CN115837806A

CN115837806A - Conveyance failure determination device and printing device

Info

Publication number: CN115837806A
Application number: CN202211055283.0A
Authority: CN
Inventors: 松岭恭守
Original assignee: Riso Kagaku Corp
Current assignee: Riso Kagaku Corp
Priority date: 2021-09-22
Filing date: 2022-08-30
Publication date: 2023-03-24
Also published as: JP2023045405A

Abstract

The invention provides a conveyance failure determination device and a printing device, which can reduce the workload of users with respect to conveyance failure. The disclosed device is provided with: a lift detection unit (70) which is provided between a printing unit (30) that performs a printing process on a printing medium (P) and a supply unit (a side paper feed unit (10) and an internal paper feed unit (20)) that supplies the printing medium to the printing unit, and which detects lift of the printing medium supplied from the supply unit; and a determination unit (61) that determines a conveyance failure of the print medium based on the detection result of the lift detection unit, wherein the determination unit does not determine the conveyance failure even when lift of the print medium is detected during a period from the start of supply of the print medium from the supply unit to the supply of the preset number of sheets, and determines the conveyance failure when lift of the print medium is detected from the time point at which the preset number of sheets of the next print medium is supplied.

Description

Conveyance failure determination device and printing device

Technical Field

The present invention relates to a conveyance failure determination device and a printing device for determining conveyance failure based on a detection result of lift of a print medium.

Background

Conventionally, it has been proposed to provide a detection unit such as a sensor for detecting a print medium in a print medium conveyance path of a printing apparatus and to perform predetermined control based on a detection result of the detection unit.

For example, patent document 1 proposes the following: the length of the first conveyed printing medium is measured by the detection unit, and when the measured length is longer than a preset length, the paper feeding of the second printing paper is stopped.

Further, patent document 2 proposes the following: the front end of the printing medium is detected, and the surface of the printing medium continuous with the front end is photographed, thereby detecting whether the surface of the printing medium is printed or not, and if the surface is printed, the operation of the device is stopped.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2008-230828

Patent document 2: japanese patent laid-open publication No. 2011-112814

Disclosure of Invention

Problems to be solved by the invention

Incidentally, in the case of using a manual paper feed tray of a printing apparatus, for example, there is a case where a user unintentionally deforms a printing medium to cause so-called lifting of the printing medium. The lifting of the printing medium refers to a state in which the printing medium is lifted from an original conveying path (conveying surface) due to the warping of the printing medium.

When such a lift-off occurs, if the lift-off is detected simply by a detection unit provided in the conveyance path, and the conveyance failure is determined, and the paper feeding of the printing apparatus is stopped, there is a problem that the stop of the printing apparatus is frequent, and the workload on the user of the conveyance failure increases.

In view of the above, an object of the present invention is to provide a conveyance failure determination device and a printing apparatus capable of reducing the workload on a user who has a conveyance failure.

Means for solving the problems

The conveyance failure determination device of the present invention includes: a lift detection unit that is provided between a printing unit that performs a printing process on a printing medium and a supply unit that supplies the printing medium to the printing unit, and that detects lift of the printing medium supplied from the supply unit; and a determination unit that determines a conveyance failure of the printing medium based on a detection result of the lift detection unit, wherein the determination unit does not determine the conveyance failure even when lift of the printing medium is detected during a period from a start of supply of the printing medium from the supply unit to a time when the preset number of sheets is supplied, and the determination unit determines the conveyance failure when lift of the printing medium is detected from a time point when a next printing medium after the preset number of sheets is supplied.

Effects of the invention

According to the conveyance failure determination device of the present invention, even when the lift of the print medium is detected during a period from the start of the supply of the print medium from the supply portion to the supply of the preset number of sheets, the conveyance failure determination device does not determine the conveyance failure, and when the lift of the print medium is detected from the time point of the next print medium after the supply of the preset number of sheets, the conveyance failure determination device determines the conveyance failure, so that the workload on the user with respect to the conveyance failure can be reduced.

Drawings

Fig. 1 is a diagram showing a schematic configuration of an embodiment of an inkjet printing apparatus according to the present invention.

Fig. 2 is a block diagram showing a schematic configuration of a control system of the inkjet printing apparatus shown in fig. 1.

Fig. 3 is a flowchart for explaining a method of determining a conveyance failure of a printing medium in the inkjet printing apparatus shown in fig. 1.

Description of reference numerals:

1: an inkjet printing device; 10: a lateral paper feeding section; 11: a paper feeding table; 12: a primary paper feeding section; 14: a secondary paper feeding section; 14a: a positioning roller; 20: an internal paper feeding section; 21a, 21b, 21c: a paper supply table; 22a, 22b, 22c: a primary paper feed unit; 30: a printing section; 31 a line head; 32: a carrying belt; 33: a first tape platen roller; 34: a second band paper pressing roller; 40: a paper discharge section; 41: a paper discharge table; 42: a paper discharge roller; 43: a switching mechanism; 50: a turning part; 51: a turning table; 52: turning over the roller; 53: a carrying roller; 60: a control unit; 61: a determination unit; 70: a tilting detection part; 70a: a swing portion; 70b: a swing sensor section; 70c: a support shaft; CR: a circulating conveyance path; FR: a paper feed conveyance path; SR: turning over the carrying path; p: a print medium.

Detailed Description

An inkjet printing apparatus using an embodiment of a conveyance failure determination apparatus according to the present invention will be described in detail below with reference to the drawings. The inkjet printing apparatus according to the present embodiment is characterized by a method of determining a conveyance failure of a printing medium, and first, the overall configuration thereof will be described. Fig. 1 is a diagram showing a schematic configuration of an inkjet printing apparatus 1 according to the present embodiment. The vertical and horizontal directions shown in fig. 1 are vertical and horizontal directions of the inkjet printing apparatus 1 according to the present embodiment. The front side of the drawing sheet in fig. 1 is the front, and the back side is the back.

As shown in fig. 1, the inkjet printing device 1 of the present embodiment includes a side sheet feeding unit 10, an internal sheet feeding unit 20, a printing unit 30, a sheet discharging unit 40, and a reversing unit 50. In the present embodiment, the side sheet feeding section 10 and the internal sheet feeding section 20 correspond to the feeding section of the present invention.

The printing unit 30 and the internal paper feed unit 20 are housed and installed in a housing made of metal, resin, or the like. The side sheet feeding unit 10 and the sheet discharging unit 40 are partially housed in the housing and partially protrude outside the housing.

The side paper feed unit 10 is called a so-called manual paper feed tray, and includes a paper feed table 11 on which the printing medium P is placed, a primary paper feed unit 12 that draws out and conveys only the uppermost printing medium P from the paper feed table 11, and a secondary paper feed unit 14 that feeds out the printing medium P conveyed by the primary paper feed unit 12 to the printing unit 30 at a predetermined timing.

The secondary paper feed unit 14 includes registration rollers 14a and a registration motor (not shown) that drives the registration rollers 14a, and the registration rollers 14a make contact with the leading end of the print medium P conveyed from the primary paper feed unit 12 or the print medium P conveyed from the internal paper feed unit 20 to temporarily stop the print medium P and loosen the print medium P, thereby correcting skew.

The internal paper feed unit 20 includes a paper feed table 21a on which the printing medium P is placed, a primary paper feed unit 22a that draws out only the uppermost printing medium P from the paper feed table 21a and conveys the uppermost printing medium P onto the paper feed conveyance path FR, a paper feed table 21b on which the printing medium P is placed, a primary paper feed unit 22b that draws out only the uppermost printing medium P from the paper feed table 21b and conveys the uppermost printing medium P onto the paper feed conveyance path FR, a paper feed table 21c on which the printing medium P is placed, and a primary paper feed unit 22c that draws out only the uppermost printing medium P from the paper feed table 21c and conveys the uppermost printing medium P onto the paper feed conveyance path FR.

As described above, in the secondary paper feed unit 14, the print medium P is conveyed from the side paper feed unit 10 or the internal paper feed unit 20, and the print medium P is also conveyed from the reversing unit 50 described later.

Therefore, a junction point where the conveyance path of the print medium P supplied from the side paper feed portion 10 or the internal paper feed portion 20 and the conveyance path of the print medium P having one surface printed by the reversing portion 50 join exists in the vicinity of the secondary paper feed portion 14 in the conveyance direction. With this joining point as a reference, a path on the paper feeding mechanism side is referred to as a paper feeding conveyance path FR, and the other path is referred to as a circulating conveyance path CR.

Further, a plurality of paper detection sensors (not shown) for detecting the printing medium P are provided in the circulating conveyance path CR, and conveyance control of the printing medium P is performed by a control unit 60, which will be described later, based on detection signals detected by the paper detection sensors.

The printing unit 30 includes four line heads 31, an endless conveying belt 32 disposed to face the line heads 31, a first belt platen roller 33, and a second belt platen roller 34.

The conveyor belt 32 is formed of an endless belt and has a plurality of suction holes formed therein. The print medium P fed from the secondary paper feed unit 14 is conveyed to an endless conveying belt 32. Then, the printing medium P is sucked to the conveyance belt 32 by a suction fan (not shown) provided on the back side of the conveyance path surface of the conveyance belt 32, and is conveyed at a predetermined conveyance speed. Then, while the printing medium P is conveyed by the conveying belt 32, the line head 31 ejects ink onto the printing medium P, thereby performing a printing process on the printing medium P.

The transport belt 32 is stretched over the first belt platen roller 33 and the second belt platen roller 34, and the transport belt 32 is rotated clockwise in fig. 1 by driving the first belt platen roller 33 and the second belt platen roller 34 with a transport motor (not shown).

Further, a lift detection unit 70 is provided between the conveyor belt 32 and the registration roller 14 a. The lift detection unit 70 detects lift of the print medium P, and includes a swing unit 70a and a swing sensor unit 70b.

The swing portion 70a is a member extending in a direction (front-rear direction) orthogonal to the conveyance direction of the printing medium P. The cross section of the surface of the swinging portion 70a orthogonal to the extending direction thereof is formed in a crank shape.

The swing portion 70a is rotatably supported by a support shaft 70c extending in the conveyance direction of the printing medium P, and is supported to be swingable in the arrow a direction and the reverse direction shown in fig. 1. When the printing medium P conveyed from the registration roller 14a is tilted, the front end of the printing medium P in the conveying direction comes into contact with one end of the swinging portion 70a, and the swinging portion 70a is pushed forward and swings in the direction of arrow a. By this swing, the other end portion of the swing portion 70a is separated from the swing sensor portion 70b. This makes it possible to detect that the lift of the print medium P is equal to or greater than a predetermined amount.

The swing portion 70a is provided such that the printing medium P passes below the swing portion 70a in a case where the lift of the printing medium P is not generated or in a case where the lift is less than a predetermined amount. The distance between the one end of the swing portion 70a and the transport belt 32 is set to be equal to or less than the distance between each line head 31 and the transport belt 32, thereby preventing the print medium P from colliding with each line head 31.

For example, when the largest one of the sizes of the printing medium P to be used is the A3 size, the length L of the swing portion 70a in the direction orthogonal to the conveying direction of the printing medium P is set to be longer than the length of the A3 size in the direction orthogonal to the conveying direction.

The swing sensor unit 70b detects contact and non-contact of the swing unit 70a as described above, and outputs a detection signal to the control unit 60. A determination unit 61, which will be described later, in the control unit 60 determines a conveyance failure of the printing medium P based on the detection result of the lift detection unit 70, and a determination method thereof will be described in detail later.

Each line head 31 extends in a direction orthogonal to the conveying direction of the printing medium P, and ejects ink onto the printing medium P conveyed by the conveying belt 32. As shown in fig. 1, four line heads 31 are arranged at predetermined intervals along the conveying path of the printing medium P. The four line heads 31 respectively eject inks of CMYK.

The printing medium P printed by the printing unit 30 is conveyed on the circulating conveyance path CR by a conveyance roller or the like disposed on the circulating conveyance path CR. A switching mechanism 43 is provided in the circulation conveyance path CR, and the switching mechanism 43 switches whether the printing medium P conveyed on the circulation conveyance path CR is guided to the paper discharge unit 40 or recirculated on the circulation conveyance path CR. Specifically, the switching mechanism 43 switches between the conveyance path on the paper discharge unit 40 side and the conveyance path on the reversing unit 50 side.

The paper discharge unit 40 includes a paper discharge table 41 formed in a tray shape protruding from the housing of the inkjet printing apparatus 1, and a pair of paper discharge rollers 42 that discharge the printing medium P to the paper discharge table 41. The printing medium P guided by the switching mechanism 43 toward the paper discharge unit 40 is discharged to the paper discharge table 41 by the paper discharge roller 42.

The reversing unit 50 includes a reversing table 51, a reversing roller 52, a reversing motor (not shown) for driving the reversing roller 52, and the like, the reversing table 51 has a reversing conveyance path SR for reversing the printing medium P, the reversing roller 52 conveys the printing medium P from the circulating conveyance path CR to the reversing table 51, and the printing medium P conveyed to the reversing table 51 is returned to the circulating conveyance path CR again.

The printing medium P guided to the reversing unit 50 by the switching mechanism 43 is conveyed from the circulation conveyance path CR to the reversing table 51 by the reversing roller 52, and is returned from the reversing table 51 to the circulation conveyance path CR again, and is conveyed on the circulation conveyance path CR in a state where the front and back sides are reversed. The print medium P with the front and back inverted is then conveyed again to the printing unit 30 by a plurality of rollers such as the conveyance roller 53 provided in the circulating conveyance path CR.

The printing medium P conveyed by the conveying roller 53 is conveyed again to the registration roller 14a of the secondary paper feed unit 14, and is sent out again to the printing unit 30 at a predetermined timing by the registration roller 14 a. Then, after passing under the swing portion 70a, the printing portion 30 performs a printing process on the back surface of the printing medium P.

Fig. 2 is a block diagram showing a schematic configuration of a control system of the inkjet printing apparatus 1 according to the present embodiment.

The control Unit 60 controls the entire inkjet printing apparatus 1, and includes a CPU (Central Processing Unit), a semiconductor memory, and the like. The control unit 60 controls the operations of the respective units of the inkjet printing apparatus 1 by causing the CPU to execute a program stored in advance in the semiconductor memory.

The control unit 60 acquires image data output from a computer or the like or image data read by a scanner or the like, and controls the printing unit 30 based on the image data to perform printing processing.

The control unit 60 further includes a determination unit 61. The determination unit 61 determines a conveyance failure of the print medium P based on the detection result of the lift detection unit 70. When the determination unit 61 determines that the conveyance is defective, the control unit 60 stops the operations of the supply systems such as the side sheet feeding unit 10, the internal sheet feeding unit 20, and the reversing unit 50, or stops the operations of the supply system and the printing unit 30.

Specifically, the determination unit 61 of the present embodiment includes a counter that counts the number of sheets of the print medium P fed from the side to the paper feed unit 10 or the internal paper feed unit 20. The determination unit 61 does not determine that conveyance is defective even when lift of the print medium P is detected during a period from the start of feeding of the print medium P associated with a predetermined print job to the feeding of a predetermined number of sheets.

The determination unit 61 determines that conveyance is defective when lift of the print medium P is detected after the time when the preset number of sheets of print medium P is fed next.

In the present embodiment, the predetermined number of sheets is one. That is, when the supplied print medium P is the first (first sheet) of the print medium P related to the predetermined print job, the determination unit 61 does not determine that the conveyance is defective and directly continues the conveyance and printing process of the print medium P even if the lift of the print medium P is detected. On the other hand, when the fed printing medium P is a second or later printing medium related to a predetermined print job, the determination unit 61 determines that conveyance is defective when lift-up is detected.

In this way, the first (first sheet) of the print medium P that is likely to be unintentionally deformed is not determined as a conveyance failure even if the lift of the print medium P is detected, and is determined as a conveyance failure when the lift is detected for the second and subsequent print media, thereby reducing the workload on the user due to the conveyance failure.

Further, the determination unit 61 acquires the attribute information of the supplied printing medium P, and switches the method of determining the conveyance failure based on the attribute information. The attribute information of the print medium P is information of the property to which the print medium P belongs, and includes, for example, information of the hardness, the thickness, and the size of the print medium P, but may be other information. The attribute information of the printing medium P may be acquired from setting information included in the print job, or may be acquired from information set and input on an operation panel (not shown) provided in the inkjet printing apparatus 1.

The determination unit 61 of the present embodiment acquires information on the type of paper of the print medium P (plain paper, coated paper, high-quality paper, special paper, thick paper, and the like) as information on the hardness of the print medium P. Then, when the acquired type information of the paper is the type information of the soft paper, as described above, the determination unit 61 does not determine that the conveyance is defective even if the lift of the print medium P is detected in the case of the first (first) print medium, and the determination unit 61 determines that the conveyance is defective in the case of the second or subsequent print medium when the lift is detected (corresponding to the first determination method of the present invention).

On the other hand, when the acquired paper type information is not the soft paper type information, that is, when the paper type information indicates the paper type of a predetermined hardness or more, the determination unit 61 determines that the conveyance is defective when the lift of the print medium P is detected regardless of the number of the print media P to be fed, that is, even when the first (first) print medium is present (corresponding to the second determination method of the present invention).

When the print medium P is hard, there is a possibility that the print medium P collides with the line head 31 and is broken, and the like, and therefore, by determining that conveyance is defective from the first print medium P as described above, breakage of the line head 31 and the like can be prevented.

In the present embodiment, the first determination method and the second determination method are switched according to the hardness of the print medium P, but the present invention is not limited to this, and the first determination method and the second determination method may be switched based on information on the thickness of the print medium P. Specifically, the determination unit 61 may determine the conveyance failure by using the first determination method when the type information of the sheet is a thin sheet, and may determine the conveyance failure by using the second determination method when the type information of the sheet is a thick sheet.

The determining unit 61 is preset with a relationship between the attribute information of the print medium P and the first determining method or the second determining method, and the determining unit 61 switches the first determining method and the second determining method based on the acquired attribute information (for example, the type information of the paper) of the print medium P and the relationship.

Next, a method for determining a conveyance failure of the printing medium P in the inkjet printing apparatus 1 according to the present embodiment will be described with reference to a flowchart shown in fig. 3. In the flowchart, the number of sheets passing through the reversing path in the duplex printing is not included in the counted number.

First, the control unit 60 waits for a print instruction for a print job (no in S10), and when the print instruction is received (yes in S10), starts to supply the print medium P. Specifically, the control unit 60 starts to supply the printing medium P from the side paper feed unit 10 or the internal paper feed unit 20 to the printing unit 30 (S12).

Then, the determination unit 61 monitors whether or not the lift-off of the printing medium P is detected by the lift-off detection unit 70 (S14), that is, whether or not a detection signal of the printing medium P is output from the swing sensor unit 70b. When the determination unit 61 detects the lift of the printing medium P (yes in S14), it checks whether or not the printing medium P is a soft printing medium (S16).

Next, when the print medium P is a flexible print medium (yes in S16), the determination unit 61 checks whether or not the print medium P is the second and subsequent print media P of the print job (S18). When the print medium P is not the second or subsequent print medium P (no in S18), that is, when the print medium P is the first (first sheet) of the print job, the determination unit 61 returns to S14 without determining that conveyance is defective (first determination method), and monitors the lift of the second or subsequent print medium P again (S14). The first print medium P is directly conveyed to the printing unit 30, and a printing process is performed.

On the other hand, in S18, if it is confirmed that the sheet is the second or subsequent printing medium P (yes in S18), the determination unit 61 determines that the conveyance is defective, and the control unit 60 stops the operations of the supply system and the printing unit 30 based on the determination result (S20). That is, the operations of the supply system and the printing section 30 are stopped in accordance with the tilting of the printing medium P. Then, for example, after the removal of the printing medium P on which the lifting has occurred, the control section 60 starts the supply of the printing medium P from the supply system again. At this time, the counter for confirming whether or not the print medium P is the second or subsequent one is reset in S18, and counting is started from "1" again.

In S16, when the determination unit 61 confirms that the print medium P is not a flexible print medium (no in S16), the determination unit 61 determines that the conveyance is defective regardless of whether or not the print medium P is the first (first sheet) of the print job (second determination method), and the control unit 60 stops the operations of the supply system and the printing unit 30. In this case, the counter for confirming whether or not the print medium P is the second or subsequent one in S18 is also reset, and counting is started from "1" again.

If the lift-off of the printing medium P is not detected in S14 (no in S14) and the processing of the print job is not completed (no in S22), the process returns to S14, and the determination unit 61 monitors the lift-off of the printing medium P sequentially supplied. When the processing of the print job is completed without detecting the lift of the print medium P (yes in S22), the control unit 60 directly stops the operations of the supply system and the printing unit 30 and ends the processing (S20).

As in the above-described embodiment, by switching the first determination method and the second determination method based on the softness (hardness) of the print medium P, the first determination method is adopted when the print medium P is soft, and thereby the workload of the user due to the occurrence of conveyance failure can be reduced. On the other hand, when the print medium P is hard, the second determination method can prevent the line head 31 from being damaged due to the collision of the print medium P with the line head 31.

In the above embodiment, when the print medium P is flexible, the first print medium P is not determined to have a conveyance failure even when lift-off is detected, and the second or subsequent print medium P is determined to have a conveyance failure when lift-off is detected.

Further, the number of sheets of the print medium P that is not determined to be a conveyance failure even when the lift-up is detected may be changed based on the attribute information of the print medium P. The above embodiment is an example in which the number of printing media P not determined as conveyance failure is one when the printing medium P is soft, and the number of printing media P not determined as conveyance failure is zero when the printing medium P is hard, but the present invention is not limited to this, and the number of printing media P not determined as conveyance failure may be two when the printing medium P is soft, and the number of printing media P not determined as conveyance failure may be one when the printing medium P is hard.

In this way, by changing the number of the print media P that is not determined to be conveyance failure even when the lift is detected based on the hardness of the print media P, both reduction of the workload for the user with conveyance failure and prevention of damage to the linetype head 31 can be achieved.

In addition, the number of sheets of the print medium P that is not determined as being conveyance failure may be two when the print medium P is thin, and may be one when the print medium P is thick. That is, the number of sheets of the print medium P not determined to be poorly conveyed may be changed based on the attribute information of the print medium P.

In this way, by changing the number of the print media P that is not determined to be conveyance failure even when the lift is detected based on the thickness of the print media P, both reduction of the workload for the user with conveyance failure and prevention of damage to the linetype head 31 can be achieved.

For example, when the size of the print medium P is large, the length in the direction (front-rear direction) orthogonal to the conveyance direction of the print medium P may be longer than the length of each line head 31 in the orthogonal direction. In this way, even if the print medium P has a large size and warps at both ends (ends extending in the conveying direction) in the orthogonal direction, the warp is outside the range where the line head 31 is disposed, and therefore the print medium P is conveyed without colliding with the line head 31.

Therefore, when the size of the print medium P is equal to or larger than a predetermined size (for example, A3 size), the determination unit 61 may not determine that the conveyance is defective from the start of feeding the print medium P for a predetermined print job regardless of the detection result of the lift detection unit 70.

This reduces unnecessary stoppage of the inkjet printing apparatus 1, and reduces the workload on the user who has failed in conveyance.

In the above-described embodiment, the conveyance failure determination control is performed for a plurality of paper feeding units (the side paper feeding unit 10 and the internal paper feeding unit 20) provided in the inkjet printing apparatus 1 without distinguishing them, but the conveyance failure determination control according to the present invention may be performed only when the side paper feeding unit 10 (manual tray) in which the paper is likely to turn up is used.

The conveyance failure determination device of the present invention is further disclosed in the following supplementary notes.

(attached note)

In the conveyance failure determination device according to the present invention, the determination unit may change the preset number of sheets, which is not determined as conveyance failure even when the lifting of the printing medium is detected, based on the attribute information of the printing medium.

In the conveyance failure determination device according to the present invention, the determination unit may switch between a first determination method in which the determination unit does not determine that the conveyance failure is caused even when the lift of the printing medium is detected during a period until the predetermined number of sheets is supplied, and a second determination method in which the determination unit determines that the conveyance failure is caused when the lift is detected from a supply start time point of the printing medium from the supply unit, based on the attribute information of the printing medium.

In the conveyance failure determination device according to the present invention, the determination unit may switch to the second determination method when the attribute information indicates that the print medium is a print medium having a predetermined hardness or higher.

In the conveyance failure determination device according to the present invention, the determination unit may switch to the second determination method when the attribute information indicates that the print medium is a print medium having a predetermined thickness or more.

In the conveyance failure determination device according to the present invention, the determination unit may not determine that conveyance is failed even when the lifting of the printing medium is detected from the start of supply of the printing medium from the supply unit when the attribute information indicates that the printing medium is not smaller than the predetermined size.

The printing apparatus of the present invention includes the conveyance failure determination device of the present invention, a supply unit, and a printing unit.

Claims

1. A conveyance failure determination device, wherein,

the conveyance failure determination device includes:

a lift detection unit that is provided between a printing unit that performs a printing process on a printing medium and a supply unit that supplies the printing medium to the printing unit, and that detects lift of the printing medium supplied from the supply unit; and

a determination unit that determines a conveyance failure of the print medium based on a detection result of the lift detection unit,

the determination unit does not determine that the conveyance is defective even when the lift of the print medium is detected during a period from the start of the supply of the print medium from the supply unit to the supply of the preset number of sheets, and determines that the conveyance is defective when the lift of the print medium is detected from a time point of the next print medium after the supply of the preset number of sheets.

2. The conveyance failure determination device according to claim 1, wherein the determination unit changes the preset number of sheets based on attribute information of the print medium.

3. The conveyance failure determination device according to claim 1 or 2,

the determination unit switches between a first determination method in which the conveyance failure is not determined even when the lift of the print medium is detected during a period from when the preset number of sheets is supplied, and a second determination method in which the conveyance failure is determined when the lift is detected from a supply start time point of the print medium from the supply unit, based on the attribute information of the print medium.

4. The conveyance failure determination device according to claim 3, wherein the determination unit switches to the second determination method when the attribute information is information indicating that the print medium is a print medium having a predetermined hardness or more.

5. The conveyance failure determination device according to claim 3, wherein the determination unit switches to the second determination method when the attribute information indicates that the print medium is a print medium having a predetermined thickness or more.

6. The conveyance failure determination device according to claim 1, wherein the determination unit does not determine that conveyance is failed even when the tilting of the print medium is detected from the start of supply of the print medium from the supply unit when the attribute information of the print medium is information indicating that the print medium is a print medium of a predetermined size or larger.

7. A printing apparatus comprising the conveyance failure determination device according to any one of claims 1 to 6, the supply unit, and the printing unit.