JP2015047756A - Image recording device, image recording method and program used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image recording device that can complete quickly recording of an image even when folding of a sheet is detected.SOLUTION: An inkjet recording device comprises: a conveyance mechanism for conveying a sheet; a recording head that records an image on the sheet to be conveyed; contour measuring means that is provided near an upstream in a conveyance direction relative to the recording head and measures the contour of the sheet to be conveyed; threshold memorizing means 81 that memorizes thresholds relating to a degree of folding or bending generated in the sheet; and a controlling portion 8 that controls the conveyance mechanism and the recording head. The controlling portion determines presence or absence of occurrence of the folding or the bending of the sheet and the degree of the folding or the bending on the basis of the measurement results by the contour measuring means, and when determining that the folding or the bending of the sheet occurs in the sheet, compares the degree of the folding or the bending occurred in the sheet with the thresholds and when the degree of the folding or the bending is equal to the thresholds or more, and controls the recording head and the conveyance mechanism so that the image is not recorded on the sheet.

Description

  The present invention relates to an image recording apparatus provided with a recording head for recording an image on a recording medium, an image recording method, and a program used for the image recording apparatus.

  2. Description of the Related Art Conventionally, an original reading apparatus that reads an original is known. In Patent Document 1, when this document reading apparatus detects an abnormality in document transportation such as double feeding or paper break during document transportation, the document reading operation is interrupted, and the document in which double feeding or paper folding has occurred is returned to the original. The contents returned to the document tray are disclosed.

JP 2004-23427 A

In order to prevent the conveyance of the paper in which the paper breakage occurs, it is conceivable to apply the above prior art to an image recording apparatus provided with a recording head for recording an image on the paper. In this case, when the image recording apparatus detects a paper conveyance abnormality due to paper breakage, it is conceivable that image recording onto the paper is interrupted and the paper with the paper breakage is returned to the paper feed tray.

When a paper break occurs, a paper jam may occur in the paper conveyance path, or the recording head may be damaged due to a portion of the paper having the paper break colliding with the print head. Therefore, when paper breakage occurs, it is effective to interrupt image recording on the paper and return the paper with the paper breakage to the paper feed tray. Here, the inventor of the present application has a novel problem that in all cases where an abnormality in paper conveyance due to paper breakage is detected, the image recording on the paper cannot be completed quickly if the image recording operation on the paper is interrupted. I found. As a result of research on this issue, even when paper breakage is detected, if the degree of paper breakage satisfies a predetermined condition, the above-mentioned paper jam or recording head damage occurs. Since the possibility is low, it has been newly found that image recording can be completed without interrupting image recording on paper. Under this predetermined condition, even if a paper break occurs, the image recording can be continued without interruption, so that the image recording on the paper can be completed quickly.
An object of the present invention is to provide an image recording apparatus, an image recording method, and the image recording apparatus capable of quickly completing the recording of an image on the recording medium even when a recording medium in which a fold or the like has occurred is detected. It is to provide a program used for the above.

An image recording apparatus includes a transport mechanism for transporting a recording medium in a transport direction, a recording head for recording an image on a recording medium transported by the transport mechanism, and an upstream side in the transport direction with respect to the recording head At least one of a threshold measuring unit for measuring the contour of the recording medium conveyed by the conveying mechanism, a threshold relating to the degree of bending generated in the recording medium, and a threshold relating to the degree of bending generated in the recording medium. A threshold storage means, and a control unit for controlling the transport mechanism and the recording head,
The controller is
Based on the measurement result by the contour measuring means, it is determined whether or not the recording medium is bent or bent, and the degree of bending or bending occurring in the recording medium, and the recording medium is bent or bent. If it is determined that the recording medium is bent, the degree of bending or bending occurring in the recording medium is compared with the threshold value.
When the degree of bending or bending occurring in the recording medium is equal to or greater than the threshold, the recording head and the transport mechanism are controlled so as not to record an image on the recording medium,
The recording head and the recording head so that an image is recorded on the recording medium when it is determined that the degree of bending or bending occurring on the recording medium is less than the threshold or that the recording medium is not folded or bent. The transport mechanism is controlled.

A transport mechanism for transporting the recording medium in the transport direction;
A recording head for recording an image on a recording medium conveyed by the conveyance mechanism;
Contour measuring means provided on the upstream side in the transport direction with respect to the recording head and for measuring the contour of a recording medium transported by the transport mechanism;
An image recording method in an image recording apparatus, comprising: a threshold storage unit that stores at least one of a threshold relating to the degree of bending occurring in the recording medium and a threshold relating to the degree of bending occurring in the recording medium,
The image recording method includes a step of determining whether or not the recording medium is bent or bent based on a measurement result of the contour measuring unit, and a degree of the bending or bending generated in the recording medium;
When it is determined that the recording medium is bent or bent, a step of comparing the degree of bending or bending generated on the recording medium with the threshold value;
A step of controlling the recording head and the transport mechanism so that an image is not recorded on the recording medium when the degree of bending or bending occurring in the recording medium is equal to or greater than the threshold;
The recording head and the recording head so that an image is recorded on the recording medium when it is determined that the degree of bending or bending occurring on the recording medium is less than the threshold or that the recording medium is not folded or bent. And a step of controlling the transport mechanism.

A transport mechanism for transporting the recording medium in the transport direction, a recording head for recording an image on the recording medium transported by the transport mechanism, and provided upstream of the recording head in the transport direction, Contour measurement means for measuring the contour of the recording medium conveyed by the conveyance mechanism, and threshold storage means for storing at least one of a threshold value relating to the degree of bending occurring in the recording medium and a threshold value relating to the degree of bending occurring in the recording medium. And a program used in an image recording apparatus comprising a control unit for controlling the transport mechanism and the recording head,
The program is stored in the control unit.
Determining whether or not the recording medium is bent or bent based on the measurement result by the contour measuring means, and determining the degree of bending or bending generated in the recording medium;
When it is determined that the recording medium is bent or bent, a step of comparing the degree of bending or bending generated on the recording medium with the threshold value;
A step of controlling the recording head and the transport mechanism so that an image is not recorded on the recording medium when the degree of bending or bending occurring in the recording medium is equal to or greater than the threshold;
The recording head and the recording head so that an image is recorded on the recording medium when it is determined that the degree of bending or bending occurring on the recording medium is less than the threshold or that the recording medium is not folded or bent. And a step of controlling the transport mechanism.

  The control unit determines the degree of folding or bending occurring on the recording medium based on the measurement result by the contour measuring means, and determines whether or not to record an image on the recording medium. As a result, it is possible to complete the recording of the image on the recording medium more quickly than in the case where the image is not formed on all the recording media in which the folding or bending occurs.

It is a figure which shows the whole structure of an inkjet recording device. FIG. 3 is a perspective view of the recording head as viewed from below. FIG. 4 is a side view showing the vertical position of a recording head and a platen. It is a side view of a wipe mechanism. FIG. 4 is an enlarged view of an ink meniscus formed in an ejection port. It is a block diagram which shows the periphery structure of a control part. It is a top view of the paper which has a fold or a bending part in a front-end | tip part and a rear-end part. (a), (b) is a top view which shows another aspect of the bending or bending part of a paper. 6 is a flowchart illustrating a control operation during conveyance of a sheet. It is a subroutine showing a first image recording stop determination operation. It is a subroutine showing preliminary discharge determination and second image recording stop determination operation. It is a subroutine which shows a 3rd image recording stop determination operation | movement.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, upper and lower indicate directions along the vertical direction. In addition, an ink jet recording apparatus is exemplified as an “image recording apparatus” according to the present invention, and the ink jet recording apparatus records an image by ejecting liquid ink onto a paper as a recording medium. The “image recording apparatus” may be a laser printer instead of the ink jet recording apparatus.

FIG. 1 is a diagram showing the overall configuration of the inkjet recording apparatus 1. The inkjet recording apparatus 1 has a rectangular parallelepiped casing 10, and a tray 11 for discharging the paper P is provided on the top plate of the casing 10. In the housing 10, the recording head 4 that discharges ink onto the paper P from the top to the bottom, the transport unit 5 that transports the paper P in the horizontal direction in FIG. A sheet feeding unit 6 for supplying to 5 is arranged. A platen 3 is provided below the recording head 4 so as to face the recording head 4 and support the conveyed paper P in a horizontal plane in FIG.
A control unit 8 that controls the operation of each mechanism and electric circuit in the housing 10 is disposed at a position where the recording head 4 does not interfere with the upper part inside the housing 10. A tank 14 that stores ink to be supplied to the recording head 4 is disposed on the lower side inside the housing 10. The tank 14 and the recording head 4 are connected by a tube (not shown).
A terminal 13 to which a signal including an image recording job transmitted from an external personal computer is input is provided on the side surface of the housing 10. A signal input from the terminal 13 is input to the control unit 8. On the upper surface of the housing 10, an operation panel 12 for inputting information by a user is provided.
The transport unit 5 is a mechanism for transporting the paper P in FIG. 1 from left to right and upward toward the tray 11. In the following description, the direction in which the paper P is transported in the region immediately below the recording head 4 is referred to as the sub-scanning direction or the first direction (transport direction). The direction in the plane in which the sheet P is conveyed in the first direction in the direction orthogonal to the direction in which the sheet P is conveyed is the main scanning direction or the second direction, and the downstream side of the sheet P in the first direction is the leading end of the sheet. The upstream side of the sheet P in the first direction is the rear end of the sheet. In FIG. 1, the first direction is a horizontal direction from left to right, and the second direction is a direction orthogonal to the paper surface of the paper P. A direction in which the paper P is transported by the transport unit 5 is referred to as a transport direction. In the region immediately below the recording head 4, the transport direction and the first direction are the same direction.

The transport unit 5 includes first and second transport roller pairs 51 and 52 disposed on both sides of the recording head 4, and third to fifth transport rollers disposed downstream of the transport roller pair 52. A pair of conveying rollers 53, 54, 55 and three guides 56, 57, 58 through which the paper P passes are configured. Between the first conveying roller pair 51 and the recording head 4, an end detection sensor SE1 that detects an end of the conveyed paper P is provided. The detection signal generated by the end detection sensor SE1 is transmitted to the control unit 8. When the leading edge of the conveyed paper P is detected by the edge detection sensor SE1, ink discharge from the recording head 4 to the paper P is started after a predetermined time has elapsed. During this predetermined time, the leading end portion on the downstream side in the transport direction of the area where the image on the sheet P is recorded after the leading end of the sheet P passes the end detection sensor SE1 is the portion where the image of the recording head 4 is recorded. It corresponds to the time to face each other.
An image sensor RK1 that is an image sensor for measuring the contour of the paper P is provided between the first transport roller pair 51 and the recording head 4. Since the paper P is usually a rectangle with a constant aspect ratio, if the paper P has a fold or a bent portion, the outline of the paper P is not a rectangle with a constant aspect ratio. Therefore, by measuring the contour of the paper P using the image sensor RK1, it can be determined whether the paper P has a fold or a bent portion. In FIG. 1, the image sensor RK1 is located downstream of the edge detection sensor SE1 in the transport direction of the paper P, but may be present upstream of the transport direction.
The sheet P to which the conveying force is applied by the first conveying roller pair 51 is conveyed in the horizontal plane while ink is ejected from the recording head 4. That is, the transport unit 5 constitutes the “transport mechanism” of the present invention.

The sheet P that has passed through the lower side of the recording head 4 is imparted with a conveying force by the second conveying roller pair 52 on the downstream side in the conveying direction, and is positioned between the second conveying roller 52 and the tray 11. The paper is fed to the tray 11 by the fifth conveyance roller pair 53, 54, 55 and the guides 56, 57, 58.
The paper feed unit 6 includes a paper feed tray 60 in which the paper P is stored, a paper feed roller 61, and a sixth and seventh transport roller pair 62 disposed between the paper feed roller 61 and the transport unit 5. , 63 and two guides 64, 65 through which the paper P passes. After feeding one sheet P out of the sheet feed tray 60, the sheet feed roller 61 takes out the next sheet P at a predetermined time interval, and guides 64, 65 and the sixth and seventh transport roller pairs 62. , 63 to transport the paper P to the upstream side of the transport unit 5 in the transport direction.

The recording head 4 is a rectangular parallelepiped line head extending in the main scanning direction (second direction), and a plurality of ejection surfaces 40 having a plurality of ejection openings for ejecting ink are formed on the lower surface of the recording head 4. .
The sheet P on which an image is recorded by the recording head 4 is discharged to the tray 11 by the second to fifth conveying roller pairs 52, 53, 54, 55 and guides 56, 57, 58.
Below the platen 3, a plurality of liquid receiving members 70 arranged horizontally are provided so as to be movable up and down with respect to the platen 3. The liquid receiving member 70 is formed in a cap shape, and when printing is performed by ejecting ink onto the paper P, the liquid receiving member 70 is positioned below the conveyance path of the paper P so as not to interfere with the printing. Yes. The liquid receiving member 70 receives ink ejected from the recording head 4 when the paper P is not conveyed to the platen 3, and is made of glass, stainless steel or the like that repels ink.

FIG. 2 is a perspective view of the recording head 4 as viewed from below. A plurality of head elements 41 protrude from the lower surface of the recording head 4, and the head elements 41 are arranged in a staggered pattern along the second direction. The ejection surface 40 is the lower surface of the head element 41, and a plurality of ejection ports 42, which are nozzles for ejecting ink, are provided on the ejection surface 40 as described above. Each head element 41 is formed in the same structure in order to make the ink ejection characteristics uniform and reduce the manufacturing cost. The recording head 4 is formed by arranging six head elements 41 in a staggered manner along the second direction, but the number of head elements 41 is not limited to six.
The head element 41 includes a flow path unit formed by laminating a plurality of metal plates and an actuator unit bonded to the upper surface of the flow path unit. When the actuator unit is energized, the flow path unit The ink inside is ejected. The lower surface of the metal plate located at the lowest position of the flow path unit constitutes the discharge surface 40, and the actuator unit is connected to the control unit 8. Such a configuration is known and will not be described in detail.

FIG. 3 is a side view showing the vertical positions of the recording head 4 and the platen 3, and the recording head 4 is viewed from the upstream side in the first direction. On the upper surface of the platen 3, there are provided a rib 32 for supporting the paper P and a through hole 33 through which the head element 41 can pass, and the paper P is supported by the tip of the rib 32 to maintain flatness during conveyance. The When the paper P is not conveyed onto the platen 3, the recording head 4 is lowered, and the head element 41 that has passed through the through-hole 33 is aligned with the liquid receiving member 70, thereby maintaining / recovering the ink ejection characteristics of the recording head 4. A purge operation is performed. The purge operation is an operation of discharging ink from a plurality of discharge ports, and corresponds to discharge of ink by pressure reduction or pressurization, discharge by liquid discharge by discharge operation, and the like. Since these are known operations, description thereof is omitted.
In addition, an operation called preliminary ejection is also performed on the paper P conveyed during image recording. This is because, regardless of the printing of the image based on the image data, a plurality of inks thickened by evaporation of bubbles, dust, or solvent by ejecting ink onto the paper P from the plurality of ejection openings 42 every predetermined period. This is an operation for preventing the remaining in the discharge port 42. The dots of ink recorded on the paper P by the preliminary ejection are dispersed on the paper P, and each dot is minute, so it is hardly noticeable on the printed paper P.

(Wipe mechanism)
Since ink is ejected from the ejection port 42 in the form of a spray, it is conceivable that the ink sprayed from the ejection port 42 adheres to the ejection surface 40. Therefore, a wipe mechanism 9 for wiping the discharge surface 40 is provided as necessary.
FIG. 4 is a side view of the wipe mechanism 9. The wipe mechanism 9 includes a box body 91 whose upper surface is opened, a wipe piece 90 that protrudes upward from the box body 91 and is formed of an elastic material, and is positioned below the platen 3 and extends in the second direction. A guide bar 92 that guides the movement of the body 91; a waste ink container 93 that is located on the side of the recording head 4 and has an upper surface open; and a drive mechanism 94 that moves the box body 91 along the guide bar 92. Composed. When the image is not recorded, the box 91 is disposed at the first position opposite to the waste ink container 93 with the recording head 4 interposed therebetween. After image recording, when the ejection surface 40 is wiped, the box 91 moves along the guide bar 92 toward the waste ink container 93 and reaches the second position where the lower surface faces the upper surface of the waste ink container 93. .

The wipe mechanism 9 wipes the discharge surface 40 as follows. After the image recording, the recording head 4 is lowered, the head element 41 passes through the through hole 33, and the ejection surface 40 protrudes downward from the platen 3.
The box body 91 moves along the guide bar 92 from the first position toward the second position. As shown in FIG. 4, the tip of the wipe piece 90 bends in contact with the ejection surface 40 and wipes ink adhering to the ejection surface 40. The wiped ink is stored in the box 91 along the wipe piece 90. When the box 91 moves to the second position, the drive mechanism stops the movement of the box 91 and discharges the wiped ink from the lower surface of the box 91 to the waste ink container 93. In this way, the ejection surface 40 is wiped off. The wipe mechanism 9 also wipes the liquid receiving member 70, but a detailed description is omitted.

As described above, the paper P is rectangular, and the long side or the short side may be bent, or the long side or the short side may be bent and bend. 3 and 5 below show the folded state of the paper P for convenience of illustration, but the technical contents of the present embodiment are similarly applied even when the paper P is bent.
When the paper P is transported onto the platen 3, as shown in FIG. 3, if the paper P has a bent or bent portion PK, as described above, the recording head 4 is a line-type head and extends in the second direction. Since the recording head 4 cannot move, the recording head 4 cannot avoid the bent or bent portion PK of the conveyed paper P. Therefore, the bent or bent portion PK may come into contact with the discharge surface 40 and damage the discharge surface 40. In addition, paper dust attached to the edge of the paper P may adhere to the discharge port 42 and clog the discharge port 42.
Further, as shown in FIG. 5, even if the ejection surface 40 is not damaged, the ink P is in contact with the meniscus (interface) of the ink formed in the ejection port 42 and the leading end of the bent or bent portion PK of the paper P. In this case, the ink is not ejected correctly thereafter, and the image is not correctly recorded on the paper P. Therefore, as described later, the ink jet recording apparatus according to the present embodiment detects the degree of the bent or bent portion PK of the paper P and performs a control operation such as stopping image recording on the paper P.

FIG. 6 is a block diagram showing a peripheral configuration of the control unit 8. The control unit 8 is composed of one CPU, but may be a combination of a plurality of CPUs. The control unit 8 may use a combination of a CPU and an ASIC (Application Specific Integrated Circuit).
In addition to the motor group M that rotates the operation panel 12, the terminal 13, the first conveyance roller pair 51 to the seventh conveyance roller pair 63, the control unit 8 includes a ROM 83 that stores an operation program, and information temporarily. RAM 84 that functions as a work memory for recording image, the recording head 4, the image sensor RK 1, the edge detection sensor SE 1, the degree of the bent or bent portion PK generated on the paper P, specifically, a threshold for storing a threshold relating to the size A storage unit 81 and an image data storage unit 82 for storing image data relating to an image recorded on the paper P are connected.

Here, the folding corresponds to the ear folding of the paper P, and the bending corresponds to the bending of the paper P. Here, the threshold regarding the size of the bent or bent portion PK is stored as at least one of the threshold related to the size of the bend generated on the paper P and the threshold related to the size of the bend generated on the paper P. Refers to that. Here, whether the bent or bent portion PK corresponds to whether it is bent or bent is determined by whether the outline shape, which is the outer shape of the paper P obtained through the image sensor RK1, is a rectangle, or the set paper P Depending on whether or not a rectangle having a certain aspect ratio corresponding to the size of the sheet P is maintained. That is, if the paper P is not rectangular, the folded or bent portion PK is broken, the paper P is rectangular, and a rectangle having a certain aspect ratio corresponding to the set size of the paper P is not maintained. It can be determined that the bent or bent portion PK is bent due to the bending of the paper P.
Although the above shows a simplified judgment for the sake of explanation, actually, the folded or bent portion PK has two portions, that is, the bent portion PK and the bent portion PK (that is, both the folded and bent portions of the paper P are generated. It is also possible to judge that. In that case, if the paper P is not rectangular and does not maintain a rectangle with a certain aspect ratio corresponding to the size of the paper P with respect to the set size of the paper P (such as A4), It can be determined that the bent or bent portion PK is two of the bent portion PK and the bent portion PK.
Here, as the threshold value, a value related to whether or not the sheet P comes into contact with the ejection surface 40 of the head due to bending or folding (for example, taking into account the deformation amount in the height direction) is stored. Actually, a suitable value is set by experiment.
For example, vector type data is input to the terminal 13 from the outside. The control unit 8 performs a known RIP (Raster Image Processor) process on the vector type data, and stores image data as bitmap data in which pixels are arranged in a matrix corresponding to the image recording area of the paper P. 82.

As shown in FIG. 7, a case is considered where there is a bent or bent portion PK at the downstream side in the transport direction of the paper P, that is, at the leading edge or the upstream side in the transport direction of the paper P, ie, at the rear end. The control unit 8 obtains an image of the paper P having a missing portion PL in the outline as shown by a one-dot chain line through the image sensor RK1. Since the missing portion PL corresponds to the bent or bent portion PK, the control unit 8 can determine from this image that the paper P has a bent or bent portion PK. In addition, since the image on the paper P is not rectangular, the control unit 8 knows that the bent or bent portion PK is broken.
The control unit 8 also obtains the dimension L1 in the first direction of the missing part PL indicated by the alternate long and short dash line and the dimension M1 in the second direction of the missing part PL from this image, and from these values, the degree of the bent or bent part PK, Specifically, the size of the bent or bent portion PK is obtained. The control unit 8 also obtains the position of the bent or bent portion PK on the paper P from the position of the missing portion PL. That is, the “contour measuring means” of the present invention is configured by the control unit 8 and the image sensor RK1. The control unit 8 performs image recording stoppage determination and preliminary discharge determination by obtaining the presence or degree (size) of the bent or bent portion PK and the position on the paper P.
Next, a method for determining that the bent or bent portion PK is bent will be described. The control unit 8 determines a size including a certain aspect ratio corresponding to the size of the paper P to be fed, based on image data, a print command, and the like. For the size including a certain aspect ratio corresponding to the paper P, the size stored in the ROM 83 or the like is used. Then, the aspect ratio of the image of the paper P obtained by the image sensor RK1 is calculated and compared with the determined fixed aspect ratio, and if it does not match, it is determined that the bent or bent portion PK is bent. The control unit 8 determines that a greater degree of bending occurs as the degree of aspect ratio mismatch increases.

(First image recording stop judgment operation)
Since the control unit 8 is connected to the image data storage means 82 in which the image data related to image recording is stored, at least a part of the image related to the image data is recorded in the bent or bent portion PK, that is, the bent. Alternatively, it can be determined whether or not the bent portion PK overlaps the image recording area. If an image is recorded on the bent or bent portion PK of the paper P, an inaccurate image is recorded on the entire paper P. Therefore, when it is determined that the image related to the image data is recorded on the bent or bent portion PK generated on the paper P, the image related to the image data is not recorded on the paper P. In this case, the control unit 8 stops the rotation of the motor group M to stop the conveyance of the paper P, displays that fact on the operation panel 12, and alerts the user. The determination not to record the image data on the paper P is performed regardless of the degree or size of the bent or bent portion PK. That is, it is performed even when the size of the bent or bent portion PK is less than the threshold value described later.
When it is determined that the image related to the image data is recorded on the bent or bent portion PK generated on the paper P, if the size of the bent portion PK is less than a threshold value described later, the control unit 8 determines that the motor group M Is stopped, the conveyance of the paper P is stopped, and the fact is displayed on the operation panel 12 to alert the user. Instead, the paper P is simply discharged to the discharge tray 11 and then conveyed. An image whose recording is interrupted may be recorded on the paper P.

(Second image recording stop judgment operation)
The threshold storage unit 81 stores a threshold corresponding to the size of the paper P, for example, A3, A4, a postcard, and the like, and this threshold varies depending on whether the paper P is bent or bent PK is bent or bent. The value is stored. For example, in the case of folding of the paper P, the tip of the folded portion is in contact with the discharge surface 40, and the discharge surface 40 may be more easily damaged than in the case of bending. The threshold value is different between the case of the bend.
The control unit 8 determines whether the bent or bent portion PK is bent or bent, and the bent or bent portion obtained from the threshold value regarding the bent or bent in the threshold storage unit 81 and the image obtained through the image sensor RK1. Compare the size of PK. The control unit 8 determines whether or not to record an image on the paper P based on the comparison result. That is, if the size of the bent or bent portion PK is equal to or greater than the threshold value related, the control unit 8 stops the conveyance of the paper P and stops image recording, and is less than the threshold value related to the size of the bent or bent portion PK. If so, image recording is performed. By stopping the conveyance of the paper P that has been bent or bent more than the threshold, it is possible to suppress the occurrence of a jam in the paper P and the expansion of the jam that has occurred in the paper P. Here, the jam indicates that the paper P is damaged such that the paper P cannot be properly discharged from the inkjet recording apparatus 1.

This threshold value is different depending on whether the folded or bent portion PK of the paper P is located at the leading edge or the trailing edge of the paper P. In the present embodiment, the upstream threshold value N1 corresponding to the trailing edge of the paper P is set smaller than the downstream threshold value N2 corresponding to the leading edge of the paper P. The upstream side threshold value N1 and the downstream side threshold value N2 are respectively set with respect to whether the bent or bent portion PK is bent or bent.
Specifically, the upstream side threshold value N1 corresponds to a size such that the bent or bent portion PK of the paper P is in contact with the ejection surface 40, but the downstream side threshold N2 is a bent or bent portion PK of the paper P. Corresponds to the size in contact with the discharge surface 40 and scratching the discharge surface 40.

(3rd image recording stop judgment operation)
When the rear end of the paper P is bent or bent, not only the occurrence and enlargement of the jam of the paper P but also the subsequent image recording on the paper P is greatly affected. That is, if the bent or bent portion PK generated at the rear end portion of the paper P breaks the ink meniscus formed on the discharge port 42 in contact with the discharge surface 40, Ink may not be ejected correctly and images may not be recorded correctly. Accordingly, when the rear end portion of the paper P is bent or bent, whether or not to record an image on the paper P is determined based on a stricter standard than when the front end portion of the paper P is bent or bent. Is going.
Specifically, if the size of the bent or bent portion PK generated at the rear end portion of the sheet P is equal to or greater than the upstream threshold N1, the control unit 8 stops the conveyance of the sheet P, that is, the motor group M is turned off. Stop. If it is determined that the bent or bent portion PK of the rear end of the paper P is in contact with the ejection surface 40 even though the conveyance of the paper P is stopped, the purge operation or the wipe mechanism 9 The wiping operation of the discharge surface 40 is performed. Both the purge operation and the wiping operation of the discharge surface 40 may be performed.
It should be noted that the determination that the bent or bent portion PK of the trailing edge of the paper P is in contact with the ejection surface 40 in spite of the stop of the conveyance of the paper P is the output of the edge detection sensor SE1 and the image sensor RK1. The control unit 8 determines based on the above. That is, the control unit 8 knows the time from when the edge detection sensor SE1 detects the leading edge of the paper P to when the motor group M is stopped and the conveyance speed of the paper P, so the paper P is detected by the edge detection sensor. You can see how far it has been transported after passing SE1. Since the position of the bent or bent portion PK is known via the image sensor RK1, the control unit 8 can determine whether the bent or bent portion PK of the rear end portion of the paper P is in contact with the ejection surface 40.

(Preliminary discharge judgment)
The threshold storage unit 81 stores a low threshold N3 smaller than the downstream threshold N2 corresponding to the leading edge of the paper P. The low threshold value N3 corresponds to a size that does not damage the discharge surface 40 even if the bent or bent portion PK of the paper P contacts the discharge surface 40, and is a value equivalent to the upstream threshold value N1. .
If the leading edge of the paper P is bent or bent, and the bent or bent portion PK is less than the downstream threshold N2 and has a size larger than the low threshold N3, that is, a size that does not damage the discharge surface 40, Even if the bent or bent portion PK comes into contact with the ejection surface 40, the liquid is ejected from the ejection port 42 in the subsequent image recording, so that the ejection port 42 is not damaged. However, there is a possibility that the ink meniscus formed in the ejection port 42 may be destroyed by contact with the paper P because the bent or bent portion PK contacts the ejection surface 40. Accordingly, preliminary ejection is performed from the plurality of ejection ports 42, and the ink ejection state from the ejection ports 42 is kept normal. In FIG. 7, preliminary ejection is performed on a hatched area A <b> 1 that is an area other than the bent or bent part PK on the paper P and overlaps the bent or bent part PK in the first direction. That is, preliminary ejection is performed from a plurality of ejection ports 42 that may have come into contact with the paper P. In addition, if preliminary ejection is performed on the bent or bent portion PK, ink attached to the paper P may adhere to the conveyance path of the paper P. Therefore, the hatched area A1 other than the bent or bent portion PK on the paper P. Pre-discharge is performed.

FIGS. 8A and 8B are plan views showing other modes of the bent or bent portion PK of the paper P. FIG. As shown in FIG. 8A, when the bent or bent portion PK of the leading end portion of the paper P extends over the entire short side on the downstream side in the first direction of the paper P, the paper P maintains a rectangular shape. Since the rectangle having a constant aspect ratio corresponding to the size of P is not maintained, the bent or bent portion PK is bent due to the bending of the paper P, and covers a wide range of the length in the second direction of the recording head 4. It is considered that it is in contact with the discharge surface 40. Therefore, if the length L1 in the first direction of the missing portion PL is large, the amount of bending, which is the size of the bent or bent portion PK, is also considered to be greater than or equal to the downstream threshold N2, so the control unit 8 stops conveying the paper P. To stop image recording. Of course, preliminary discharge is not performed.
As shown in FIG. 8 (b), when the central portion of the short side on the downstream side in the first direction of the paper P is torn and a bent or bent portion PK is generated, the bent or bent portion PK is less than the downstream threshold N2. If the size is equal to or larger than the low threshold value N3, preliminary ejection is performed from the plurality of ejection ports 42, and the ink ejection state from the ejection ports 42 is kept normal. The preliminary discharge area in this case is an area other than the bent or bent part PK on the paper P, and is a hatched area A2 that overlaps the bent or bent part PK in the first direction.

(Control action)
The ink jet recording apparatus 1 according to the present embodiment performs the control operation shown in the flowchart of FIG.
First, when the paper P passes through the image sensor RK1, the control unit 8 determines whether or not a folded or bent portion PK has occurred in the paper P from the contour image of the paper P obtained via the image sensor RK1 (step S1). S1). If there is no bent or bent portion PK on the paper P, an image is recorded on the paper P (step S2).
If the sheet P has a bent or bent portion PK, the control unit 8 performs a first image recording stop determination operation (step S3). FIG. 10 is a subroutine showing the first image recording stop determination operation. The control unit 8 determines whether or not the image related to the image data is recorded on the bent or bent portion PK generated on the paper P (step S10), and determines that the image is recorded on the bent or bent portion PK. In this case, the conveyance of the paper P is stopped and the image recording on the paper P is stopped (step S11). The control unit 8 displays the fact on the operation panel 12 to alert the user.
If the control unit 8 determines that the image related to the image data is not recorded on the bent or bent portion PK generated on the paper P, the process returns to step S4.
In the first image recording stop determination operation in step S3, the bending of the paper P covers the entire first direction or the second direction of the paper P, and it is possible to specify which part of the paper P is bent. It can be difficult. Accordingly, when it is determined that the paper P is bent, the image recording may be interrupted.

The control unit 8 determines whether the bent or bent portion PK is related to whether it is bent or bent, and determines whether the bent or bent portion PK is at the leading end of the paper P (step S4). If it is determined that the bent or bent portion PK is at the leading end of the sheet P, the control unit 8 performs a preliminary discharge determination operation and a second image recording stop determination operation (step S5). FIG. 11 is a subroutine showing the preliminary ejection determination operation and the second image recording stop determination operation. The control unit 8 determines whether or not the size of the bent or bent portion PK is equal to or greater than the downstream threshold N2 (step S20). If the size of the bent or bent portion PK is equal to or larger than the downstream side threshold N2, the bent or bent portion PK may contact the discharge surface 40 and damage the discharge surface 40. The conveyance is stopped (step S21), and the image recording is stopped. The control unit 8 displays the fact on the operation panel 12 to alert the user.
If the control unit 8 determines that the size of the bent or bent portion PK is less than the downstream threshold value N2, it next determines whether or not the bent or bent portion PK has a size greater than or equal to the low threshold value N3 (step). S22). If the bent or bent portion PK has a size less than the low threshold N3, the bent or bent portion PK is less likely to come into contact with the ejection surface 40, so the subroutine is exited and the process proceeds to step S6. If the bent or bent portion PK has a size equal to or larger than the low threshold value N3, preliminary ejection is performed from the plurality of ejection ports 42 as described above (step S23), and the ink ejection state from the ejection ports 42 is kept normal.

Next, the control unit 8 determines whether or not the bent or bent portion PK is at the rear end portion of the paper P (step S6). If it is determined that the bent or bent portion PK is at the rear end portion of the paper P, the control unit 8 performs a third image recording stop determination operation (step S7). FIG. 12 is a subroutine showing the third image recording stop determination operation. The control unit 8 determines whether or not the size of the bent or bent portion PK is equal to or greater than the upstream threshold N1 (step S30). If the size of the bent or bent portion PK is less than the upstream threshold value N1, there is little possibility that the bent or bent portion PK contacts the discharge surface 40. An image is recorded on (step S31).
If the size of the bent or bent portion PK is equal to or larger than the upstream threshold value N1, the bent or bent portion PK may come into contact with the ejection surface 40 and adversely affect image recording on the subsequent paper P. Then, the control unit 8 stops the conveyance of the folded sheet P or the bent sheet P and the subsequent sheet P (step S32), and stops the image recording. Next, the control unit 8 determines whether or not the bent or bent portion PK is in contact with the ejection surface 40 (step S33). If the bent or bent portion PK does not contact the ejection surface 40, the conveyance stop state of the paper P is maintained. If the bent or bent portion PK is in contact with the ejection surface 40, the ink meniscus formed at the ejection port 42 may be destroyed. Therefore, the control unit 8 lowers the recording head 4 and operates the purge operation or the wiping mechanism 9 to perform the wiping operation of the ejection surface 40 (step S34) to prepare for the subsequent image recording of the paper P.
The control unit 8 continues the above-described control operation until the image recording operation is completed, specifically, until the image recording is completed on all sheets P (step S8).

The ink jet recording apparatus 1 according to this embodiment has the following advantages.
1. Based on the measurement result obtained via the image sensor RK1, the control unit 8 determines the degree of folding or bending of the paper P and determines whether to record an image on the paper P. . As a result, image recording on the paper P can be completed more quickly than when no image is formed on all the paper P that has been bent or bent. When the degree of bending or bending of the paper P is equal to or greater than the threshold, the control unit 8 controls the transport mechanism so as to stop the transport of the paper P. That is, by stopping the conveyance of the paper P that has been bent or bent, the jam of the paper P and the expansion of the jam that has occurred on the paper P can be suppressed.

In the above embodiment, the “contour measurement unit” of the present invention is configured by the control unit 8 and the image sensor RK1. However, instead of this, the size and position of the missing portion PL of the paper P may be determined by the image sensor RK1. That is, only the image sensor RK1 may constitute the “contour measuring unit” of the present invention.
As for the threshold value, the bending threshold value and the bending threshold value are different, and the judgment is made based on each threshold value as described above, but a common threshold value may be used.

  The present invention is useful when used for an image recording apparatus including a recording head for recording an image on paper P, an image recording method, and a program used for the image recording apparatus.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 3 Platen 4 Recording head 8 Control part 9 Wipe mechanism 40 Discharge surface 42 Discharge port 83 Threshold storage means

Claims (9)

A transport mechanism for transporting the recording medium in the transport direction;
A recording head for recording an image on a recording medium conveyed by the conveyance mechanism;
Contour measuring means provided on the upstream side in the transport direction with respect to the recording head and for measuring the contour of a recording medium transported by the transport mechanism;
Threshold storage means for storing at least one of a threshold relating to the degree of bending occurring in the recording medium and a threshold relating to the degree of bending occurring in the recording medium;
A controller for controlling the transport mechanism and the recording head,
The controller is
Based on the measurement result by the contour measuring means, the presence or absence of occurrence of bending or bending of the recording medium, and the degree of bending or bending occurring in the recording medium,
When it is determined that the recording medium is bent or bent, the degree of bending or bending generated in the recording medium is compared with the threshold value,
When the degree of bending or bending occurring in the recording medium is equal to or greater than the threshold, the recording head and the transport mechanism are controlled so as not to record an image on the recording medium,
The recording head and the recording head so that an image is recorded on the recording medium when it is determined that the degree of bending or bending occurring on the recording medium is less than the threshold or that the recording medium is not folded or bent. An image recording apparatus for controlling the transport mechanism.   The image recording apparatus according to claim 1, wherein the control unit controls the transport mechanism so as to stop the transport of the recording medium when the degree of bending or bending is equal to or greater than a threshold value. The recording head has an ejection surface provided with a plurality of ejection ports for ejecting a liquid for recording an image on a recording medium.
The image recording apparatus according to claim 2, wherein the threshold value corresponds to a degree that a size of the bent or bent portion generated in the recording medium is in contact with the ejection surface. Image data storage means for storing image data relating to an image recorded on the recording medium;
The control unit also determines the occurrence position of the folding or bending occurring in the recording medium based on the measurement result of the contour measuring unit, and at least a part of the image related to the image data is generated in the recording medium. The recording head and the recording head to prevent the recording medium from recording an image related to the image data even if the degree of the bending or bending is less than the threshold value. The image recording apparatus according to claim 1, wherein the image recording apparatus controls a conveyance mechanism. The recording head has an ejection surface provided with a plurality of ejection ports for ejecting a liquid for recording an image on a recording medium.
A low threshold value that is a threshold value that is lower than the threshold value is stored in the threshold value storage means, and the low threshold value also corresponds to the extent that the size of a bent or bent portion generated in the recording medium contacts the ejection surface,
The control unit folds or bends at the downstream end in the conveyance direction of the recording medium based on the measurement result of the contour measuring unit, and the degree of the fold or bend is less than the threshold and greater than or equal to the low threshold. When it is determined that the recording medium is preliminarily ejected from the plurality of ejection ports, the preliminary ejection that is unrelated to the image recording based on the image data is performed on the recording medium. The image recording apparatus described. The recording head has an ejection surface provided with a plurality of ejection ports for ejecting a liquid for recording an image on a recording medium.
A liquid receiving member provided on the opposite side of the recording head with respect to the recording medium conveyance path, and a wiping mechanism that moves along the discharge surface and performs a wiping operation on the discharge surface; Prepared,
The control unit forcibly applies the liquid receiving member from the discharge surface when the bent or bent portion generated in the recording medium comes into contact with the discharge surface when the transport operation of the transport mechanism is stopped. The image recording apparatus according to claim 2, wherein a purge operation for discharging the liquid and a discharge surface wiping operation by the wiping mechanism are executed. The control unit also determines the occurrence position of the fold or bend based on the measurement result of the contour measuring means,
The threshold value storage means stores an upstream threshold value with respect to the degree of bending or bending occurring in the upstream portion of the recording medium in the conveying direction and a downstream threshold value with respect to the degree of bending or bending occurring in the downstream portion of the recording medium in the conveying direction. Has been
The upstream threshold is smaller than the downstream threshold;
When the control unit compares the degree of bending or bending occurring in the recording medium with the threshold value, the control unit sets the upstream threshold value with respect to the degree of bending or bending occurring in the upstream part of the recording medium in the conveyance direction. 7. The comparison is performed using the threshold value, and the downstream threshold value is used as the threshold value for the degree of bending or bending occurring in the downstream portion of the recording medium in the conveyance direction. The image recording apparatus described in 1. A transport mechanism for transporting the recording medium in the transport direction;
A recording head for recording an image on a recording medium conveyed by the conveyance mechanism;
Contour measuring means provided on the upstream side in the transport direction with respect to the recording head and for measuring the contour of a recording medium transported by the transport mechanism;
An image recording method in an image recording apparatus, comprising: a threshold storage unit that stores at least one of a threshold relating to the degree of bending occurring in the recording medium and a threshold relating to the degree of bending occurring in the recording medium,
Determining whether or not the recording medium is bent or bent based on the measurement result by the contour measuring means, and determining the degree of bending or bending generated in the recording medium;
When it is determined that the recording medium is bent or bent, a step of comparing the degree of bending or bending generated on the recording medium with the threshold value;
A step of controlling the recording head and the transport mechanism so that an image is not recorded on the recording medium when the degree of bending or bending occurring in the recording medium is equal to or greater than the threshold;
The recording head and the recording head so that an image is recorded on the recording medium when it is determined that the degree of bending or bending occurring on the recording medium is less than the threshold or that the recording medium is not folded or bent. And a step of controlling the transport mechanism. A transport mechanism for transporting the recording medium in the transport direction;
A recording head for recording an image on a recording medium conveyed by the conveyance mechanism;
Contour measuring means provided on the upstream side in the transport direction with respect to the recording head and for measuring the contour of a recording medium transported by the transport mechanism;
Threshold storage means for storing at least one of a threshold relating to the degree of bending occurring in the recording medium and a threshold relating to the degree of bending occurring in the recording medium;
A program used for an image recording apparatus including a control unit for controlling the transport mechanism and the recording head,
In the control unit,
Determining whether or not the recording medium is bent or bent based on the measurement result by the contour measuring means, and determining the degree of bending or bending generated in the recording medium;
When it is determined that the recording medium is bent or bent, a step of comparing the degree of bending or bending generated on the recording medium with the threshold value;
A step of controlling the recording head and the transport mechanism so that an image is not recorded on the recording medium when the degree of bending or bending occurring in the recording medium is equal to or greater than the threshold;
The recording head and the recording head so that an image is recorded on the recording medium when it is determined that the degree of bending or bending occurring on the recording medium is less than the threshold or that the recording medium is not folded or bent. A program for executing the step of controlling the transport mechanism.

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