes a housing 7 forming part of the appearance of the apparatus and a device body 9 provided within the housing 7 . The apparatus main body 9 includes a medium feeding device 10 which is an embodiment of the "medium feeding device" according to the present invention, and an image reading section 21 (FIG. 4) for reading an image of a document fed by the medium feeding device 10. I have.
The housing 7 is composed of a lower unit 2 that constitutes the lower portion of the housing 7 and an upper unit 3 that opens and closes with respect to the lower unit 2 .

In the XYZ coordinate system shown in each drawing, the X direction is the device width direction, the paper width direction, and the Y direction is the paper transport direction. The Z direction is a direction that intersects the Y direction, and generally indicates a direction that is perpendicular to the surface of the paper being conveyed. The +Y direction side is the device front side, and the -Y direction side is the device rear side. The right side as viewed from the front side of the device is the +X direction, and the left side is the -X direction. In addition, the +Z direction is defined as the upper side of the device (including the upper portion, the upper surface, etc.), and the -Z direction side is defined as the lower side of the device (including the lower portion, the lower surface, etc.).
Further, in the scanner 1, the paper P as a medium is configured to be transported in the +Y direction in each drawing. Hereinafter, the direction in which the paper P is conveyed (+Y direction side) is called "downstream", and the opposite direction (−Y direction side) is called "upstream".

The upper unit 3 is attached to the lower unit 2 so as to be rotatable with respect to the lower unit 2 with the downstream side (+Y side) in the sheet conveying direction as the fulcrum of rotation. The upper unit 3 is closed with respect to the lower unit 2 and constitutes a paper transport path for the paper P together with the lower unit 2 (see FIG. 2). An open state (see FIG. 12) in which the paper transport path of the paper P is exposed and maintenance such as handling of a paper jam of the paper P can be easily performed can be taken.

A paper support 4 that opens and closes with respect to the upper unit 3 is provided on the upper part of the upper unit 3 . The paper support 4 is a "medium support" that supports a document (hereinafter sometimes referred to as "paper P") as an example of a medium in an open state (see FIG. 2).

The paper support 4 has a non-feeding state covering the upper portion of the upper unit 3 and the feeding port 6 (FIG. 2) as shown in FIG. to open the feed opening 6 and set the paper P on the back surface of the paper support 4 (medium stacking portion 11 for the paper P).

Further, an auxiliary paper support 15 (FIGS. 2 and 3) is provided on the upstream side of the paper support 4. As shown in FIG. The auxiliary paper support 15 is configured to be retractable into and drawable from the hollow paper support 4 . By pulling out the auxiliary paper support 15, it is possible to stably support even the paper P having long sides along the transport direction.

A discharge port 8 for discharging the paper P is provided on the front side of the lower unit 2 . The lower unit 2 also includes a paper discharge tray 5 that can be pulled out from the discharge port 8 toward the front side of the apparatus. The paper discharge tray 5 can be stored in the bottom of the lower unit 2 (see FIG. 1) or pulled out toward the front side of the apparatus (see FIG. 2). Further, in this embodiment, the paper ejection tray 5 is configured by connecting a plurality of tray members, and the length of the paper P to be ejected can be adjusted from the ejection port 8 according to the length.

<Regarding the feed path in the scanner>
Next, referring to FIG. 4, the paper transport path in the scanner 1 will be described.
The paper P set in the feed port 6 is placed on the medium stacking portion 11 . A plurality of sheets of paper P can be set in the feed port 6 .
4, reference numeral 12 denotes a pair of edge guides (see also FIG. 2) for guiding both side edges of the sheet P in the width direction (X-axis direction). The edge guide 12 is provided so as to be slidable in the X-axis direction according to the size of the paper P. As shown in FIG.

The paper P set in the feed port 6 is fed by the medium feeding device 10 and sent toward the image reading section 21 described later. The medium feeding device 10 includes a feeding roller 13 that feeds the paper P placed on the medium stacking portion 11 and a transport roller 20 that is provided downstream of the feeding roller 13 . The driving mechanism of the medium feeding device 10 will be detailed later.
A separating roller 14 that nips and separates the paper P between itself and the feeding roller 13 is provided at a position facing the feeding roller 13 .
The outer peripheral surfaces of the feed roller 13 and the separation roller 14 are made of a high-friction material (for example, an elastomer such as rubber).

The paper P is picked up by a feeding roller 13 rotatably provided with respect to the lower unit 2 and fed downstream (+Y direction side). Specifically, the paper P is fed downstream by rotating while the feeding roller 13 is in contact with the surface of the paper P facing the mounting surface of the medium stacking portion 11 . Therefore, when a plurality of sheets P are set in the feed port 6 in the scanner 1, the sheets are fed downstream in order from the bottom sheet.

In FIG. 4 , reference G denotes a bundle of sheets placed on the medium stacking section 11 . Before the start of feeding, the sheet bundle G is held at the feeding standby position (position shown in FIG. 4) by the flap 38 at its leading end, and is restricted from entering between the feeding roller 13 and the separation roller 14 . The flap 38 is provided on a pressing unit 39 (FIG. 8).
The pressing unit 39 presses the paper P placed on the medium stacking portion 11 toward the feeding roller 13 by moving forward.

A regulating portion 40 is provided around the feeding roller 13 . The restricting portion 40 is configured to be switchable between a restricting state that restricts the pressing unit 39 from advancing toward the feeding roller 13 and a permitting state that allows the pressing unit 39 to move toward the feeding roller 13 .
The bundle of documents G is supported from below by the regulating portion 40 which is in a regulating state before the start of feeding, and is pushed up to be separated from the feeding roller 13 . That is, contact with the feeding roller 13 is prevented. A drive mechanism for the restricting portion 40 will be described in detail later.

When the document feed starts, the regulating portion 40 is retracted downward, the lowest document in the document bundle G comes into contact with the feeding roller 13, and the flap 38 is in a swingable state (posture switching). possible state). Therefore, the lowest document is sent downstream by the rotation of the feeding roller 13 . The flap 38 is swung downstream by the document sent downstream, and assumes a posture of opening the medium feeding path.

A conveying roller 20 is provided downstream of the feeding roller 13 . The transport roller 20 includes a transport drive roller 23 provided in the lower unit 2 and a transport driven roller 24 that is provided in the upper unit 3 and rotates following the transport drive roller 23 .

The paper P fed by the feeding roller 13 is transported through a transport path 30 formed by guide surfaces facing each other. Of the guide surfaces that face each other, the surface that supports the sheet P from below is referred to as a lower guide surface 29a, and the surface that faces the lower guide surface 29a is referred to as an upper guide surface 29b.
The feeding roller 13 and the transport driving roller 23 are arranged so that a part thereof protrudes from the lower guide surface 29a.

An image reading unit 21 as a “reading unit” for reading an image is provided downstream of the transport roller 20 , and the paper P is transported to the image reading unit 21 by the transport roller 20 .
The image reading section 21 includes an upper image reading sensor 25 provided on the upper unit 3 side and a lower image reading sensor 26 provided on the lower unit 2 side. In this embodiment, the upper image reading sensor 25 and the lower image reading sensor 26 are configured as a contact image sensor module (CISM) as an example.

After the image on at least one of the front surface and the back surface of the paper P is read by the image reading unit 21 , the paper P is sent by the discharge roller 22 located downstream of the image reading unit 21 , and is sent to the lower unit 2 . It is discharged from the discharge port 8 provided on the front side of the device. The discharge rollers 22 are composed of a discharge drive roller 27 provided in the lower unit 2 and a discharge driven roller 28 provided in the upper unit 3 and rotating following the discharge drive roller 27 .
With the paper discharge tray 5 pulled out, the paper P discharged from the discharge port 8 is stacked on the paper discharge tray 5 .

<Regarding the media feeder>
Next, the medium feeding device 10 described above will be described in more detail.
First, the medium feeding device 10 (FIGS. 5 and 6) includes a first motor 31 as a "first driving source" for driving the feeding roller 13 and a "second driving source" for driving the transport roller 20. and a second motor 32 as a second drive source. The first motor 31 and the second motor 32 are provided in the same housing 7 as the feed roller 13 and the transport roller 20 .

Then, as shown in FIG. 5, the first motor 31 and the second motor 32 are arranged with respect to the central portion A of the lower unit 2 in the width direction (X-axis direction) intersecting the medium transport direction (Y-axis direction). Each is provided so as to be located on both sides.
In this way, the medium feeding device 10 is provided by arranging the two drive sources (the first motor 31 and the second motor 32) on both sides of the central portion of the lower unit in the width direction of the device. The weight balance of the scanner 1 can be improved.
Further, since both the first motor 31 and the second motor 32 are provided in the lower unit 2, the stability of the housing 7 can be maintained even when the upper unit 3 is opened with respect to the lower unit 2. can. As described above, the scanner 1 can be stably installed.

Next, a driving mechanism of the medium feeding device 10 will be described.
First, the driving mechanism of the feeding roller 13 driven by the first motor 31 will be described.
In this embodiment, the first motor 31 is a DC motor, and as shown in FIG. 10, comprises a motor body 31a and a motor output shaft 31b extending from the motor body 31a. The first motor 31 is arranged with the device width direction (X-axis direction) as the axial direction of the motor output shaft 31b of the first motor 31 .
The first motor 31 has a motor main body 31a fixed to a right side frame 33 (FIG. 7) provided on the right side (+X side) when viewed from the front side of the apparatus. A left side frame 34 (FIG. 6) is provided on the left side (-X side) as viewed from the front side of the device.

The motor output shaft 31b of the first motor 31 is connected with a first transmission gear 41 as a “first transmission mechanism” for transmitting the power of the motor to the feed roller 13. is attached so as to be located outside (+X side) in the width direction of the device from the motor main body 31a. In this embodiment, the first transmission gear 41 is positioned outside the right side frame 33 (see FIGS. 7 and 10).

As shown in FIG. 7 , the power of the first motor 31 is transmitted from the first transmission gear 41 to the second transmission gear 42 via the timing belt 49 . The second transmission gear 42 engages with the third transmission gear 43 , and the third transmission gear 43 engages with the fourth transmission gear 44 . The rotation shaft 47 of the fourth transmission gear 44 extends inside the right side frame 33 (between the right side frame 33 and the left side frame 34), and is located inside the right side frame 33 on the -X side. A fifth transmission gear 45 is provided at the end (FIG. 10).

The fifth transmission gear 45 shown in FIG. 10 is engaged with a sixth transmission gear 46 provided on the +X side end of the rotating shaft 48 of the feeding roller 13, and the power of the first motor 31 is transmitted by these gear trains. is transmitted to the feeding roller 13 .
In the present embodiment, when power is transmitted from the first transmission gear 41 provided on the motor output shaft 31b of the first motor 31 to the second transmission gear 42, the timing belt 49 is interposed so that the power of the first motor 31 is Power can be transmitted with less influence of vibration.

Further, the first motor 31 is provided with a first scale 36 that rotates according to driving of the first motor 31 and a first encoder 37 that detects the amount of rotation of the first scale 36 . The scanner 1 includes a control section 35 ( FIG. 17 ), and the control section 35 is configured to control driving of the first motor 31 based on information detected by the first encoder 37 . By controlling the drive of the first motor 31 based on the information detected by the first encoder 37, the feed roller 13 can be driven according to the rotation state of the driven object, and when the paper is fed, can be suppressed.

Here, the first encoder 37 is provided on the inner side (-X side) of the motor main body 31a of the first motor 31 in the device width direction. In this embodiment, the first encoder 37 is provided inside the right side frame 33 . As a result, the first encoder 37 can be arranged in a space-saving manner in the width direction of the device, so that the size of the scanner 1 in the width direction can be made compact.

Next, a drive mechanism by the second motor 32 will be described. In this embodiment, the second motor 32 is a drive source for the transport drive roller 23 that constitutes the transport roller 20 .
Like the first motor 31, the second motor 32 is a DC motor, and as shown in FIG. 6, comprises a motor body 32a and a motor output shaft 32b extending from the motor body 32a. The second motor 32 is arranged with the device width direction (X-axis direction) as the axial direction of the motor output shaft 32b of the second motor 32 .
The second motor 32 has a motor main body 32a fixed to a left side frame 34 (FIG. 11) provided on the left side (-X side) when viewed from the front side of the device.

The motor output shaft 32b of the second motor 32 is connected with a seventh transmission gear 51 as a "second transmission mechanism" for transmitting the power of the motor. It is attached so as to be located outside (-X side) in the width direction of the apparatus. In this embodiment, the seventh transmission gear 51 is positioned outside the left side frame 34 .

The power of the second motor 32 is configured to be transmitted to the eighth transmission gear 52 via the timing belt 53 from the seventh transmission gear 51 provided on the motor output shaft 32b. In the second motor 32 as well, when power is transmitted from the seventh transmission gear 51 to the eighth transmission gear 52, the timing belt 53 is interposed, so that the power is transmitted while reducing the influence of the vibration of the second motor 32. be able to.

The timing belt 53 is configured to be given a predetermined tension by a belt tension mechanism 80 (FIG. 18). The belt tension mechanism 80 includes a driven pulley 81 that is rotatable following the rotating timing belt 53, and a pulley holder 82 that supports the driven pulley 81 and is movable in the directions of double arrows +C and -C in FIG. , and a tension spring 83 as an urging member that applies tension to the timing belt 53 . The driven pulley 81 is pulled in the +C direction by the tension spring 83 to apply tension to the timing belt 53 .

A boss 84 is provided on the left side frame 34, and a groove 85 provided in the pulley holder 82 is inserted into the boss 84, so that the pulley holder 82 can be positioned in both directions indicated by +C and -C. Guided in the direction of the arrow. Also, the pulley holder 82 is fixed in its mounting position by a screw 86 .

The eighth transmission gear 52 is a drive gear that receives power from the second motor 32 via the seventh transmission gear 51 and rotates the rotary shaft 54 . The eighth transmission gear 52 is attached to one end (-X side end 54a) of the rotation shaft 54 of the transport driving roller 23, and the power of the second motor 32 is transmitted to the transport driving roller 23. It looks like
In other words, the eighth transmission gear 52 is a “one-side holder” of the rotating shaft 54 that is attached to the side on which the second motor 32 is arranged, which is the one-side end 54 a of the rotating shaft 54 of the transport driving roller 23 . is.

A D-cut portion 55 (FIG. 15) having a shape obtained by cutting a part of a circular cross section is formed on one end portion 54a of the rotating shaft 54, and the eighth transmission gear 52 as a "one side holder" has a D cut portion 55 (FIG. 15). , a D-cut hole 56 (FIG. 16) having a shape corresponding to the D-cut portion 55 and into which the D-cut portion 55 is press-fitted is formed. The D-cut portion 55 of the rotating shaft 54 is press-fitted into the D-cut hole 56 of the eighth transmission gear 52 , and the rotating shaft 54 is attached to the eighth transmission gear 52 . Co-rotation of 52 can be suppressed or avoided.
16, the rib 74 provided inside the D-cut hole 56 is a crushing rib that is crushed when the D-cut portion 55 of the rotary shaft 54 is press-fitted.

In addition, the second motor 32 is provided with a second scale 57 that rotates according to the drive of the second motor 32, and a second encoder 58 (FIG. 9) that detects the amount of rotation of the second scale 57. ing. The control unit 35 (FIG. 17) is configured to control the driving of the second motor 32 based on the information detected by the second encoder 58 . By controlling the drive of the second motor 32 based on the information detected by the second encoder 58, it is possible to drive the transport drive roller 23 according to the rotation state of the driven object, and to feed the paper. can be suppressed.

In this embodiment, the second scale 57 of the second encoder 58 is provided outside the eighth transmission gear 52 and is configured to rotate integrally with the rotary shaft 54 .
More specifically, the second scale 57 is a round press-fit holder 59 integrally attached to the rotary shaft by press-fitting the +X side end 54b (FIGS. 7 and 11) of the circular rotary shaft 54 into the circular hole. (Fig. 7). That is, the round press-fit holder 59 is provided at the other end 54b in the axial direction of the rotating shaft 54 with respect to the one end 54a where the D cut portion 55 is formed.

In order to achieve highly accurate transport by the transport drive roller 23 (transport roller 20), the second scale 57 of the second encoder 58 should be provided so as to rotate integrally with the rotary shaft 54 of the transport drive roller 23. is desirable.
On the other hand, the attachment of the rotating shaft 54 to the eighth transmission gear 52 as a driving gear for rotating the rotating shaft 54 causes the D-cut portion 55 formed at one end 54a of the rotating shaft 54 to be attached to the eighth transmission gear 54. If it is made by press-fitting into the D-cut hole 56 of the gear 52, the press-fitting may cause the eighth transmission gear 52 to become eccentric. Therefore, if the second scale 57 is provided on the eighth transmission gear 52, the second scale 57 is also eccentric, and there is a possibility that the rotation of the rotating shaft 54 cannot be accurately detected.

In this embodiment, the second scale 57 is provided on a round press-fitting holder 59, which is a component other than the eighth transmission gear 52 into which the D-cut portion 55 is press-fitted, and rotates integrally with the rotating shaft 54. Therefore, the rotation of the rotating shaft 54 can be detected with less influence of the eccentricity, and the transport driving roller 23 can be controlled with high precision.
Further, since the second scale 57 is attached to the round press-fitting holder 59 which is integrally attached to the rotating shaft 54 by press-fitting the rotating shaft 54 into the circular hole, the D-cut portion 55 of the rotating shaft 54 fits into the D-cut hole 56. The influence of the eccentricity in the press-fitted eighth transmission gear 52 can be reduced, and the second scale 57 can be mounted so as to rotate integrally with the rotary shaft 54 .

Also, the round press-fitting holder 59 to which the second scale 57 of the second encoder 58 is attached rotates with respect to the one side end portion 54 a having the D-cut portion 55 press-fitted into the D-cut hole 56 of the eighth transmission gear 52 . Since the eighth transmission gear 52 and the round press-fit holder 59 are provided at the other end 54b of the shaft 54 in the axial direction, that is, the eighth transmission gear 52 and the round press-fit holder 59 are provided on both sides of the rotating shaft 54, the eighth transmission gear 52 and the round press-fit holder 59 are provided on the same side with respect to the rotating shaft 54, the device width dimension can be suppressed. Therefore, the scanner 1 can be made compact.

In addition, in this embodiment, the second motor 32 is a drive source for the transport drive roller 23, and also serves as a drive roller for the separation roller 14 and the discharge roller 22 as a "downstream transport roller" provided downstream of the transport roller 20. It is also used as a drive source for (the discharge drive roller 27 ) and the regulation section 40 . Each drive mechanism will be described below.

First, the drive mechanism of the separation roller 14 will be described with reference to FIG. As described above, the power of the second motor 32 drives the transport drive roller 23 to rotate. A ninth transmission gear 60 is provided inside (-X side) of the round press-fitting holder 59 on the rotating shaft 54 of the transport drive roller 23 . The ninth transmission gear 60 is engaged with the tenth transmission gear 61 . Further, the tenth transmission gear 61 is engaged with an eleventh transmission gear 63 included in a wheel train 62 composed of a plurality of gears. Furthermore, a rotating shaft 64 connected to one gear of the gear train 62, a 12th transmission gear 65 provided on the rotating shaft 64, a 13th transmission gear 66 engaged with the 12th transmission gear 65, and a 13th transmission gear 66 A fourteenth transmission gear 67 is provided for engagement. A fourteenth transmission gear 67 is provided on the rotating shaft 68 of the separation roller 14 .
As described above, the gear train from the seventh transmission gear 51 to the fourteenth transmission gear 67 transmits the power of the second motor 32 to the separation roller 14 .

Although the separation roller 14 is provided in the upper unit 3, in the drive mechanism of the separation roller 14, the constituent members from the second motor 32 to the ninth transmission gear 60 provided on the rotation shaft 54 of the transport drive roller 23 are It is provided in the lower unit 2 , and constituent members from the tenth transmission gear 61 to the separation roller 14 are provided in the upper unit 3 .
When the upper unit 3 is opened with respect to the lower unit 2 (FIG. 12), as shown in FIG. and are separated.

Next, the driving mechanism of the ejection driving roller 27, which is the driving roller of the ejection roller 22, will be described with reference to FIG.
A 16th transmission gear 72 is provided at the +X side end portion 70a of the rotating shaft 70 of the discharge driving roller 27, which is the side where the second motor 32 is located in the device width direction. The sixteenth transmission gear 72 engages with the fifteenth transmission gear 71 that engages with the eighth transmission gear 52 that is a drive gear that rotates the rotary shaft 54 of the transport drive roller 23 . That is, the power of the second motor 32 is transmitted to the 16th transmission gear 72 via the 7th transmission gear 51, the 8th transmission gear 52, and the 15th transmission gear 71, and the rotation shaft 70 of the discharge driving roller 27 rotates. It is configured to

Next, the operation and driving mechanism of the regulating section 40 that switches between the regulating state and the allowing state of the pushing unit 39 that presses the sheet placed on the medium stacking section 11 toward the feeding roller 13 toward the feeding roller 13. , with reference to FIG.
First, the operation of the regulation section 40 will be described. The pressing unit 39 is provided so as to move forward and backward with respect to the feed roller 13 and is biased in a direction to advance with respect to the feed roller 13 by a biasing means (not shown).

The restricting portion 40 is provided so as to be able to swing around a swing shaft 40a. It is possible to switch between a permissible state (lower diagram in FIG. 14) in which the pressing unit 39 is permitted to advance toward the feeding roller 13 .
In the regulated state, the regulating portion 40 supports the bundle of documents G set as described above, and prevents the lowermost document from coming into contact with the feeding roller 13 .

On the other hand, the restricting portion 40 is formed with a recess 40b as an engaging portion, and in the restricting state of the restricting portion 40, the tip 38b of the flap 38 enters the recess 40b as shown in the upper diagram of FIG. In this state, the pressing unit 39 is pushed up by the regulating portion 40 via the flap 38 against the biasing force of the biasing means (not shown), and is kept separated from the feeding roller 13 . In this feeding standby state, the pressing unit 39 does not press the bundle of documents G. As shown in FIG.

Further, in this feeding standby state, the tip 38b of the flap 38 is inserted into the concave portion 40b of the restricting portion 40, so that the flap 38 is restricted from rotating about the pivot shaft 38a and blocks the medium feeding path. Maintains cover position. That is, the rocking motion is restricted so that the attitude cannot be changed.
14 shows a state in which the pressing unit 39 is separated from the feeding roller 13, that is, a restricted state in which the regulating portion 40 restricts the pressing unit 39 from advancing toward the feeding roller 13. FIG. Conversely, the lower diagram of FIG. 14 shows a state in which the pressing unit 39 has advanced toward the feeding roller 13 , that is, an allowable state in which the pressing unit 39 is allowed to advance toward the feeding roller 13 .
The flap 38 is urged toward a shielding posture (upper diagram of FIG. 14) shielding the medium feeding path by a coil spring (not shown) provided on the swing shaft 38a, for example.

When the document starts to be fed, the regulating portion 40 switches from the regulating state to the allowable state shown in the lower diagram of FIG. As a result, the pressing unit 39 is no longer pushed upward from the restricting portion 40 via the flap 38, so that the pressing unit 39 advances toward the feeding roller 13 by the biasing force of the biasing means (not shown), thereby G is pressed toward the feeding roller 13 side.

Then, when the feeding roller 13 rotates, the lowermost document in contact with the feeding roller 13 is sent downstream. The flap 38 is switched to a position in which the medium feeding path is opened as shown in the lower diagram of FIG. 14 by the document sent downstream. In this manner, the flap 38 stops the document bundle G from advancing downstream in the feeding standby state (upper diagram in FIG. 14), but hinders the feeding of the document during sheet feeding (lower diagram in FIG. 14). never do.

Next, the driving mechanism of the restricting portion 40 will be described.
A seventeenth transmission gear 73 is engaged with the eighth transmission gear 52 , which is the driving gear of the rotary shaft 54 of the transport drive roller 23 . A driving cam 76 (FIGS. 8 and 9) of the restricting portion 40 is provided on the rotary shaft 75 of the seventeenth transmission gear 73 . The seventeenth transmission gear 73 is provided with a one-way clutch, and when the eighth transmission gear 52 rotates to rotate the transport drive roller 23 in the paper transport direction, that is, in FIG. The rotary shaft 75 of the seventeenth transmission gear 73 is configured not to rotate when it rotates. At this time, the restricting portion 40 is in the allowable state (lower diagram in FIG. 14).
On the other hand, when the eighth transmission gear 52 rotates in the opposite direction (counterclockwise in FIG. 8) to the direction in which the transport drive roller 23 rotates in the paper transport direction, the seventeenth transmission gear 73 rotates clockwise and drives When the cam 76 pushes the restricting portion 40 upward, the restricting portion 40 switches from the allowable state (lower diagram in FIG. 14) to the restricted state (upper diagram in FIG. 14).

Note that while the transport drive roller 23 is rotating in the paper transport direction, the rotating shaft 75 of the seventeenth transmission gear 73 does not rotate because the seventeenth transmission gear 73 is provided with the above-described one-way clutch. , the rotation shaft 75 of the 17th transmission gear 73 rattles due to vibration caused by the rotation of the 8th transmission gear 52 or the transport drive roller 23, which may cause noise. In order to suppress this rattling, as shown in FIG. 18, a tension spring 78 is attached between a rotating shaft 75 of the seventeenth transmission gear 73 and a hook portion 77 provided on the left side frame 34. A rotation shaft 75 of the seventeenth transmission gear 73 is biased by a tension spring 78 in a direction crossing the axial direction. In FIG. 18, the seventeenth transmission gear 73 is omitted in order to make the rotary shaft 75 easier to see.

As means for suppressing rattling of the rotating shaft 75, for example, it is conceivable to provide a bearing portion of the rotating shaft 75 with a plate spring, a bush, or the like for biasing the rotating shaft 75 in the axial direction. It is difficult, and the load on the rotation of the rotating shaft 75 tends to increase.
However, in the configuration in which the tension spring 78 biases the rotating shaft 75 in the direction intersecting with the axial direction, the load of the tension spring 78 for suppressing rattling of the rotating shaft 75 is small enough, and the rotation of the rotating shaft 75 is suppressed. It is advantageous in that the load is less likely to increase and it is easy to install. Grease or the like for reducing friction between the rotating shaft 75 and the tension spring 78 when the rotating shaft 75 rotates can be used for the mounting portion of the tension spring 78 on the rotating shaft 75 side.

Incidentally, in this embodiment, the first motor 31 may also be used as a drive source for a drive system other than the feeding roller 13 . The second motor 32 may also be used as a drive source for other drive systems in addition to the transport roller 20, the separation roller 14, the discharge roller 22, and the regulating section 40.

In addition, the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say.

1... Scanner (image reader), 2... Lower unit, 3... Upper unit,
4... Paper support, 5... Output tray, 6... Feed port, 7... Case,
8... Ejection port, 9... Apparatus main body, 10... Medium feeding device, 11... Medium placement unit,
12... Edge guide, 13... Feed roller, 14... Separation roller,
15... Auxiliary paper support, 20... Conveying roller, 21... Image reading unit (reading unit),
22... discharge roller (downstream transport roller), 23... transport drive roller,
24...Conveyance driven roller, 25...Upper image reading sensor, 26...Lower image reading sensor, 27...Ejection drive roller, 28...Ejection driven roller,
29a... Lower guide surface, 29b... Upper guide surface, 30... Conveying path,
31... First motor (first drive source), 31a... Motor body,
31b... motor output shaft, 32... second motor (second drive source),
32a...Motor body, 32b...Motor output shaft, 33...Right side frame,
34... left side frame, 35... control section, 36... first scale,
37... First encoder, 38... Flap, 39... Pressing unit, 40... Regulating part,
41... First transmission gear (first transmission mechanism), 42... Second transmission gear,
43... Third transmission gear, 44... Fourth transmission gear, 45... Fifth transmission gear, 46... Sixth transmission gear, 47... Rotary shaft, 48... Rotary shaft, 49... Timing belt,
51... Seventh transmission gear, 52... Eighth transmission gear (second transmission mechanism),
53...Timing belt, 54...Rotating shaft, 55...D cut portion, 56...D cut hole,
57... second scale, 58... second encoder,
59... Round press-fit holder, 60... Ninth transmission gear, 61... Tenth transmission gear,
62... train wheel, 63... eleventh transmission gear, 64... rotating shaft, 65... twelfth transmission gear,
66... 13th transmission gear, 67... 14th transmission gear, 68... rotating shaft,
70... Rotary shaft, 71... 15th transmission gear, 72... 16th transmission gear,
73... 17th transmission gear, 74... rib, 75... rotary shaft, 76... drive cam,
77 Hook portion 78 Tension spring 80 Belt tension mechanism
81... driven pulley, 82... pulley holder, 83... extension spring,
84...Boss, 85...Groove, 86...Screw, P...Paper

Claims (12)

a reading unit for reading a medium;
a feeding roller that feeds the medium placed on the medium placement unit toward the reading unit;
a pressing unit that is provided to move forward and backward with respect to the feeding roller and presses the medium placed on the medium stacking portion toward the feeding roller by advancing with respect to the feeding roller;
a transport roller provided downstream of the feed roller;
a first drive source that drives the feeding roller ;
a second drive source that drives the transport roller ;
a housing internally provided with the feed roller, the transport roller, the first drive source, and the second drive source ;
An image reading device comprising
The first drive source and the second drive source are provided on both sides of the central portion of the housing in a width direction that intersects with the medium conveying direction,
The housing is
a lower unit constituting the lower part of the housing;
an upper unit that opens and closes with respect to the lower unit;
with
The lower unit is driven by the second drive source to be in a regulated state for regulating the advance of the pressing unit with respect to the feed roller and an allowable state for allowing the advance of the press unit with respect to the feed roller. A switchable regulation part is provided,
The upper unit is provided with a separation roller that nips and separates the medium from the feeding roller,
Further comprising a plurality of transmission gears for rotating the separation roller,
the plurality of transmission gears are separated when the lower unit is open relative to the upper unit and engaged when the lower unit is closed relative to the upper unit;
An image reading device characterized by: The image reading device according to claim 1,
The pressing unit is provided with a swingable flap,
The restricting portion is provided with a concave portion,
In the regulated state, the tip of the flap enters the recess, and the pressing unit is pushed up by the regulating portion via the flap,
In the allowable state, the tip of the flap does not enter the recess, and the pressing unit presses the medium toward the feeding roller.
An image reading device characterized by: a reading unit for reading a medium;
a feeding roller that feeds the medium placed on the medium placement unit toward the reading unit;
a pressing unit that is provided to move forward and backward with respect to the feeding roller and presses the medium placed on the medium stacking portion toward the feeding roller by advancing with respect to the feeding roller;
a transport roller provided downstream of the feed roller;
a first drive source that drives the feeding roller ;
a second drive source that drives the transport roller ;
a housing internally provided with the feed roller, the transport roller, the first drive source, and the second drive source ;
An image reading device comprising
The first drive source and the second drive source are provided on both sides of the central portion of the housing in a width direction that intersects with the medium conveying direction,
The housing is
a lower unit constituting the lower part of the housing;
an upper unit that opens and closes with respect to the lower unit;
with
The lower unit is driven by the second drive source to be in a regulated state for regulating the advance of the pressing unit with respect to the feed roller and an allowable state for allowing the advance of the press unit with respect to the feed roller. A switchable regulation part is provided,
the regulating portion switches between the regulated state and the allowable state by rocking about a rocking axis;
The upper unit is provided with a separation roller that nips and separates the medium from the feeding roller,
The pressing unit is provided with a swingable flap,
The restricting portion is provided with a concave portion,
In the regulated state, the tip of the flap enters the recess, and the pressing unit is pushed up by the regulating portion via the flap,
In the allowable state, the tip of the flap does not enter the recess, and the pressing unit presses the medium toward the feeding roller.
An image reading device characterized by: In the image reading device according to claim 2,
The plurality of transmission gears are
a lower transmission gear provided in the lower unit;
an upper transmission gear provided in the upper unit and engaged with the lower transmission gear;
The second drive source outputs power to the lower transmission gear when the lower unit is in a closed state with respect to the upper unit.
An image reading device characterized by: 5. The image reading device according to claim 1 , wherein the second drive source is a DC motor,
an encoder that detects the amount of rotation of the scale that rotates according to the drive of the second drive source;
a control unit that controls driving of the corresponding drive source based on the information detected by the encoder ;
An image reading device characterized by: In the image reading device according to claim 5,
A first encoder that detects the amount of rotation of the scale that rotates according to the drive of the first drive source,
The first drive source is arranged with the direction along the width direction as the axial direction of the motor output shaft of the first drive source, and the motor output shaft extending from the motor main body of the first drive source. a first transmission mechanism connected to and transmitting the power of the motor is attached so as to be positioned outside the motor body in the width direction,
The first encoder is provided inside the motor body of the first drive source in the width direction,
An image reading device characterized by: 7. The image reading device according to claim 6, wherein a timing belt is used in said first transmission mechanism.
An image reading device characterized by: In the image reading device according to any one of claims 1 to 7 ,
The second drive source is arranged with the direction along the width direction as the axial direction of the motor output shaft of the second drive source, and the motor output shaft extending from the motor main body of the second drive source. A second transmission mechanism connected to the second drive source for transmitting power of the motor is attached so as to be located outside the motor body of the second drive source in the width direction.
An image reading device characterized by: 9. The image reading device according to claim 8, wherein a timing belt is used in said second transmission mechanism.
An image reading device characterized by: The image reading device according to claim 9 ,
a rotating shaft provided with the transport roller;
It is mounted on one side end of the rotating shaft in the axial direction and on the side where the second driving source is arranged, and receives power from the second driving source via the second transmission mechanism to rotate the rotating shaft. a one-sided holder with a drive gear that rotates the shaft;
a second encoder that detects the amount of rotation of the scale that rotates according to the drive of the second drive source;
with
A press- fit portion having a shape obtained by cutting a part of a circular cross section is formed at the one end of the rotating shaft,
The one-side holder is formed with a press- fitting portion having a shape corresponding to the press-fitting portion and into which the press- fitting portion is press-fitted,
The scale of the second encoder is provided outside the one-side holder and is configured to rotate integrally with the rotating shaft,
An image reading device characterized by: In the image reading device according to claim 10 ,
The scale of the second encoder is attached to a round press-fit holder that is integrally attached to the rotating shaft by press-fitting the rotating shaft into a circular hole.
An image reading device characterized by: The image reading device according to claim 11 , wherein
The round press-fit holder is provided on the other side of the rotating shaft in the axial direction with respect to the one side end of the rotating shaft,
An image reading device characterized by:

Images