WO2019058975A1

WO2019058975A1 - Cleaning device, image forming apparatus, and web cassette

Info

Publication number: WO2019058975A1
Application number: PCT/JP2018/032916
Authority: WO
Inventors: 竹内　誠
Original assignee: 富士フイルム株式会社
Priority date: 2017-09-22
Filing date: 2018-09-05
Publication date: 2019-03-28
Also published as: JPWO2019058975A1; JP6985400B2

Abstract

Provided are a cleaning device, an image forming apparatus, and a web cassette that are capable of suppressing erroneous detection of a marker provided to a web. This cleaning device is provided with: a web (10) that wipes the surface of an object to be cleaned; markers (70A, 70B) that are provided to the web; and a marker detection unit that detects the markers by receiving transmitted light or reflected light of light projected toward the web (10), wherein the initial shapes of the markers before application of tension to the web (10) are such that the initial lengths of the markers in a web width direction orthogonal to a web conveying direction are larger than the initial lengths of the markers in the conveying direction.

Description

Cleaning device, image forming apparatus and web cassette

The present invention relates to a cleaning device, an image forming device, and a web cassette, and more particularly to a cleaning device that wipes the surface of an object using a web, an image forming device provided with the cleaning device, and a cleaning device. The web cassette

An inkjet recording apparatus, which is an embodiment of an image forming apparatus, includes an inkjet head as a print head. Foreign matter such as ink residue and paper dust may adhere to the nozzle surface of the inkjet head. Foreign matter adhering to the nozzle surface adversely affects the ink ejection performance of the ink jet head, and causes deterioration of the quality of a printed image. For this reason, many inkjet recording apparatuses are equipped with a cleaning device for cleaning the nozzle surface of the inkjet head. In the inkjet recording apparatus, the inkjet head cleaning device is an important mechanism for maintaining the ink ejection performance.

Patent Document 1 discloses a nozzle surface cleaning device that cleans the nozzle surface of an inkjet head using a web. The “nozzle surface cleaning device” in Patent Document 1 is a term corresponding to the “cleaning device” in the present specification.

In the case of a cleaning apparatus using a web, a remaining amount detection mechanism for detecting the remaining amount of web is provided. The web remaining amount detection mechanism is an important mechanism to determine whether cleaning can be performed. As an example of the web remaining amount detection mechanism, a configuration is provided in which the web itself is provided with a marker and the device side is provided with a sensor that detects the web marker.

Patent Document 2 describes a configuration in which a web-like cleaner for wiping the nozzle surface of a recording head having a nozzle for discharging droplets is provided with a scale for feed amount detection. The image forming apparatus described in Patent Document 2 includes a sensor that detects a scale provided on the cleaner, and the sensor can detect the feed amount of the cleaner by detecting the scale on the cleaner. . The "cleaner" in Patent Document 2 is understood as a term corresponding to the "web" in the present specification. The "scale" in Patent Document 2 is a term corresponding to the "marker" in the present specification.

Patent Document 3 describes a configuration in which a notch is provided at a web position on the near side of the terminal end of the cleaning web for detecting the remaining amount of the cleaning web. The cleaning device described in Patent Document 3 includes a sensor that detects a notch formed in the cleaning web itself, and the sensor is used to detect the notch of the cleaning web to detect the cleaning web. It warns the user that the remaining amount is low. The "cleaning web" in Patent Document 3 is a term corresponding to the "web" in the present specification. The "notch" in Patent Document 3 is a term corresponding to the "marker" in the present specification.

JP, 2013-169761, A JP 2014-8763 A JP, 2015-152815, A

However, when a stretchable belt-like web is transported by a roll-to-roll method or the like, the tension applied to the web deforms the markers on the web. That is, when the web is transported, tension is applied to the web in a direction parallel to the transport direction, and the web extends in the transport direction and contracts in the web width direction orthogonal to the transport direction. Along with such deformation of the web, the marker also shrinks in the web width direction orthogonal to the transport direction. As a result, in the conventional web remaining amount detection mechanism, the positional relationship between the detection range of the sensor and the area of the marker may be shifted, and the sensor may not detect the marker normally.

This problem is not limited to the cleaning device used for wiping the nozzle surface of the inkjet head, but is a problem common to cleaning devices for various uses for wiping the surface of the object to be cleaned using a web.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a cleaning device capable of suppressing false detection of a marker provided on a web. The present invention also provides an image forming apparatus including a cleaning device capable of suppressing false detection of a marker provided on a web, and a web cassette.

In order to solve the problems, the following invention aspects are provided.

The cleaning device according to the first aspect detects the marker by receiving the web for wiping the surface of the object to be cleaned, the marker provided on the web, and the reflected light or the transmitted light of the light projected toward the web In the initial shape of the marker before tension is applied to the web, the initial length of the marker in the web width direction orthogonal to the transport direction when transporting the web is the initial length of the marker in the transport direction Is a shape larger than

The initial shape of the marker means the shape of the marker in the initial state before tension is applied to the web. The markers have a two-dimensional extent in the plane of the web. The term "marker shape" includes the concept of the shape and size (size) of the area of the marker.

The initial length of the marker in the web width direction refers to the length in the web width direction of the initial shape of the marker. The initial length of the marker in the transport direction refers to the length in the transport direction of the initial shape of the marker.

In the cleaning device according to the first aspect, the initial shape of the marker is configured to be long in the web width direction, in anticipation of the deformation of the marker accompanying the deformation of the web when tension is applied to the web. According to the aspect 1, the shape of the marker in a state where tension is applied to the web, that is, the shape of the marker after deformation can be secured to a necessary size, and the false detection by the marker detection unit is suppressed. Becomes possible.

A second aspect of the invention is the cleaning device according to the first aspect, wherein the initial shape of the marker is an elliptical shape with the long axis in the web width direction.

In the case of the second aspect, the length of the major axis corresponds to "the initial length of the marker in the web width direction", and the length of the minor axis corresponds to the "initial length of the marker in the transport direction".

In the cleaning device according to mode 2, when the length of the major axis of the elliptical shape is d1 [mm] and the length of the minor axis is d2 [mm] in the cleaning device according to mode 2, the elliptical shape has a relationship shown in the following equation. It is a cleaning device that meets.

d1> c / (1 + ε _x )
d2> c / (1 + ε _y )
here,
With the web width direction as the x-axis direction and the web transport direction as the y-axis direction,
ε _y = σ _y / E
ε _x = −ν · σ _y / E
σ _y = F / (w · t)
However,
F: tension applied to the web [N],
t: Web thickness [mm],
w: Initial web width [mm],
E: Young's modulus of the web [N / mm ² ],
ν: Poisson's ratio of the web,
ε _x : strain in the x-axis direction of the web when tension is applied,
ε _y : strain in the y-axis direction of the web when tension is applied,
c: Diameter [mm] of detection range of marker detection unit,
σ _y : vertical stress due to tension F Aspect 4 is the cleaning device according to aspect 1, wherein the initial shape of the marker is square. For example, the initial shape of the marker may be rectangular or rhombus.

A fifth aspect is the cleaning device according to any one of the first to fourth aspects, wherein the marker detection unit includes a photo sensor, and the deformed shape of the marker in a state in which the web is deformed by applying tension to the web is The cleaning device has a shape that includes the detection range of the marker detection unit.

The marker detection unit may be configured using a reflective photo sensor, or may be configured using a transmissive photo sensor. “Include the detection range of the marker detection unit” means that the shape of the marker after deformation matches the detection range of the marker detection unit, or the detection range of the marker detection unit is inside the shape of the marker after deformation. It says the relation which the whole enters.

A sixth aspect is the cleaning device according to the fifth aspect, wherein the marker detection unit is a cleaning device in which a light emitting diode is used for a light emitting unit that projects light on the web.

Aspect 7 is the cleaning device according to aspect 5 or aspect 6, wherein the initial length of the marker in the web width direction in the initial shape of the marker is d1 [mm], the initial length of the marker in the transport direction is d2 [mm], marker detection The diameter of the detection range of the part is c [mm], the post-deformation length of the marker in the web width direction is d1A [mm] in the shape after deformation of the marker in the deformed state of the web by applying tension to the web Assuming that the post-deformation length of the marker in the transport direction in the shape after deformation is d2A [mm], the following equation can be applied to at least one specific d [mm] satisfying c ≦ d:
d1> d
d2 ≦ d
d1A> d
d2A> d
This cleaning device satisfies

According to the seventh aspect, the marker after deformation has a shape that includes a circle of diameter d [mm]. That is, the shape of the marker after deformation includes the detection range of the marker detection unit.

In an eighth aspect according to the cleaning device of any one of the first to seventh aspects, the initial position of the marker before tension is applied to the web is offset in the web width direction with respect to the detection position of the marker detection unit on the web. The distance from the center of the width of the web to the initial position of the marker is a cleaning device that is larger than the distance from the center of the width of the web to the detection position of the marker detection unit.

The initial position of the marker means the position of the marker in the initial state before tension is applied to the web. In the cleaning device according to the eighth aspect, the initial position of the marker deviates in the web width direction with respect to the detection position of the marker detection unit in advance in consideration of the movement of the marker accompanying the deformation of the web when tension is applied to the web. Are configured in the same position. According to the eighth aspect, the position of the marker in a state where tension is applied to the web, that is, the position of the marker after deformation matches the detection position of the marker detection unit or the detection position of the marker detection unit It becomes possible to position the difference in position within the allowable range, and it is possible to further suppress false detection by the marker detection unit.

Aspect 9 is the cleaning device according to any one of aspects 1 to 8, wherein the initial position of the marker before tension is applied to the web is offset in the web width direction with respect to the detection position of the marker detection unit on the web. The initial position of the marker is a cleaning device whose distance from the center position of the width of the web is a distance e [mm] satisfying the following equation.

e = f / (1 + ε _x )
here,
With the web width direction as the x-axis direction and the web transport direction as the y-axis direction,
ε _y = σ _y / E
ε _x = −ν · σ _y / E
σ _y = F / (w · t)
However,
F: tension applied to the web [N],
t: Web thickness [mm],
w: Initial web width [mm],
E: Young's modulus of the web [N / mm ² ],
ν: Poisson's ratio of the web,
ε _x : strain in the x-axis direction of the web when tension is applied,
ε _y : strain in the y-axis direction of the web when tension is applied,
e: The distance [mm] from the center of the web width to the initial position of the marker,
f: distance [mm] from the center position of the web width to the detection position of the marker detection unit
sigma _y: According to the normal stresses embodiment 9 according to the tension F, the position of the marker in a state where tension is applied to the web (the position of the marker after deformation), it is possible to match the detection position of the marker detecting unit.

Aspect 10 is the cleaning device according to any one of aspects 1 to 9, wherein the marker is at least one of a marker indicating the remaining amount of web and a marker indicating the feed amount of web. It is.

An image forming apparatus according to aspect 11 is an image forming apparatus including the cleaning device according to any one of aspects 1 to 10, and a drawing unit that forms an image on a recording medium.

A twelfth aspect of the invention is the image forming apparatus according to the eleventh aspect, wherein the drawing unit includes an ink jet head, and the cleaning device is an image forming apparatus that wipes the nozzle surface of the ink jet head as an object to be cleaned using a web.

The web cassette according to the thirteenth aspect includes a web for wiping the surface of the object to be cleaned, a case for containing the web wound in a roll, a supply shaft provided for the case, for feeding the web by rotation, and for the case And a take-up shaft for taking up the web by rotation, wherein the web is provided with a marker, and the initial shape of the marker before the web is tensioned conveys the web It is a web cassette which is a shape whose initial length of the marker of the web width direction orthogonal to the conveyance direction at the time is larger than the initial length of the marker of the conveyance direction.

The web cassette of aspect 13 can be used by being attached to the cleaning device specified in aspect 1 to aspect 10. The web cassette is preferably configured to be replaceable with respect to the cleaning device. About the web cassette which concerns on aspect 13, the matter similar to the specific matter of the cleaning apparatus specified in aspect 2 to aspect 10 can be combined suitably.

According to the present invention, false detection of a marker provided on a web can be suppressed.

FIG. 1 is a front sectional view schematically showing the structure of the cleaning device. FIG. 2 is a perspective view schematically showing a configuration example of the marker detection unit. FIG. 3 is a plan view showing a part of a web according to a comparative example. FIG. 4 is a plan view showing a state where tension is applied to the web shown in FIG. FIG. 5 is a plan view showing a part of a web used for the cleaning device according to the first embodiment of the present invention. FIG. 6 is a plan view showing a state in which tension is applied to the web shown in FIG. FIG. 7 is a plan view of the web in an initial state before tension is applied. FIG. 8 is a plan view of the web in a tensioned state (after deformation). FIG. 9 is an explanatory view showing a first form example of the marker provided on the web. FIG. 10 is a plan view showing a reference example of the positional relationship between the position of the marker before tension is applied to the web (before deformation) and the detection position of the sensor. FIG. 11 is a plan view showing the positional relationship between the position of the marker and the detection position of the sensor when tension is applied to the web shown in FIG. 10 (after deformation). FIG. 12 is an explanatory view showing the outline of the second embodiment, and is a plan view showing the positional relationship between the position of the marker before tension is applied to the web (before deformation) and the detection position of the sensor. FIG. 13 is a plan view showing the positional relationship between the position of the marker and the detection position of the sensor in a state (after deformation) in which tension is applied to the web shown in FIG. FIG. 14 is an explanatory view showing another example 2 of the marker provided on the web. FIG. 15 is an overall configuration diagram showing an overall configuration of the inkjet recording apparatus. FIG. 16 is a block diagram showing a schematic configuration of a control system of the ink jet recording apparatus. FIG. 17 is a perspective view showing a schematic configuration of the ink jet head. FIG. 18 is a plan view showing a schematic configuration of the nozzle surface of the ink jet head. FIG. 19 is an enlarged plan view of the nozzle surface of one head module which is a part of the nozzle surface. FIG. 20 is a plan view of the maintenance unit and the drawing unit. FIG. 21 is a schematic configuration diagram of the cleaning device.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

<< Configuration Example of Cleaning Device >>
FIG. 1 is a front sectional view schematically showing the structure of the cleaning device. The cleaning device 1 illustrated in FIG. 1 is a nozzle surface cleaning device that wipes the nozzle surface 52 of the inkjet head 50 using the web 10. The inkjet head 50 is an object to be cleaned, and is an example of an object to be cleaned. The nozzle surface 52 is an example of the surface of the object to be cleaned.

The inkjet head 50 may be, for example, a line head. The cleaning device 1 presses and abuts the web 10 on the nozzle surface 52 of the moving inkjet head 50 to wipe the nozzle surface 52. The inkjet head 50 moves from right to left in FIG. The moving direction of the inkjet head 50 shown in FIG. 1 is a direction along the longitudinal direction of the inkjet head 50.

The cleaning device 1 includes a web 10, a case 12 for containing the web 10, a supply shaft 14 for delivering the web 10, a take-up shaft 16 for winding the web 10, a pressure roller 18, a front stage guide portion 20, and a rear stage A guide portion 22 and a feed roller 24 are provided. The cleaning device 1 also includes a supply shaft rotation drive motor 32 that rotationally drives the winding shaft 16, a winding shaft rotation drive motor 34 that rotationally drives the winding shaft 16, and a feed roller rotation that rotationally drives the feed roller 24. You may provide the drive motor 36 and the control circuit 38 which controls the drive of each motor.

The web 10 is formed of a band-like sheet material having absorbency. As the web 10, for example, a sheet material made of knitting or weaving using ultrafine fibers such as polyethylene terephthalate (PET), polyethylene (PE), nylon (NY), acrylic, etc. may be used it can.

The width of the web 10 is not particularly limited. For example, the width of the web 10 corresponds to the width of the nozzle surface 52 of the inkjet head 50 in the lateral direction, and the width of the nozzle surface 52 is the same as the width of the nozzle surface 52 The width is larger than the width in the short direction. The “same width” is not limited to strictly equal but includes a tolerance that can be regarded as substantially the same width. The width in the short direction of the nozzle surface 52 of the inkjet head 50 is the width of the nozzle surface 52 in the direction orthogonal to the moving direction (longitudinal direction) of the inkjet head 50.

The supply shaft 14 is rotatably supported by a bearing (not shown) provided on the case 12. A reel (not shown) is detachably mounted on the supply shaft 14. The web 10 is wound around the reel in a roll and attached to the supply shaft 14. The supply shaft 14 is driven by the supply shaft rotation drive motor 32 to rotate.

The winding shaft 16 is rotatably supported by a bearing (not shown) provided on the case 12. A reel (not shown) is detachably mounted on the winding shaft 16. The winding shaft 16 is driven by the winding shaft rotation drive motor 34 to rotate. The web 10 is rolled up on a reel mounted on the winding shaft 16.

The pressure roller 18 is a roller that presses and abuts the web 10 on the nozzle surface 52. The pressure roller 18 is rotatably and vertically movably supported by a shaft support (not shown) provided on the case 12. The pressure roller 18 is supported by the shaft support in a state of being biased upward in FIG. 1, that is, in a direction to press and abut on the nozzle surface 52. The traveling path of the web 10 is set so as to be wound around the upper circumferential surface of the pressing roller 18. The web 10 is in pressure contact with the nozzle surface 52 of the inkjet head 50 via the pressure roller 18.

The front stage guide portion 20 guides the traveling of the web 10 between the supply shaft 14 and the pressing roller 18. The front stage guide unit 20 is configured to include a plurality of

guide rollers

20A, 20B, and 20C as guide members. Each of the plurality of

guide rollers

20A, 20B, 20C is disposed at a predetermined position of the case 12. Each

guide roller

20A, 20B, 20C is rotatably supported by a bearing (not shown) provided on the case 12. The web 10 is wound around each of the

guide rollers

20A, 20B, and 20C, and travels between the supply shaft 14 and the pressing roller 18.

The rear stage guide portion 22 guides the traveling of the web 10 between the pressure roller 18 and the feed roller 24. The rear stage guide portion 22 is configured to include a plurality of

guide rollers

22A and 22B. Each of the plurality of

guide rollers

22A, 22B is disposed at a predetermined position of the case 12. Each

guide roller

22A, 22B is rotatably supported by a bearing (not shown) provided on the case 12.

The number and installation positions of the guide rollers constituting each of the front stage guide portion 20 and the rear stage guide portion 22 are appropriately adjusted according to the installation positions of the supply shaft 14, the winding shaft 16, the pressing roller 18 and the like. .

The feed roller 24 feeds the web 10. The feed roller 24 is rotatably supported by a bearing (not shown) provided on the case 12. The feed roller 24 is driven by the feed roller rotation drive motor 36 to rotate. As a result, the web 10 wound around the feed roller 24 is fed. A nip roller (not shown) is disposed at a position facing the feed roller 24.

The supply shaft rotation drive motor 32 is a power source for rotating the supply shaft 14. The supply shaft rotation drive motor 32 may be provided in the case 12 or may be disposed outside the case 12. The supply shaft 14 is rotated by driving the supply shaft rotation drive motor 32. In addition, the supply shaft 14 is stopped from rotating by stopping the drive of the supply shaft rotation drive motor 32. Thereby, the delivery of the web 10 is stopped. That is, the supply shaft rotation drive motor 32 also functions as a braking means, and brakes the traveling of the web 10 on the upstream side of the pressing roller 18.

The winding shaft rotation drive motor 34 is a power source for rotating the winding shaft 16. The take-up shaft rotation drive motor 34 may be provided to the case 12 or may be disposed outside the case 12.

The feed roller rotation drive motor 36 is a power source for rotating the feed roller 24. The feed roller rotation drive motor 36 may be provided in the case 12 or may be disposed outside the case 12.

The control circuit 38 controls the drive of the feed shaft rotation drive motor 32, the take-up shaft rotation drive motor 34, and the feed roller rotation drive motor 36 to control the traveling of the web 10.

The cleaning device 1 also includes a marker detection unit 42 that detects a marker provided on the web 10. The illustration of the markers is omitted in FIG. For example, a reflective photo sensor or a transmissive photo sensor is employed as the marker detection unit 42. The marker detection unit 42 is connected to the control circuit 38.

The marker detection unit 42 projects light toward the web 10, receives the reflected light or the transmitted light, and detects the presence or absence of a marker. The marker detection unit 42 sends a detection signal indicating the presence or absence of a marker to the control circuit 38. The control circuit 38 can determine the remaining amount of the web 10 based on the detection signal obtained from the marker detection unit 42, and can perform processing according to the determination result. For example, the control circuit 38 is connected to a notification unit (not shown), and can control the operation of the notification unit to provide information for notifying the user of the time to replace the web 10. The notification unit includes, for example, a display device, a warning lamp, an audio output device, or a combination thereof.

In the present specification, the marker detection unit 42 may be simply referred to as a “sensor”. The light projected from the marker detection unit 42 onto the web 10 may be referred to as “sensor light”.

The web 10 is transported by a roll-to-roll method from a reel on the supply shaft 14 side toward a reel on the take-up shaft 16 side. The web 10 has elasticity and can be deformed by the tension applied at the time of conveyance.

<< Description of the task >>
FIG. 2 is a perspective view schematically showing a configuration example of the marker detection unit 42. As shown in FIG. Here, an example using the web 10 shown in FIG. 2 to FIG. 4 as the web 10 shown in FIG. 1 will be shown, and a configuration example of the marker detection unit 42 and technical problems will be described.

The web 10 is conveyed upward from the bottom in FIG. The white arrows in FIG. 2 indicate the transport direction of the web 10. The transport direction of the web 10 is synonymous with the "traveling direction" or the "feed direction" of the web 10 directed from the supply shaft 14 to the take-up shaft 16. The web 10 is provided with

markers

60A and 60B. The

markers

60A, 60B are, for example, through holes. The

markers

60A and 60B illustrated in FIG. 2 are so-called end-end detection markers that indicate that the remaining amount of the web 10 is close to the end and is low. The

markers

60A and 60B are provided at a predetermined position away from the terminal end of the web 10 in the transport direction of the web 10 by a predetermined distance.

The cleaning device 1 includes

marker detection units

42A and 42B as means for detecting the

markers

60A and 60B. The marker detection unit 42A is a sensor for detecting the marker 60A. The marker detection unit 42B is for detecting the marker 60B. Each of the

marker detection units

42A and 42B is configured using, for example, a reflection type photo sensor. The reflective photosensor includes a light emitting unit and a light receiving unit. A light emitting diode (LED: Light Emitting Diode) is used for the light emitting part, and a phototransistor is used for the light receiving part.

In the example of FIG. 2, from the viewpoint of more reliable detection of the remaining amount, the marker detection unit is made redundant, the web 10 is provided with two

markers

60A and 60B, and the cleaning device 1 is provided with two markers. The

detection units

42A and 42B are provided.

The relationship between the marker detection unit 42A and the marker 60A, and the relationship between the marker detection unit 42B and the marker 60B are common, and the configurations of the two

marker detection units

42A and 42B are also common.

The

marker detection units

42A and 42B receive the light reflected from the web 10 in a normal use state where the remaining amount of the web 10 is sufficiently remaining, and detect "no marker", that is, "with web". Detect When the

markers

60A and 60B arranged immediately before the web 10 is used up or in front of the specified amount come to the front of the

marker detection units

42A and 42B, no light is reflected to the

marker detection units

42A and 42B, so the

marker detection unit

42A , 42B detect "with marker", that is, detect "without web". The “front” of the

marker detection units

42A and 42B corresponds to the irradiation position on the web of the light projected from the

marker detection units

42A and 42B.

FIG. 3 is a plan view showing a part of the web 10 according to the comparative example. FIG. 3 shows the web 10 in an initial state in which the web 10 is not tensioned. The

markers

60A, 60B provided on the web 10 shown in FIG. 3 are through holes. The shape of the

markers

60A and 60B is circular according to the shape of the detection range of the

marker detection units

42A and 42B. The detection range of the photosensors used for the

marker detection units

42A and 42B is generally circular. The detection range of each

marker detection part

42A, 42B may be described as "the detection range of a sensor." The detection range of the sensor is defined by the irradiation range of the sensor light projected onto the web and the visual field range (light receiving range) of the light receiving unit. Since the irradiation range of the sensor light on the web and the visual field range of the light receiving unit on the web substantially match, the detection range of the sensor may be regarded as the irradiation range of the sensor light on the web. Alternatively, it may be regarded as the view range of the light receiving unit on the web.

The diameter of each

marker

60A, 60B is equal to or larger than the diameter of the detection range of the sensor, and preferably includes a moderate margin with respect to the diameter of the detection range of the sensor.

FIG. 4 shows the web 10 shown in FIG. 3 in a tensioned state. During web transport, tension is applied to the web 10 in a direction parallel to the transport direction, and the web 10 extends in a direction parallel to the transport direction and contracts in the web width direction. That is, due to the resistance when transporting the web 10, a force is exerted to stretch the web 10 in the direction parallel to the transport direction, and the web width direction is contracted. As a result, the width of the

markers

60A and 60B is also smaller than in the initial state, and part of the sensor light is reflected by the surface of the web 10 without being transmitted through the through holes of the

markers

60A and 60B. The light reflected by the surface of the light source is received by the

marker detection units

42A and 42B and erroneously detected.

First Embodiment
FIG. 5 is a plan view showing a part of the web 10 used in the cleaning device 1 according to the first embodiment of the present invention. FIG. 5 shows the web 10 in an initial state in which the web 10 is not tensioned. FIG. 6 shows the web 10 shown in FIG. 5 in a tensioned state.

As shown in FIG. 5, the web 10 used in the cleaning device 1 according to the first embodiment includes the markers 70 </ b> A and 70 </ b> B having an elliptical shape in the initial state. That is, the initial shapes of the

markers

70A and 70B are elliptical shapes in which the direction parallel to the conveyance direction of the web 10 is the short axis and the web width direction is the long axis in anticipation of deformation due to tension applied to the web 10 during conveyance. ing. The initial shape means a shape in an initial state in which the web 10 is not tensioned. As shown in FIG. 6, the

markers

70A and 70B whose initial shape is an elliptical shape are stretched in a direction parallel to the conveyance direction as shown in FIG. obtain. The term "perfect circle" as used herein is not limited to a strictly true circle but substantially includes an allowable range that can be regarded as a true circle. In this specification, an initial state in which tension is not applied to the web 10 may be referred to as "before deformation", and a state in which tension is applied to the web 10 may be referred to as "after deformation". Also, the web width direction may be simply referred to as "width direction".

Design Example 1 of Shape of Marker
The following calculation method can be applied as a concept when designing the shape of the marker in consideration of the tension applied to the web.

As coordinate axes used for the calculation, the web width direction is taken as the x-axis direction, and the direction parallel to the web conveyance direction is taken as the y-axis direction. The tension applied to the web is F [N], the thickness of the web t [mm], the initial width of the web w [mm], the Young's modulus of the web E [N / mm ² ], the Poisson's ratio of the web をDo. The unit of F is Newton [N]. The unit of t and w is a millimeter [mm]. The unit of Young's modulus is Newton per square millimeter [N / mm ² ]. The initial width of the web refers to the width of the web in the initial state before tension is applied to the web.

The strain ε _{x in} the x-axis direction of the web when tension is applied, the strain ε _{y in} the y-axis direction, and the vertical stress σ _y by the tension F are expressed by the following equations.

ε _y = σ _y / E [Equation 1]
ε _x = −ν · σ _y / E ... [Equation 2]
σ _y = F / (w · t) ... [Equation 3]
Here, when making the shape of the marker into a circular shape of diameter d [mm] in a state where tension F [N] is applied to the web, x axis diameter d1 [mm] of the ellipse before tension is applied, y axis The relationship between the diameter d2 [mm] and d is as follows. The x-axis diameter of the ellipse means the length of the major axis in the x-axis direction, and is synonymous with the major axis. The y-axis diameter of an ellipse means the length of the minor axis in the y-axis direction, and is synonymous with the minor axis.

d1 + d1 · ε _x = d [Equation 4]
d 2 + d 2 · ε _y = d ... [Equation 5]
Therefore, d1 and d2 may be set as follows.

d1 = d / (1 + ε _x ) ... [Equation 6]
d2 = d / (1 + ε _y ) ... [Equation 7]
In addition, assuming that the detection range of the sensor that detects the marker is a circular shape of diameter c [mm], more preferably, d c c,
d> c ... [Equation 8]
By setting so as to be, it is possible to suppress false detection of the sensor.

D1 is an example of the initial length of the marker in the web width direction. d2 is an example of the initial length of the marker in the transport direction.

FIG. 7 is a plan view of the web in an initial state before tension is applied. FIG. 8 is a plan view of the web in a tensioned state (after deformation). 7 and 8 show an example in which only one marker 70 is provided at the center position in the width direction of the web 10 in order to simplify the description.

Assuming that the detection range of the sensor that detects the marker 70 is a circular shape of diameter c [mm], d を満たす satisfying d c c, more preferably, for d 1 and d 2 of the marker 70 with respect to d satisfying 式By setting the values 6 and 7 to be satisfied, false detection of the sensor can be suppressed.

<Design Example 2 of Shape of Marker>
In Design Example 1 described above, calculation is made on an example in which the deformed marker shape is a true circle of diameter d [mm], but the deformed marker shape may be an ellipse.

Assuming that the x-axis diameter d1A [mm] and the y-axis diameter d2A [mm] of the ellipse after deformation, the relationship between d1 and d1A and the relationship between d2 and d2A become the following equations, respectively.

d1 + d1 · ε _x = d1A ... [Equation 9]
d 2 + d 2 · ε _y = d 2 A · · · [Equation 10]
Therefore, in order to make the shape of the marker after deformation elliptical, d1 and d2 may be set as in the following equation.

d1 = d1A / (1 + ε _x ) ... [Equation 11]
d2 = d2A / (1 + ε _y ) ... [Equation 12]
When this design example 2 is adopted, if d1A> c and d2A> c are set, false detection of the sensor can be suppressed. The deformed ellipse has a margin in each of the x-axis direction and the y-axis direction with respect to the detection range of the sensor. That is, the deformed ellipse has a margin of "d1A-c" in the x-axis direction and a margin of "d2A-c" in the y-axis direction with respect to the detection range of the sensor. For this reason, for example, even if a deviation occurs from the amount of deformation of the initial calculation due to a change (fluctuation) in tension applied to the web, no erroneous detection occurs immediately.

D1A is an example of the post-deformation length of the marker in the web width direction. d2A is an example of the post-deformation length of the marker in the transport direction.

<< specific example of calculation about shape of marker >>
For example, it is assumed that the configuration of the cleaning device has the parameters shown in Table 1 below.

Reference Example 1
In the case of the conditions having the parameters shown in Table 1, assuming that the marker shape in the initial state has the same x-axis diameter D1 and y-axis diameter D2, that is, a circular shape, the deformed ellipse has the dimensions shown in Table 2 below. It becomes a shape.

In the case of the first reference example shown in Table 2, since the x-axis diameter D1A of the deformed ellipse is smaller than the diameter c of the detection range of the sensor (D1A <c), false detection may occur.

Example 1
On the other hand, in the cleaning device according to the embodiment to which the present invention is applied, for example, the case where the parameters shown in Table 3 below are given is considered.

In the case of the first embodiment, the x-axis diameter d1A of the deformed ellipse is larger than the diameter c of the detection range of the sensor (d1A> c), and the y-axis diameter d2A of the deformed ellipse is the detection of the sensor It becomes larger than the diameter c of the range (d2A> c) and no false detection occurs.

<< Conditions on initial shape of marker >>
Preferred conditions when the initial shape of the marker is an elliptical shape can be summarized in the following equation.

d1> d2 ・・・ [equation 13]
d1> c / (1 + ε _x ) ... [Equation 14]
d2> c / (1 + ε _y ) ... [Equation 15]
By satisfying Expressions 13 to 15, erroneous detection can be suppressed.

"About the upper limit of the size of the marker"
According to the formulas shown in Design Example 1 and Design Example 2 of the shape of the marker, the larger the marker size than the detection range of the sensor, the more advantageous it looks, but there is a limit to the size of the marker. is there. For example, when the marker is a through hole, if the opening area of the through hole is too large, both ends in the web width direction, which is the web area around the through hole, become thin and the web becomes tensioned when the web is tensioned. There is a risk of breakage. Also, making the marker too large will reduce the area of the part that can be used for cleaning. Therefore, it is preferable to avoid making the size of the marker larger than necessary.

The size of the marker satisfies the condition that the shape of the marker after deformation in a state where tension is applied to the web is a shape including a target circle of diameter d including a reasonable margin for the detection range of the sensor, It is desirable to make the size as small as possible.

<< Preferred condition of initial shape of marker >>
In addition to the viewpoint of making the size of the marker as small as possible, and arranging the preferable conditions regarding the initial shape of the marker, by satisfying the following equation as the diameter d of the target circle which is larger than the diameter c of the detection range of the sensor, False detection can be suppressed.

d1> d2 ・・・ [equation 16]
d1> d ··· [Equation 17]
d2 d d · · · [equation 18]
d1A> d... [equation 19]
d2A> d ··· [Equation 20]
This means that Equations 16 to 20 are satisfied for a specific value of d that satisfies c ≦ d.

Note that the value of specific d is not limited to one. In other words, it means that there exist values of d that satisfy the five inequalities of Expression 16 to Expression 20 and satisfy c ≦ d. For example, it may be d2 <c from equation 18 as d = c.

<< Standard for the size of tension F [N] applied to the web >>
The tension F [N] applied to the web is, for example, 0.1 to 2 [N]. The tension F [N] applied to the web in the situation where it is usually used is about 0.1 to 2 [N] for the cleaning device for various uses such as the cleaning device for the purpose of wiping the nozzle face of the inkjet head It is common.

"Guide to Young's Modulus of the Web"
The Young's modulus of the web is, for example, 7 to 60 [N / mm ² ]. Although various types of webs are assumed to be used depending on the application of the cleaning device, the Young's modulus of various webs used in the cleaning device is generally in the range of 7 to 60 [N / mm ² ]. is there.

<< Example 1 of marker provided on the web >>
FIG. 9 is an explanatory view showing a first form example of the marker provided on the web. FIG. 9 shows an example of the

markers

70A and 70B for detecting the end terminal described in FIGS. 5 and 6.

The

markers

70A and 70B are provided at positions separated from the end terminal on the supply axis side of the web 10 by a predetermined distance in the transport direction. As described in FIG. 5, the initial shape of the

markers

70A and 70B has an elliptical shape whose major axis is in the web width direction. When two markers 70A and markers 70B are arranged side by side in the width direction of the web within the width of the web 10, the two

markers

70A and 70B are symmetrical with respect to the center line of the width of the web 10. Is preferably provided.

In the case of arranging two markers 70A and markers 70B side by side in the width direction of the web within the width of the web 10, as shown in FIG. 6, two tensions are applied to the web 10 in a tensioned state. The width of the web area between 70A and the marker 70B is preferably equal to or greater than the width in the short direction of the nozzle surface 52 of the inkjet head 50. According to such a configuration, even if the two

markers

70A and 70B are both erroneously detected as "no marker" to transport the web 10, the nozzle is used with the web area between the marker 70A and the marker 70B. Surface 52 can be wiped off.

Second Embodiment
When the position of the marker on the web deviates from the center position of the width of the web, when the web is subjected to tension, not only the shape of the marker changes (deforms), but the position of the marker moves. In the second embodiment, in an initial state, the detection position of the sensor and the position of the marker are shifted in advance in anticipation of the movement of the marker when tension is applied to the web.

The position of the marker refers to the center position of the marker. The central position of the width of the web refers to the position of a center line that bisects the width of the web. In the present specification, the center position of the width of the web may be referred to as “the center of the web”. The detection position of the sensor refers to the center position of the detection range of the sensor on the web.

Here, the position of the marker in the width direction of the web and the detected position of the sensor are considered. The respective positions of the marker position and the detection position of the sensor can be represented by, for example, the distance from the center position of the width of the web, with the center position of the width of the web as a reference (origin).

Here, the possibility of false detection due to the movement of the marker when tension is applied to the web will be described using Reference Example 2.

Reference Example 2
FIG. 10 is a plan view showing a reference example of the positional relationship between the position of the marker before tension is applied to the web (before deformation) and the detection position of the sensor. In Figure 10, for simplicity of illustration, a single marker 72, although the detection range 44 of the sensor for detecting them, in symmetrical positions with respect to the center line C _L of the web 10, other Two unshown markers may be provided. The marker 72 is, for example, a through hole. The initial shape of the marker 72 is an elliptical shape which satisfies the conditions described in the first embodiment.

The position of the marker 72 is at a distance of e [mm] in the width direction from the center of the web 10. The position of the distance of e [mm] in the width direction from the center of the web 10 is referred to as "position e". This position e is called the initial position of the marker.

On the other hand, the center position of the detection range 44 of the sensor, that is, the detection position of the sensor is at a distance of f [mm] in the width direction from the center of the web 10. The position of a distance of f [mm] in the width direction from the center of the web 10 is denoted as "position f". The reference example shown in FIG. 10 is the case where e = f.

FIG. 11 is a plan view showing the positional relationship between the position of the marker and the detection position of the sensor when tension is applied to the web shown in FIG. 10 (after deformation).

As shown in FIG. 11, the deformation of the web 10 moves the position of the marker 72. That is, as the web 10 is deformed by the tension applied to the web 10, the position of the marker 72 is shifted in the width direction toward the center of the web 10. The position of the marker 72 after deformation is at a distance of e _A [mm] in the width direction from the center of the web 10. e _A is a value smaller than e (e _A <e).

_A position at a distance of e _A [mm] in the width direction from the center of the web 10 is denoted as “position e _A ”. This position e _A is called the position of the marker after deformation.

On the other hand, since the detection position of the sensor is fixed (immobile), the edge of the marker 72 after deformation enters the detection range 44 of the sensor, which may cause erroneous detection.

<Overview of Second Embodiment>
In the second embodiment, in order to suppress the erroneous detection as described with reference to FIGS. 10 and 11, in the second embodiment, the sensor detection position f is offset by half the amount of shrinkage of the web described in the first embodiment. , Provide a marker.

12 and 13 are explanatory views showing an outline of the second embodiment. FIG. 12 is a plan view showing the positional relationship between the position of the marker before tension is applied to the web (before deformation) and the detection position of the sensor. Although one marker 74 and a detection range 44 of a sensor for detecting this are shown in FIG. 12 for simplification of illustration, one marker 74 and another detection position 44 of the web 10 at the symmetrical position across the center line C _L are shown. Two unshown markers may be provided. The marker 74 is, for example, a through hole.

The initial shape of the marker 74 is an elliptical shape satisfying the conditions described in the first embodiment. The position of the marker 74 is at a distance of e [mm] in the width direction from the center of the web 10. On the other hand, the center position of the detection range 44 of the sensor, that is, the detection position of the sensor is at a distance of f [mm] in the width direction from the center of the web 10.

In the second embodiment shown in FIG. 12, the detection position of the sensor and the initial position of the marker 74 are shifted in advance. That is, the position of the marker 74 in the initial state is at a distance farther from the center of the web 10 than the detection position of the sensor (e> f).

FIG. 13 is a plan view showing the positional relationship between the position of the marker and the detection position of the sensor in a state (after deformation) in which tension is applied to the web shown in FIG.

As shown in FIG. 13, the deformation of the web 10 moves the position of the marker 74. That is, as the web 10 is deformed by the tension applied to the web 10, the position of the marker 74 moves toward the center of the web 10.

In FIG. 13, the marker 74 after deformation deforms to a shape that includes the detection range 44 of the sensor, and the position e _A of the marker 74 after deformation coincides with the detection position f of the sensor.

In this manner, false detection can be suppressed by shifting the marker 74 in advance relative to the initial position of the marker 74 and the detection position of the sensor in anticipation of the movement of the marker 74 after deformation.

<< Example of calculating marker position >>
Here, with respect to the second embodiment, an example of calculation of the position of the marker will be described.

The tension applied to the web is F [N], the thickness of the web t [mm], the initial width of the web w [mm], the Young's modulus of the web E [N / mm ² ], the Poisson's ratio of the web をDo.

ε _y = σ _y / E ... [Equation 1]
ε _x = −ν · σ _y / E ... [Equation 2]
σ _y = F / (w · t) ... [Equation 3]
Here, assuming that the position of the marker before deformation is e, the position e _A of the marker after deformation is represented by the following equation.

e _A = e + (e · ε _x ) ··· [Equation 21]
Therefore, to make the position e _A of the marker after deformation the same as the detection position f of the sensor,
f = e _A = e + (e · ε _x ) · · · [equation 22]
And the marker position e before deformation is
e = f / (1 + ε _x ) · · · [equation 23]
It should be set to

The relative shift amount between the position e of the marker before deformation and the detection position f of the sensor is expressed by the following equation.

| E-f | = |-(ε _x · f) / (1 + ε _x ) | ... [Formula 24]
<< specific example of calculation about the position of the marker >>
For example, it is assumed that the configuration of the cleaning device has the parameters shown in Table 4 below.

Reference Example 3
In the case of the condition having the parameters shown in Table 4, when the detection position f of the sensor and the position e of the marker are designed to be the same in the state before deformation (initial state), the marker after deformation is as shown in Table 5 There is a difference of 1 mm between the position of the marker after deformation and the detection position of the sensor.

In this case, as described in the second embodiment of FIG. 11, erroneous detection may occur.

Example 2
On the other hand, when the contents of the second embodiment of the present invention are applied, each parameter is as shown in Table 6 below, and the position of the marker after deformation and the detection position of the sensor coincide.

Third Embodiment
The marker provided on the web is not limited to the marker for detecting the end terminal, but may be a marker for detecting the feed amount of the web.

FIG. 14 is an explanatory view showing another example 2 of the marker provided on the web. In the web 10 illustrated in FIG. 14, a plurality of

markers

76A and 76B used as a scale for feed amount detection are arranged side by side at regular intervals along the transport direction. A large number of

markers

76A, 76B are provided over the usable section of the web 10 from the use start position on the take-up shaft side of the web 10 to the use end position on the supply shaft side.

The initial shape of the

markers

76A, 76B is designed in the same manner as the

markers

70A, 70B described in the first embodiment. In addition, the initial positions of the

markers

76A and 76B are designed in the same manner as the markers 74 described in the second embodiment.

In place of or in combination with the marker for detecting the end terminal described in the first embodiment and the second embodiment, a web 10 having

markers

76A and 76B for feed amount detection as shown in FIG. 14 is employed. The following forms are possible. The feed

amount detection markers

76A and 76B can also function as markers for detecting the remaining amount of the web 10. The marker provided on the web may be at least one of a marker indicating the remaining amount of the web and a marker indicating the feed amount of the web.

<< Configuration Example of Inkjet Recording Device According to Embodiment >>
An example of an inkjet recording apparatus as an example of an image forming apparatus provided with a cleaning device will be described.

FIG. 15 is an overall configuration diagram showing an overall configuration of the inkjet recording apparatus. The inkjet recording apparatus 110 is a color inkjet printer that performs color printing on a sheet P as a recording medium by the inkjet method.

The inkjet recording apparatus 110 includes a paper feed unit 112, a treatment liquid application unit 114, a treatment liquid drying unit 116, a drawing unit 118, a post-processing unit 120, and a paper discharge unit 122.

<Paper Feeder>
The sheet feeding unit 112 feeds sheets P, which are recording media, to the processing liquid application unit 114 one by one. The sheet feeding unit 112 includes a sheet feeding table 130, a sheet feeding device 132, a pair of sheet feeding rollers 134, a feeder board 136, a front contact 138, and a sheet feeding drum 140.

The sheet feeding table 130 is a table on which the sheet P is placed. The sheets P are placed on the sheet feed table 130 in the form of a bundle (sheet bundle) in which a large number of sheets are stacked. The sheet feeding table 130 is provided with a sheet feeding table lifting device (not shown). The sheet feeding table lifting device lifts and lowers the sheet feeding block 130 in conjunction with the increase and decrease of the sheets P so that the sheet P located at the top position is always positioned at a fixed height.

The sheet feeding device 132 picks up the sheets P stacked on the sheet feeding table 130 one by one in order from the top and feeds the sheet P to the sheet feeding roller pair 134. The sheet feed roller pair 134 feeds the sheet P fed from the sheet feed device 132 toward the feeder board 136.

The feeder board 136 receives the sheet P fed from the sheet feed roller pair 134 and conveys the sheet P toward the sheet feed drum 140. The front support 138 is provided at the end position of the feeder board 136 and corrects the posture of the sheet P conveyed by the feeder board 136.

The sheet feeding drum 140 receives the sheet P whose posture has been corrected by the front pad 138 from the feeder board 136, and conveys the sheet P to the treatment liquid application unit 114. The paper feed drum 140 includes a gripper 140A, and conveys the paper P to the treatment liquid application unit 114 by gripping and rotating the leading end of the paper P by the gripper 140A.

Treatment solution application section
The treatment liquid application unit 114 applies the treatment liquid to the sheet P. The treatment liquid is a liquid having a function of aggregating, insolubilizing or thickening the coloring material components in the ink. The treatment liquid application unit 114 includes a treatment liquid application drum 142 and a treatment liquid application device 144.

The treatment liquid application drum 142 receives the sheet P from the sheet feeding drum 140 and conveys the sheet P along a predetermined conveyance path. The processing liquid application drum 142 is provided with a gripper 142A, and by gripping and rotating the leading end of the sheet P by the gripper 142A, the sheet P is wound around the circumferential surface and the sheet P is transported.

The treatment liquid application device 144 applies the treatment liquid to the sheet P conveyed by the treatment liquid application drum 142. In the process of conveying the sheet P by the treatment liquid application drum 142, the application roller is pressed and abutted against the surface of the sheet, and the treatment liquid is applied to the sheet P through the application roller.

<Processing solution drying processing unit>
The treatment liquid drying processor 116 dries the sheet P to which the treatment liquid has been applied. The processing liquid drying processing unit 116 includes a processing liquid drying processing drum 146, a sheet guide 148, and a processing liquid drying processing unit 150.

The treatment liquid drying treatment drum 146 receives the paper P from the treatment liquid application drum 142, and conveys the paper P along a predetermined conveyance path. The processing liquid drying processing drum 146 includes a gripper 146A, and conveys the sheet P by gripping and rotating the leading end of the sheet P by the gripper 146A.

The sheet guide 148 is disposed along the conveyance path of the sheet P by the treatment liquid drying processing drum 146 and guides the sheet P.

The processing liquid drying processing unit 150 is installed inside the processing liquid drying processing drum 146 and blows hot air toward the sheet guide 148. Thereby, hot air is blown to the surface (the surface to which the processing liquid is applied) of the sheet P conveyed by the processing liquid drying processing drum 146.

In the process of being transported by the processing liquid drying processing drum 146, the sheet P is dried by blowing hot air blown from the processing liquid drying processing unit 150 onto the surface. An ink aggregation layer is formed on the surface of the paper P by this drying process.

<Drawing part>
The drawing unit 118 draws C, M, Y, and K inks onto the sheet P, and draws a color image on the sheet P. The drawing unit 118 includes a drawing drum 152, a sheet pressing roller 154, inkjet heads 156C, 156M, 156Y, and 156K, and a scanner 160.

The drawing drum 152 receives the sheet P from the treatment liquid drying processing drum 146, and conveys the sheet P along a predetermined conveyance path. The drawing drum 152 is provided with a gripper 152A, and by gripping and rotating the leading end of the sheet P by the gripper 152A, the sheet P is wound around the circumferential surface to convey the sheet P. Further, the drawing drum 152 is provided with a large number of suction holes (not shown) on the circumferential surface, and suctions the sheet P from the suction holes to suction and hold the sheet P wound around the circumferential surface.

The sheet pressing roller 154 presses the surface of the sheet P transferred to the drawing drum 152 to press the sheet P against the circumferential surface of the drawing drum 152 and brings the sheet P into close contact with the circumferential surface of the drawing drum 152.

The inkjet heads 156C, 156M, 156Y, and 156K eject ink droplets of cyan (C), magenta (M), yellow (Y), and black (K) on the sheet P. The inkjet heads 156C, 156M, 156Y, and 156K are line heads corresponding to the width of the sheet P. The inkjet heads 156C, 156M, 156Y, and 156K are disposed at regular intervals along the sheet P conveyance path, and are disposed orthogonal to the sheet P conveyance direction. Ink is supplied to each of the inkjet heads 156C, 156M, 156Y, and 156K from an ink tank (not shown) which is an ink supply source of the corresponding color through a piping path (not shown).

In the inkjet recording apparatus 110 shown in FIG. 15, since the sheet P is rotationally conveyed by the drawing drum 152, the respective inkjet heads 156 C, 156 M, 156 Y, and 156 K are arranged around the drawing drum 152 in an inclined manner. For this reason, the nozzle surface provided at the tip of each

ink jet head

156C, 156M, 156Y, 156K is arranged to be inclined with respect to the horizontal plane.

During the conveyance of the sheet P by the drawing drum 152, ink droplets are ejected from the ink jet heads 156C, 156M, 156Y, and 156K, and an image is drawn on the surface.

In this example, the configuration of the standard colors (four colors) of CMYK is exemplified, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink, dark ink, special color ink, etc. may be used as needed. You may add it. For example, it is possible to add an ink jet head that ejects light ink such as light cyan and light magenta, or add an ink jet head that ejects a special color ink such as green or orange. The arrangement order of the heads is not particularly limited.

The scanner 160 reads an image recorded on the sheet P. The scanner 160 is an example of an image reading unit, and is an optical reading device that optically reads an image recorded on a sheet P by the inkjet heads 156C, 156M, 156Y, and 156K and generates electronic image data indicating the read image. is there. The scanner 160 includes an imaging device that captures an image recorded on the sheet P and converts the image into an electrical signal indicating image information. The scanner 160 may include, in addition to an imaging device, an illumination optical system that illuminates an object to be read, and a signal processing circuit that processes signals obtained from the imaging device to generate digital image data. Based on the data of the read image read using the scanner 160, information such as the density of the image and the ejection failure of the inkjet heads 156C, 156M, 156Y, and 156K can be obtained.

<Post-processing unit>
The post-processing unit 120 performs post-processing on the sheet P on which the image is drawn. The post-treatment of this example includes a drying process and an ultraviolet irradiation process. The post-processing unit 120 includes an ink drying processing unit 120A that performs drying processing, an ultraviolet irradiation unit 120B that applies ultraviolet light to the dried paper P to fix the image, and a chain gripper 164 that transports the paper P. Prepare.

The chain gripper 164 receives the sheet P from the drawing unit 118, and conveys the sheet P along a predetermined conveyance path. The chain gripper 164 conveys the sheet P by gripping the leading edge of the sheet P by a gripper 164B provided on an endless chain 164A.

The sheet P is conveyed to the chain gripper 164, and is conveyed to the sheet discharge unit 122 through the flat first section, the second section having a constant rising slope, and the flat third section.

In the first section and the second section, a guide plate 172 for guiding the conveyance of the sheet P is disposed. The guide plate 172 has a large number of suction holes (not shown) on the sliding surface of the paper P, and sucks the paper P from the suction holes. Thereby, back tension is applied to the sheet P conveyed on the guide plate 172 by the chain gripper 164.

The ink drying processing unit 120A heats and dries the sheet P after drawing, and removes the liquid component remaining on the surface of the sheet P. The ink drying processing unit 120A includes a dryer 168 that blows hot air. The dryer 168 is installed inside the chain gripper 164 and blows hot air toward the sheet P conveyed in the first section.

The ultraviolet irradiation unit 120B irradiates the image surface with ultraviolet light. When an ultraviolet curable ink is used as the ink, the ultraviolet light is irradiated to the image surface in the ultraviolet irradiation unit 120B. The ultraviolet irradiation unit 120B includes an ultraviolet irradiation device 174 that irradiates ultraviolet light. The ultraviolet irradiation device 174 is installed inside the chain gripper 164 and irradiates the sheet P conveyed in the second section with ultraviolet light. In addition, in the case of the apparatus structure using the normal ink which is not an ultraviolet curing type, the structure of the ultraviolet irradiation part 120B can be abbreviate | omitted.

<Paper output unit>
The paper discharge unit 122 collects the sheet P on which the image is drawn. The paper discharge unit 122 includes a paper discharge tray 176 that stacks and collects the sheets P. The chain gripper 164 opens the sheet P on the sheet discharge tray 176 and stacks the sheet P on the sheet discharge tray 176.

Maintenance section
Although not shown in FIG. 15, the inkjet recording apparatus 110 includes a maintenance unit 124 (see FIG. 16). The maintenance unit 124 performs maintenance of the inkjet heads 156C, 156M, 156Y, and 156K. The maintenance unit 124 is disposed adjacent to the drawing unit 118. The inkjet heads 156C, 156M, 156Y, and 156K move to the maintenance unit 124 to receive various maintenance. The maintenance unit 124 includes the cleaning device 260 according to the embodiment of the present invention. The configuration of the maintenance unit 124 will be described in detail later.

Control system
FIG. 16 is a block diagram showing a schematic configuration of a control system of the ink jet recording apparatus. The inkjet recording apparatus 110 includes a system controller 200, a communication unit 202, a storage unit 204, an operation unit 206, a display unit 208, and the like.

The system controller 200 includes a microcomputer including a central processing unit (CPU), a read only member (ROM), a random access memory (RAM), and the like, and executes various control functions by executing a predetermined control program. To realize. The system controller 200 executes a predetermined control program to carry the conveyance control unit 210, the paper feed control unit 212, the treatment liquid application control unit 214, the treatment liquid drying control unit 216, the drawing control unit 218, and the ink drying control unit 220A. It functions as an ultraviolet irradiation control unit 220B, a paper discharge control unit 222, a maintenance control unit 224, and the like.

The system controller 200 also functions as an image processing unit by executing a predetermined image processing program. The ROM stores a control program that the system controller 200 executes, and various data necessary for control.

The communication unit 202 includes a required communication interface, and transmits and receives data to and from a host computer connected to the communication interface.

The storage unit 204 functions as a temporary storage unit of various data including image data, and reading and writing of data are performed through the system controller 200.

The operation unit 206 includes a required input device, and outputs information input from the input device to the system controller 200. The input device may be, for example, an operation button, a keyboard, a mouse, a touch panel, or a voice input device, or an appropriate combination thereof. The system controller 200 executes various processes in accordance with the operation information input from the operation unit 206.

The display unit 208 includes a display device such as a liquid crystal panel, and displays required information on the display device according to an instruction from the system controller 200.

The conveyance control unit 210 controls the conveyance system 111 of the sheet P. The transport system 111 includes the feeder board 136, the feed drum 140, the treatment liquid application drum 142, the treatment liquid drying treatment drum 146, the drawing drum 152, and the chain gripper 164 shown in FIG. The conveyance control unit 210 controls the sheet conveyance mechanism of each unit so that the sheet P fed from the sheet feeding unit 112 is conveyed to the sheet discharge unit 122 without any delay.

The sheet feeding control unit 212 controls the operation of the sheet feeding unit 112. The sheet feeding control unit 212 controls the driving of the sheet feeding device 132 and the sheet feeding table lifting device so that the sheets P stacked on the sheet feeding table 130 are sequentially fed one by one.

The treatment liquid application control unit 214 controls the operation of the treatment liquid application unit 114. The treatment liquid application control unit 214 controls the driving of the treatment liquid application device 144 so that the treatment liquid is applied to the sheet P conveyed by the treatment liquid application drum 142.

The treatment liquid drying control unit 216 controls the operation of the treatment liquid drying processing unit 116. The processing liquid drying control unit 216 controls the driving of the processing liquid drying processing unit 150 so that the sheet P conveyed by the processing liquid drying processing drum 146 is subjected to the drying processing.

The drawing control unit 218 controls the operation of the drawing unit 118. The drawing control unit 218 controls driving of the inkjet heads 156C, 156M, 156Y, and 156K so that a desired image is recorded on the sheet P conveyed by the drawing drum 152. In addition, the operation of the scanner 160 is controlled so that the recorded image is read.

The ink drying control unit 220A controls the operation of the ink drying processing unit 120A. The ink drying control unit 220A controls the drive of the dryer 168 so that the hot air is blown to the sheet P conveyed by the chain gripper 164.

The ultraviolet irradiation control unit 220B controls the operation of the ultraviolet irradiation unit 120B. The ultraviolet irradiation control unit 220B controls the driving of the ultraviolet irradiation device 174 so that the sheet P conveyed by the chain gripper 164 is irradiated with ultraviolet light.

The paper discharge control unit 222 controls the operation of the paper discharge unit 122. The paper discharge control unit 222 controls the driving of the paper discharge stand lifting device and the like so that the sheets P are stacked on the paper discharge stand 176.

The maintenance control unit 224 controls the operation of the maintenance unit 124. The maintenance control unit 224 controls the maintenance unit 124 so that predetermined maintenance is performed. The maintenance unit 124 includes the cleaning device 260 according to the embodiment of the present invention. The information detected by the marker detection unit 42 of the cleaning device 260 is sent to the maintenance control unit 224 and / or the system controller 200. The maintenance control unit 224 and / or the system controller 200 plays the role of the control circuit 38 described in FIG. For example, based on the information obtained from the marker detection unit 42, the system controller 200 can cause the display unit 208 to display warning information for notifying the user of the time to replace the web 10.

A job relating to image recording is taken into the inkjet recording apparatus 110 from the host computer via the communication unit 202. The job includes, in addition to image data of an image to be printed on the sheet P, various information necessary for printing, such as information on the number of sheets to be printed. Information of image data included in the job is stored in the storage unit 204.

The system controller 200 performs required signal processing on the image data stored in the storage unit 204 to generate dot data. The system controller 200 controls the drive of each of the inkjet heads 156C, 156M, 156Y, and 156K of the drawing unit 118 according to the generated dot data, and records an image represented by the image data on the sheet P.

Dot data is generally generated by performing color conversion processing and halftone processing on image data. The color conversion process is a process of converting image data expressed in a color system such as RGB into ink amount data of each color of ink used in the ink jet recording apparatus 110. In this example, it is converted into ink amount data of each color of C, M, Y and K. The halftone process is a process of converting the ink amount data of each color generated by the color conversion process into dot data of each color using a process such as dithering or error diffusion.

<< Configuration example of inkjet head >>
The inkjet recording apparatus 110 according to the present embodiment includes four inkjet heads 156C, 156M, 156Y, and 156K. However, since the configurations of the respective inkjet heads 156C, 156M, 156Y, and 156K are the same, they are common here. The configuration will be described using reference numeral 156.

FIG. 17 is a perspective view showing a schematic configuration of the ink jet head. The inkjet head 156 used in the present embodiment is a line-type inkjet head. In the inkjet head 156, a plurality of head modules 156-i are connected to form a bar-like inkjet head. “I” in the code notation of the head module 156-i represents the number of the head module. In the example of FIG. 17, since 17 head modules are connected, “i” represents an integer of 1 to 17.

Each head module 156-i is attached to and integrated with the bar frame 158. Each head module 156-i can be replaced individually.

FIG. 18 is a plan view showing a schematic configuration of the nozzle surface of the ink jet head. The nozzle surface 157 of the ink jet head 156 has a generally rectangular shape as a whole, and includes a nozzle disposition area 157A at a central portion in a direction orthogonal to the longitudinal direction. A nozzle, which is a discharge port for discharging ink droplets, is provided in the nozzle arrangement area 157A.

FIG. 19 is an enlarged plan view of the nozzle surface of one head module which is a part of the nozzle surface. In FIG. 19, the direction of the X axis is the longitudinal direction of the inkjet head 156. The direction of the X axis is referred to as the head longitudinal direction. The head longitudinal direction corresponds to the main scanning direction. The Y-axis direction in FIG. 19 is a direction along the conveyance direction of the sheet P at the time of drawing. The direction of the Y axis is referred to as the sheet conveyance direction. The sheet conveyance direction corresponds to the sub-scanning direction. The direction of the X-axis shown in FIG. 19 is the y-axis direction described as the web conveyance direction, and the direction of the Y-axis shown in FIG. 19 is the x-axis direction described as the web width direction.

On the nozzle surface 157 of the inkjet head 156, a plurality of nozzles N are arranged in a matrix. For example, in the nozzle surface 157, the nozzles N are arranged at a constant pitch along a straight line X1 inclined at a predetermined angle (γ) with respect to the X axis, and a straight line inclined at a predetermined angle (α) with respect to the Y axis The nozzles N are arranged at a constant pitch along Y1. By arranging the nozzles N in this manner, it is possible to narrow the distance between the nozzles N substantially projected so as to be aligned in the main scanning direction, and the nozzles N can be arranged with high density. The substantial arrangement direction of the nozzles N in this case is the direction of the X axis. That is, the nozzles N will be disposed substantially along the longitudinal direction of the inkjet head 156.

The liquid repellent process is performed on the nozzle arrangement area 157A. As a result, it is possible to suppress the adhesion of dirt around the nozzle N.

<< Example of configuration of maintenance part >>
FIG. 20 is a plan view of the maintenance unit 124 and the drawing unit 118. The maintenance unit 124 is disposed adjacent to the drawing unit 118. When maintenance is performed on the inkjet heads 156C, 156M, 156Y, and 156K, the inkjet heads 156C, 156M, 156Y, and 156K are moved to the maintenance unit 124. The inkjet recording apparatus 110 is provided with a head moving device 238 as a moving mechanism for moving the inkjet heads 156C, 156M, 156Y, and 156K between the drawing position and the maintenance position. The drawing position is the installation position of the inkjet heads 156C, 156M, 156Y, and 156K at the time of drawing. The drawing position is set on the conveyance path of the sheet P by the drawing drum 152. The maintenance position is the installation position of the inkjet heads 156C, 156M, 156Y, and 156K at the time of drawing standby, power off, and maintenance. The maintenance position is set outside the conveyance path of the sheet P by the drawing drum 152.

<Head moving device>
The head moving device 238 includes a head mounting frame 240 for mounting the inkjet heads 156C, 156M, 156Y, and 156K, and a head mounting frame moving device 242 for moving the head mounting frame 240 horizontally.

The head mounting frame 240 has a head mounting frame main body 240 a. The head mounting frame main body 240a has a head mounting portion 240b for mounting the ink jet heads 156C, 156M, 156Y, and 156K. The head mounting portion 240b has a pair of head support portions 240c, and supports the both end portions of the respective inkjet heads 156C, 156M, 156Y, and 156K with the pair of head support portions 240c, and the inkjet heads 156C, 156M, 156Y, and 156K. Horizontally support.

The head mounting portion 240b is provided with a head elevation mechanism (not shown) for raising and lowering the inkjet heads 156C, 156M, 156Y and 156K. The head elevating means raises and lowers each of the ink jet heads 156C, 156M, 156Y, and 156K mounted on the head mounting portion 240b in the direction perpendicular to the respective nozzle surfaces along the radial direction of the drawing drum 152.

The head mounted frame moving device 242 includes a pair of guide rails 246 and a feeding device 248.

The pair of guide rails 246 are disposed parallel and horizontally along the rotation axis of the drawing drum 152. The head mounting frame 240 is slidably supported by the guide rails 246 via the sliders 247.

The feeding device 248 includes a threaded rod 248A, a nut member 248B screwed to the threaded rod 248A, and a motor 248C for rotating the threaded rod 248A. The threaded rod 248A is disposed along the guide rail 246. The nut member 248 B is coupled to the head mounting frame 240.

When the motor 248 C is rotated forward, the head mounting frame 240 moves from the drawing unit 118 toward the maintenance unit 124 along the guide rails 246. In addition, when the motor 248 C is reversely rotated, the head mounting frame 240 moves from the maintenance unit 124 toward the drawing unit 118 along the guide rails 246.

Maintenance section
The maintenance unit 124 includes: a wiping unit 258 for wiping the nozzle surfaces of the inkjet heads 156C, 156M, 156Y, and 156K; a cap unit 256 for capping the nozzle surfaces of the inkjet heads 156C, 156M, 156Y, and 156K; Equipped with

[Wiping unit]
The wiping unit 258 is disposed on the movement path of the inkjet heads 156C, 156M, 156Y, and 156K moving between the drawing position and the maintenance position. The wiping unit 258 includes cleaning

devices

260C, 260M, 260Y, and 260K that individually clean the nozzle surfaces of the inkjet heads 156C, 156M, 156Y, and 156K. The

cleaning devices

260C, 260M, 260Y and 260K clean the nozzle surfaces of the inkjet heads 156C, 156M, 156Y and 156K in the process of the inkjet heads 156C, 156M, 156Y and 156K moving between the drawing position and the maintenance position.

As the configuration of each of the

cleaning devices

260C, 260M, 260Y, and 260K, the same configuration as that of the cleaning device 1 described in the first to third embodiments may be employed.

FIG. 21 is a schematic configuration diagram of the cleaning device. The basic configuration of each of the

cleaning devices

260C, 260M, 260Y, and 260K is the same, so the reference numeral 260 is used here to describe the configuration of the cleaning device. In FIG. 21, members identical or similar to the configuration described in FIG. 1 are denoted by the same reference numerals.

The cleaning device 260 presses the web 10 against the nozzle surface 157 of the inkjet head 156 moving along the longitudinal direction of the head to wipe the nozzle surface 157 of the inkjet head 156. The cleaning device 260 includes, in a case 261, a supply reel 262, a take-up reel 263 for taking up the web 10, a pressure roller 18, a plurality of

guide rollers

20A, 20B, 20C, 22A, 22B, and a feed roller 24; A cleaning solution supply nozzle 267 and a lifting device 268 are provided.

The supply reel 262 is a reel that supplies the web 10. The web 10 is rolled around a supply reel 262. The take-up reel 263 takes up the web 10 fed from the supply reel 262. The case 261 is a member corresponding to the case 12 described in FIG. The supply reel 262 is a member corresponding to the supply shaft 14 described in FIG. The winding reel 263 is a member corresponding to the winding shaft 16 described in FIG. 1.

The pressure roller 18 brings the web 10 traveling between the supply reel 262 and the take-up reel 263 into contact with the nozzle surface 157. The pressure roller 18 is formed of, for example, a rubber roller, and is disposed to be inclined in accordance with the inclination of the nozzle surface 157 of the ink jet head 156.

The cleaning solution supply nozzle 267 is disposed on the upstream side of the pressing roller 18 in the transport direction of the web 10 and supplies the cleaning solution to the web 10. The cleaning solution supply nozzle 267 receives the supply of the cleaning solution from a cleaning solution supply device (not shown) and supplies the cleaning solution to the web 10.

The lifting device 268 is configured using, for example, a cylinder, and moves the case 261 vertically in the vertical direction. By moving the case 261 up and down using the lifting and lowering device 268, the pressing roller 18 has a contact position where the web 10 contacts the nozzle surface 157, and a retraction position where the web 10 does not contact the nozzle surface 157. Move between

When the ink jet head 156 is moved from the maintenance position to the drawing position with the pressure roller 18 positioned at the abutting position, or when it is moved from the drawing position to the maintenance position, the web 10 is on the nozzle surface 157 of the ink jet head 156 Abut. Thus, the nozzle surface 157 is cleaned.

On the other hand, when the ink jet head 156 is moved with the pressing roller 18 positioned at the retracted position, the ink jet head 156 can be moved without the web 10 coming into contact with the nozzle surface 157.

[Web cassette]
The cleaning device 260 can be removed together with the case 261 in which the web 10 is housed. That is, the case 261 in which the web 10 is accommodated functions as a web cassette and can be replaced in units of web cassettes. The web cassette includes a case 261, a web 10, a supply reel 262, and a take-up reel 263. In addition, the web cassette may include the pressing roller 18, a plurality of

guide rollers

20A, 20B, 20C, 22A, 22B, and the feed roller 24.

The marker detection unit 42, the cleaning solution supply nozzle 267, and part or all of the lifting and lowering device 268 may be provided on the frame of the cleaning device 260 without the configuration of the web cassette.

[Cap unit]
The cap unit 256 includes

caps

300C, 300M, 300Y and 300K for capping the nozzle surfaces of the inkjet heads 156C, 156M, 156Y and 156K. The respective caps 300C, 300M, 300Y and 300K are arranged corresponding to the arrangement positions of the inkjet heads 156C, 156M, 156Y and 156K when located at the maintenance position.

Each of the

caps

300C, 300M, 300Y, and 300K has a box shape with a bottom and an open top, and accommodates the discharge-side leading end portions of the inkjet heads 156C, 156M, 156Y, and 156K to cap the nozzle surface. In the inkjet recording apparatus 110 of the present embodiment, since the inkjet heads 156C, 156M, 156Y, and 156K are installed obliquely to the horizontal plane, the

caps

300C, 300M, 300Y, and 300K are also disposed inclined.

The inkjet heads 156C, 156M, 156Y, and 156K are disposed immediately above the

caps

300C, 300M, 300Y, and 300K by moving to the maintenance position. The nozzle faces are capped by moving the inkjet heads 156C, 156M, 156Y and 156K toward the

caps

300C, 300M, 300Y and 300K.

A moisturizing fluid reservoir is provided inside each of the

caps

300C, 300M, 300Y, and 300K, and the moisturizing fluid is supplied to the moisturizing fluid reservoir through a moisturizing fluid supply passage (not shown). Moreover, the suction pump which is not shown in figure is connected to each

cap

300C, 300M, 300Y, and 300K.

The maintenance operation of at least one of the preliminary ejection, the pressure purge, and the nozzle suction is performed in a state where the nozzle surfaces of the inkjet heads 156C, 156M, 156Y, and 156K are capped by the

caps

300C, 300M, 300Y, and 300K.

<Hardware Configuration of Each Processing Unit and Control Unit>
The transport control unit 210, the paper feed control unit 212, the treatment liquid application control unit 214, the treatment liquid drying control unit 216, the drawing control unit 218, the ink drying control unit 220A, and the ultraviolet radiation control unit 220B of the system controller 200 described with FIG. The hardware-like structure of the processing unit (processing unit) that executes various processes, such as the paper discharge control unit 222 and the maintenance control unit 224, is various processors as described below.

Various processors are processors that can change the circuit configuration after manufacturing a central processing unit (CPU) or a field programmable gate array (FPGA) that is a general-purpose processor that executes programs and functions as various processing units. The circuit includes a dedicated electric circuit which is a processor having a circuit configuration specially designed to execute a specific process such as a programmable logic device (PLD) or an application specific integrated circuit (ASIC).

One processing unit may be configured of one of these various processors, or may be configured of two or more processors of the same or different types. For example, one processing unit may be configured by a plurality of FPGAs or a combination of a CPU and an FPGA. In addition, a plurality of processing units may be configured by one processor. As an example in which a plurality of processing units are configured by one processor, first, one processor or more is configured by a combination of one or more CPUs and software, as represented by computers such as clients and servers. There is a form in which a processor functions as a plurality of processing units. Second, as typified by a system on chip (SoC) or the like, there is a form using a processor that realizes the functions of the entire system including a plurality of processing units in one IC (Integrated Circuit) chip. is there. Thus, the various processing units are configured using one or more of the above-described various processors as a hardware structure.

Furthermore, the hardware-like structure of these various processors is, more specifically, an electrical circuit (circuitry) combining circuit elements such as semiconductor elements.

<< Advantages of Embodiments According to the Present Disclosure >>
(1) According to each embodiment described above, in anticipation of the deformation of the marker due to the tension applied to the web, the shape of the marker in the initial state in advance so that the shape of the marker after deformation becomes a shape including the detection range of the sensor Therefore, false detection due to deformation of the marker can be suppressed. Thereby, the web remaining amount detection mechanism can be operated reliably.

(2) Further, according to the second embodiment, in consideration of the movement of the marker due to the tension applied to the web, the marker in the initial state is in advance such that the position of the marker after deformation matches the detection position of the sensor. Since the position of (1) and the detection position of the sensor are shifted, false detection due to movement of the marker after deformation can be suppressed.

(3) According to each embodiment described above, the marker can be detected with high accuracy by using a relatively inexpensive photosensor using an LED in the light emitting unit.

<< Modification 1 >>
The marker is not limited to the through hole, but may be a marker that suppresses light reflection, such as a black fill applied to the web. That is, the form of the marker may be such that a clear difference occurs in the amount of light received by the marker detection unit between the area of the marker and the area other than the marker (non-marker area).

<< Modification 2 >>
The initial shape of the marker is not limited to the elliptical shape, but may be a shape similar to the elliptical shape, for example, a long circle including a straight portion. Also, the initial shape of the marker may be square. For example, the initial shape of the marker may be a rectangle having the long side in the width direction of the web and the short side in the transport direction. Also, for example, the initial shape of the marker may be a rhombus in which the web width direction is a first diagonal and the transport direction is a second diagonal. In this case, the length of the first diagonal is greater than the length of the second diagonal.

The initial shape of the marker may be any shape as long as the marker length in the transport direction is larger than the marker length in the web width direction, and various shapes can be adopted.

<< Modification 3 >>
The marker may be a notch provided at the widthwise edge of the web 10. The notches play the same role as the through holes. The initial shape of the notch may be a part of an ellipse (for example, a semi-elliptic) whose long axis is the width direction of the web. When the initial shape of the notch is a semi-elliptic shape, the semi-elliptical semi-major axis length (major axis) corresponds to the initial width of the marker in the web width direction, and the semi-elliptic minor axis length The length (short diameter) corresponds to the initial length of the marker in the transport direction.

<< Modification 4 >>
From the configuration of the cleaning device 1 shown in FIG. 1, it is also possible to omit the supply shaft rotation drive motor 32. Further, some or all of the feed shaft rotation drive motor 32, the take-up shaft rotation drive motor 34, the feed roller rotation drive motor 36 and the control circuit 38 are removed from the configuration of the cleaning device 1 and mounted on the ink jet printing apparatus side. An alternative is also possible.

<< Modification 5 >>
Although the cleaning device described in the above-described embodiment illustrates an example in which the cleaning is performed while moving the inkjet head, which is the object to be cleaned, to the cleaning device, the cleaning device is moved to the object to be cleaned You may do cleaning while. The mechanism for moving the object to be cleaned and the cleaning device relative to each other is not particularly limited, and various structures can be adopted.

<< Modification 6 >>
In each embodiment mentioned above, although the cleaning device which wipes the nozzle side of an ink jet head was illustrated, the applicable range of the present invention is applicable not only to the illustrated cleaning device but the cleaning device of various uses.

For example, the present invention can be applied to a cleaning device that wipes off the dirt of a thermal head of a thermal printer, or a cleaning device that wipes off dirt of a cleaning roller that recovers offset toner from a fixing roller such as an electrophotographic apparatus. Of course, the cleaning apparatus of the present invention is applicable not only to the image forming apparatus but also to various apparatuses.

"About terms"
"Web" is synonymous with wiping web or cleaning web.

The term "image forming apparatus" includes the concept of terms such as a printing machine, a printer, a printing apparatus, a printing apparatus, an image recording apparatus, an image output apparatus, or a drawing apparatus. Moreover, the term "image forming apparatus" includes the concept of a printing system combining a plurality of apparatuses.

The term "image" is to be interpreted in a broad sense, and includes color images, black and white images, single color images, gradation images, uniform density (solid) images, and the like. The “image” is not limited to a photographic image, and is used as a generic term including symbols, characters, symbols, line drawings, mosaic patterns, colored division patterns, various other patterns, or a suitable combination thereof.

In the present specification, the terms "orthogonal" or "vertical" mean that, when crossing at an angle of substantially 90 °, in an aspect of crossing at an angle of less than 90 ° or at an angle of more than 90 °. And the like. In the present specification, the term "parallel" includes, among the strictly non-parallel embodiments, those embodiments that can be regarded as substantially parallel, in which substantially the same effects as those obtained in parallel can be obtained.

<< Combination of Embodiment and Modifications >>
The items described in the configurations and modifications described in the above embodiments can be used in appropriate combination, and some items can be replaced.

[Others]
In the embodiment of the present invention described above, it is possible to appropriately change, add, or delete the constituent features without departing from the spirit of the present invention. The present invention is not limited to the embodiments described above, and many modifications can be made by those skilled in the art of the present invention within the technical concept of the present invention.

DESCRIPTION OF SYMBOLS 1 cleaning device 10 web 12 case 14 supply shaft 16 winding shaft 18 pressure roller 20 front stage guide portions 20A, 20B, 20C guide roller 22 rear stage guide portions 22A, 22B guide roller 24 feed roller 32 supply shaft rotation drive motor 34 winding shaft Rotation drive motor 36 Feed roller Rotation drive motor 38 Control circuit 42, 42A, 42B Marker detection unit 44 Detection range 50 Inkjet head 52 Nozzle surface 60A, 60B Marker 70, 70A, 70B, 72, 74, 76A, 76B Marker 110 Inkjet recording Apparatus 111 Conveying system 112 Feeding unit 114 Treating liquid applying unit 116 Treating solution drying processing unit 118 Drawing unit 120 Post-processing unit 120A Ink drying processing unit 120B Ultraviolet irradiation unit 122 Discharge unit 124 Maintenance unit 130 Feeding table 13 Feed device 134 Feed roller pair 136 Feeder board 138 Front contact 140 Feed drum 140A Gripper 142 Treatment liquid application drum 142A Gripper 144 Treatment liquid application device 146 Treatment liquid drying processing drum 146A Gripper 148 Paper guide 150 Treatment liquid drying processing unit 152 Drawing drum 152A Gripper 154 Paper holding roller 156 Inkjet heads 156C, 156M, 156Y, 156K Ink jet head 156-i Head module 157 Nozzle surface 157A Nozzle surface area 158 Bar frame 160 Scanner 164 Chain gripper 164A Chain 164B Gripper 168 Dryer 172 Guide plate 174 Ultraviolet irradiation device 176 delivery stand 200 system controller 202 communication unit 204 storage unit 206 Operating unit 208 Display unit 210 Transport control unit 212 Feed control unit 214 Treatment liquid application control unit 216 Treatment liquid drying control unit 218 Drawing control unit 220A Ink drying control unit 220B Ultraviolet irradiation control unit 222 Discharge control unit 224 Maintenance control unit 238 Head moving device 240 Head mounting frame 240a Head mounting frame body 240b Head mounting portion 240c Head support portion 242 Head mounting frame moving device 246 Guide rail 247 Slider 248 Feeding device 248A Screw rod 248B Nut member 248C Motor 254 Waste tray 256 Cap unit 258 Wiping Unit 260, 260C, 260M, 260Y, 260K Cleaning device 261 Case 262 Supply reel 263 Take-up reel 267 Cleaning solution supply nozzle 268 Lifting device 300 , 300M, 300Y, 300K cap N nozzle P paper

Claims

A web for wiping the surface of the object to be cleaned;
A marker provided on the web;
A marker detection unit that detects the marker by receiving reflected light or transmitted light of light projected toward the web;
Equipped with
The initial shape of the marker before tension is applied to the web is such that the initial length of the marker in the web width direction orthogonal to the transport direction when transporting the web is greater than the initial length of the marker in the transport direction Cleaning device that is a large shape.
The cleaning device according to claim 1, wherein the initial shape of the marker is an elliptical shape whose major axis is the web width direction.
When the length of the major axis of the elliptical shape is d1 [mm] and the length of the minor axis is d2 [mm], the elliptical shape satisfies the relationship shown in the following equation. .
d1> c / (1 + ε x )
d2> c / (1 + ε y )
here,
With the web width direction as the x-axis direction and the web transport direction as the y-axis direction,
ε y = σ y / E
ε x = −ν · σ y / E
σ y = F / (w · t)
However,
F: tension applied to the web [N],
t: Web thickness [mm],
w: Initial web width [mm],
E: Young's modulus of the web [N / mm 2 ],
ν: Poisson's ratio of the web,
ε x : strain in the x-axis direction of the web when tension is applied,
ε y : strain in the y-axis direction of the web when tension is applied,
c: Diameter [mm] of detection range of marker detection unit,
σ y : Normal stress by tension F
The cleaning device according to claim 1, wherein the initial shape of the marker is square.
The marker detection unit includes a photosensor.
The shape after deformation of the marker in a state in which the web is deformed by the application of the tension to the web is a shape including the detection range of the marker detection unit. Cleaning device.
The cleaning device according to claim 5, wherein the marker detection unit uses a light emitting diode for a light emitting unit that projects light to the web.
The initial length of the marker in the web width direction in the initial shape of the marker is d1 [mm], the initial length of the marker in the transport direction is d2 [mm], and the diameter of the detection range of the marker detection unit c [mm], a post-deformation length of the marker in the web width direction in a shape after deformation of the marker in a deformed state of the marker in a state where the web is deformed by applying the tension to the web d1A [mm]; Assuming that the post-deformation length of the marker in the transport direction in the post-deformation shape is d2A [mm], the following equation can be obtained for a specific d [mm] satisfying c ≦ d,
d1> d
d2 ≦ d
d1A> d
d2A> d
The cleaning device according to claim 5 or 6, wherein
The initial position of the marker before tension is applied to the web is offset in the web width direction with respect to the detection position of the marker detection unit on the web,
The distance from the center position of the width of the web to the initial position of the marker is larger than the distance from the center position of the width of the web to the detection position of the marker detection unit. The cleaning device according to claim 1.
The initial position of the marker before tension is applied to the web is offset in the web width direction with respect to the detection position of the marker detection unit on the web,
The cleaning apparatus according to any one of claims 1 to 8, wherein the initial position of the marker is a distance e [mm] which satisfies the following equation: the distance from the center position of the width of the web.
e = f / (1 + ε x )
here,
With the web width direction as the x-axis direction and the web transport direction as the y-axis direction,
ε y = σ y / E
ε x = −ν · σ y / E
σ y = F / (w · t)
However,
F: tension applied to the web [N],
t: Web thickness [mm],
w: Initial web width [mm],
E: Young's modulus of the web [N / mm 2 ],
ν: Poisson's ratio of the web,
ε x : strain in the x-axis direction of the web when tension is applied,
ε y : strain in the y-axis direction of the web when tension is applied,
e: The distance [mm] from the center of the web width to the initial position of the marker,
f: distance [mm] from the center position of the web width to the detection position of the marker detection unit
σ y : Normal stress by tension F
The cleaning device according to any one of claims 1 to 9, wherein the marker is at least one of a marker indicating the remaining amount of the web and a marker indicating the feed amount of the web.
The cleaning device according to any one of claims 1 to 10.
A drawing unit that forms an image on a recording medium;
An image forming apparatus equipped with
The drawing unit includes an inkjet head,
The image forming apparatus according to claim 11, wherein the cleaning device wipes the nozzle surface of the inkjet head as the cleaning target using the web.
A web for wiping the surface of the object to be cleaned;
A case for containing the web wound in a roll shape;
A feed shaft provided in the case for feeding the web by rotation;
A winding shaft provided in the case and configured to wind the web by rotation;
A web cassette provided with
The web is provided with a marker,
The initial shape of the marker before tension is applied to the web is such that the initial length of the marker in the web width direction orthogonal to the transport direction when transporting the web is greater than the initial length of the marker in the transport direction Web cassettes that are large in shape.