阅读说明：本技术 介质供送装置 (medium feeding device ) 是由 金光正智 于 2019-05-30 设计创作，主要内容包括：本发明提供了一种能够提高偏斜的检测精度的介质供送装置。介质供送装置(11)具备：供送部(15),供送介质(99)；传感器(16),检测介质,供送部具有供送辊(24)及分离辊,传感器通过在所供送的介质的供送方向上排列有多个,从而形成传感器列(31),传感器列在所供送的介质的宽度方向(X)上以传感器彼此重叠的方式配置有两列,构成为在供送方向上遍及位于供送辊及分离辊互相接触的夹持点(P)上游的上游区域(B)、包括夹持点的夹持区域(C)、位于夹持点下游的下游区域(D)而延伸。(The invention provides a medium feeding device capable of improving the detection precision of deflection. A medium feeding device (11) is provided with: a feeding unit (15) for feeding a medium (99); and a sensor (16) that detects the medium, wherein the feeding section includes a feeding roller (24) and a separation roller, the sensor forms a sensor row (31) by arranging a plurality of sensors in the feeding direction of the fed medium, the sensor row is arranged in two rows in the width direction (X) of the fed medium such that the sensors overlap each other, and the sensor row is configured to extend in the feeding direction over an upstream region (B) located upstream of a nip point (P) where the feeding roller and the separation roller contact each other, a nip region (C) including the nip point, and a downstream region (D) located downstream of the nip point.)

1. A medium feeding device is characterized by comprising:

A feeding section that feeds a medium;

A sensor for detecting the medium,

the feeding section has a feeding roller and a separating roller,

The sensor is arranged in a plurality in a feeding direction of the medium to be fed, thereby forming a sensor column,

the sensor rows are arranged in two rows in the width direction of the medium to be fed such that the sensors overlap each other, and are configured to extend in the feeding direction over an upstream area located upstream of a nip point where the feeding roller and the separation roller contact each other, a nip area including the nip point, and a downstream area located downstream of the nip point.

2. The media supply of claim 1,

The medium feeding device is provided with a setting guide for supporting the set medium,

The sensor row is configured to extend from an installation area located upstream of the upstream area to the downstream area in the feeding direction,

The sensor detects the medium supported by the setting guide at the setting area.

3. The medium feeding device according to claim 1 or 2,

the sensor row is located at a position sandwiching the feeding portion in the width direction.

4. The media supply of claim 1,

The medium feeding device includes a double feed sensor that detects double feed of the medium fed by the feeding section,

the sensor column is located upstream of the overlapping feed sensor in the feeding direction.

5. the media supply of claim 1,

The sensors are provided in two or more areas.

6. the media supply of claim 1,

The medium feeding device is provided with an end sensor that detects the medium downstream of the downstream area in the feeding direction,

Changing to a first mode if the sensor in the downstream area does not detect the medium and a second mode if the sensor in the downstream area detects the medium when the end sensor changes from a state in which the medium is detected to a state in which the medium is not detected,

The second mode is a mode in which the separation roller that separates the medium has a larger separation force than the first mode.

7. The media supply of claim 1,

the medium feeding device is provided with an end sensor that detects the medium downstream of the downstream area in the feeding direction,

Changing to a first mode if the sensor in the downstream area does not detect the medium, a second mode if a part of the sensors in the downstream area detect the medium, and a third mode if all the sensors in the downstream area detect the medium, when the end sensor changes from a state in which the medium is detected to a state in which the medium is not detected,

the second mode is a mode in which a separation force of the separation roller that separates the medium is larger than the first mode,

The third mode is a mode in which the separation roller that separates the medium has a larger separation force than the second mode.

Technical Field

The present invention relates to a medium feeding device that feeds a medium.

Background

As an example of a medium feeding device, patent document 1 describes an image input device including a detection sensor that detects a fed medium. In this image input device, the skew of the medium is detected by a plurality of detection sensors arranged in series in the width direction of the fed medium.

Patent document 1: japanese patent laid-open publication No. 2006-165857

in such an image input device, there is room for improvement in detection accuracy when detecting a skew of a fed medium.

Disclosure of Invention

The medium feeding device for solving the above problems comprises a feeding part for feeding a medium; and a sensor that detects the medium, wherein the feeding unit includes a feeding roller and a separation roller, the sensor forms a sensor row by arranging a plurality of the sensors in a feeding direction of the fed medium, and the sensor row is arranged in at least two rows in a width direction of the fed medium and is configured to extend in the feeding direction over an upstream region located upstream of a nip point where the feeding roller and the separation roller contact each other, a nip region including the nip point, and a downstream region located downstream of the nip point.

Drawings

fig. 1 is a side view schematically showing an embodiment of a medium feeding apparatus.

Fig. 2 is a side view of the positioning guide in a first position.

Fig. 3 is a side view of the positioning guide in a second position.

fig. 4 is a top view of the housing.

Fig. 5 is a flowchart showing a processing procedure of the feeding action.

Description of reference numerals:

A media supply; a housing; a cover; a shaft; a feeding portion; a sensor; a tray; a reading portion; transport rollers; a first motor; a second motor; a control portion; a delivery path; a supply roll; a separation roller; a torque limiter; a clutch; a pressing mechanism; a light emitting element; a light receiving element; a sensor column; a lens; providing a guide; a stop; a shaft; a shaft; a slot; an overlapping feed sensor; an end sensor; 99.. media; setting a region; a region upstream; c. clamping the area; a downstream region; p.. a clamping point; a width direction; a transport direction.

Detailed Description

Next, an embodiment of the medium feeding device will be described with reference to the drawings. The medium feeding device is, for example, a sheet-fed scanner that reads images such as characters and photographs recorded on a medium such as a fed sheet.

As shown in fig. 1, the medium feeding device 11 includes a housing 12 and a cover 13 that opens and closes with respect to the housing 12. The cover 13 is opened and closed with respect to the housing 12 by rotating about the shaft 14, for example. In fig. 1, the lid 13 is closed. When the cover 13 is opened, the inside of the case 12 is exposed.

The medium feeding device 11 includes a feeding unit 15 for feeding the medium 99 and a sensor 16 for detecting the medium 99. The medium feeding device 11 includes a tray 17 on which the fed medium 99 is placed, a reading unit 18 that reads the medium 99, and a conveying roller 19 that conveys the medium 99. The medium feeding device 11 includes a first motor 21A, a second motor 21B, and a control unit 22 for controlling the entire device.

The medium feeding device 11 has a conveyance path 23 for conveying the medium 99. The conveyance path 23 of the present embodiment extends between the housing 12 and the cover 13 as indicated by a one-dot chain line in fig. 1. Along the conveying path 23, the feeding unit 15, the sensor 16, the reading unit 18, and the conveying roller 19 are provided. The medium 99 fed by the feeding unit 15 is conveyed on the conveying path 23 and is read by the reading unit 18. Therefore, in the conveyance path 23, the direction from the feeding unit 15 to the reading unit 18 is the conveyance direction Y of the medium 99. In the present embodiment, the feeding direction of the medium 99 fed by the feeding unit 15 coincides with the conveying direction Y.

The feeding unit 15 feeds the medium 99 placed on the tray 17 to the conveying path 23. The feeding section 15 includes a feeding roller 24 and a separation roller 25. The feeding unit 15 feeds the medium 99 by rotating the feeding roller 24 and the separation roller 25 while nipping the medium 99. The feed roller 24 is rotated by the driving of the first motor 21A. The separation roller 25 is rotated by the driving of the second motor 21B. The feed roller 24 and the separation roller 25 may be configured to be rotated by a common motor. The feeding roller 24 and the separation roller 25 are located at positions where nip points P in contact with each other are formed. Accordingly, the feeding roller 24 and the separation roller 25 nip the medium 99 at the nip point P.

The feed roller 24 of the present embodiment is attached to the housing 12. The feed roller 24 is configured to rotate clockwise in fig. 1 by the driving of the first motor 21A. The feeding roller 24 is rotated in a state of being in contact with the lowest medium 99 among the media 99 placed on the tray 17, thereby feeding the medium 99 to the nip point P. The feeding roller 24 rotates to feed the medium 99 downstream in the feeding direction Y.

when the feeding roller 24 guides the medium 99 to the nip point P, a plurality of sheets of the medium 99 may be guided to the nip point P due to frictional force between the media 99. In this case, the plurality of media 99 are sandwiched between the feed roller 24 and the separation roller 25 in a stacked state. That is, a plurality of media 99 may be fed in a stacked state. In this manner, feeding the media 99 in a state where a plurality of media 99 are overlapped is also referred to as overlapped feeding. When the media 99 are fed in a superimposed manner, there is a possibility that the image recorded on the media 99 cannot be correctly read by the reading unit 18. In order to suppress such double feeding of the media 99, the separation roller 25 is configured to separate a plurality of media 99 that are overlapped one by one. In such a medium feeding apparatus, there is room for improvement in detection accuracy for detecting double feeding of the fed media.

the separation roller 25 of the present embodiment is attached to the cover 13. The separation roller 25 is configured to rotate clockwise in fig. 1 by the driving of the second motor 21B. The separation roller 25 rotates to return the medium 99 upstream in the conveyance direction Y. In the present embodiment, the rotation direction of the medium 99 to the downstream in the conveyance direction Y is defined as a forward rotation direction, and the rotation direction of the medium 99 to the upstream in the conveyance direction Y is defined as a reverse rotation direction. In this case, the feed roller 24 is configured to rotate in the normal rotation direction by the driving of the first motor 21A. The separation roller 25 is configured to rotate in the reverse rotation direction by the driving of the second motor 21B.

A torque limiter 26A and a clutch 26B are attached to the separator roller 25. The torque limiter 26A and the clutch 26B are mechanisms for connecting the second motor 21B and the separator roller 25 so as to transmit the driving force of the second motor 21B to the separator roller 25. The torque limiter 26A is configured to disconnect the separation roller 25 and the second motor 21B when a rotational load equal to or greater than a predetermined value is applied to the separation roller 25. That is, when a rotational load of a predetermined value or more is applied to the separation roller 25, the connection between the separation roller 25 and the second motor 21B by the torque limiter 26A is cut off. Thereby, the driving of the separation roller 25 by the second motor 21B is stopped. The clutch 26B is configured to disconnect the separation roller 25 and the second motor 21B by the control of the control unit 22.

When the feeding roller 24 and the separation roller 25 nip one sheet of the medium 99, the torque of the feeding roller 24 rotating in the forward rotation direction is transmitted to the separation roller 25 rotating in the reverse rotation direction via the medium 99. That is, the torque of the feeding roller 24 becomes the rotational load of the separation roller 25. When the feeding roller 24 and the separation roller 25 nip one sheet of the medium 99, the torque of the feeding roller 24 is easily transmitted to the separation roller 25. Therefore, in this case, the torque limiter 26A cuts off the connection of the separation roller 25 and the second motor 21B. When the connection between the separation roller 25 and the second motor 21B is disconnected, the separation roller 25 rotates in a driven manner with respect to the rotation of the feed roller 24. At this time, the separation roller 25 rotates in the normal rotation direction, similarly to the feed roller 24.

When the feeding roller 24 and the separation roller 25 nip the plurality of media 99, the media 99 in contact with the feeding roller 24 is different from the media 99 in contact with the separation roller 25. The frictional force of the medium 99 with respect to the medium 99 is smaller than the frictional force of the medium 99 with respect to the feeding roller 24 and the frictional force of the medium 99 with respect to the separating roller 25. That is, since the medium 99 in contact with the separation roller 25 and the medium 99 in contact with the feeding roller 24 slide with each other, the torque of the feeding roller 24 rotating in the forward direction is hardly transmitted to the separation roller 25. Therefore, in this case, the medium 99 in contact with the feeding roller 24 is fed downstream in the conveying direction Y. The medium 99 in contact with the separation roller 25 is returned upstream in the conveyance direction Y. In this manner, the separation roller 25 separates the plurality of media 99. As a result, the separation roller 25 suppresses the overlapped feeding of the medium 99.

the separation roller 25 may be configured such that the frictional force with respect to the medium 99 is higher than the frictional force with respect to the medium 99 of the supply roller 24. Even if the separation roller 25 is configured in this way, double feeding of the media 99 can be suppressed. The separation roller 25 may be configured to rotate in the normal rotation direction by the driving of the second motor 21B. In this case, by setting the rotation speed of the separation roller 25 slower than the rotation speed of the feeding roller 24, the double feeding of the medium 99 can be suppressed.

The separation roller 25 of the present embodiment is configured to vary the separation force for separating the medium 99. A pressing mechanism 27 is attached to the separation roller 25. The pressing mechanism 27 is a mechanism that presses the separation roller 25 against the feed roller 24. In the present embodiment, the separating force of the separating roller 25 is determined by the pressing force of the pressing mechanism 27.

The pressing mechanism 27 is formed of a spring, for example. The pressing mechanism 27 presses the shaft of the separation roller 25 against the feed roller 24, thereby pressing the separation roller 25 against the feed roller 24. The pressing mechanism 27 presses the separation roller 25, and a force for nipping the medium 99 at the nip point P is secured. The pressing mechanism 27 is configured to be variable in pressing force to press the separation roller 25. The pressing force of the pressing mechanism 27 is changed by the control unit 22.

The rotational load applied to the separation roller 25 changes according to the pressing force of the pressing mechanism 27 pressing the separation roller 25 against the feed roller 24. The greater the pressing force of the pressing mechanism 27, the stronger the contact between the separation roller 25 and the feed roller 24, and therefore the more easily the torque of the feed roller 24 is transmitted to the separation roller 25. That is, in this case, the rotational load applied to the separation roller 25 tends to increase. As the pressing force of the pressing mechanism 27 against the separation roller 25 is smaller, the load of the separation roller 25 is less likely to be applied to the feed roller 24, and thus the torque of the feed roller 24 is less likely to be transmitted to the separation roller 25. That is, in this case, the rotational load applied to the separation roller 25 is likely to be small.

if the torque of the feeding roller 24 is easily transmitted to the separation roller 25, the connection between the separation roller 25 and the second motor 21B by the torque limiter 26A is easily cut off. Therefore, the separating force of the separating roller 25 for separating the medium 99 becomes small. On the other hand, if the torque of the feeding roller 24 is hard to be transmitted to the separation roller 25, the separation force of the separation roller 25 becomes large. In this way, in the present embodiment, the pressing force of the pressing mechanism 27 is changed, and the separating force of the separating roller 25 is changed.

When the clutch 26B is provided in the separator roller 25, the torque limiter 26A may not be provided. For example, when the rotational load applied to the separator roller 25 is equal to or greater than a predetermined value, the controller 22 may control the clutch 26B to disconnect the separator roller 25 and the second motor 21B from each other by the clutch 26B. In this way, the control unit 22 can change the separating force of the separating roller 25.

The sensor 16 of the present embodiment is located at a position overlapping the feeding portion 15 in the conveying direction Y. That is, the sensor 16 is located at a position overlapping the feeding portion 15 when viewed from the width direction X. The sensor 16 includes a light emitting element 28 that emits light and a light receiving element 29 that receives light. The light emitting element 28 and the light receiving element 29 are located at positions facing each other. The light emitting element 28 and the light receiving element 29 sandwich the conveyance path 23. The light emitting element 28 is mounted on the housing 12. The light receiving element 29 is attached to the cover 13.

When the light receiving element 29 receives the light emitted from the light emitting element 28, the sensor 16 is turned off. The off state is a state in which the medium 99 is not detected. When the light receiving element 29 does not receive the light emitted from the light emitting element 28, the sensor 16 is turned on. The on state is a state in which the medium 99 is detected. That is, the sensor 16 detects the medium 99 by blocking the medium 99 with the light from the light emitting element 28 toward the light receiving element 29. As described above, the sensor 16 of the present embodiment is a transmission type optical sensor.

The sensor 16 may also be a reflective optical sensor. The sensor 16 may be a contact sensor that detects the medium 99 by contacting the rod. The sensor 16 may be a sensor configured to detect the medium 99 by imaging.

A plurality of sensors 16 are provided. The sensor 16 of the present embodiment is composed of a pair of light emitting elements 28 and light receiving elements 29. The sensor 16 is formed by arranging a plurality of sensors in the feeding direction of the fed medium 99 to form a sensor row 31. That is, the sensor array 31 of the present embodiment extends in the conveyance direction Y. When a plurality of sensors 16 are arranged to form a sensor array 31, the medium 99 can be detected at a plurality of positions.

the sensor array 31 of the present embodiment is formed of eight sensors 16. Therefore, according to the sensor array 31, the medium 99 can be detected at eight positions. In the present embodiment, eight light emitting elements 28 are provided, and only one light receiving element 29 is provided. That is, the plurality of sensors 16 are configured to share one light receiving element 29. The plurality of sensors 16 are each composed of an independent light emitting element 28 and a common light receiving element 29. By shifting the timing of light emission from each light emitting element 28, the medium 99 can be detected at a plurality of positions using one light receiving element 29.

When the plurality of sensors 16 are configured by sharing the light receiving element 29, the lens 32 may be disposed between the light emitting element 28 and the light receiving element 29. The lens 32 is, for example, a convex lens, a fresnel lens, a diffractive lens, or the like. The lens 32 refracts light emitted from the light emitting element 28 toward the light receiving element 29. In this way, since the light emitted from each light emitting element 28 can be collected toward the light receiving element 29, the medium 99 can be detected at a plurality of positions with high accuracy. The same number of light receiving elements 29 as the number of light emitting elements 28 may be provided.

The reading unit 18 is located downstream of the feeding unit 15 and the sensor 16 in the conveying direction Y. The reading unit 18 reads an image recorded on one surface of the medium 99 conveyed on the conveying path 23. The reading unit 18 is constituted by an image sensor, for example. The reading unit 18 of the present embodiment is provided in two. The two reading units 18 are located at positions facing each other, sandwiching the conveyance path 23. In this way, the respective reading units 18 can collectively read both images recorded on one surface and the other surface of the medium 99.

the conveying rollers 19 are arranged in pairs. The conveying rollers 19 are disposed so as to sandwich the conveying path 23. One or more conveying rollers 19 are provided. In the present embodiment, the pair of conveying rollers 19 are provided at two positions in the conveying direction Y, upstream of the reading section 18 and downstream of the reading section 18. The conveyance roller 19 conveys the medium 99 along the conveyance path 23 by rotating in a state of nipping the medium 99. The conveying roller 19 is rotated in the normal rotation direction by the driving of the second motor 21B. The pair of conveying rollers 19 may be configured such that one is driven relative to the other. That is, the pair of conveying rollers 19 may be configured to be rotated by the driving of the second motor 21B.

The control unit 22 is configured to include, for example, a CPU, a memory, and the like. The control unit 22 controls the medium feeding device 11 by the CPU executing a program stored in the memory. The control unit 22 has a first mode, a second mode, and a third mode as modes in which the medium feeding device 11 operates. The medium feeding device 11 of the present embodiment normally operates in the first mode. The second mode is a mode in which the separation force of the separation roller 25 is larger than that of the first mode. The third mode is a mode in which the separation force of the separation roller 25 is larger than that of the second mode.

The first mode is a mode in which the separation roller 25 is not driven. In the first mode, the separation roller 25 is driven with respect to the rotation of the feeding roller 24 when the medium 99 is fed. In the present embodiment, the state in which the clutch 26B disconnects the separation roller 25 from the second motor 21B is the first mode. When a plurality of media 99 are stacked, the separation roller 25 separates the media 99 by its own rotation resistance and a frictional force against the media 99. Therefore, the separating force of the separating roller 25 in the first mode is small.

the second mode is a mode in which the separation roller 25 is driven by the driving of the second motor 21B. In the second mode, the separation roller 25 rotates in the reverse rotation direction as long as a rotational load of a predetermined value or more is not applied from the feed roller 24. Therefore, the separating force of the separating roller 25 in the second mode is larger than the separating force of the separating roller 25 in the first mode.

The third mode is a mode in which the separation roller 25 is driven by the driving of the second motor 21B and the pressing force of the pressing mechanism 27 is small. The pressing force of the pressing mechanism 27 in the third mode is smaller than the pressing force of the pressing mechanism 27 in the second mode. In the third mode, the pressing force by the pressing mechanism 27 is small, and the separation roller 25 is less likely to be applied with a rotational load from the feeding roller 24. Therefore, the separating force of the separating roller 25 in the third mode is larger than the separating force of the separating roller 25 in the second mode.

in the first mode, the separation roller 25 may be driven. In this case, in the first mode, the second mode, and the third mode, the pressing force of the pressing mechanism 27 is preferably different in stages. That is, the pressing force of the pressing mechanism 27 in the second mode may be smaller than the pressing force of the pressing mechanism 27 in the first mode. The pressing force of the pressing mechanism 27 in the third mode may be smaller than the pressing force of the pressing mechanism 27 in the second mode. In this way, the first mode, the second mode, and the third mode can be configured to have different separating forces of the separating roller 25.

As shown in fig. 2, the medium feeding device 11 may include an installation guide 34 that supports the installed medium 99. The setting guide 34 supports the medium 99 placed on the tray 17. The setting guide 34 supports the front end portion of the medium 99 placed on the tray 17. The guide 34 is provided to support the medium 99 so that the leading end portion of the medium 99 placed on the tray 17 does not contact the feed roller 24. The setting guide 34 is mounted to the housing 12.

the medium feeding device 11 may include a stopper 35 for determining the position of the medium 99. The stopper 35 is located at a position abutting on the front end portion of the medium 99 placed on the tray 17. The stopper 35 determines the position of the medium 99 by contacting the leading end portion of the medium 99. The stopper 35 supports the medium 99 so that the medium 99 does not contact the separation roller 25. The stopper 35 is attached to the cover 13.

as shown in fig. 2 and 3, the installation guide 34 is configured to rotate about a shaft 36. The shaft 36 is provided at a base end portion of the guide 34 on the opposite side of the leading end portion that contacts the medium 99. The setting guide 34 is displaced between a first position shown in fig. 2 and a second position shown in fig. 3 by rotating about a shaft 36. The setting guide 34 supports the leading end portion of the medium 99 placed on the tray 17 in the first position. The setting guide 34 does not support the leading end portion of the medium 99 placed on the tray 17 in the second position. By providing the guide 34 at the second position, the leading end portion of the medium 99 placed on the tray 17 can be brought into contact with the feeding roller 24.

The stopper 35 is configured to rotate about a shaft 37. The shaft 37 is located at a base end portion of the stopper 35 on the opposite side of the leading end portion that contacts the medium 99. The stopper 35 is rotated about the shaft 37 to be displaced between a first position shown in fig. 2 and a second position shown in fig. 3. The stopper 35 determines the position of the medium 99 by contacting, in the first position, the leading end portion of the medium 99 placed on the tray 17. When the stopper 35 is located at the second position, the leading end portion of the medium 99 placed on the tray 17 can be brought into contact with the separation roller 25.

In the present embodiment, by providing the guide 34 and the stopper 35 both at the second position, the medium 99 placed on the tray 17 can be fed. When the medium feeding device 11 does not feed the medium 99, the setting guide 34 and the stopper 35 are both located at the first position.

The setting guide 34 may have a groove 38 at the first position configured to engage with the tip end portion of the stopper 35. The possibility of displacement of the stopper 35 due to the load of the medium 99 can be reduced by engaging the tip end portion of the stopper 35 with the groove 38 of the installation guide 34 located at the first position.

When the medium 99 is fed, the setting guide 34 is displaced from the first position to the second position by the control unit 22. At this time, the engagement between the guide 34 and the stopper 35 is released by the setting of the groove 38. The stopper 35 is displaced from the first position to the second position by the load of the medium 99 placed on the tray 17.

A spring may also be provided on the shaft 37 of the stopper 35. When the medium 99 placed on the tray 17 runs out in this manner, the stopper 35 is displaced from the second position to the first position by the elastic force of the spring. The stopper 35 may be controlled by the control unit 22 in the same manner as the installation guide 34.

As shown in fig. 4, a plurality of sensor rows 31 are arranged so that the sensors 16 overlap each other in the width direction X. The sensor array 31 of the present embodiment is arranged in two rows in the width direction X. The sensor array 31 is configured to extend in the conveyance direction Y as a feeding direction in an upstream area B located upstream of the nip point P, a nip area C including the nip point P, and a downstream area D located downstream of the nip point P. Therefore, the sensor 16 is configured to detect the medium 99 in the upstream zone B, the nip zone C, and the downstream zone D. In the present embodiment, the light emitting elements 28 constituting the sensor 16 are positioned in the upstream area B, the nip area C, and the downstream area D, respectively, so that the medium 99 is detected in each area.

in the sensor row 31 of two rows, the sensors 16 located in the upstream area B overlap each other in the width direction X. In the sensor row 31 of two rows, the sensors 16 located in the nip region C overlap each other in the width direction X. In the sensor row 31 of two rows, the sensors 16 located in the downstream area D overlap each other in the width direction X. The two sensor rows 31 are located at positions overlapping when viewed from the width direction X. In the present embodiment, the sensor rows 31 of two rows are located at positions where the light emitting elements 28 overlap each other when viewed from the width direction X.

in the sensor rows 31 of two rows, when the leading end of the medium 99 is detected in the upstream area B in one sensor row 31 and the leading end of the medium 99 is detected in the nip area C in the other sensor row 31, it is known that the medium 99 is inclined. In this manner, the control unit 22 detects the inclination, i.e., the skew, of the medium 99 based on the detection result of the sensor 16. That is, the inclination of the leading end of the medium 99 is detected by the two sensors 16 overlapped in the width direction X. Thereby, the skew of the medium 99 is detected. The sensor rows 31 may be provided with three or more rows in the width direction X. The more the sensor columns 31 are, the more the detection accuracy of the skew is improved. The two sensor rows 31 may be present at intervals in the width direction X. Thus, the detection accuracy of the skew will be improved.

The sensors 16 may be provided in two or more areas. That is, a plurality of sensors 16 may be disposed in each of the upstream zone B, the nip zone C, and the downstream zone D. Two sensors 16 are provided in each of the upstream zone B, the nip zone C, and the downstream zone D. If a plurality of sensors 16 are arranged in each area, the detection accuracy of the skew will be improved.

The sensor row 31 may be configured to extend from the installation area a located upstream of the upstream area B to the downstream area D in the conveyance direction Y that coincides with the feeding direction. The sensor 16 detects the medium 99 supported by the setting guide 34 in the setting area a. Thereby, the medium 99 placed on the tray 17 is detected by the sensor 16. In the sensor row 31 of two rows, the sensors 16 located in the installation area a overlap each other in the width direction X. That is, the presence or absence of the medium 99 on the tray 17 can be detected by the sensor 16 provided in the area a. In the installation area a, the skew of the medium 99 supported by the installation guide 34 can be detected by the two sensors 16 overlapping in the width direction X. In the installation area a, two or more sensors 16 may be arranged.

The sensor row 31 may be located at a position sandwiching the feeding portion 15 in the width direction X. In this manner, the intervals between the sensor columns 31 in the width direction X are widened. This improves the accuracy of detecting the skew. In the present embodiment, two feeding rollers 24 are disposed with a space therebetween in the width direction X. The sensor row 31 is located at a position where the two feeding rollers 24 are sandwiched in the width direction X. The separation rollers 25 are disposed so as to oppose the feed rollers 24, and are provided in the same number as the feed rollers 24. The setting guide 34 is located between the feeding roller 24 and the sensor line 31 in the width direction X. The setting guide 34 may be provided in plurality.

The medium feeding device 11 may include a double feed sensor 41 that detects double feeding of the medium 99 fed by the feeding unit 15. The double feed sensor 41 is configured to detect a state in which two or more media 99 are stacked. The double feed sensor 41 detects the double feed of the medium 99 by, for example, ultrasonic waves. The sensor row 31 is located upstream of the overlap feed sensor 41 in the conveying direction Y that coincides with the feeding direction. In this way, the skew of the medium 99 can be detected before the double feed of the medium 99 is detected by the double feed sensor 41. The double feed sensor 41 of the present embodiment is located at a position downstream of the feed roller 24 and upstream of the feed roller 19 in the feed direction Y.

the medium feeding device 11 may include an end sensor 42 that detects the medium 99 downstream of the downstream area D in the feeding direction Y that coincides with the feeding direction. The end sensor 42 is, for example, a contact sensor that detects the medium 99 by the medium 99 contacting the rod. The end sensor 42 is turned on when the medium 99 is detected, and is turned off when the medium 99 is not detected.

the end sensor 42 is located between the reading section 18 and the conveying roller 19 in the conveying direction Y. When the end sensor 42 is turned from the off state to the on state, the leading end of the medium 99 is known to reach the end sensor 42. When the end sensor 42 is changed from the on state to the off state, the rear end of the medium 99 is known to pass through the end sensor 42. The medium feeding device 11 of the present embodiment starts reading by the reading unit 18 by changing the end sensor 42 from the off state to the on state.

Next, a feeding operation performed by the medium feeding device 11 will be described. The medium feeding device 11 performs a feeding operation when the medium 99 is fed by the feeding section 15.

As shown in fig. 5, the control unit 22 that executes the feeding operation first switches the mode of the medium feeding device 11 to the first mode in step S11. At this time, the control unit 22 controls the clutch 26B to disconnect the connection between the separator roller 25 and the second motor 21B via the clutch 26B.

In step S12, the control unit 22 drives the second motor 21B. The second motor 21B drives the conveyance roller 19 to rotate. When the mode of the medium feeding device 11 is the first mode, the connection between the separation roller 25 and the second motor 21B is cut off. Therefore, in this case, even if the second motor 21B is driven, the separation roller 25 does not rotate. Therefore, in step S12, when the medium feeding device 11 is in the first mode, the conveyance roller 19 is rotated but the separation roller 25 is not rotated by the driving of the second motor 21B. In step S12, when the medium feeding device 11 is in the second mode or the third mode, the separation roller 25 and the conveyance roller 19 are both rotated by the driving of the second motor 21B.

In step S13, the control unit 22 drives the first motor 21A. The feed roller 24 is rotated by driving of the first motor 21A. The medium 99 placed on the tray 17 is fed by the rotation of the feeding roller 24.

In step S14, the control unit 22 determines whether or not the sensor 16 in the downstream area D is in the on state. That is, the control unit 22 determines whether or not the medium 99 is located in the downstream area D in step S14. When the sensor 16 in the downstream area D is in the on state, the control unit 22 proceeds to step S15. When the sensor 16 in the downstream region D is in the off state, the control unit 22 proceeds to step S31.

The control unit 22 determines in step S31 whether or not a predetermined time has elapsed. In step S31, the control unit 22 refers to the time elapsed since the first motor 21A was driven in step S13. That is, the control unit 22 determines in step S31 whether or not the time elapsed since the first motor 21A was driven exceeds a predetermined time. When the predetermined time has elapsed, the control unit 22 proceeds to step S32. When the predetermined time has not elapsed, the control unit 22 returns the process to step S14.

The control unit 22 determines in step S14 and step S31 whether or not the medium 99 placed on the tray 17 reaches the downstream area D before a predetermined time elapses after the first motor 21A is driven. That is, the control unit 22 determines whether the medium 99 is normally fed in step S14 and step S31. When the medium 99 is normally fed, the control unit 22 moves the process to step S15. If the medium 99 is not normally fed, the control unit 22 moves the process to step S32.

In step S32, the control unit 22 stops the first motor 21A and the second motor 21B. Thereby, the feed roller 24, the separation roller 25, and the transport roller 19 are stopped. After stopping the first motor 21A and the second motor 21B, the control unit 22 indicates that the medium 99 is not normally fed and ends the feeding process. At this time, the medium 99 may not be set on the tray 17 as a reason why the medium 99 is not normally fed. Therefore, when the feeding process is executed, it is also possible to determine whether the medium 99 is set on the tray 17 using the sensor 16 located in the setting area a.

when the sensor 16 in the downstream area D is in the on state in step S14, the control unit 22 determines whether or not the end sensor 42 is in the on state in step S15. When the end sensor 42 is in the on state, the control unit 22 proceeds to step S16. When the end sensor 42 is in the off state, the control unit 22 proceeds to step S41.

The control unit 22 determines in step S41 whether or not a predetermined time has elapsed. The control section 22 refers to the time elapsed since the sensor 16 of the downstream area D became on state in step S14 in step S41. That is, the control unit 22 determines in step S41 whether or not the time elapsed since the sensor 16 in the downstream area D detected the medium 99 exceeds a predetermined time. When the predetermined time has elapsed, the control unit 22 proceeds to step S42. When the predetermined time has not elapsed, the control unit 22 returns the process to step S15.

The controller 22 determines in steps S15 and S41 whether or not the medium 99 reaches the end sensor 42 before a predetermined time elapses after the medium 99 is detected by the sensor 16 in the downstream area D. That is, the control unit 22 determines whether or not the medium 99 is normally fed on the conveyance path 23 from the downstream area D to the end sensor 42 in step S15 and step S41. When the medium 99 is normally fed, the control unit 22 moves the process to step S16. If the medium 99 is not normally fed, the control unit 22 moves the process to step S42.

In step S42, the control unit 22 stops the first motor 21A and the second motor 21B. Thereby, the feed roller 24, the separation roller 25, and the transport roller 19 are stopped. After stopping the first motor 21A and the second motor 21B, the control unit 22 indicates that the medium 99 is not normally fed and ends the feeding process.

when the end sensor 42 is in the on state in step S15, the control unit 22 stops the first motor 21A in step S16. Thereby, the feed roller 24 is stopped. When the end sensor 42 detects the medium 99, the medium 99 is nipped by the conveyance roller 19. Therefore, when the end sensor 42 detects the medium 99, it indicates that the medium 99 is normally fed and the first motor 21A is stopped.

The control unit 22 determines in step S17 whether or not the end sensor 42 is in the on state. When the end sensor 42 is in the on state, the control unit 22 proceeds to step S51. When the end sensor 42 is in the off state, the control unit 22 proceeds to step S18.

The control unit 22 determines in step S51 whether or not a predetermined time has elapsed. The control section 22 refers to the time elapsed since the stop of the first motor 21A in step S16 in step S51. That is, the control unit 22 determines in step S51 whether or not the time elapsed since the stop of the first motor 21A exceeds a predetermined time. When the predetermined time has elapsed, the control unit 22 proceeds to step S52. When the predetermined time has not elapsed, the control unit 22 returns the process to step S17.

The control unit 22 determines whether or not the medium 99 has passed the end sensor 42 before a predetermined time has elapsed since the stop of the first motor 21A in step S17 and step S51. That is, the controller 22 determines whether or not the medium 99 is normally conveyed on the conveyance path 23 in step S17 and step S51. In a case where the medium 99 is normally conveyed, the rear end of the medium 99 passes through the end sensor 42 before a predetermined time elapses. Therefore, when the medium 99 is normally conveyed, the end sensor 42 is turned from the on state to the off state before a predetermined time elapses. When the medium 99 is normally conveyed, the control unit 22 proceeds to step S18. When the medium 99 is not normally conveyed, the control unit 22 moves the process to step S52.

The control unit 22 stops the second motor 21B in step S52. Thereby, the conveying roller 19 is stopped. In step S52, when the medium feeding device 11 is in the second mode or the third mode, the second motor 21B is stopped, and the separation roller 25 and the conveyance roller 19 are both stopped. After stopping the second motor 21B, the control unit 22 indicates that the medium 99 is not being conveyed normally and ends the feeding process.

When the end sensor 42 is in the off state in step S17, the control unit 22 determines whether or not the sensor 16 in the downstream area D is in the on state in step S18. When the sensor 16 in the downstream area D is in the on state, the control unit 22 proceeds to step S61. When the sensor 16 in the downstream region D is in the off state, the control unit 22 proceeds to step S19.

When the medium 99 is fed from step S11 to step S17, the next medium 99 may be fed together with the medium 99. Thus, when the trailing end of the preceding medium 99 passes the end sensor 42, the leading end of the following medium 99 may be positioned downstream of the nip point P. If the feeding of the medium 99 is continued in this state, there is a possibility that the overlapped feeding of the medium 99 occurs. Therefore, it is preferable that the medium feeding device 11 be set to the first mode if the sensor 16 in the downstream area D does not detect the medium 99 and to the second mode if the sensor 16 in the downstream area D detects the medium 99 when the state in which the end sensor 42 detects the medium 99 is changed to the non-detection state. More preferably, when the medium feeding device 11 is changed from a state in which the end sensor 42 detects the medium 99 to a state in which the medium 99 is not detected, the first mode is changed if the sensor 16 in the downstream area D does not detect the medium 99, the second mode is changed if a part of the sensors 16 in the downstream area D detect the medium 99, and the third mode is changed if all the sensors 16 in the downstream area D detect the medium 99.

In step S18, when the sensor 16 in the downstream area D is in the off state, it is found that the following medium 99 is not located in the downstream area D. In this case, the possibility of overlapped feeding of the media 99 is small. In step S18, when the sensor 16 in the downstream area D is in the on state, it is found that the following medium 99 is located in the downstream area D. If the feeding is continued in this state, the possibility that the overlapped feeding of the medium 99 occurs is high. Therefore, when the sensor 16 in the downstream area D is in the on state in step S18, the control unit 22 increases the separating force of the separating roller 25.

In step S61, the control unit 22 determines whether or not all the sensors 16 in the downstream area D are in the on state. In the present embodiment, there are four sensors 16 located in the downstream region D. When all the sensors 16 in the downstream area D are in the on state, the control unit 22 proceeds to step S71. If all the sensors 16 in the downstream area D are not in the on state, that is, if some of the sensors 16 in the downstream area D are in the on state, the control unit 22 proceeds to step S62.

The control unit 22 switches to the second mode in step S62. At this time, the control unit 22 controls the clutch 26B to connect the separation roller 25 and the second motor 21B via the clutch 26B. After the switching to the second mode is completed, the control unit 22 proceeds to step S20.

If all the sensors 16 in the downstream area D are in the on state in step S61, the control unit 22 switches to the third mode in step S71. At this time, the control unit 22 controls the clutch 26B to connect the separation roller 25 and the second motor 21B via the clutch 26B. The control unit 22 reduces the pressing force of the pressing mechanism 27. After the switching to the third mode is completed, the control unit 22 proceeds to step S20.

When all the sensors 16 in the downstream region D are in the on state, the leading end of the following medium 99 is positioned downstream of the sensors 16 in the downstream region D. Therefore, the possibility of occurrence of overlapped feeding of the media 99 is high. Therefore, when all the sensors 16 in the downstream region D are in the on state, the third mode in which the separating force is the largest is used.

When the sensor 16 in the downstream area D is in the off state in step S18, the control unit 22 switches to the first mode in step S19. At this time, the control unit 22 controls the clutch 26B to disconnect the connection between the separator roller 25 and the first motor 21A via the clutch 26B. After the switching to the first mode is completed, the control unit 22 proceeds to step S20.

The control unit 22 determines in step S20 whether or not there is a next page. That is, it is determined whether or not the medium 99 remains on the tray 17. When there is the next page, the control unit 22 returns the process to step S13. If there is no next page, the control unit 22 moves the process to step S21.

The control unit 22 stops the second motor 21B in step S21. The conveying roller 19 is stopped by the stop of the second motor 21B. In step S21, when the medium feeding device 11 is in the second mode or the third mode, the second motor 21B is stopped, and the separation roller 25 and the conveyance roller 19 are both stopped. After stopping the second motor 21B, the control unit 22 ends the feeding process.

Next, the operation and effect of the above embodiment will be described.

(1) The sensor line 31 is configured such that two lines of sensors 16 are arranged in the width direction X of the medium 99 being fed so as to overlap each other, and extends in the feeding direction in an upstream area B located upstream of a nip point P where the feeding roller 24 and the separation roller 25 contact each other, a nip area C including the nip point P, and a downstream area D located downstream of the nip point P. This allows the skew of the medium 99 to be detected in each of the upstream zone B, the nip zone C, and the downstream zone D. Therefore, the accuracy of detecting the skew can be improved.

(2) The sensor 16 detects the medium 99 supported by the setting guide 34 in the setting area a. This allows detection of the skew of the medium 99 in the setting area a. That is, the skew of the medium 99 can be detected before feeding. Therefore, skew can be easily eliminated.

(3) the sensor row 31 is located at a position sandwiching the feeding portion 15 in the width direction X. This widens the interval between the sensor rows 31 in the width direction X, and therefore, the accuracy of detecting the skew can be improved.

(4) The sensor row 31 is located at a position upstream of the overlapped feeding sensor 41 in the feeding direction. Thus, the skew of the medium 99 can be detected by the sensor 16 before the double feed of the medium 99 is detected by the double feed sensor 41.

(5) The sensors 16 are provided in two or more areas. In this way, the accuracy of detecting the skew can be improved as compared with the case where one sensor 16 is provided in each region.

(6) When the end sensor 42 is in a state of detecting the medium 99 and is not in a state of detecting the medium 99, the medium feeding device 11 changes to the first mode if the sensor 16 in the downstream area D does not detect the medium 99, and changes to the second mode if the sensor 16 in the downstream area D detects the medium 99.

When the end sensor 42 changes from a state in which the medium 99 is detected to a state in which the medium 99 is not detected, it is known that the feeding of the medium 99 is completed. At this time, when the sensor 16 located in the downstream area D does not detect the medium 99, it is known that the medium 99 following the medium 99 whose feeding is completed does not reach the downstream area D. On the other hand, when the sensor 16 located in the downstream area D detects the medium 99, it is known that the medium 99 subsequent to the medium 99 whose feeding has been completed has been fed to the downstream area D. In this case, there is a possibility that the overlapped feeding of the media 99 occurs. In contrast, if the separating force of the separating roller 25 that separates the media 99 is increased, the possibility of double feeding in which a plurality of media 99 are fed is reduced. That is, according to the above configuration, when there is a possibility of double feed of the medium 99, the double feed of the medium 99 can be suppressed by using the second mode.

(7) When the end sensor 42 is in a state of not detecting the medium 99 from a state of detecting the medium 99, the medium feeding device 11 changes to the first mode if the sensor 16 in the downstream area D does not detect the medium 99, changes to the second mode if a part of the sensors 16 in the downstream area D detect the medium 99, and changes to the third mode if all the sensors 16 in the downstream area D detect the medium 99.

When the end sensor 42 changes from a state in which the medium 99 is detected to a state in which the medium 99 is not detected, it is known that the feeding of the medium 99 is completed. At this time, when the sensor 16 located in the downstream area D does not detect the medium 99, it is known that the medium 99 following the medium 99 whose feeding is completed does not reach the downstream area D. On the other hand, when the sensor 16 located in the downstream area D detects the medium 99, it is known that the medium 99 subsequent to the medium 99 whose feeding has been completed is fed to the downstream area D. In this case, there is a possibility that the overlapped feeding of the media 99 occurs. In addition, when all the sensors 16 located in the downstream area D detect the medium 99, there is a possibility that the medium 99 subsequent to the medium 99 whose feeding has been completed is fed downstream of the downstream area D. In this case, the possibility of occurrence of overlapping feeding is high. In contrast, if the separating force of the separating roller 25 that separates the media 99 is increased, the possibility of double feeding in which a plurality of media 99 are fed is reduced. That is, according to the above configuration, when there is a possibility of double feed of the medium 99, the double feed of the medium 99 can be suppressed by using the second mode. When the possibility of double feed of the medium 99 is high, the use of the third mode can suppress the double feed of the medium 99.

This embodiment can be modified as follows. This embodiment and the following modifications can be combined and implemented within a range not technically contradictory to each other.

The feed roller 24, the separation roller 25, and the conveyance roller 19 may be driven by one motor.

instead of the clutch 26B, a plunger may be used. The separating force of the separating roller 25 can also be changed by controlling the plunger.

Instead of the clutch 26B, a planetary gear that switches the torque value of the torque limiter 26A may be used. For example, a plurality of torque limiters 26A may be provided, and the torque limiter 26A connecting the separation roller 25 and the second motor 21B can be selected by a planetary gear. In this case, the separating force of the separating roller 25 can be changed by configuring the torque values of the plurality of torque limiters 26A to be different from each other.

The number of sensors 16 located in each of the installation area a, the upstream area B, the nip area C, and the downstream area D may be different.

the medium feeding device 11 may be configured to return the medium 99 to the tray 17 by rotating the separation roller 25 in the reverse rotation direction when the double feed of the medium 99 may occur.

The sensor array 31 may be formed by a plurality of sensors 16 arranged at intervals in the conveying direction Y that coincides with the feeding direction.

The technical idea and the operational effects thereof grasped from the above-described embodiment and the modification will be described below.

Idea 1

A medium feeding device is characterized by comprising:

A feeding section that feeds a medium;

A sensor for detecting the medium,

The feeding section has a feeding roller and a separating roller,

The sensor is arranged in a plurality in a feeding direction of the medium to be fed, thereby forming a sensor column,

The sensor rows are arranged in two rows in the width direction of the medium to be fed such that the sensors overlap each other, and are configured to extend in the feeding direction over an upstream area located upstream of a nip point where the feeding roller and the separation roller contact each other, a nip area including the nip point, and a downstream area located downstream of the nip point.

According to this configuration, the skew of the medium can be detected in each of the upstream area, the nip area, and the downstream area. Therefore, the accuracy of detecting the skew can be improved.

Idea 2

The medium feeding apparatus according to idea 1, wherein,

The medium feeding device is provided with a setting guide for supporting the set medium,

The sensor row is configured to extend from an installation area located upstream of the upstream area to the downstream area in the feeding direction,

the sensor detects the medium supported by the setting guide at the setting area.

According to this configuration, the skew of the medium can be detected in the set area. That is, since the skew of the medium can be detected before feeding, the skew can be easily eliminated.

Idea 3

The medium feeding device according to idea 1 or 2, wherein the sensor array is located at a position that sandwiches the feeding portion in the width direction.

According to this configuration, since the interval between the sensor rows in the width direction is widened, the detection accuracy of the skew can be improved.

Idea 4

The medium feeding apparatus according to any one of idea 1 to idea 3, characterized in that,

The medium feeding device includes a double feed sensor that detects double feed of the medium fed by the feeding section,

The sensor column is located upstream of the overlapping feed sensor in the feeding direction.

according to this configuration, before the overlapped feeding of the medium is detected by the overlapped feeding sensor, the skew of the medium can be detected by the sensor.

Idea 5

The medium feeding device according to any one of idea 1 to idea 4, wherein two or more sensors are provided in each area.

according to this configuration, the accuracy of detecting the skew can be improved as compared with a case where one detection unit is provided in each region.

Idea 6

The medium feeding apparatus according to any one of ideas 1 to 5, characterized in that,

The medium feeding device is provided with an end sensor that detects the medium downstream of the downstream area in the feeding direction,

Changing to a first mode if the sensor in the downstream area does not detect the medium and a second mode if the sensor in the downstream area detects the medium when the end sensor changes from a state in which the medium is detected to a state in which the medium is not detected,

The second mode is a mode in which the separation roller that separates the medium has a larger separation force than the first mode.

When the end sensor changes from a state in which the medium is detected to a state in which the medium is not detected, it is known that the feeding of the medium is completed. At this time, when the sensor located in the downstream area does not detect the medium, it is known that the subsequent medium to the medium whose feeding has been completed does not reach the downstream area. On the other hand, in the case where the sensor located in the downstream area detects the medium, it is known that the subsequent medium to the medium whose feeding has been completed has been fed to the downstream area. In this case, there is a possibility that overlapping feeding of media occurs. In contrast, if the separation force of the separation roller that separates the media is increased, the possibility of double feeding in which a plurality of media are fed decreases. That is, according to the above configuration, when there is a possibility of double feed of media, double feed of media can be suppressed by using the second mode.

Idea 7

The medium feeding device according to any one of ideas 1 to 5, characterized in that,

The medium feeding device is provided with an end sensor that detects the medium downstream of the downstream area in the feeding direction,

Changing to a first mode if the sensor in the downstream area does not detect the medium, a second mode if a part of the sensors in the downstream area detect the medium, and a third mode if all the sensors in the downstream area detect the medium, when the end sensor changes from a state in which the medium is detected to a state in which the medium is not detected,

The second mode is a mode in which a separation force of the separation roller that separates the medium is larger than the first mode,

the third mode is a mode in which the separation roller that separates the medium has a larger separation force than the second mode.

when the end sensor changes from a state in which the medium is detected to a state in which the medium is not detected, it is known that the feeding of the medium is completed. At this time, when the sensor located in the downstream area does not detect the medium, it is known that the subsequent medium to the medium whose feeding has been completed does not reach the downstream area. On the other hand, in the case where a part of the sensors located in the downstream area detect the medium, it is known that the subsequent medium to the medium whose feeding has been completed has been fed to the downstream area. In this case, there is a possibility that overlapping feeding of media occurs. In addition, when all the sensors located in the downstream area detect the medium, there is a possibility that the medium subsequent to the medium whose feeding has been completed is fed downstream of the downstream area. In this case, the possibility of occurrence of overlapped feeding of media is high. In contrast, if the separation force of the separation roller that separates the media is increased, the possibility of double feeding in which a plurality of media are fed decreases. That is, according to the above configuration, when there is a possibility of double feed of media, double feed of media can be suppressed by using the second mode. When the possibility of double feed of media is high, the use of the third mode can suppress double feed of media.