JP2019142606A - Medium conveying device and image reading device - Google Patents

Abstract

To provide a medium conveying device capable of more properly detecting jamming by sound.SOLUTION: A medium conveying device 10 in a scanner 1 includes: a conveying part 9 for conveying a medium; a housing 2 internally having a medium conveying path R through which a sheet P conveyed by the conveying part 9 passes; detection means 30 for detecting a change in a value used for determining jamming caused on the sheet P in the medium conveying path R; and a control part 19 for controlling an operation of the conveying part 9. The detection means 30 includes: a first sound detection part 31 provided on the medium conveying path R to detect a sound; and a second sound detection part 32 provided outside the housing 2 to detect a sound. The control part 19 determines whether or not jamming is caused on the sheet P on the basis of a first sound signal corresponding to an intensity of a sound detected in the first sound detection part 31 and a second sound signal corresponding to an intensity of a sound detected in the second sound detection part 32 to control driving and stopping of the conveying part 9 on the basis of the determination results.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a medium conveying apparatus that conveys a medium, and an image reading apparatus that reads a medium conveyed by the medium conveying apparatus.

Some scanners, which are examples of image reading apparatuses, are equipped with a jam detection sensor for the purpose of detecting a jam of a medium conveyed toward a reading unit by a medium conveying apparatus.
In such a jam detection sensor, for example, as shown in Patent Document 1, a configuration in which occurrence of a jam is detected by a sound generated when the jam occurs (for example, a sound when a medium is crushed due to wrinkles) is detected. There are things.

JP 2014-43300 A

Here, in a jam detection sensor that detects the occurrence of a jam by sound, for example, if there is a loud sound generated around the installation location of the scanner, for example, a living sound (voice, footsteps, door opening / closing sound, etc.) In some cases, such ambient sounds were mistakenly detected as jams.
In addition, the sound at the time of occurrence of a jam is confused with the surrounding sound due to such surrounding sounds, and the occurrence of the jam may not be detected.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a medium conveying apparatus capable of more appropriately performing jam detection by sound, and an image reading apparatus including the medium conveying apparatus. It is in.

  In order to solve the above problems, a medium transport apparatus according to a first aspect of the present invention includes a transport unit that transports the medium toward a processing unit that performs processing on the medium, and a medium transported by the transport unit. A housing having a medium conveyance path therethrough, a detection means for detecting a change in a value used to determine whether the medium has jammed in the medium conveyance path, a control unit for controlling the operation of the conveyance unit, The detection means includes a first sound detection unit that is provided in the medium conveyance path and detects sound, and a second sound detection unit that is provided outside the housing and detects sound, The control unit includes a first sound signal corresponding to the sound intensity detected by the first sound detection unit, and a second sound signal corresponding to the sound intensity detected by the second sound detection unit. Based on the above, it is determined whether or not the medium jam has occurred. Hazuki controls and stopping the driving of the transport unit, characterized in that.

  According to this aspect, the control unit responds to the first sound signal corresponding to the sound intensity detected by the first sound detection unit and the sound intensity detected by the second sound detection unit. It is determined whether or not the medium has jammed based on the second sound signal, and the driving and stopping of the transport unit are controlled based on the determination result. It is possible to reduce the possibility of the conveyance operation being stopped due to erroneous detection by determining that the sound is a sound when a jam of the medium occurs.

  In the medium transport apparatus according to a second aspect of the present invention, in the first aspect, the control unit is configured such that the first sound signal exceeds a first threshold value and the second sound signal reaches a second threshold value. When it does not exceed, when it is determined that a jam has occurred and driving of the transport unit is stopped, the first sound signal exceeds a first threshold value, and the second sound signal exceeds a second threshold value And when the first sound signal does not exceed the first threshold value and the second sound signal does not exceed the second threshold value, it is determined that a jam has not occurred, and the conveyance unit is driven. It is characterized by that.

  According to this aspect, the control unit determines that a jam has occurred when the first sound signal exceeds the first threshold value and the second sound signal does not exceed the second threshold value, and the control unit determines that the jam has occurred. When the driving of the transport unit is stopped, the first sound signal exceeds the first threshold value, the second sound signal exceeds the second threshold value, and the first sound signal exceeds the first threshold value. If the second sound signal does not exceed the second threshold value, it is determined that a jam has not occurred, and the conveyance unit is driven, so that the effect of the first aspect is achieved.

  In the medium transport apparatus according to a third aspect of the present invention, in the first aspect, the control unit causes the jam to occur when a difference between the first sound signal and the second sound signal exceeds a predetermined threshold. When it is determined that the conveyance unit has been generated, the driving of the transport unit is stopped, and when the difference between the first sound signal and the second sound signal is equal to or less than a predetermined threshold, it is determined that no jam has occurred and The conveyance unit is driven.

  According to this aspect, when the difference between the first sound signal and the second sound signal exceeds a predetermined threshold, the control unit determines that a jam has occurred and stops driving the transport unit. When the difference between the first sound signal and the second sound signal is equal to or less than a predetermined threshold value, it is determined that a jam has not occurred, and the conveyance unit is driven to operate the first aspect. There is an effect.

  In the medium transport apparatus according to a fourth aspect of the present invention, in the first aspect, the control unit determines that the absolute value of the change amount of the difference between the first sound signal and the second sound signal is a predetermined threshold value. Is exceeded, the driving of the transport unit is stopped and the absolute value of the change amount of the difference between the first sound signal and the second sound signal is equal to or less than a predetermined threshold value. In this case, it is determined that a jam has not occurred, and the conveyance unit is driven.

  According to this aspect, the control unit determines that a jam has occurred when the absolute value of the change amount of the difference between the first sound signal and the second sound signal exceeds a predetermined threshold, and When the driving of the transport unit is stopped and the absolute value of the change amount of the difference between the first sound signal and the second sound signal is equal to or less than a predetermined threshold, it is determined that a jam has not occurred and the By driving the transport unit, the effect of the first aspect is achieved.

  A medium transport apparatus according to a fifth aspect of the present invention is the medium transport apparatus according to any one of the first to fourth aspects, wherein at least a part of the medium transport apparatus is exposed to the outside of the housing and is sent to the medium transport path. A medium placement unit on which the medium is placed, wherein the second sound detection unit is provided on a portion of the medium placement unit opposite to the side on which the medium is placed. And

According to this aspect, the second sound detection unit can be arranged such that the medium placement unit is located between the first sound detection unit and the second sound detection unit.
This makes it difficult for the second sound detection unit to detect the sound inside the housing, thereby further reducing the possibility of erroneous detection in the detection means.

  The medium transport apparatus according to a sixth aspect of the present invention is the medium transport device according to the fifth aspect, wherein the processing unit is provided inside the housing, and the transport unit is mounted on the medium mounting unit. It includes a feeding unit that feeds the medium toward the processing unit, and the first sound detection unit is provided between the feeding unit and the processing unit.

  According to this aspect, it is possible to more reliably detect the jam of the medium that has occurred in the medium conveyance path between the feeding unit and the processing unit. Further, it is possible to detect a jam that occurs before the processing unit processes the medium.

  In the medium carrying device according to a seventh aspect of the present invention, in any one of the first to sixth aspects, the first sound detection unit is disposed invisible from the outside of the housing, The second sound detection unit is arranged to be visible from the outside of the housing.

  According to this aspect, since the first sound detection unit is disposed so as not to be visually recognized from the outside of the casing, it is possible to make it difficult to be affected by a sound emitted outside the casing. In addition, since the second sound detection unit is disposed so as to be visible from the outside of the casing, it is possible to more reliably detect a sound emitted outside the casing. Accordingly, it is possible to improve the accuracy of determination as to whether or not a medium jam has occurred.

  An image reading apparatus according to an eighth aspect of the present invention includes: a reading unit that reads a medium; and the medium conveyance device according to any one of the first to seventh aspects that includes the reading unit as the processing unit. It is characterized by providing.

  According to this aspect, in the image reading apparatus including the reading unit that reads the medium, the same function and effect as any one of the first to seventh aspects can be obtained.

1 is an external perspective view showing a scanner according to the present invention. FIG. 3 is a side sectional view showing a medium conveyance path in the scanner according to the invention. 1 is a schematic sectional side view of a scanner according to the present invention. 1 is a block diagram illustrating a scanner according to the present invention. The figure which shows the state which both the 1st sound signal and the 2nd sound signal do not exceed the threshold value. The figure which shows the state in which both the 1st sound signal and the 2nd sound signal have exceeded the threshold value. The figure which shows the state in which only a 1st sound signal has exceeded the threshold value. The figure which shows the other example in the state where only the 1st sound signal has exceeded the threshold value. The flowchart which shows the flow of control of the conveyance part by the control part based on the detection result by a detection means.

[First Embodiment]
First, an outline of an image reading apparatus according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, as an example of the image reading apparatus, a document scanner 1 (hereinafter, simply referred to as a scanner 1) that can read at least one of the front and back surfaces of a sheet as a “medium” is given as an example.

  In the XYZ coordinate system shown in each figure, the X direction is the apparatus 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 orthogonal to the surface of the sheet being conveyed. Further, the + Y direction side is the front side of the apparatus, and the −Y direction side is the back side of the apparatus. Further, the left side when viewed from the front side of the apparatus is the + X direction, and the right side is the −X direction. Further, the + Z direction is the upper side of the apparatus (including the upper and upper surfaces), and the −Z direction side is the lower side of the apparatus (including the lower and lower surfaces). The direction in which the paper P is fed (+ Y direction side) is referred to as “downstream”, and the opposite direction (−Y direction side) is referred to as “upstream”.

■■■ Overview of scanner ■■■
Hereinafter, the scanner 1 according to the present invention will be described mainly with reference to FIGS. 1 and 2.
The scanner 1 includes a reading unit 20 illustrated in FIG. 2 as a “processing unit” that performs a reading process on a sheet (medium) conveyed along the medium conveyance path R.
The scanner 1 shown in FIG. 1 includes a medium transport device 10 that transports a sheet toward a reading unit 20.

  The medium transport apparatus 10 includes a housing 2 having therein a medium transport path R shown in FIG. 2 and a reading unit 20 (processing unit) that reads an image of a sheet P transported through the medium transport path R. . The medium transport path R will be described in detail after the outline of the scanner 1 is described.

  The housing 2 includes a lower unit 3 and an upper unit 4. The upper unit 4 is attached to the lower unit 3 so as to be openable and closable with the downstream side in the sheet conveyance direction as a rotation fulcrum, and the upper unit 4 is rotated and opened to the front side of the apparatus to expose the medium conveyance path R. It is configured so that paper jam processing can be easily performed.

On the back side of the apparatus, which is the −Y-axis direction side of the housing 2, a medium placement unit 11 on which the paper P to be sent to the medium conveyance path R is placed is provided. At least a part of the medium placement unit 11 is provided outside the housing 2. In the present embodiment, the medium placement unit 11 is provided so as to protrude from the apparatus rear side of the housing 2. The medium placement unit 11 according to the present embodiment can be rotated to the front side of the apparatus when the scanner 1 is not used, and can be used as a cover of the housing 2.
In addition to being able to place a bundle of sheets on which a plurality of sheets P are stacked, the medium placing unit 11 can place a booklet in which a plurality of sheets are formed into a booklet as a document. Reference numeral 11 a is a placement surface 11 a of the paper P.

In addition, the medium placement unit 11 is provided with a pair of left and right edge guides 12 each including a guide surface 13 that guides a side edge in the width direction (X-axis direction) intersecting the medium conveyance direction (+ Y direction).
The edge guides 12 and 12 are provided so as to be slidable in the X-axis direction according to the size of the paper P. In this embodiment, the edge guides 12 and 12 follow the X movement of one edge guide 12 (for example, the + X side) by a known rack and pinion mechanism, and the other edge guide 12 (the −X side) faces the other. Configured to move to.
In the medium loading unit 11, the paper P is aligned at the center in the width direction, and is configured to be fed by a so-called center paper feeding method by a later-described feed roller 14 provided in the center region in the width direction. ing.

  The medium loading unit 11 includes an auxiliary paper support 8. The auxiliary paper support 8 can be housed in the medium placement section 11 and can be pulled out from the medium placement section 11 as shown in FIG. 1 so that the length of the placement surface 11a can be adjusted. It has become.

As shown in FIG. 1, an operation panel 7 is provided on the front side of the upper unit 4 to display various reading settings, reading execution operations, reading setting contents, and the like.
The upper unit 4 is provided with a feeding port 6 connected to the inside of the housing 2, and the paper P placed on the medium loading unit 11 is fed from the feeding port 6 to the reading unit 20 shown in FIG. 2. Sent to.

Further, on the front side of the apparatus of the lower unit 3, a paper discharge tray 5 for discharging the paper P after being read by the reading unit 20 is provided.
The paper discharge tray 5 is provided in the lower unit 3 so that it can be pulled out from the discharge port 18 toward the front side of the apparatus. The paper discharge tray 5 can be in a state where it is housed in the bottom of the lower unit 3 as shown in FIG. 2, or in a state where it is pulled out to the front side of the apparatus as shown in FIG. In a state where the paper discharge tray 5 is pulled out, the paper P discharged from the discharge port 18 can be stacked on the paper discharge tray 5.

■■■ About the media transport path in the scanner ■■■
Hereinafter, the medium transport path R in the scanner 1 will be described while mainly describing the medium transport apparatus 10 with reference to FIG. Note that a dotted line indicated by a symbol P in FIG. 2 indicates the paper P that is transported along the medium transport path R.

  The medium transport apparatus 10 includes a transport unit 9 that transports paper. The transport unit 9 is provided in the medium transport path R inside the housing 2. In the present embodiment, the transport unit 9 includes a feeding roller 14, a separation roller 15, a first transport roller pair 16, and a second transport roller pair 17. The feeding roller 14 is a “feeding unit” that feeds the paper P placed on the medium placing unit 11 toward the reading unit 20.

The first transport roller pair 16 includes a first drive roller 16a and a first driven roller 16b. The second transport roller pair 17 includes a second drive roller 17a and a second driven roller 17b.
Further, the medium transport apparatus 10 includes a detection unit 30 that detects a change in a value used for determining whether or not a paper jam has occurred in the medium transport path R, and a control unit 19 that controls the operation of the transport unit 9. Yes.
The detection unit 30 and the control of the transport unit 9 by the control unit 19 based on the detection result of the detection unit 30 will be described in detail after describing the medium transport path R.

The medium transport path R is a path through which the paper P transported by the transport unit 9 passes, and overlaps the paper P indicated by a dotted line in FIG.
As shown in FIG. 3, the medium transport path R is a space sandwiched between the lower path surface R1 of the lower unit 3 and the upper path surface R2 of the upper unit 4.
The feeding roller 14, the first driving roller 16 a, and the second driving roller 17 a are provided to be rotatable with respect to the lower unit 3. In addition, the separation roller 15, the first driven roller 16 b, and the second driven roller 17 b provided at a position facing the feeding roller 14 are provided to be rotatable with respect to the upper unit 4.

The paper P placed on the medium placement unit 11 is sent toward the reading unit 20 by the feeding roller 14.
In FIG. 2, a separation roller 15 that nips the paper P with the feeding roller 14 to separate the paper P is provided at a position facing the feeding roller 14. The separation roller 15 is configured to be rotationally driven in a direction opposite to the paper feeding direction (counterclockwise direction in FIG. 2) by a second drive source 27 described later.
As described above, the feeding roller 14 is configured to feed paper by the center feeding method, and the feeding roller 14 and the separation roller 15 are in the medium width direction (X-axis direction) intersecting the medium transport direction (+ Y direction). In the central region.

A first transport roller pair 16 and a second transport roller pair 17 that transport the paper P fed by the feed roller 14 are provided on the downstream side of the feed roller 14.
A reading unit 20 is provided between the first transport roller pair 16 and the second transport roller pair 17.

  The paper P placed on the medium placement unit 11 is picked up by the feed roller 14 and fed downstream (+ Y direction side). Specifically, the sheet P is fed toward the downstream side by rotating while the feeding roller 14 is in contact with the surface of the sheet P facing the medium placement unit 11. Therefore, when a plurality of sheets P are set in the medium loading unit 11 in the scanner 1, the sheets are fed in order from the sheet P on the loading surface 11a side toward the downstream side.

  The first transport roller pair 16 is provided on the upstream side of the reading unit 20 and transports the paper P fed by the feeding roller 14 toward the reading unit 20. Similarly to the feeding roller 14, the first transport roller pair 16 is also provided in the center region in the medium width direction.

The reading unit 20 includes a first reading unit 20a provided on the upper unit 4 side and a second reading unit 20b provided on the lower unit 3 side. In the present embodiment, the first reading unit 20a and the second reading unit 20b are configured as a contact image sensor module (CISM) as an example.
The first reading unit 20a reads a front surface (surface facing upward) as the first surface of the paper P, and the second reading unit 20b is a back surface (second surface) opposite to the first surface ( Read the surface facing downward.

  The sheet P is nipped by the second conveying roller pair 17 located on the downstream side of the reading unit 20 after the image of at least one of the front surface and the back surface of the sheet P is read by the reading unit 20. It is discharged from a discharge port 18 provided on the front side of the lower unit 3.

As shown in FIG. 4, in the present embodiment, the feeding roller 14 is rotationally driven by a first drive source 26. Further, the separation roller 15, the first drive roller 16 a, and the second drive roller 17 a are rotationally driven by the second drive source 27. The first drive source 26 and the second drive source 27 are provided in the lower unit 3.
The first drive source 26 and the second drive source 27 are controlled by the control unit 19, so that the feeding roller 14, the separation roller 15, the first drive roller 16 a, and the second drive roller 17 a as the transport unit 9. Drive is controlled.

A plurality of medium detection units for detecting the paper P are provided in the medium conveyance path R shown in FIG.
For example, the first detection unit 22 that detects the presence or absence of the paper P placed on the medium placement unit 11 is located upstream of the feeding roller 14 and within the paper placement region of the medium placement unit 11. Is provided. Further, on the downstream side of the feeding roller 14, the downstream side of the first transport roller pair 16, and the downstream side of the second transport roller pair 17, the second detection unit 23, the third detection unit 24, and the first 4 detector 25 is provided. The position of the paper P in the medium feeding direction can be detected by the second detection unit 23 and the third detection unit 24.
Further, on the upstream side of the first transport roller pair 16, a double feed detection unit 28 that detects double feed in which a plurality of sheets P are transported in an overlapping manner is provided.

  As the 1st detection part 22, the 2nd detection part 23, the 3rd detection part 24, and the 4th detection part 25, the light emission part (illustration omitted) which emits light, and the reflected light of the light emitted from the said light emission part are used. An optical sensor including a light receiving unit (not shown) that receives light can be used. In addition to the optical sensor, it is also possible to use an ultrasonic sensor that includes a transmission unit that emits ultrasonic waves and a reception unit that is provided to face the transmission unit across a sheet to be conveyed. In addition, a lever type sensor that detects the displacement of the mechanical lever that is moved by the contact of the conveyed paper with an optical or electric contact type may be used. As the double feed detection unit 28, the above-described ultrasonic sensor can be used.

■■■ About detection means ■■■
The detection means 30 will be described with reference to FIGS.
The medium conveyance device 10 of the scanner 1 includes a detection unit 30 that detects a change in a value used to determine whether or not a paper P jam occurs in the medium conveyance path R. When a jam occurs, a sound is generated that the paper P is crushed or wrinkled. In the scanner 1, the control unit 19 determines whether or not a jam has occurred based on a change in sound volume.
The detection means 30 includes a first sound detection unit 31 that is provided in the medium transport path R and detects sound, and a second sound detection unit 32 that is provided outside the housing 2 and detects sound. .
Each of the first sound detection unit 31 and the second sound detection unit 32 includes a sound collection mechanism such as a microphone, and is configured to send a signal corresponding to the sound intensity to the control unit 19.
Hereinafter, a signal corresponding to the sound intensity detected by the first sound detector 31 is referred to as a first sound signal A1, and a signal corresponding to the sound intensity detected by the second sound detector 32 is referred to as a first sound signal A1. This is called a two-tone signal A2. The strengths of the first sound signal A1 and the second sound signal A2 increase or decrease corresponding to the increase or decrease of the sound intensity.

  Based on the difference between the sound detected by the first sound detection unit 31 (first sound signal) and the sound detected by the second sound detection unit 32 (second sound signal), In this configuration, the presence or absence of a jam of the paper P in the transport path R is detected. The detection of the jam by the detection unit 30 will be described later together with the control of the transport unit 9 by the control unit 19 based on the detection result of the detection unit 30.

In the present embodiment, the first sound detection unit 31 is provided between the feeding roller 14 (feeding unit) and the reading unit 20 (processing unit) in the medium transport direction.
More specifically, the first sound detection unit 31 is provided between the feeding roller 14 and the first conveyance roller pair 16 provided on the upstream side of the reading unit 20 in the medium conveyance direction, It is provided at a position close to the roller 14.
As in the present embodiment, the first sound detection unit 31 is provided immediately downstream of the feeding roller 14, and thus occurs in the medium conveyance path R between the feeding roller 14 and the reading unit 20. The jam sound of the paper P can be detected more reliably. Therefore, it is possible to easily detect a jam that occurs before the reading unit 20 reads the paper P.

  It is desirable that the first sound detection unit 31 is provided in the vicinity of a portion where the jam of the paper P is likely to occur in the medium conveyance path R. For example, since the interval between the first reading unit 20a and the second reading unit 20b is set narrow in order to improve the reading image quality in the reading unit 20, the sheet P is between the first reading unit 20a and the second reading unit 20b. Jam may occur when entering. In order to detect a jam around the reading unit 20, the first sound detection unit 31 may be provided between the first transport roller pair 16 and the reading unit 20.

The second sound detection unit 32 is provided in a portion of the medium placement unit 11 opposite to the side on which the paper P is placed. In other words, the second sound detection unit 32 is provided on the side of the surface 11 b opposite to the placement surface 11 a in the medium placement unit 11.
The second sound detection unit 32 may be provided outside the housing 2 and may be provided on the placement surface 11a side. It can also be provided on the housing 2 itself. When providing the 2nd sound detection part 32 in the housing | casing 2, it is good to provide in a back surface or a side surface, for example. Of course, it can also be provided on the front side.

■■■ About the control of the transport unit by the control unit based on the detection result of the detection means ■■■
Hereinafter, the detection of the jam by the detection unit 30 and the control of the transport unit 9 by the control unit 19 based on the detection result of the detection unit 30 will be described.
The control unit 19 that controls the operation of the transport unit 9 includes the first sound signal A1 corresponding to the sound intensity detected by the first sound detection unit 31 and the sound intensity detected by the second sound detection unit 32. Based on the second sound signal A2 corresponding to the above, it is determined whether or not a jam of the paper P has occurred, and based on the determination result of the detection means 30, the drive and stop of the transport unit 9 are controlled.

When the jam of the paper P occurs, the first sound detection unit 31 provided in the medium conveyance path R detects a sound (such as a sound when the paper is crushed due to a wrinkle) that is generated due to the occurrence of the jam.
However, if a jam is determined based only on the sound detected by the first sound detection unit 31, sounds generated around the installation location of the scanner 1, for example, living sounds such as voices and footsteps, are detected. It may be erroneously detected as occurring. In addition, there are cases where the sound at the time of jam occurrence is drowned out by such surrounding sounds and the jam cannot be detected.
In the present embodiment, the first sound signal A1 corresponding to the intensity of the sound detected by the first sound detection unit 31 and the sound detected by the second sound detection unit 32 provided outside the housing 2 are used. By referring to the second sound signal A2 corresponding to the intensity of the sound, it is possible to suppress the surrounding sound from affecting the detection of the jam by the detecting means 30.

  More specifically, a predetermined threshold is set for each of the first sound signal A1 and the second sound signal A2. The first threshold value A1max with respect to the first sound signal A1 does not exceed when the paper P is normally conveyed, and exceeds a value when a sound generated due to the occurrence of a jam occurs. The second threshold value A2max with respect to the second sound signal A2 does not exceed the normal state of the installation environment of the scanner 1, and is, for example, a value that exceeds when a sudden life sound (door opening / closing sound or talking voice) is emitted. It is.

When the first sound signal A1 exceeds the first threshold A1max and the second sound signal A2 exceeds the second threshold A2max as shown in FIG. 6, and as shown in FIG. When the first sound signal A1 does not exceed the first threshold value A1max and the second sound signal A2 does not exceed the second threshold value A2max, it is determined that no jam has occurred and the transport unit 9 is driven.
5 to 7 show changes in the intensity of the first sound signal A1 and the second sound signal A2 when a plurality of sheets P are read.
When the environment around the scanner 1 is quiet, the first sound detection unit 31 that easily picks up the sound of the drive system inside the housing 2 is larger than the second sound detection unit 32 outside the housing 2. Since there is a tendency to detect sound, in FIGS. 5 to 7, the first threshold A1max is set to a value higher than the second threshold A2max.

  When reading of the paper P by the scanner 1 is started, the driving sound of the driving source (the first driving source 26 and the second driving source 27) that drives the transport unit 9, the rotational sound of each roller constituting the transport unit 9, and the paper P However, if reading is performed with normal conveyance, as shown in FIG. 5, the first sound signal A1 and the second sound signal A2 are the first threshold values that are the respective threshold values. It changes with a weaker intensity than the threshold value A1max and the second threshold value A2max.

Hereinafter, control by the control part 19 is demonstrated along the flowchart shown in FIG.
After the start of conveyance, in step S1, the control unit 19 determines whether at least one of the first sound signal A1 and the second sound signal A2 exceeds a threshold value.
If NO in step S1, that is, if the first sound signal A1 does not exceed the first threshold value A1max and the second sound signal A2 does not exceed the second threshold value A2max (as shown in FIG. 5). Since no sound is generated due to the occurrence of a jam, the process proceeds to step S2, and it is determined that no jam has occurred.
Since no jam has occurred, the control unit 19 continues to drive the transport unit 9 in step S3.

If YES in step S1, the process proceeds to step S4 to refer to which of the first sound signal A1 and the second sound signal A2 exceeds the corresponding threshold value.
When the first sound signal A1 exceeds the first threshold A1max and the second sound signal A2 also exceeds the second threshold A2max (as shown in FIG. 6), that is, the first sound signal A1 and the second sound When both of the signals A2 exceed the respective thresholds, it is considered that the first sound detection unit 31 has detected the sound around the scanner 1. Therefore, the process proceeds to step S2 and it is determined that no jam has occurred.

On the other hand, in step S4, when the first sound signal A1 exceeds the first threshold A1max and the second sound signal A2 does not exceed the second threshold A2max (as shown in FIG. 7), that is, the first sound When only the signal A1 exceeds the first threshold value A1max, the second sound detection unit 32 outside the housing 2 has not detected a loud sound exceeding the second threshold value A2max. Since it is considered that the surrounding sound is unlikely to affect the first sound detection unit 31 inside the housing 2, it is considered that the first sound detection unit 31 has detected a sound generated when a jam occurs. Accordingly, the process proceeds to step S5, and it is determined that a jam has occurred.
When the occurrence of a jam is detected by the detection unit 30, the process proceeds to step S6, and the control unit 19 stops driving the transport unit 9.

  In this way, the control unit 19 responds to the first sound signal A1 corresponding to the sound intensity detected by the first sound detection unit 31 and the sound intensity detected by the second sound detection unit 32. Based on the second sound signal A2, it is determined whether or not a jam of the paper P has occurred, and based on the determination result, the driving and stopping of the transport unit 9 are controlled, so that the outside of the housing 2 is controlled. It is possible to reduce misdetection caused by judging the generated sound as the sound when the jam of the paper P occurs, and to appropriately detect the jam.

In this embodiment, in step S4, the determination is not made when the first sound signal A1 does not exceed the first threshold A1max and the second sound signal A2 exceeds the second threshold A2max.
When only the second sound signal A2 exceeds the second threshold value A2max, it can be said that the sound at the time of occurrence of the jam is not detected in the first sound detection unit 31 inside the housing 2, and therefore it is determined that no jam occurs. it can.
However, since the ambient sound that usually affects the sound detection of the first sound detection unit 31 is larger than the sound when the paper P is jammed, such ambient sound is generated. In many cases, not only the second sound signal A2 but also both the first sound signal A1 and the second sound signal A2 exceed the respective threshold values. For this reason, the determination when only the second sound signal A2 exceeds the second threshold A2max in step S4 is omitted.

  Further, when the scanner 1 is installed in an environment where ambient sounds are louder than usual, as shown in FIG. 8, the second threshold A2max should be set to a value higher than the first threshold A1max. You can also. FIG. 8 shows a state in which only the first sound signal A1 exceeds the first threshold value A1max, as in FIG.

In the example of FIG. 6, when the first sound signal A1 exceeds the first threshold value A1max and the second sound signal A2 exceeds the second threshold value A2max, it is determined that no jam has occurred. This is based on the fact that the first sound detection unit 31 and the second sound detection unit 32 pick up external sounds simultaneously.
Here, there is a possibility that the timing at which the jam of the paper P occurs and the timing at which the sound is generated outside the scanner 1 are almost the same. In this case, the first sound signal A1 is also generated. Although the first threshold value A1max is exceeded and the second sound signal A2 exceeds the second threshold value A2max, it can be said that there is almost no possibility that the jammed sound and the external sound are generated at the same timing.
Therefore, in the example of FIG. 6, a threshold is set as a time difference between the timing at which the first sound signal A1 exceeds the first threshold A1max and the timing at which the second sound signal A2 exceeds the second threshold A2max. If it is less than the threshold value, that is, if the timing at which the first sound signal A1 exceeds the first threshold value A1max and the timing at which the second sound signal A2 exceeds the second threshold value A2max are almost simultaneous, a jam occurs. If the time difference exceeds a threshold value, that is, if the time difference is long, it may be determined that a jam has occurred. For example, the threshold value may be less than 1 second.

Next, a series of controls by the control unit 19 based on the detection result of the detection unit 30 will be described from another viewpoint.
When the difference T between the first sound signal A1 and the second sound signal A2 exceeds a predetermined threshold, the control unit 19 determines that a jam has occurred, stops the driving of the transport unit 9, and stops the first sound signal. When the difference T between A1 and the second sound signal A2 is equal to or less than a predetermined threshold, it is determined that no jam has occurred, and the transport unit 9 is driven.

5 to 8, T1 to T5 represent the difference between the first sound signal A1 and the second sound signal A2 when reading the first to fifth sheets.
As shown in FIG. 5, when both the first sound detection unit 31 and the second sound detection unit 32 detect neither a sound at the time of jam occurrence nor an ambient sound, the first sound signal A1 and the second sound signal A2 The difference T is less than or equal to a predetermined threshold value. Further, as shown in FIG. 6, when both the first sound detection unit 31 and the second sound detection unit 32 detect surrounding sounds, one sound detection unit (for example, the first sound detection unit 31). Since the intensity of the sound detected by the above changes so as to follow the change in the intensity of the sound detected by the other (for example, the second sound detector 32), the first sound signal A1 and the second sound signal are also changed in this case. The difference T from the sound signal A2 becomes a predetermined threshold value or less.

  On the other hand, when a jam occurs and only the first sound signal A1 changes greatly as shown in FIG. 7, the difference T (T5 in FIG. 7) between the first sound signal A1 and the second sound signal A2 increases. As described above, when the difference T greatly changes and exceeds a predetermined threshold value, the control unit 19 determines that the jam of the paper P has occurred, and stops the transport unit 9.

  As described above, the control unit 19 determines that a jam has occurred when the difference T between the first sound signal A1 and the second sound signal A2 exceeds a predetermined threshold value, and stops driving the transport unit 9. When the difference T between the first sound signal A1 and the second sound signal A2 is equal to or smaller than a predetermined threshold value, it is determined that no jam has occurred, and the conveyance unit 9 is driven to thereby jam the paper P. The paper P can be appropriately conveyed by detection.

  Further, the control unit 19 determines that a jam has occurred when the absolute value | ΔT | of the change amount ΔT of the difference T between the first sound signal A1 and the second sound signal A2 exceeds a predetermined threshold value. The jamming has occurred when the driving of the transport unit 9 is stopped and the absolute value | ΔT | of the change amount ΔT of the difference T between the first sound signal A1 and the second sound signal A2 is equal to or less than a predetermined threshold value. The conveyance unit 9 may be driven by determining that there is no.

As shown in FIG. 5 and FIG. 6, when both the first sound detection unit 31 and the second sound detection unit 32 do not detect the sound at the time of occurrence of the jam and the surrounding sound, the first sound detection unit 31 and the second sound detection unit 32 When both the sound detectors 32 detect ambient sounds, the differences T1 to T5 between the first sound signal A1 and the second sound signal A2 when reading the first to fifth sheets are as follows. Almost no change. Therefore, for example, the absolute value | ΔT | = | T5−T4 | of the difference T of the difference T when the fourth sheet reading is shifted to the fifth sheet reading becomes a small value.
Therefore, when the absolute value | ΔT | of the change amount ΔT of the difference T between the first sound signal A1 and the second sound signal A2 is equal to or less than a predetermined threshold value, it is determined that no jam has occurred and the transport unit 9 is driven.

On the other hand, when a jam occurs and only the first sound signal A1 changes greatly as shown in FIG. 7, the difference T (T5 in FIG. 7) between the first sound signal A1 and the second sound signal A2 is larger than before. Also grows.
In addition, since the scanner 1 is installed in an environment where ambient sounds are louder than usual, as shown in FIG. 8, the second threshold A2max is set to a value higher than the first threshold A1max. The difference T (T5 in FIG. 8) between the first sound signal A1 and the second sound signal A2 is smaller than before.
Therefore, the absolute value | ΔT | = | T5-T4 | of the change amount ΔT = T5-T4 of the difference T when the reading from the fourth sheet shifts to the fifth sheet reading becomes a large value.
Therefore, if the absolute value | ΔT | of the change amount ΔT of the difference T between the first sound signal A1 and the second sound signal A2 exceeds a predetermined threshold value, it is determined that a jam has occurred and the transport unit 9 is driven. To stop.
Accordingly, it is possible to detect the jam of the paper P and appropriately transport the paper P.

  In the present embodiment, the second sound detection unit 32 is disposed on the opposite surface 11 b of the medium placement unit 11, so that the first sound detection unit 31 and the second sound detection unit 32 are interposed. Since the medium placement unit 11 is located, it is difficult for the second sound detection unit 32 to detect the sound inside the housing 2. Therefore, the possibility of erroneous detection in the detection means 30 can be further reduced.

Further, as described above, the first sound detection unit 31 is provided in the medium conveyance path R on the downstream side of the feeding roller 14, and the second sound detection unit 32 is provided on the placement surface of the medium placement unit 11. It is provided on the opposite surface 11b of 11a.
That is, the first sound detection unit 31 is disposed so as not to be visible from the outside of the housing 2, and the second sound detection unit 32 is disposed so as to be visible from the outside of the housing 2.
Since the first sound detection unit 31 is disposed so as not to be visible from the outside of the housing 2, it is possible to make the first sound detection unit 31 less susceptible to the sound emitted outside the housing 2. In addition, since the second sound detection unit 32 is disposed so as to be visible from the outside of the housing 2, it is possible to more reliably detect a sound emitted outside the housing 2. Accordingly, it is possible to increase the accuracy of the determination by the determination unit as to whether or not the medium has jammed.

  In addition, the present invention is not limited to the above-described 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.

  For example, the medium conveying apparatus 10 described above can be mounted not only on the image reading apparatus but also on other apparatuses. As an example, it may be provided in a recording apparatus that records on a conveyed paper (medium).

DESCRIPTION OF SYMBOLS 1 ... Document scanner (image reading apparatus), 2 ... Housing | casing, 3 ... Lower unit, 4 ... Upper unit, 5 ... Discharge tray, 6 ... Feeding port, 7 ... Operation panel, 8 ... Auxiliary paper support, 9 ... Conveying unit, 10 ... medium conveying device, 11 ... medium placing unit, 11a ... mounting surface, 12 ... edge guide, 13 ... guide surface, 14 ... feed roller, 15 ... separating roller, 16 ... first conveying roller pair , 16a ... first driving roller, 16b ... first driven roller, 17 ... second transport roller pair, 17a ... second driving roller, 17b ... second driven roller, 18 ... discharge port, 19 ... control unit, 20 ... reading (Processing unit), 20a ... first reading unit, 20b ... second reading unit, 22 ... first detection unit, 23 ... second detection unit, 24 ... third detection unit, 25 ... fourth detection unit, 26 ... 1st drive source, 27 ... 2nd drive source, 28 ... Heavy Detector, 30 ... detection unit, 31 ... first sound detector, 32 ... second sound detector, P ... paper (medium)

Claims (8)

A transport unit that transports the medium toward a processing unit that performs processing on the medium;
A housing having therein a medium transport path through which the medium transported by the transport section passes;
Detecting means for detecting a change in a value used for judging occurrence of jam of the medium in the medium conveying path;
A control unit for controlling the operation of the transport unit,
The detection means includes
A first sound detection unit provided in the medium conveyance path for detecting sound;
A second sound detector provided on the outside of the housing for detecting sound,
The controller is
Based on the first sound signal corresponding to the sound intensity detected in the first sound detection unit and the second sound signal corresponding to the sound intensity detected in the second sound detection unit, It is determined whether or not a medium jam has occurred, and based on the determination result, the driving and stopping of the transport unit are controlled.
A medium conveying apparatus characterized by the above. The medium conveying apparatus according to claim 1,
The controller is
When the first sound signal exceeds the first threshold and the second sound signal does not exceed the second threshold, it is determined that a jam has occurred, and the driving of the transport unit is stopped.
When the first sound signal exceeds a first threshold and the second sound signal exceeds a second threshold, and when the first sound signal does not exceed the first threshold, the second sound signal Is not exceeding the second threshold, it is determined that a jam has not occurred, and the conveyance unit is driven.
A medium conveying apparatus characterized by the above. The medium conveying apparatus according to claim 1,
The controller is
When the difference between the first sound signal and the second sound signal exceeds a predetermined threshold, it is determined that a jam has occurred, and driving of the transport unit is stopped.
When the difference between the first sound signal and the second sound signal is equal to or less than a predetermined threshold value, it is determined that a jam has not occurred, and the transport unit is driven.
A medium conveying apparatus characterized by the above. The medium conveying apparatus according to claim 1,
The controller is
When the absolute value of the change amount of the difference between the first sound signal and the second sound signal exceeds a predetermined threshold, it is determined that a jam has occurred, and the driving of the transport unit is stopped.
When the absolute value of the change amount of the difference between the first sound signal and the second sound signal is equal to or less than a predetermined threshold value, it is determined that no jam has occurred, and the conveyance unit is driven.
A medium conveying apparatus characterized by the above. In the medium conveying apparatus as described in any one of Claims 1-4,
A medium mounting portion on which at least a part is exposed outside the housing and on which the medium sent to the medium transport path is mounted;
The second sound detection unit is provided in a portion of the medium placement unit opposite to the side on which the medium is placed.
A medium conveying apparatus characterized by the above. The medium conveying apparatus according to claim 5, wherein
The processing unit is provided inside the housing,
The transport unit includes a feeding unit that feeds the medium placed on the medium placing unit toward the processing unit,
The first sound detection unit is provided between the feeding unit and the processing unit.
A medium conveying apparatus characterized by the above. In the medium conveying apparatus as described in any one of Claims 1-6,
The first sound detection unit is disposed invisible from the outside of the housing,
The second sound detection unit is disposed so as to be visible from the outside of the housing.
A medium conveying apparatus characterized by the above. A reading unit for reading a medium;
The medium conveying device according to any one of claims 1 to 7, comprising the reading unit as the processing unit.
An image reading apparatus.

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