JP2016140038A - Medium conveyance device, image forming apparatus, and image processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide means that detects the size of a medium to be conveyed with a simple configuration.SOLUTION: A medium conveyance device comprises: a guide part that is arranged movably relative to a medium mounting part to regulate the position of media mounted on the medium mounting part; a paper feeding part that feeds the media mounted on the medium mounting part; a multi-feeding detection part that detects multi-feeding of the media fed on the downstream side of the paper feeding part in the direction of conveyance of the media; and a medium size detection member that is arranged at a position facing the multi-feeding detection part and operates in conjunction with the movement of the guide part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a medium conveying apparatus, an image forming apparatus, and an image processing apparatus for conveying a medium.

  A conventional medium transport apparatus feeds a medium such as a document by a paper feed unit and transports the fed medium by a transport unit (see, for example, Patent Document 1).

JP 2011-66707 A

However, in the conventional technique, it is required to detect the size of a medium conveyed with a simple configuration.
An object of the present invention is to detect the size of a medium conveyed with a simple configuration.

  Therefore, the present invention provides a guide unit that is movably arranged with respect to the medium mounting unit and regulates the position of the medium mounted on the medium mounting unit, and a medium mounted on the medium mounting unit At a position opposite to the double feed detection unit, a double feed detection unit for detecting double feed of the medium fed downstream of the paper feed unit in the medium conveyance direction, and a double feed detection unit. And a medium size detecting member that is arranged and operates in conjunction with the movement of the guide portion.

  The present invention thus configured has the effect of being able to detect the size of the medium conveyed with a simple configuration.

Explanatory drawing which shows the structure of the scanner part in an Example Explanatory drawing which shows the structure of the image forming apparatus in an Example. Explanatory drawing which shows the structure of the paper width detection sensor in an Example. Explanatory drawing which shows the structure of the paper width detection mechanism in an Example. Sectional view of the paper width detection disk in the embodiment Flowchart showing the flow of document reading processing in the embodiment Explanatory drawing of the output waveform of the paper width detection sensor in the embodiment Explanatory drawing of the output waveform of the paper width detection sensor in the embodiment Explanatory drawing which shows the structure of the paper width detection sensor in a modification.

  Hereinafter, embodiments of a medium conveying device, an image forming apparatus, and an image processing apparatus according to the present invention will be described with reference to the drawings.

FIG. 2 is an explanatory diagram illustrating a configuration of the image forming apparatus in the embodiment.
2, the image forming apparatus 1 includes a medium conveying device that conveys a document 11 as a medium, a scanner unit 2 that reads an image of the conveyed document 11, and a printer unit that prints image data on a medium such as paper. 3, for example, a multi-function peripheral (MFP). The scanner unit 2 includes an operation panel 31 having a display, a touch panel, and the like.

FIG. 1 is an explanatory diagram illustrating a configuration of a scanner unit in the embodiment.
In FIG. 1, the scanner unit 2 includes a document tray 13, a document paper guide 12, a paper feed roller 14, a double feed detection sensor 15, a medium width detection disk 17, a transport roller 18, a scanner 19, The reflector 20, the discharge roller 22, and the discharge tray 23 are included.
In the scanner unit 2, the document tray 13, the document sheet guide 12, the paper feed roller 14, the double feed detection sensor 15, the medium width detection disk 17, and the transport roller 18 constitute a medium transport device.

A document tray 13 serving as a medium placement unit is for placing and storing the document 11.
An original paper guide 12 serving as a guide and a side guide is disposed so as to be movable in the width direction of the medium with respect to the original tray 13 and regulates the position of the medium 11 placed on the original tray 13. . The document sheet guide 12 regulates and guides both end portions in a direction (width direction of the document 11) orthogonal to the transport direction of the document 11 placed on the document tray 13.

A paper feed roller 14 serving as a paper feed unit is placed on the document tray 13, abuts on the stored document 11, and rotates to feed the document 11 one by one.
In this embodiment, the document tray 13, the document sheet guide 12, and the sheet feed roller 14 constitute an ADF (Auto Document Feeder).
The double feed detection sensor 15 serving as a double feed detection unit overlaps a plurality of documents 11 fed by the paper feed roller 14 on the downstream side of the paper feed roller 14 in the conveyance direction of the document 11 indicated by an arrow A in the drawing. This is a sensor that detects the double feed being transported and detects the size (width) of the document 11 placed on the document tray 13, and is composed of, for example, an ultrasonic sensor.

In this embodiment, the double feed detection sensor 15 includes an ultrasonic sensor transmission unit 15a as a transmission unit that transmits a signal and an ultrasonic sensor reception unit 15b as a reception unit that receives a signal transmitted by the transmission unit 15a. They are arranged to face each other.
A medium width detection disk 17 as a medium size detection member is disposed at a position facing the double feed detection sensor 15 and operates in conjunction with the movement of the document sheet guide 12. This medium width detection disk 17 is rotatably arranged on a line connecting the ultrasonic sensor transmitter 15a and the ultrasonic sensor receiver 15b between the ultrasonic sensor transmitter 15a and the ultrasonic sensor receiver 15b. The plate thickness is formed with a different thickness for each predetermined angle in the rotation direction.

The medium width detecting disk 17 is preferably formed of a resin member. In the present embodiment, the ultrasonic sensor transmission unit 15a and the ultrasonic sensor reception unit 15b are used as the double feed detection sensor 15. However, for example, if the medium width detection disk 17 is formed of metal, the ultrasonic wave is not transmitted. For this reason, the ultrasonic wave from the ultrasonic sensor transmitter 15a cannot be received by the ultrasonic sensor receiver 15b. Therefore, the medium width detecting disk 17 is preferably formed of a resin member having a characteristic of transmitting ultrasonic waves.
A conveyance roller 18 as a conveyance unit is disposed downstream of the paper feed roller 14 and the double feed detection sensor 15 in the document conveyance direction indicated by an arrow A in the drawing, and conveys the original 11 fed by the paper feed roller 14. It is.

The scanner 19 is a sensor that is disposed downstream of the conveyance roller 18 in the document conveyance direction and reads an image of the document 11 conveyed by the conveyance roller 18. In this embodiment, the document 11 is composed of a light emitting unit 19a that irradiates light and a light receiving unit 19b that receives the light.
The reflection plate 20 is disposed so as to face the scanner 19 with the conveyance path of the document 11 interposed therebetween, and reflects light emitted from the light emitting unit 19 a of the scanner 19. Therefore, the light receiving unit 19 b of the scanner 19 receives light reflected from the reflecting plate 20 and the document 11.
The discharge roller 22 is disposed downstream of the scanner 19 in the document transport direction, and discharges the document 11 read by the scanner 19.

The discharge tray 23 is disposed downstream of the discharge roller 22 in the document conveyance direction, and accommodates the document 11 discharged by the discharge roller 22.
The scanner unit 2 configured as described above includes a control unit configured by a CPU (Central Processing Unit) and a storage unit configured by a memory and the like, and is controlled according to a control program (software) stored in the storage unit. The operation of the entire scanner unit 2 is controlled by the unit.

FIG. 3 is an explanatory diagram showing the configuration of the paper width detection sensor in the embodiment.
In FIG. 3, the double feed detection sensor 15 includes an ultrasonic sensor transmission unit 15a and an ultrasonic sensor reception unit 15b, which are an upper conveyance guide member 30a as a first conveyance guide and a lower side as a second conveyance guide. They are arranged opposite to each other with the conveyance guide member 30b interposed therebetween.
The upper conveyance guide member 30a and the lower conveyance guide member 30b pass through the conveyance path of the document 11 conveyed in the document conveyance direction indicated by the arrow A in the figure between the paper feed roller 14 and the conveyance roller 18 shown in FIG. It is a member to be formed, and is arranged to face each other at a predetermined distance.

The upper transport guide member 30a guides the upper surface side (first surface side) of the document 11 transported in the document transport direction indicated by the arrow A in the figure, and the lower transport guide member 30b is the lower surface side (first surface side). The second surface side that is the opposite surface) is guided.
Here, the upper conveyance guide member 30a and the lower conveyance guide member 30b are preferably formed of a resin material in order to reduce attenuation of ultrasonic waves. Further, in order to reduce the attenuation of ultrasonic waves by the upper conveyance guide member 30a and the lower conveyance guide member 30b, an opening 31a as a through hole is formed at a position facing the ultrasonic sensor transmission unit 15a of the upper conveyance guide member 30a. Is preferably provided. Similarly, it is preferable to provide an opening 31b as a through hole at a position facing the ultrasonic sensor receiver 15b of the lower conveyance guide member 30b.

The rotation center 17a as the rotation axis of the medium width detection disk 17 is arranged so as not to coincide with a line connecting the ultrasonic sensor transmission unit 15a and the ultrasonic sensor reception unit 15b. The disc portion 17b is disposed between the ultrasonic sensor transmitter 15a and the ultrasonic sensor receiver 15b, that is, on the extension connecting the opening 31a and the opening 31b.
Thus, in this embodiment, in the direction from the ultrasonic sensor transmitter 15a to the ultrasonic sensor receiver 15b, the ultrasonic sensor transmitter 15a, the upper conveyance guide member 30a, the lower conveyance guide member 30b, and the medium The width detection disk 17 and the ultrasonic sensor receiver 15b are arranged in this order.

  In this embodiment, the ultrasonic sensor transmission unit 15a is arranged on the upper conveyance guide member 30a side, and the ultrasonic sensor reception unit 15b is arranged on the lower conveyance guide member 30b side. Instead, as in the modification shown in FIG. 9, the ultrasonic sensor transmission unit 15a is arranged on the lower conveyance guide member 30b side, and the ultrasonic sensor reception unit 15b is arranged on the upper conveyance guide member 30a side. Also good.

That is, in the direction from the ultrasonic sensor transmitter 15a to the ultrasonic sensor receiver 15b, the ultrasonic sensor transmitter 15a, the medium width detection disk 17, the lower conveyance guide member 30b, the upper conveyance guide member 30a, You may make it arrange | position in order of the sound wave sensor receiving part 15b.
FIG. 4 is an explanatory diagram showing the configuration of the paper width detection mechanism in the embodiment. 4 is a view of the original paper guide 12 and the medium width detecting disk 17 of the scanner unit 2 shown in FIG. 1 as viewed from above (the direction in which the rotation center 17a extends). In FIG. 4, the upper conveyance guide member 30a and the lower conveyance guide member 30b shown in FIG. 3 are omitted.

In FIG. 4, the paper width detection mechanism 10 includes a document paper guide 12 (12a, 12b), a double feed detection sensor 15, a medium width detection disk 17, a belt 24 (24a, 24b), a gear 25, And pulleys 26a and 26b.
The document sheet guide 12 includes a right document sheet guide 12a that contacts the right end portion of the document in the document transport direction indicated by arrow A in the figure, and a left document sheet guide 12b that contacts the left end section of the document. It is configured to be movable in the document width direction indicated by an arrow B in the drawing orthogonal to the document conveyance direction indicated by A.

A rack 121a as a right sliding member extending in the document width direction indicated by arrow B in the figure is attached to the right document sheet guide 12a, and a document width direction indicated by arrow B in the figure is attached to the left document sheet guide 12b. A rack 121b as a left sliding member extending in the direction is attached, and the right sliding member 121a and the left sliding member 121b are arranged with a predetermined interval in the medium transport direction.
Teeth that mesh with the gear 25 are formed on the surface of the right sliding member 121a on the left sliding member 121b side. Further, teeth that mesh with the gear 25 are formed on the surface of the left sliding member 121b on the right sliding member 121a side.

The belt 24 (24a, 24b), the gear 25, and the pulleys 26a, 26b as power transmission members connect the original paper guide 12 (12a, 12b) and the medium width detecting disk 17 to the original paper guide 12 ( 12a, 12b) is transmitted to the medium width detecting disk 17, and the original moves in a direction (direction indicated by arrow B in the figure) perpendicular to the medium conveyance direction (direction indicated by arrow A in the figure). The power of the paper guide 12 (12a, 12b) is transmitted as the power of the rotational movement of the medium width detecting disk 17.
The gear 25 is disposed between the right sliding member 121a and the left sliding member 121b, and is rotatably disposed so as to mesh with both teeth formed on the right sliding member 121a and the left sliding member 121b. Has been.

Therefore, if the right document sheet guide 12a and the left document sheet guide 12b are moved so as to contact both ends of the document in the direction orthogonal to the document conveyance direction (the direction indicated by the arrow B in the figure), the gear is moved along with the movement. 25 is configured to rotate. A pulley 26 b is formed coaxially with the gear 25 so as to rotate integrally with the gear 25.
The pulley 26b is connected to the pulley 26a via the belt 24a, and the pulley 26a is connected to the rotating shaft 17a of the medium width detecting disk 17 via the belt 24b.
Therefore, the medium width detecting disk 17 rotates in the same direction as the gear 25 as the gear 25 rotates by the movement of the right original paper guide 12a and the left original paper guide 12b.

  The medium width detection disk 17 has a disk portion 17b formed around the rotation shaft 17a. The disc portion 17b is formed such that the plate thickness changes every predetermined angle in the rotation direction around the rotation shaft 17a. In the present embodiment, the disc portion 17b is formed with a plurality of different plate thicknesses in the rotation direction, for example, plate thicknesses of six stages of plate thicknesses 171 to 176, and plate thickness 171 <plate thickness 172 <plate thickness 173 <plate thickness. 174 <plate thickness 175 <plate thickness 176. In addition, plate | board thickness is not restricted to 6 steps, You may form in 5 steps or less or 7 steps or more.

The sheet width detection mechanism 10 configured as described above detects the medium width along with the movement of the document sheet guide 12 (12a, 12b) when the document sheet guide 12 (12a, 12b) is moved according to the width of the document. The disc 17 rotates, and the disc portion 17b of the medium width detecting disc 17 having a thickness corresponding to the width of the document moves to a position where it is detected by the double feed detection sensor 15.
In this embodiment, the thickness of the disk portion 17b of the medium width detecting disk 17 is increased as the width of the document is increased.

FIG. 5 is a cross-sectional view of the paper width detection disk in the embodiment, and is a CC cross-sectional view in FIG.
In FIG. 5, the ultrasonic sensor transmission unit 15 a and the ultrasonic sensor reception unit 15 b are disposed so as to face each other with the disc portion 17 b of the medium width detection disc 17 interposed therebetween. The ultrasonic sensor receiving unit 15b receives the ultrasonic wave emitted from the ultrasonic sensor transmitting unit 15a via the disc portion 17b.

  The ultrasonic sensor receiver 15b detects the thickness of the disk portion 17b by detecting the attenuation rate of the level of the ultrasonic signal emitted from the ultrasonic sensor transmitter 15a and transmitted through the disk portion 17b. The ultrasonic sensor receiving unit 15b is transmitted from the ultrasonic sensor transmitting unit 15a, and the attenuation rate of the level of the ultrasonic signal transmitted through the thick disc portion 17b is reduced to the thin disc portion 17b. It is detected that the attenuation rate of the level of the transmitted ultrasonic signal is larger.

That is, the double feed detection sensor 15 constituted by the ultrasonic sensor transmission unit 15a and the ultrasonic sensor reception unit 15b determines the thickness of the disc portion 17b of the medium width detection disc 17 rotated corresponding to the width of the document. The width of the document guided by the document sheet guide 12 (12a, 12b) shown in FIG. 4 can be detected.
The operation of the above configuration will be described.
A document reading process performed by the image forming apparatus will be described with reference to FIGS. 1 and 4 in accordance with a step represented by S in the flowchart showing the flow of the document reading process in the embodiment of FIG.

S1: The document 11 is placed (set) on the document tray 13 by the user's operation, and the document is matched with the width of the document 11 (the direction indicated by the arrow B in FIG. 4 perpendicular to the document transport direction). The paper guide 12 (12a, 12b) is moved, and the width direction of the document 11 is regulated.
S2: When the manuscript paper guide 12 (12a, 12b) moves, the medium width detecting disk 17 is interlocked with the manuscript paper guide 12 (12a, 12b) via the gear 25, pulleys 26a, 26b and belts 24a, 24b. The disk portion 17b having a thickness corresponding to the width of the original is arranged on an axis between the ultrasonic sensor receiving portion 15b and the disk portion 17b of the medium width detecting disk 17.

S3: When the disc portion 17b having a thickness corresponding to the width of the document is disposed on the axis between the ultrasonic sensor receiving portion 15b and the disc portion 17b of the medium width detecting disc 17, the control unit The ultrasonic sensor receiver 15b detects the ultrasonic waves received from the ultrasonic sensor transmitter 15a via the disk portion 17b.
S4: When the ultrasonic sensor receiving unit 15b detects the ultrasonic wave, the control unit compares the ultrasonic wave emitted from the ultrasonic sensor transmitting unit 15a with the ultrasonic wave received by the ultrasonic sensor receiving unit 15b. And the size (width) of the document placed on the document tray 13 is detected from the calculated attenuation rate.

  The ultrasonic wave emitted from the ultrasonic sensor transmitter 15a and transmitted through the disk part 17b of the medium width detecting disk 17 is attenuated, but the attenuation factor varies depending on the thickness of the disk part 17b. Detects the thickness of the disk portion 17b by obtaining the attenuation rate of the level of the ultrasonic waveform received by the ultrasonic sensor receiver 15b with respect to the level of the ultrasonic waveform emitted from the ultrasonic sensor transmitter 15a. Then, the width of the document placed on the document tray 13 is detected. Note that the attenuation rate of the level of the ultrasonic waveform is calculated by a known technique.

  For example, as shown in FIG. 7, the control unit obtains the attenuation rate of the level of the received waveform of the ultrasonic wave received by the ultrasonic sensor receiving unit 15b with respect to the transmission waveform of the ultrasonic wave emitted from the ultrasonic sensor transmitting unit 15a. The width of the document placed on the tray 13 is detected. FIG. 7A schematically shows an ultrasonic transmission waveform and a reception waveform when an A3-size original is placed on the original tray 13, and the ultrasonic wave due to the thickness of the disc portion 17b. The attenuation rate of the waveform level is -10 dB. FIG. 7B schematically shows a transmission waveform and a reception waveform of an ultrasonic wave when an A4-size original is placed on the original tray 13, and the ultrasonic wave according to the plate thickness of the disc portion 17b. The attenuation level of the waveform level is −20 dB.

When an A4 size document is placed on the document tray 13, the absolute value of the attenuation factor due to the thickness of the disk portion 17b is larger than when an A3 size document is placed on the document tray 13. This is because the thickness of the disc portion 17b is thicker than when an A3-size original is placed on the original tray 13.
As described above, the control unit compares the ultrasonic wave emitted from the ultrasonic sensor transmission unit 15a with the ultrasonic wave received by the ultrasonic sensor reception unit 15b, determines the attenuation rate of the ultrasonic signal, and calculates the attenuation rate from the calculated attenuation rate. The width of the document placed on the document tray 13 is detected.

S5: The control unit that has detected the width of the document starts scanning the document.
S6: At this time, the control unit overlaps the level of the ultrasonic waveform emitted from the ultrasonic sensor transmission unit 15a, transmitted through the disc portion 17b of the medium width detection disc 17, and received by the ultrasonic sensor reception unit 15b. It is determined as a reference level for feed detection and stored in the storage unit. The reference level is a value corresponding to the thickness of the medium corresponding to the medium width detection result.

S <b> 7: The control unit feeds and feeds the document 11 placed on the document tray 13 by the feed roller 14, and sends it to the double feed detection sensor 15.
When the control unit sends the document 11 to the double feed detection sensor 15, the ultrasonic sensor reception unit 15b detects the ultrasonic wave received from the ultrasonic sensor transmission unit 15a via the disc portion 17b.
Although the ultrasonic wave transmitted from the ultrasonic sensor transmission unit 15a and transmitted through the medium 11 to be conveyed is attenuated, the attenuation rate varies depending on the number of the media 11, and therefore the control unit is controlled by the ultrasonic sensor transmission unit 15a. The double feed of the medium 11 is detected by obtaining the attenuation rate of the level of the ultrasonic waveform received by the ultrasonic sensor receiver 15b with respect to the level of the generated ultrasonic waveform.

  For example, as shown in FIG. 8, the control unit obtains the attenuation rate of the level of the received waveform of the ultrasonic wave received by the ultrasonic sensor receiving unit 15 b with respect to the transmission waveform of the ultrasonic wave emitted from the ultrasonic sensor transmitting unit 15 a. 11 double feeds are detected. FIG. 8A schematically shows a transmission waveform and a reception waveform of an ultrasonic wave when a single document 11 is conveyed. The attenuation rate of the level of the ultrasonic waveform by the document 11 is a reference level. Is -10 dB. FIG. 8B schematically shows an ultrasonic transmission waveform and a reception waveform when two originals 11 are conveyed, and the attenuation rate of the level of the ultrasonic waveform by the original 11 is a reference level. Is -80 dB. In FIG. 8, the medium width detection disk 17 is omitted, and the transmission waveform represents a reference level transmission waveform.

As described above, when the number of documents 11 is one, attenuation of the received waveform of ultrasonic waves by the document 11 occurs with respect to the reference level, but no significant attenuation occurs. When there are two originals 11, a slight air layer is formed between the two originals 11, and therefore the original 11 and a little air with respect to the reference level due to the influence of ultrasonic characteristics such as acoustic impedance and reflection. A large attenuation of the received waveform of the ultrasonic wave due to the layer (large attenuation compared with the case of one original 11) occurs.
S8: When the attenuation rate with respect to the reference level exceeds a threshold value (for example, −60 dB or less), the control unit determines that the document 11 is being double-fed and moves the process to S9, where the attenuation rate with respect to the reference level is determined. If the threshold value does not exceed the threshold value, it is determined that the document 11 is not double-fed and the process proceeds to S10.

S9: The control unit that determines that the document 11 is double-fed issues an alarm that the document 11 has been double-fed, stops the scanning operation, and ends the present process.
S10: The control unit that has determined that the document 11 is not double-fed continues the scan operation until there is no document placed on the document tray 13. At this time, each time the document 11 is fed and transported, the control unit detects the double feed of the document 11 in S8. When the control unit reads all the documents placed on the document tray 13, the process is terminated.

As described above, the control unit detects the double feed of the document 11 by the double feed detection sensor 15 and also detects the size (width) of the document placed on the document tray 13.
As described above, in this embodiment, in the medium transport apparatus having the double feed detection sensor for detecting the double feed of the transported medium, the medium width detection disk disposed facing the double feed detection sensor is the document. By rotating in conjunction with the document paper guide on the tray, it is possible to detect the double feed as well as the size of the medium.

Therefore, it is possible to detect the size of the medium conveyed with a simple configuration.
In this embodiment, an example is disclosed in which when the user performs scanning, the detected paper width of the document is detected (S4), and double feed detection (S8) is performed based on the reference level corresponding to the detection result. However, based on the detection result of S4, the paper size and type corresponding to the detected paper width may be displayed on the operation panel 31 shown in FIG.

In this embodiment, the image forming apparatus has been described as a multifunction peripheral having a scanner unit and a printer unit. However, the image forming apparatus is not limited thereto, and may be a printer or the like as long as it includes a medium transport device. In addition, the image forming apparatus may be an image processing apparatus such as a scanner apparatus, a facsimile apparatus, a printer, or a multi-function machine that includes a medium conveying apparatus.
In this embodiment, the medium transport apparatus is described as having an ADF. However, the present invention is not limited to this, and includes a paper feed tray, a paper feed cassette, an MPT (multipurpose tray), and the like. It may be a medium transport device.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Scanner part 3 Printer part 12 Document paper guide 13 Document tray 14 Paper feed roller 15 Double feed detection sensor 15a Transmission part 15b Reception part 17 Medium width detection disk 17a Rotating shaft 17b Disk part 18 Conveyance roller 19 Scanner 22 discharge roller 23 discharge tray 24 belt 25 gear 26a, 26b pulley 30a upper conveyance guide member 30b lower conveyance guide member 31 operation panel 121a, 121b rack

Claims (9)

A guide unit that is movably arranged with respect to the medium mounting unit and regulates the position of the medium mounted on the medium mounting unit;
A paper feed unit that feeds the medium placed on the medium placement unit;
A double feed detection unit for detecting double feed of a medium fed downstream of the paper feed unit in the conveyance direction of the medium;
A medium size detection member disposed at a position facing the double feed detection unit and operating in conjunction with the movement of the guide unit;
A medium conveying apparatus comprising: The medium conveying apparatus according to claim 1,
A transport unit disposed on the downstream side in the medium transport direction of the paper feed unit;
A first conveyance guide for guiding a first surface side of a medium to be conveyed between the paper feeding unit and the conveyance unit;
A second transport guide that is arranged to face the first transport guide at a predetermined distance and guides the opposite surface side of the transported medium;
Have
The double feed detection unit includes a transmission unit that transmits a signal and a reception unit that receives the signal.
In the direction from the transmitter to the receiver,
The medium conveying apparatus, wherein the transmitting unit, the first conveying guide, the second conveying guide, the medium size detecting member, and the receiving unit are arranged in this order. The medium conveying apparatus according to claim 1,
A transport unit disposed on the downstream side in the medium transport direction of the paper feed unit;
A first conveyance guide for guiding a first surface side of a medium to be conveyed between the paper feeding unit and the conveyance unit;
A second transport guide that is arranged to face the first transport guide at a predetermined distance and guides the opposite surface side of the transported medium;
Have
The double feed detection unit includes a transmission unit that transmits a signal and a reception unit that receives the signal.
In the direction from the transmitter to the receiver,
The medium conveying apparatus, wherein the transmitting unit, the medium size detecting member, the second conveying guide, the first conveying guide, and the receiving unit are arranged in this order. In the medium conveying apparatus in any one of Claims 1-3,
The medium conveyance device, wherein the medium size detection member is formed of a resin material. In the medium conveyance apparatus of Claim 2 or Claim 3,
The medium transport apparatus, wherein the first transport guide and the second transport guide are made of a resin material. In the medium conveying apparatus in any one of Claims 1-5,
The medium size detection member has a rotating shaft and a disk portion attached to the rotating shaft and rotating together with the rotating shaft,
The disk transport device according to claim 1, wherein the disk portion is formed so that a plate thickness changes in a rotation direction. In the medium conveying apparatus in any one of Claims 1-6,
A power transmission member that couples the guide unit and the medium size detection member and transmits movement of the guide unit as a rotational power of the medium size detection member;
The power transmission member includes a gear that meshes with a sliding member of the guide portion that moves in a direction orthogonal to the medium conveyance direction, and a belt that connects the gear and a rotation shaft of the medium size detection member. A medium conveying apparatus comprising:   An image forming apparatus comprising the medium carrying device according to claim 1.   An image processing apparatus comprising the medium carrying device according to claim 1.

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