CLEANING DEVICE, IMAGE FORMING APPARATUS AND CLEANING METHOD

Abstract

To obtain, beforehand, proper information on a contact state between a cleaning member and a cleaning object surface that may change during a cleaning operation.SOLUTION: A cleaning device 135 according to an embodiment comprises: a cleaning member 625 which cleans a cleaning object surface 1262 by contacting the cleaning object surface 1262 of a cleaning object member 630; a drive unit 1210 which relatively moves the cleaning member 625 with respect to the cleaning object surface 1262 of the cleaning object member 630; and a distribution estimation unit 1220 which estimates the distribution of a first index value indicating a degree of contact between the cleaning object member 630 and the cleaning member 625 on the cleaning object surface 1262 before the cleaning member 625 cleans the cleaning object surface 1262 by relatively moving the cleaning member 625 with respect to the cleaning object surface 1262 by the drive unit 1210.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present disclosure relates to a cleaning device, an image forming apparatus, and a cleaning method. [Background technology]

[0002] In general, an image forming apparatus that forms an image on a recording medium is equipped with a cleaning device for cleaning recording agents such as toner or ink, dust, dirt, and the like that adhere to an image forming section. In the cleaning device, a cleaning member such as a roller or a blade comes into contact with a surface to be cleaned of a member to be cleaned in the image forming section and wipes the surface to be cleaned.

[0003] Regarding cleaning devices, for example, JP 2013-173265 A discloses a nozzle surface cleaning device that cleans the nozzle surface of an inkjet head with a wiping member. This nozzle surface cleaning device includes a lifting means for relatively raising and lowering the nozzle surface and the wiping member, a detection means for detecting contact of the wiping member, a wiping means for relatively moving the wiping member and the nozzle surface along the nozzle surface, and a control means for stopping the lifting and lowering means based on the detection result of the detection means and causing the wiping means to perform wiping at the lifting and lowering stop position (see [Summary]), and adjusts the lifting and lowering position (pressing force) of a pressure roller in advance using a dummy head before wiping and cleaning (see paragraph

[0121] ). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-173265 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a cleaning device, it is necessary to maintain an appropriate contact state between the cleaning member and the member to be cleaned. For example, if the contact is insufficient, the cleaning member cannot adequately clean the dirt and the like that has adhered to the surface of the member to be cleaned. On the other hand, if the contact is excessive, the cleaning member and the member to be cleaned will wear out or deteriorate, resulting in a shortened lifespan of these members.

[0006] Here, since cleaning members such as rollers and blades are used repeatedly, the contact state between the cleaning member and the member to be cleaned may change during the cleaning operation. Patent Document 1 does not take into consideration that the contact state between the wiping member as the cleaning member and the inkjet head as the member to be cleaned may change during the cleaning operation. Therefore, when the elevation position (pressing force) of the pressure roller is adjusted in advance as in Patent Document 1, the contact state may not be properly maintained during the cleaning operation. In order to properly maintain the contact state, it is necessary to obtain appropriate information about the contact state in advance, assuming that the contact state may change during the cleaning operation.

[0007] The present disclosure has been made in view of the above-mentioned background. In one aspect, a technique is disclosed for obtaining appropriate information in advance regarding a contact state between a cleaning member and a surface to be cleaned, which may change during a cleaning operation. [Means for solving the problem]

[0008] A cleaning device according to one embodiment includes a cleaning member that contacts a surface to be cleaned of a member to be cleaned to clean the surface to be cleaned, a drive unit that moves the cleaning member relatively to the surface to be cleaned of the member to be cleaned, and a distribution estimation unit that estimates a distribution of first index values ​​indicating the degree of contact between the member to be cleaned and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by the drive unit moving the cleaning member relative to the surface to be cleaned.

[0009] In one aspect, the cleaning device further includes an alternative member having an alternative surface that is contacted by the cleaning member in place of the surface to be cleaned. The drive unit moves the cleaning member relatively to the alternative surface. The cleaning device further includes a detection unit that detects a second index value that indicates a degree of contact between the alternative member and the cleaning member. The distribution estimation unit estimates a distribution of the first index value based on the second index value detected by the detection unit.

[0010] In one aspect, the second index value includes a length of a contact area of ​​the replacement surface where the cleaning member and the replacement member are in contact, in a direction in which the drive unit moves the cleaning member relative to the replacement surface.

[0011] In one aspect, the distribution estimation section estimates a distribution of the first index value according to a position in a direction perpendicular to a direction in which the drive section moves the cleaning member relatively to the surface to be cleaned.

[0012] In one aspect, the cleaning member is configured to be rotatable. The distribution estimator estimates the distribution of the first index value according to an amount of rotation of the cleaning member.

[0013] In one aspect, the surface to be cleaned includes a nozzle surface of an inkjet head as the member to be cleaned.

[0014] In one aspect, the cleaning member is made of a porous elastic body. In one aspect, the surface to be cleaned is wiped by the cleaning member in a state in which the cleaning liquid has been absorbed.

[0015] In one aspect, the cleaning device further includes a replacement member having a replacement surface that is in contact with the cleaning member in place of the surface to be cleaned, the drive unit moves the cleaning member relative to the replacement surface, and the replacement member is provided near a position where the cleaning member waits before cleaning the surface to be cleaned.

[0016] In one aspect, the cleaning device further includes an alternative member having an alternative surface that is contacted by the cleaning member in place of the surface to be cleaned. The drive unit moves the cleaning member relatively to the alternative surface. The cleaning device further includes a detection unit that detects a second index value that indicates a degree of contact between the alternative member and the cleaning member. The surface to be cleaned and the alternative surface form the same plane.

[0017] In one aspect, the cleaning device further includes an alternative member having an alternative surface that is contacted by the cleaning member in place of the surface to be cleaned. The drive unit moves the cleaning member relatively to the alternative surface. The cleaning device further includes a detection unit that detects a second index value indicating the degree of contact between the alternative member and the cleaning member. The second index value includes a length in a direction in which the drive unit moves the cleaning member relative to the alternative surface in a contact area of ​​the alternative surface where the cleaning member and the alternative member are in contact. The detection unit detects the second index value based on the presence or absence of contact between the cleaning member and the alternative surface at multiple points along the direction in the contact area.

[0018] In one aspect, the cleaning device further includes an alternative member having an alternative surface that is contacted by the cleaning member in place of the surface to be cleaned. The drive unit moves the cleaning member relatively to the alternative surface. The cleaning device further includes a detection unit that detects a second index value indicating a degree of contact between the alternative member and the cleaning member. The second index value includes a length in a direction in which the drive unit moves the cleaning member relative to the alternative surface in a contact area of ​​the alternative surface where the cleaning member and the alternative member are in contact. The detection unit detects the second index value based on a detection time of contact between the cleaning member and the alternative surface.

[0019] In one aspect, the cleaning device further includes a substitute member having a substitute surface that is contacted by the cleaning member in place of the surface to be cleaned. The drive unit moves the cleaning member relative to the substitute surface. The cleaning device further includes a detection unit that detects a second index value that indicates a degree of contact between the substitute member and the cleaning member.

[0020] The second index value includes a length of a contact area of ​​the replacement surface where the cleaning member and the replacement member are in contact with each other in a direction in which the drive unit moves the cleaning member relative to the replacement surface. A member for the detection unit to detect the second index value includes a plurality of electrodes provided on the replacement member. The detection unit determines that the cleaning member has come into contact with the replacement surface based on a change in impedance between a first electrode and a second electrode of the plurality of electrodes.

[0021] In one aspect, the first electrode and the second electrode are adjacent to each other, and the change in impedance between the first electrode and the second electrode includes a change in a resistance component between the first electrode and the second electrode.

[0022] In one aspect, the first electrode and the second electrode are adjacent to each other, and the change in impedance between the first electrode and the second electrode includes a change in a capacitance component between the first electrode and the second electrode.

[0023] In one aspect, the cleaning device further includes an alternative member having an alternative surface that is contacted by the cleaning member in place of the surface to be cleaned. The drive unit moves the cleaning member relatively to the alternative surface. The cleaning device further includes a detection unit that detects a second index value that indicates a degree of contact between the alternative member and the cleaning member. The cleaning device further includes a discrimination unit that discriminates a position of a portion of the cleaning member where the second index value is outside a predetermined range, and an output unit that outputs a discrimination result of the discrimination unit.

[0024] In one aspect, the surface to be cleaned includes a nozzle surface of an inkjet head as the member to be cleaned. While ink is being ejected from nozzles of the inkjet head, the distribution estimation unit estimates the distribution of the first index value.

[0025] In one aspect, the cleaning device further includes a determination unit that determines cleaning conditions when the cleaning member cleans the surface to be cleaned based on the position of the portion in the distribution of the first index values ​​where the first index value is outside a threshold range.

[0026] In one aspect, the cleaning conditions include the number of times N (N is a natural number) that the cleaning member cleans the surface to be cleaned, and at least one other condition.

[0027] The determination unit determines the at least one other cleaning condition when the cleaning member cleans the surface to be cleaned the nth time (1≦n≦N) so as to be different from the at least one other cleaning condition when the cleaning member cleans the surface to be cleaned the mth time (1≦m≦N and n≠m).

[0028] According to another embodiment, there is provided an image forming apparatus comprising an image forming section for forming an image on a recording medium, and the above-mentioned cleaning device.

[0029] According to yet another embodiment, there is provided a cleaning method including the steps of: moving a cleaning member, which contacts a surface to be cleaned of a cleaning member to clean the surface to be cleaned, relative to the surface to be cleaned; and estimating a distribution of first index values ​​on the surface to be cleaned, the distribution indicating a degree of contact between the cleaning member and the cleaning member, before the cleaning member cleans the surface to be cleaned by moving the cleaning member relative to the surface to be cleaned. Effect of the Invention

[0030] According to the present disclosure, it is possible to obtain appropriate information in advance about the contact state between the cleaning member and the surface to be cleaned, which may change during the cleaning operation.

[0031] The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0032] [Figure 1] FIG. 2 is a diagram illustrating a hardware configuration of an image forming apparatus 100. [Diagram 2] FIG. 2 is a diagram showing the external appearance of a cleaning device 135. [Diagram 3] 13 is a diagram showing the head nozzle surface 222 and the alternative surface 213 as viewed from the -z direction. [Figure 4] FIG. 3 illustrates an example of a hardware configuration of a sensor 320. [Diagram 5] FIG. 2 is a diagram showing the configuration of a circuit included in a cleaning device 135. [Figure 6] FIG. 2 is a diagram showing a hardware configuration of a cleaning device 135. [Figure 7] 2A and 2B are a side view and a cross-sectional view of the wiping roller 200. FIG. [Figure 8] 13 is a diagram for explaining the principle of detection of the length Lt of the contact area between the cleaning member 625 and the substitute member 212. FIG. [Figure 9] FIG. 13 is a diagram showing an example of a signal output by a detection circuit 505. [Figure 10] FIG. 13 is a diagram showing an example of an output signal of a detection circuit 505. [Figure 11] FIG. 11 is a diagram showing a distribution 1100 of the length Lt of the contact area detected during one rotation of the wiping roller 200. [Figure 12] FIG. 2 is a block diagram showing functions for explaining a process executed by a cleaning device 135 in an image forming apparatus 100. [Figure 13] 11 is a timing chart for explaining an example of a series of cleaning operations performed when the cleaning member 625 is a roller-shaped member such as the wiping roller 200. [Figure 14]5 is a flowchart showing an example of a procedure for performing a cleaning operation in the image forming apparatus 100 of the first embodiment. [Figure 15] FIG. 13 shows an example of a screen displayed on the display 635 in step S1430. [Figure 16] FIG. 16 shows a wiping roller 200 having a recess 1600 in a small portion. [Figure 17] 17 is a diagram showing a distribution 1700 of the second index values ​​when the wiping roller 200 having the recess 1600 comes into contact with the replacement member 212. FIG. [Figure 18] 18A and 18B show a blade 1800 with a uniform free length Lf and a blade 1802 with a non-uniform free length Lf. [Figure 19] FIG. 13 is a diagram showing an example of a signal output from a detection circuit 505. [Figure 20] FIG. 18 shows the distribution of contact area lengths Lt detected while blades 1800, 1802 are in contact with alternative surface 213. [Figure 21] FIG. 2 shows a blade 2100 having a chip 2102 in one portion. [Figure 22] 2 shows a distribution 2200 of the contact area lengths Lt obtained when a blade 2100 having a chip 2102 contacts an alternative surface 213. FIG. [Diagram 23] FIG. 13 is a diagram showing a configuration of a circuit for detecting the length Lt of a contact area based on a change in impedance between a line electrode 400 and a point electrode 500 adjacent to each other. [Figure 24] FIG. 6 illustrates that when cleaning member 625 contacts the insulating layer on alternate surface 213, current flows through adjacent electrodes 400 and 500k. [Diagram 25] 13 shows that when the cleaning member 625 contacts the insulating layer 2400, the impedance between the line electrode 400 and the point electrode 500k changes. [Figure 26] 1A to 1C are diagrams for explaining the principle of detection of the length Lt of the contact area. [Figure 27]1A to 1C are diagrams for explaining the principle of detection of the length Lt of the contact area. [Figure 28] FIG. 13 is a diagram showing an example of a circuit for the CPU 520 to detect the length Lt of the contact area based on the detection time detected when the cleaning member 625 is in contact with the point-electrode pair 2600k. [Figure 29] FIG. 29 is a diagram showing a distribution 2900 of the length Lt of the contact area detected based on the detection time Tk. [Diagram 30] FIG. 13 is a diagram showing an example of a hardware configuration of a sensor 320 for detecting a length Lt of a contact area in the fifth embodiment. [Diagram 31] 13 is a diagram for explaining how the CPU 520 estimates the distribution of the first index values ​​without using the cleaning member 625 or the alternative member 212. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the same components are given the same reference numerals. Their names are also the same. Therefore, detailed description thereof will not be repeated. In the following description, a plurality of identical components may be expressed as components 123A, 123B, 123A, and 123B. When these components are collectively referred to, they are expressed as component 123.

[0034] [Special challenges in inkjet head cleaning] First, the background of the proposal of the cleaning device according to the present disclosure will be described. When the surface to be cleaned is the nozzle surface of an inkjet head, even if there is adhesion only in the vicinity of some of the nozzles, the meniscus, which is the liquid surface of the ink ejected from the nozzle, may not be properly formed, and a defect called "curve" may occur in the ink ejection. As a result, there is a problem that the quality of the image formed on the recording medium is reduced. Therefore, on the nozzle surface of the inkjet head, it is necessary to properly clean the adhesion that is attached only in the vicinity of some of the nozzles. However, for example, if the cleaning member comes into strong contact with the nozzle surface of the head, the liquid repellency of the ejection surface may deteriorate, the nozzle hole may be scratched, shortening the life of the member to be cleaned, or dirt may be pushed into the inside of the nozzle.

[0035] In order to avoid such inconvenience, a cleaning member made of a porous body that has absorbed the cleaning liquid may be used. In this case, the cleaning member cleans the deposits in a state where the pressure is dispersed and reduced in the area where the surface to be cleaned and the cleaning member are in contact. Here, if the pressure is stronger than an appropriate value, the cleaning liquid is discharged excessively onto the head nozzle surface, and the discharged liquid may remain on the head nozzle surface without being collected by the cleaning member. On the other hand, if the pressure is lower than an appropriate value, the pressure is low in the above area, so that it is difficult to detect the contact between the surface to be cleaned and the cleaning member using, for example, a pressure sensor, and there are cases where the cleaning conditions cannot be appropriately determined depending on the degree of contact. In addition, the shape of the porous body is easily changed as it is used, and as a result, the shape of the cleaning member changes depending on the amount of cleaning liquid contained in the cleaning member, and as a result, there is a problem that the contact state between the cleaning member and the member to be cleaned changes and it is difficult to stably maintain an appropriate contact state.

[0036] The cleaning device according to the present disclosure is particularly useful for solving the above problems. The configuration of the device will be specifically described below.

[0037] <Embodiment 1> [Hardware configuration of image forming device and cleaning device] 1 to 6, the hardware configuration of the image forming apparatus 100 and the cleaning device 135 will be described. FIG.

[0038] The image forming apparatus 100 includes a head unit 105 as an image forming section that forms an image on a recording medium, a first drive motor 107, a second drive motor (not shown), a payout roll 110, a take-up roll 115, back rolls 120 and 125, a fixing device 130, and a cleaning device 135.

[0039] The head unit 105 forms an image on the recording medium P by ejecting ink toward the recording medium P at a predetermined position 108. The head unit 105 is fixed to a substrate 106 that moves back and forth up and down or left and right. The first drive motor 107 and the second drive motor operate independently of each other. The first drive motor 107 moves the substrate 106 in the left and right direction via a mechanism such as a gear or a cam. The second drive motor moves the substrate 106 in the up and down direction via a mechanism similar to the above mechanisms.

[0040] The payout roll 110 pays out the recording medium P in the direction indicated by the arrow AR1. The recording medium P is, for example, paper or cloth. The take-up roll 115 takes up the recording medium P that has been paid out from the payout roll 110 and on which an image has been formed by the head unit 105. The back rolls 120 and 125 are provided between the payout roll 110 and the take-up roll 115. The fixing device 130 fixes the ink supplied onto the recording medium P to the recording medium P.

[0041] The cleaning device 135 cleans the surface to be cleaned of the head unit 105 which is fixed to the substrate 106 and moves in the direction of the arrow AR2.

[0042] In the above description, the image forming unit included in image forming apparatus 100 has been described as forming an image on recording medium P by an inkjet method. In another aspect, the image forming unit may form an image on recording medium P by an electrophotographic method. The method by which the image forming unit forms an image on recording medium P is not limited. In yet another aspect, image forming apparatus 100 may form an image on a cut recording medium, such as cut paper.

[0043] 2 is a diagram showing the external appearance of the cleaning device 135. The cleaning device 135 includes a wiping roller 200 as a cleaning member, a water tank 205, a pressing member 210, a replacement member 212, and a drive motor 215.

[0044] The wiping roller 200 is configured to be rotatable, and is provided so that a portion of the wiping roller 200 is immersed in the cleaning liquid 207 in the water tank 205. In the example of FIG. 2, the wiping roller 200 is configured of a porous elastic body such as a sponge. In another aspect, the wiping roller 200 may be configured of a material containing rubber. The wiping roller 200, in a state in which it has absorbed the cleaning liquid 207, wipes the head nozzle surface 222, which is the surface to be cleaned, of the head unit 105.

[0045] The pressing member 210 is provided to face the wiping roller 200, and rotates in accordance with the rotation of the wiping roller 200. In one aspect, the pressing member 210 is made of stainless steel, and the diameter of the pressing member 210 is 8 mm. The axis distance between the rotation axis of the pressing member 210 and the rotation axis of the wiping roller 200 is 4 mm. The pressing member 210 is provided to bite into the wiping roller 200, and is used to adjust the amount of moisture contained in the wiping roller 200 in a state in which the cleaning liquid 207 has been absorbed.

[0046] The alternative member 212 can contact the wiping roller 200 in place of the head unit 105. The alternative member 212 is used by a distribution estimation unit (described later) to estimate the contact state between the wiping roller 200 and the head unit 105. The alternative member 212 has an alternative surface 213, which is a surface for another driving mechanism (described later) to relatively move the wiping roller 200 in place of the head nozzle surface 222. In the example of FIG. 2, the alternative member 212 is provided in the vicinity of a position 230 where the wiping roller 200 waits while the nozzle of the head of the head unit 105 ejects ink at the position 108 (while the image forming unit forms an image on a recording medium). As an example of the vicinity of the position 230, a position within a three-dimensional area having a z coordinate within a threshold range from the z coordinate of the wiping roller 200 as a cleaning member and having x coordinates and y coordinates within the threshold ranges from the x coordinates and y coordinates of the wiping roller 200, respectively, can be exemplified. 2, the alternative member 212 is provided as a member separate from the head unit 105. In another aspect, the alternative member 212 may be provided integrally with the head unit 105.

[0047] The drive motor 215 rotates the wiping roller 200 via a mechanism (not shown) such as a cam. More specifically, the rotation of the drive motor 215 causes the wiping roller 200 to rotate via the mechanism.

[0048] The second drive motor brings the wiping roller 200 into contact with, wipes, or separates from the head nozzle surface 222. For example, the second drive motor moves (lowers) the head nozzle surface 222 in the -z direction to bring the wiping roller 200 into contact with the head nozzle surface 222. Next, the first drive motor 107 moves the head nozzle surface 222 in the -x direction. As a result, the wiping roller 200 moves (slides) relatively to the head nozzle surface 222 in the +x direction to wipe the head nozzle surface 222. Here, for example, while the first drive motor 107 moves the wiping roller 200 relatively in the +x direction, the drive motor 215 rotates the wiping roller 200. After that, the second drive motor moves the head nozzle surface 222 in the +z direction to separate (raise) the head nozzle surface 222 from the wiping roller 200. In this way, a series of cleaning operations are performed by the first drive motor 107 and the second drive motor (hereinafter also referred to as "first drive motor 107, etc.") contacting, wiping, and separating the wiping roller 200 from the head nozzle surface 222.

[0049] Unlike the example of FIG. 2, the cleaning device 135 may further include another driving mechanism for moving the wiping roller 200 and the water tank 205. More specifically, instead of the first driving motor 107 or the like moving the head unit 105 as the member to be cleaned as shown in FIG. 2, the other driving mechanism may move (contact, wipe, or separate) the wiping roller 200 relative to the head nozzle surface 222. The other driving mechanism may also move (contact, wipe, or separate) the wiping roller 200 relative to the alternative surface 213. The cleaning device 135 may further include another driving mechanism for moving the alternative member 212. That is, the cleaning device 135 may include a driving mechanism for relatively moving a cleaning member such as the wiping roller 200 relative to the surface to be cleaned such as the head nozzle surface 222 or the alternative surface 213. The image forming apparatus 100 may also include the mechanism.

[0050] In the embodiment, as an example, the case where the cleaning member is a wiping roller 200 or a blade will be mainly described. In other aspects, the cleaning member may be a web or a brush, etc. The case where the cleaning member is a blade will be described in the second and fourth embodiments.

[0051] The member to be cleaned is not limited to the inkjet head (head unit). For example, when the image forming unit forms an image on a recording medium by an electrophotographic method, the member to be cleaned may be a photoconductor or an intermediate transfer belt.

[0052] Fig. 3 is a view of the head nozzle surface 222 and the alternative surface 213 as viewed from the -z direction. In Fig. 3, the +z direction is a direction perpendicular to the head nozzle surface 222 and the alternative surface 213, and is a direction in which the head nozzle surface 222 and the alternative surface 213 move away from the wiping roller 200. The +x direction is a direction in which the wiping roller 200 wipes the head nozzle surface 222 or the alternative surface 213. The +y direction is a direction perpendicular to the x-axis in the head nozzle surface 222 and the alternative surface 213.

[0053] The head nozzle surface 222 is provided with a plurality of heads including heads 300A, 300B, and 300C. The replacement surface 213 is provided with a sensor 320. The sensor 320 is divided into a plurality of zones including zones a1 to a6 in the y direction. In another aspect, unlike the example of FIG. 3, the replacement surface 213 may be divided into a plurality of zones in the x and y directions. For example, the zone divided into n zones in the y direction may be represented as zone ai (i=1, 2, ... n), the zone divided into m zones in the x direction may be represented as zone bj (j=1, 2, ... m), and each zone divided in the x and y directions may be represented as zone aibj.

[0054] Head 300A includes nozzles 310A, 310B, and 310C, which are ink ejection ports. Head 300A may include other nozzles (not shown) in addition to nozzles 310A, 310B, and 310C. Similarly, head 300B may include nozzles 310D, 310E, and 310F, and other nozzles (not shown). Each head other than heads 300A and 310B also includes multiple nozzles, similar to heads 300A and 300B. For example, head 300C includes multiple nozzles including nozzle 310G. These nozzles may be provided at predetermined intervals along the x direction or y direction.

[0055] The sensor 320 detects that a cleaning member such as the wiping roller 200 has come into contact with the alternative surface 213. The sensor 320 is provided at a position where a CPU (described later) can detect that the alternative surface 213 and the wiping roller 200 are in contact with each other at the timing when the alternative surface 213 and the wiping roller 200 come into contact with each other. In the example of Fig. 3, the sensor 320 provided on the alternative surface 213 is provided upstream (in the -x direction) of the head nozzle surface 222.

[0056] Information indicating the positions of the sections a1 to a6 (for example, the x-coordinate and the y-coordinate in FIG. 3) is stored in a non-volatile memory (described later). For example, if a contact failure occurs when the wiping roller 200 contacts the sensor 320 in the section a2, a contact failure may also occur when the wiping roller 200 contacts any of the nozzles 310A, 310B, and 310C corresponding to the position (x-coordinate and y-coordinate) of the section a2 while wiping the head nozzle surface 222 in the x-direction. Similarly, if a contact failure occurs when the wiping roller 200 contacts the sensor 320 in the section a3, a contact failure may also occur when the wiping roller 200 contacts any of the nozzles 310D, 310E, and 310F corresponding to the position (x-coordinate and y-coordinate) of the section a3 while wiping the head nozzle surface 222 in the x-direction. In this way, each of the nozzles in the head nozzle surface 222 may correspond to any of the multiple sections a1 to a6 divided by the sensor 320. The principle by which the sensor 320 detects contact with the cleaning member will be described later.

[0057] Here, as described above, the contact state between the wiping roller 200 as the cleaning member and the head nozzle surface 222 as the surface to be cleaned may change during the cleaning operation. In the embodiment, the cleaning device 135 estimates the contact state in advance by using the alternative surface 213. More specifically, the cleaning device 135 detects the contact state between the wiping roller 200 and the alternative surface 213 before the cleaning operation is performed (the wiping roller 200 wipes the head nozzle surface 222). The cleaning device 135 estimates the contact state between the wiping roller 200 and the head nozzle surface 222 in advance based on the result of the detection. For example, if the sensor 320 detects that the contact between the wiping roller 200 and the alternative member 212 is insufficient or excessive in the area a2 before the cleaning operation is performed, it can be estimated in advance that the contact between the wiping roller 200 and the nozzles 310A to 310C will be insufficient or excessive when the cleaning operation is performed. Similarly, before a cleaning operation is performed, the sensor 320 detects the contact state between the wiping roller 200 and the replacement member 212, for example in area a3, so that the contact state between the wiping roller 200 and the nozzles 310D to 310F when the cleaning operation is performed can be estimated in advance.

[0058] 3, the height of the alternative surface 213 in the z direction relative to the wiping roller 200 and the height of the head nozzle surface 222 in the z direction relative to the wiping roller 200 are equal, and the head nozzle surface 222 and the alternative surface 213 form the same xy plane. Therefore, the pressing amount of the wiping roller 200 against the head nozzle surface 222 and the pressing amount of the wiping roller 200 against the alternative surface 213 are equal regardless of the z coordinate of the position of the wiping roller 200. Therefore, the contact state between the wiping roller 200 and the head nozzle surface 222 can be estimated from the contact state between the wiping roller 200 and the alternative surface 213 without considering the difference between the z coordinate of the position of the head nozzle surface 222 and the z coordinate of the position of the alternative surface 213. The "pressure amount" of the wiping roller 200 against the head nozzle surface 222 refers to the distance traveled by the wiping roller 200 from the -z direction in Figure 2 to the +z direction (the direction approaching the head nozzle surface 222 or the alternative surface 213) where the wiping roller 200 begins to contact the head nozzle surface 222 or the alternative surface 213, until it is further pressed in the +z direction.

[0059] As described above, in the embodiment, the contact state between the wiping roller 200 and the head nozzle surface 222 is estimated by detecting the contact state between the wiping roller 200 and the alternative member 212 in advance. Therefore, it is not necessary to interrupt the formation of an image on the recording medium in order to provide time for detecting the contact state in order to adjust the contact state between the wiping roller 200 and the head nozzle surface 222. As a result, it is possible to continue the formation of an image on the recording medium while avoiding a situation in which the formation of an image on the recording medium is interrupted for maintenance of the cleaning device 135.

[0060] As described above, the alternative member 212 is provided near the position 230 where the wiping roller 200 waits while the nozzles of the head of the head unit 105 are ejecting ink (while the image forming unit is forming an image on the recording medium). Therefore, it is possible to easily simultaneously estimate the contact state between the wiping roller 200 and the head nozzle surface 222 in advance and form an image on the recording medium by the head unit 105 or apply cleaning liquid to the head unit 105.

[0061] FIG. 4 is a diagram showing an example of a hardware configuration of the sensor 320. In the example of FIG. 4, the sensor 320 includes a substrate 401, a line electrode 400, and six point electrodes 405A to 405F. Hereinafter, the point electrodes 405A to 405F may be collectively referred to as point electrodes 405. Each point electrode 405 is provided along the y direction. The line electrode 400 and the point electrode 405 are formed by etching a copper foil formed on the substrate 401. In another aspect, each electrode may be formed by patterning using a conductive ink, or may be formed by a general method such as photolithography.

[0062] The width Lx of the line electrode 400 in the x direction is 0.2 mm. The length Ly of the line electrode 400 in the y direction is 55 mm. The interval I in the x direction between the line electrode 400 and each point electrode 405 is 2 mm. The diameter d of each point electrode 405 is 1 mm. The interval Iy between each point electrode 405 in the y direction is 10 mm. In the example of FIG. 4, the point electrodes 405A to 405F are provided in the sections a1 to a6, respectively.

[0063] The substrate 401 is provided with through holes (not shown) corresponding to the point electrodes 405A to 405F, respectively. The through holes are provided so that a current flows between the line electrode 400 and the point electrode 405 provided on the substrate 401 and the detection circuit 505 (FIG. 5). As a result, when the line electrode 400 and the point electrode 405 come into contact with the wiping roller 200, a signal indicating that these electrodes have come into contact with the wiping roller 200 is transmitted to the detection circuit 505 in FIG. 5.

[0064] FIG. 5 is a diagram showing a configuration of a circuit included in the cleaning device 135. FIG. 6 is a diagram showing a hardware configuration of the cleaning device 135. The detection circuit 505 is provided in the cleaning device 135. The detection circuit 505 detects a capacitance C k and TTL (Transistor-Transistor-Logic) element TT K A subcircuit 506 having k Includes 500 point electrodes k-1 ,500 k and 500 k+1 are provided in this order in the y direction, and each may correspond to three adjacent electrodes among the point-electrodes 405A to 405F.

[0065] Although not shown for ease of explanation, the point electrode 500 k-1 ,500 k and 500 k+1 In addition, a plurality of other point electrodes are provided on the alternative surface 213. k-1 ,point electrode 500 k and 500 point electrodes k+1 The other electrodes correspond to the electrodes 405A to 405F. k-1 ,506 k and 506 k+1 The other partial circuits are connected to the other point-electrodes, respectively.

[0066] When a cleaning member such as the wiping roller 200 contacts both the line electrode 400 and the point electrode 500k on the alternative surface 213, a DC signal from the signal source DC1 is transmitted through the resistive element R1, the line electrode 400, the cleaning member, and the point electrode 500k to the partial circuit 506. k is entered into

[0067] Partial circuit 506 kThe wiper roller 200 operates as a low-pass filter to remove high-frequency components from the input signal, and then converts the signal from which the components have been removed into a TTL signal. k Only when contact is made with the partial circuit 506 k Otherwise, the subcircuit 506 outputs a high signal. k does not output a High signal (outputs a Low signal). The output signal is transmitted to the CPU 520 via a PIO (Programmed Input and Output) 510.

[0068] Based on the signal, the CPU 520 determines that the wiping roller 200 has come into contact with the replacement surface 213. More specifically, the CPU 520 k Based on receiving a signal from the subcircuit 506 k It is determined that the wiping roller 200 has come into contact with the replacement surface 213 in a section of the replacement surface 213 (for example, any of the sections a1 to a6) in which the point electrode 500k connected to the

[0069] Here, the CPU 520 k When a High signal is received from the line electrode 400, the wiping roller 200 k In this case, therefore, it is considered that the length in the x direction of the contact area of ​​the replacement surface 213 where the wiping roller 200 and the replacement member 212 are in contact with each other is equal to or greater than the interval I. In contrast, the partial circuit 506 k When a Low signal is received from the line electrode 400 and the point electrode 500, the wiping roller 200 k Therefore, in this case, it is considered that the length in the x direction of the contact area of ​​the replacement surface 213 where the wiping roller 200 and the replacement member 212 are in contact is less than the interval I. The length of the contact area is highly related to whether the degree of contact between the wiping roller 200 and the replacement surface 213 is appropriate or inappropriate (insufficient or excessive).

[0070] Here, if the interval I is determined so that the length of the contact area (hereinafter also referred to as the "target length") when the degree of contact between the wiping roller 200 and the substitute member 212 is the target degree is equal to the interval I, the CPU 520 controls the partial circuit 506 k Based on whether a signal has been received from the CPU 520, it can be determined whether the degree of contact between the wiping roller 200 and the substitute member 212 is insufficient. In the example of FIG. 6, the interval I is set to be the target length. Therefore, the CPU 520 controls the partial circuit 506 k Based on whether a signal has been received from the point electrode 500k, it can be determined whether the degree of contact between the wiping roller 200 and the replacement surface 213 is insufficient in the area where the point electrode 500k is provided (for example, any of a1 to a6).

[0071] 6, the cleaning device 135 includes a central processing unit (CPU) 520, a non-volatile memory 605, a volatile memory 607, a timer 610, a PIO 510, a display driver 617, a motor driver 620, a cleaning member 625, and an alternative member 212.

[0072] The CPU 520 executes a program stored in the non-volatile memory 605, for example, a program for performing a cleaning operation, or a program for detecting a contact state between the substitute member 212 and the wiping roller 200 before performing the operation. The CPU 520 receives a signal output from the detection circuit 505 via the PIO 510. In a certain aspect, instead of the CPU 520, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array), or a combination of the above circuit elements may be used.

[0073] The non-volatile memory 605 stores various programs and data used by the cleaning device 135, such as cleaning conditions in a cleaning operation. The non-volatile memory 605 stores, for example, information indicating the positions (e.g., x and y coordinates in FIGS. 3 and 4) of each point electrode 405 provided on the replacement surface 213. In one aspect, an auxiliary storage device such as a hard disk drive (HDD) or a solid state drive (SSD) is used as the non-volatile memory 605.

[0074] The volatile memory 607 includes a random access memory (RAM). The RAM temporarily stores programs executed by the CPU 520 and data referenced by the CPU 520. In one aspect, a static random access memory (SRAM) or a dynamic random access memory (DRAM) is used as the volatile memory 607.

[0075] The motor driver 620 is a circuit that outputs a signal for relatively moving the cleaning member 625 and the replacement member 212, or the cleaning member 625 and the member to be cleaned 630. The motor driver 620 outputs a signal for driving at least one of the other driving mechanisms and the first driving motor 107 described above. In addition, when the cleaning member 625 is configured to be rotatable, the motor driver 620 outputs a signal for driving the driving motor 215 to rotate the cleaning member 625. The display driver 617 displays a screen including characters or images on the display 635. The display 635 may be a touch screen having a touch sensor incorporated therein and a plurality of buttons. The screen will be described later.

[0076] The cleaning member 625 comes into contact with the surface to be cleaned of the member to be cleaned 630 to clean the surface. The cleaning member 625 may be any of the wiping roller 200, a blade, a brush, a web, and the like.

[0077] As described above, the alternative member 212 is used by a distribution estimation unit (described later) to estimate the contact state between the cleaning member 625 and the member to be cleaned 630. The alternative member 212 has an alternative surface 213 that is a surface that is contacted by the wiping roller 200 as a cleaning member in place of the head nozzle surface 222 as the surface to be cleaned.

[0078] [Principle for detecting the length Lt of the contact area] As described above, before the cleaning operation is performed, the cleaning device 135 detects the contact state between the wiping roller 200 and the replacement surface 213. This allows the contact state between the wiping roller 200 and the head nozzle surface 222 to be estimated in advance when the cleaning operation is performed.

[0079] The cleaning device 135 detects an index value indicating the degree of contact between the wiping roller 200 and the alternative surface 213. In the embodiment, as the index value, the length in the x direction (the direction in which the wiping roller 200 moves relative to the alternative surface 213) of the contact area of ​​the alternative surface 213 where the wiping roller 200 and the alternative member 212 are in contact is mainly used. As described above, the length of the contact area is highly related to whether the degree of contact between the wiping roller 200 and the alternative surface 213 is appropriate or inappropriate. Therefore, the length of the contact area is useful when estimating the degree of contact between the head nozzle surface 222 and the wiping roller 200 based on the degree of contact, and is suitable as the index value.

[0080] The principle of detecting the length Lt of the contact area between the cleaning member 625 and the substitute member 212 will be described with reference to FIGS.

[0081] Fig. 7(A) and Fig. 7(B) are a side view and a cross-sectional view, respectively, of the wiping roller 200. Fig. 8 is a diagram for explaining the principle of detection of the length Lt of the contact area between the cleaning member 625 and the substitute member 212. Fig. 9 is a diagram showing an example of a signal output by the detection circuit 505.

[0082] Here, "length Lt of contact area" refers to the length in the x direction (the direction in which the cleaning member 625 moves relatively to the alternative surface 213) in the contact area (nip area) where the cleaning member 625 and the alternative member 212 are in contact. In the example of FIG. 8, this direction corresponds to the direction indicated by the arrow 830. The relative movement of the cleaning member 625 with respect to the alternative surface 213 may be either the movement of the cleaning member 625 with respect to the alternative surface 213 or the movement of the alternative surface 213 with respect to the cleaning member 625.

[0083] In the embodiment, when the length Lt of the contact area is within a threshold range (hereinafter also referred to as the "target range") from the target length, the CPU 520 determines that the degree of contact between the cleaning member 625 and the alternative member 212 is appropriate. Therefore, when the cleaning member 625 contacts the head nozzle surface 222 with the same degree of contact as the target contact, the degree of contact between the cleaning member 625 and the head unit 105 also becomes appropriate. For example, it is considered that the head nozzle surface 222 is appropriately cleaned by applying the pushing amount of the cleaning member 625 against the alternative surface 213 in the above case to the pushing amount of the cleaning member 625 against the head nozzle surface 222. The target length and the target range can be determined in advance by experiments, etc., based on the type of material constituting the cleaning member 625, the alternative member 212, or the member to be cleaned 630. In the embodiment, for the sake of simplicity of explanation, the lower limit of the target range is the target length.

[0084] On the other hand, if the length Lt of the contact area is outside the target range, the CPU 520 determines that the degree of contact is not appropriate. For example, if the length Lt of the contact area is less than the target length, the CPU 520 determines that the degree of contact between the cleaning member 625 and the substitute member 212 is insufficient. If the length Lt of the contact area is so large that it exceeds the target range, the CPU 520 determines that the degree of contact is excessive.

[0085] 8(A) and 8(B) respectively show a state in which the length Lt of the contact area is the target length when the cleaning member 625 is in contact with the alternative member 212, and a state in which the length Lt of the contact area is less than the target length.

[0086] As shown in FIG. 8A, the length Lt of the contact area is the length of the line electrode 400 and the point electrode 500. k When the distance between the line electrode 400 and the point electrode 500 is equal to or greater than I, the cleaning member 625 is k As described above, a current flows between the line electrode 400 and the point electrode 500. k The interval I between the contact area and the contact region is set to be the target length. Therefore, when the current flows, the length Lt of the contact area is equal to or greater than the target length. In the example of FIG. 8A, the length Lt of the contact area detected by the CPU 520 is the target length.

[0087] In contrast, as shown in FIG. 8B, when the length Lt of the contact area is less than the interval I, the line electrode 400 and the point electrode 500 k No current flows between the contact area Lt and the target length. Therefore, when no current flows, the contact area length Lt is less than the target length. In the example of FIG. 8B, the contact area length Lt detected by the CPU 520 is a value less than the target length (for example, 0).

[0088] The cleaning member 625 is moving relative to the line electrode 400 and the point electrode 500k provided on the replacement surface 213. Therefore, the CPU 520 controls the partial circuit 506 based on the program stored in the non-volatile memory 605. k The length Lt of the contact area is detected by receiving a signal output from the cleaning member 625 at an appropriate timing. When the cleaning member 625 is a rotating body such as the wiping roller 200, the CPU 520 can also grasp the circumferential shape of the rotating body based on the time during which the length Lt of the contact area is outside the target range.

[0089] [Distribution of contact area length Lt] The distribution of the length Lt of the contact area will be described with reference to Figs. 9 to 11. Figs. 9(A) and 9(B) are a side view and a cross-sectional view, respectively, of the wiping roller 200 having a recess 905 in a portion thereof. Fig. 10(A) is a diagram showing an example of an output signal of the detection circuit 505 when the wiping roller 200 has no recess. Fig. 10(B) is a diagram showing an example of an output signal of the detection circuit 505 when the wiping roller 200 has a recess 905.

[0090] As described above, the contact state between the cleaning member 625 and the member to be cleaned 630 (alternative member 212) may change while the cleaning device 135 is operating, and so there is a problem in that it is difficult to maintain the contact state appropriately. In order to solve this problem, the inventors focused on the distribution of index values ​​indicating the degree of the contact state. More specifically, they focused on the fact that the index value changes depending on the time or position (area) at which the index value is detected. For example, cleaning defects may occur at a position and time when a portion of the wiping roller 200 with a recess 905 contacts the head nozzle surface 222.

[0091] In the first to sixth embodiments, the distribution of the index value (first index value) representing the degree of contact between the member to be cleaned 630 and the cleaning member 625 is estimated before the cleaning operation is performed. This makes it possible to prevent cleaning defects from occurring based on the result of the estimation. In the first to fifth embodiments, the distribution of the first index value is estimated based on the distribution of the second index value representing the degree of contact between the substitute member 212 and the cleaning member 625. The length Lt of the contact area between the substitute member 212 and the cleaning member 625 is used as the second index value. As will be described later, the length Lt1 of the contact area between the member to be cleaned 630 and the cleaning member 625 is used as the first index value.

[0092] 10(A) and 10(B) respectively show an example of a signal output from the detection circuit 505 when the wiping roller 200 is in contact with the alternative surface 213 when there is no indentation in the wiping roller 200 (FIG. 7) or when there is an indentation 905 (FIG. 9).

[0093] Referring to FIG. 10A, the wiping roller 200 is provided on the replacement surface 213. The wiping roller 200 includes a line electrode 400 and a point electrode 500. k-1 ,500 k and 500 k+1 When contact is made with the partial circuit 506 k-1 ,506 k and 506 k+1 outputs a high signal (at time t a After that, each partial circuit 506 is rotated until the wiping roller 200 rotates once. k-1 ,506 k and 506 k+1 outputs a high signal (at time t a ~time t d ).

[0094] Therefore, as shown in FIG. 10(A), the partial circuit 506 k-1 ,506 k and 506 k+1 But at time t a ~time t d During this period, the output of a High signal indicates that the point electrode 500 is k-1 ,500 k and 500 k+1 In each of the regions where the length Lt of the contact area is provided, the length Lt of the contact area is equal to or greater than the target length. This indicates that there is no lack of contact in each region, which is consistent with the absence of depressions in the wiping roller 200 as shown in FIG.

[0095] Referring to FIG. 10B, the wiping roller 200 includes a line electrode 400 and a point electrode 500. k-1 ,500 k and 500 k+1 When contacted with each of the subcircuits 506 k-1 ,506 k and 506 k+1 outputs a high signal (at time t a While the wiping roller 200 is rotating in contact with the replacement surface 213, each of the subcircuits 506 k-1 ,506 k and 506k+1 continues to output a high signal (time t a ~time t b ). Then, each subcircuit 506 k-1 ,506 k and 506 k+1 stops outputting the high signal (at time t b ~time t c Further thereafter, when the wiping roller 200 comes into contact with the electrode (at time t a ) to the time it completes one rotation (time t c ), each partial circuit 506 k-1 ,506 k and 506 k+1 continues to output a high signal (time t c ~t d ).

[0096] Here, when a contact shortage occurs in the contact area between the wiping roller 200 and the replacement member 212 due to the portion of the wiping roller 200 with the recess 905 in FIG. 9, it is assumed that the contact shortage occurs uniformly in the y direction due to the shape of the recess 905 of the wiping roller 200. As shown in FIG. 10B, the partial circuit 506 k-1 ,506 k and 506 k+1 But at time t b ~time t c During this period, the fact that the high signal was not uniformly outputted is due to the fact that the point electrode 500 on the alternative surface 213 k-1 ,500 k and 500 k+1 In each of the sections (sections divided along the y direction) in which the length Lt of the contact area is provided is shorter than the target length, indicating that insufficient contact occurs uniformly. This is consistent with the fact that the recess 905 present in a portion of the wiping roller 200 in the θ direction extends in the y direction, as shown in FIG.

[0097] Fig. 11(A) is a diagram showing a distribution 1100 of the lengths Lt of the contact area detected while the wiping roller 200 makes one rotation when there is no dent in the wiping roller 200. The result is displayed on the screen of the display 635. Fig. 11(B) is a diagram showing a distribution 1105 of the lengths Lt of the contact area detected while the wiping roller 200 makes one rotation when there is a dent 905 in the wiping roller 200. The result is displayed on the screen of the display 635.

[0098] The CPU 520 detects the length Lt of the contact area during the time from when the wiping roller 200 moves in the +z direction and makes contact with the alternative surface 213 until it makes one rotation. In the example of FIG. 11, the wiping roller 200 rotates without moving in the x direction after it comes into contact with the alternative surface 213. In another aspect, the wiping roller 200 may rotate while moving in the x direction after it comes into contact with the alternative surface 213. This makes it possible to estimate, from the length Lt of the contact area detected on the alternative surface 213 (the second index value), a distribution closer to the distribution of the first index value when the first index value is actually detected when the cleaning operation is performed.

[0099] 11(A) and 11(B), distributions 1100 and 1105 show the change over time in the length Lt of the contact area in the sections a1 to a6 divided in the y direction by the sensor 320 provided on the alternative surface 213. More specifically, the distributions 1100 and 1105 show the distributions of the lengths Lt of the contact area detected in the sections a1 to a6 in each of the time intervals T1 to T12 in the period T when the wiping roller 200 makes one rotation. In the distributions 1100 and 1105, a predetermined period may be used instead of the period T.

[0100] According to the distribution 1100, the lengths Lt of the contact areas detected in the sections a1 to a6 in the time intervals T1 to T12 are all equal to or greater than the target length. That is, there is no insufficient contact between the wiping roller 200 and the substitute member 212. This is consistent with the absence of dents in the wiping roller 200, as shown in FIG.

[0101] According to the distribution 1105, the length Lt of the contact area detected in each of the sections a1 to a6 in the time intervals T1, T2, and T4 to T12 is equal to or greater than the target length. Furthermore, in the time interval T3, the length Lt of the contact area detected in each of the sections a1 to a6 is uniformly less than the target length. Here, the sections a1 to a6 divided along the y direction i (i=1,2,…,6) and time interval T j Among the cells designated by (j=1, 2, ..., 12), the cells in which the length Lt of the contact area is less than the target length are hatched. The distribution 1105 is consistent with the fact that the depression 905 present in a part of the wiping roller 200 in the θ direction extends in the y direction as shown in Fig. 9 .

[0102] 11A and 11B, the distribution 1100 or 1105 is a distribution showing the change over time in the length Lt of the contact area in the areas a1 to a6 specified by the y coordinate. That is, the distribution 1100 or 1105 is a distribution according to time and coordinates indicating a position on the surface to be cleaned 1262. In another aspect, the distribution 1100 or 1105 may be a distribution according to the area specified by the y coordinate as described above and the amount of rotation of the wiping roller 200.

[0103] 11(A) and (B), if the angular velocity of the wiping roller 200 is ω, a rotation angle θ as an amount of rotation represented by multiplying the time t that has elapsed since the wiping roller 200 started to contact the replacement surface 213 by the angular velocity ω may be used instead of the time t in the distribution 1100 or 1105. That is, the θ-axis may be used instead of the t-axis in the distribution 1100 or 1105. In still another aspect, the rotation distance l that the wiping roller 200 has rotated in the θ direction in the distribution 1100 or 1105 may be expressed as rmay be used as the amount of rotation instead of the time t. In this way, the distribution 1100 or 1105 may be a distribution that indicates that the length Lt of the contact area between the wiping roller 200 and the alternative surface 213 changes depending on the amount of rotation in the circumferential direction of the wiping roller 200 (for example, the rotation angle of the cleaning member 625, the rotation distance rotated in the θ direction). This distribution is a distribution according to the position (zone) in the y direction, and is also a distribution according to the amount of rotation of the wiping roller 200.

[0104] In yet another aspect, unlike the example of Fig. 3, when the alternative surface 213 is divided into a plurality of sections in the x-direction and the y-direction, the distribution 1100 or 1105 may be represented by a distribution showing a temporal change in the length Lt of the contact area detected in each section (e.g., a1b1, a1b2, ...). That is, the distribution 1100 or 1105 may represent the length Lt of the contact area associated with each coordinate of the x-axis, the y-axis, and the t-axis.

[0105] The CPU 520 can estimate the distribution of the length Lt1 of the contact area between the wiping roller 200 and the head unit 105 (distribution of the first index value) from the distribution 1100 or 1105 as the distribution of the second index value detected when the wiping roller 200 makes one rotation. For example, when the wiping roller 200 rotates n times while wiping the head unit 105 (while moving at a speed v in the x direction relative to the head nozzle surface 222), if the first index value is detected on the head nozzle surface 222, the distribution of the first index value obtained during that time can be estimated based on the distribution of the second index value obtained using the alternative member 212. As an example, it is assumed that the distribution of the second index value detected in each of the areas a1 to a6 on the alternative surface 213 is obtained while the wiping roller 200 makes one rotation while moving at a speed v in the x direction relative to the alternative surface 213. The CPU 520 can estimate, based on the distribution of the second index value, that the distribution of the second index value is periodically repeated n times to be the distribution of the first index value. The coordinate axes (e.g., y-axis and t-axis) constituting the distribution of the second index value are also the coordinate axes constituting the distribution of the first index value. Based on the distribution of the first index value, the cleaning device 135 can estimate in advance the positions where insufficient or excessive contact may occur in the nozzles of the head unit 105 (positions where the first index value is outside the threshold range).

[0106] For example, the CPU 520 determines from the distribution 1105 that the portion of the wiping roller 200 with the recess 905 hits the areas a1 to a6 at the time interval T3. Based on the distribution 1105, the CPU 520 can determine from the distribution of the second index values ​​that the portion of the wiping roller 200 with the recess 905 hits the nozzles (e.g., the nozzles 310A, 310D, etc.) having the same y coordinate as the areas a1 to a6 in the head nozzle surface 222 at a specific time. The specific time can be a period designated by a time interval T3 after the time intervals T1 and T2 have elapsed since the cleaning member 625 came into contact with the head nozzle surface 222, and a period after the period, which is a cycle T×n (n is the number of rotations of the wiping roller 200 during the cleaning operation).

[0107] Based on the result of the estimation, the cleaning device 135 determines appropriate cleaning conditions in advance. The determination of the cleaning conditions will be described below. [Determining cleaning conditions] The CPU 520 estimates the distribution of the first index value based on the distribution of the contact area length Lt as the second index value detected before the cleaning operation is performed, and determines in advance appropriate cleaning conditions for the cleaning member 625 to clean the head nozzle surface 222. Examples of cleaning conditions include the relative movement speed, relative position, pushing amount, and cleaning count of the cleaning member 625 with respect to the surface to be cleaned, as well as the rotation speed of the cleaning member 625.

[0108] The non-volatile memory 605 stores in advance a program or data for the CPU 520 to determine cleaning conditions based on the distribution (e.g., distributions 1100, 1105, etc.) of the contact area length Lt as the second index value. More specifically, when the contact area length Lt is outside the threshold range, the non-volatile memory 605 stores data for determining cleaning conditions according to the difference between the detected contact area length Lt and the upper limit or lower limit of the target range. In another aspect, the data may be stored in a storage area of ​​the CPU 520.

[0109] For example, the CPU 520 estimates that there is a portion where the length Lt1 of the contact area is smaller than the lower limit of the target range when the cleaning member 625 contacts the head nozzle surface 222 based on the distribution of the first index value (where insufficient cleaning occurs due to insufficient contact). When the CPU 520 estimates that there is such a portion on the head nozzle surface 222, the CPU 520 can determine the cleaning conditions so that the relative movement speed of the wiping roller 200 with respect to the head nozzle surface 222 when the wiping roller 200 wipes the portion is smaller than the currently set value. This makes it possible to make the time during which the cleaning member 625 contacts the portion longer than the time during which the cleaning member 625 contacts the portion other than the portion. As a result, it is possible to eliminate the insufficient cleaning of the nozzles on the head nozzle surface 222. The currently set value can be a value indicating the speed v when the wiping roller 200 moves relatively to the alternative surface 213 in order to obtain the distribution of the second index value described above. Furthermore, the currently set value can be applied to the movement speed when the wiping roller 200 wipes the parts of the head nozzle surface 222 other than the parts where insufficient cleaning may occur.

[0110] On the other hand, the CPU 520 may estimate that there is a portion where the length Lt1 of the contact area is greater than the upper limit of the target range (excessive contact causes overcleaning). If the CPU 520 estimates that there is such a portion on the head nozzle surface 222, it may determine the cleaning conditions so that the relative movement speed of the wiping roller 200 with respect to the head nozzle surface 222 when the wiping roller 200 wipes the portion is greater than the currently set value. This makes it possible to make the time that the cleaning member 625 is in contact with the portion shorter than the time that the cleaning member 625 is in contact with portions other than the portion, and thus to eliminate overcleaning of the nozzles.

[0111] Furthermore, the CPU 520 may estimate that there is a portion where the length Lt1 of the contact area is smaller than the lower limit of the target range. When the CPU 520 estimates that there is such a portion on the head nozzle surface 222, it may determine the cleaning conditions so that the pressing amount of the wiping roller 200 against the head nozzle surface 222 when the wiping roller 200 wipes the portion is larger than the currently set value. The CPU 520 adjusts the pressing amount by controlling the motor driver 620. The currently set value may be the pressing amount when the wiping roller 200 contacts the replacement surface 213 to obtain the above-mentioned distribution of the second index value. This makes it possible to increase the pressure applied to the portion, and to eliminate the insufficient cleaning of the nozzles.

[0112] On the other hand, the CPU 520 may estimate that there is a portion where the length Lt1 of the contact area is greater than the upper limit of the target range. When the CPU 520 estimates that there is such a portion on the head nozzle surface 222, it determines the cleaning conditions so that the pressing amount of the wiping roller 200 against the head nozzle surface 222 when the wiping roller 200 wipes the portion is smaller than the currently set value. This makes it possible to further reduce the pressure applied to the portion, and to eliminate excessive cleaning of the nozzles.

[0113] Furthermore, the CPU 520 may estimate that there is a portion where the length Lt1 of the contact area is smaller than the lower limit of the target range (where insufficient cleaning occurs). If the CPU 520 estimates that such a portion exists on the head nozzle surface 222, it may determine cleaning conditions such that the wiping roller 200 cleans the head nozzle surface 222 at least twice when wiping the portion. This may eliminate insufficient cleaning of the nozzles.

[0114] On the other hand, the CPU 520 may estimate that there is a portion where the length Lt1 of the contact area is greater than the upper limit of the target range (where excessive cleaning occurs). If the CPU 520 estimates that such a portion exists on the head nozzle surface 222, the CPU 520 may determine cleaning conditions such that the number of cleaning operations of the wiping roller 200 on the head nozzle surface 222 when the wiping roller 200 wipes the portion is less than the currently set number of times.

[0115] In a certain aspect, the CPU 520 may determine the cleaning conditions so that the number of cleanings of a specific nozzle (for example, nozzle 310A) in the head nozzle surface 222 is different from the number of cleanings of other nozzles (for example, nozzle 310D). For example, when the wiping roller 200 has a recess 905 as shown in FIG. 9, the distribution of the length Lt1 of the contact area between the head nozzle surface 222 and the cleaning member 625 (distribution of the first index value) may be estimated based on the distribution of the second index value (for example, distribution 1105). Here, when the wiping roller 200 and the head nozzle surface 222 come into contact with each other, the contact state between the part of the wiping roller 200 where the recess 905 is located and a specific head (for example, head 310A) may differ from the contact state between the part of the wiping roller 200 other than the recess 905 and a head other than the specific head (for example, head 310D). If these contact states differ, cleaning defects may occur in the specific head. In this case, the CPU 520 may determine that the contact states may differ based on the distribution 1105, and may determine cleaning conditions so that a cleaning operation is performed again on the entire head nozzle surface 222. The CPU 520 may also determine cleaning conditions so that a cleaning operation is performed again only on that specific head in order to eliminate a localized cleaning defect.

[0116] Furthermore, the CPU 520 may estimate that there is a portion where the length Lt1 of the contact area is smaller than the target length (where insufficient cleaning occurs). When the CPU 520 estimates that there is such a portion on the head nozzle surface 222, it may determine the cleaning conditions so that the rotation speed of the wiping roller 200 when the wiping roller 200 wipes the portion is set to be greater than the currently set value. The currently set value may be a value indicating the rotation speed when the wiping roller 200 contacts the alternative surface 213 and rotates in order to obtain the above-mentioned distribution of the second index value (for example, the distribution 1105). This makes it easier to remove foreign matter attached to the nozzles in the portion. When a web is used as the cleaning member 625 instead of the wiping roller 200, the rotation speed corresponds to the winding speed of the web.

[0117] On the other hand, the CPU 520 may estimate that there is a portion where the length Lt1 of the contact area is greater than the target length (where excessive cleaning occurs). If the CPU 520 estimates that such a portion exists on the head nozzle surface 222, it may determine the cleaning conditions so that the rotation speed of the wiping roller 200 when the wiping roller 200 wipes the portion is smaller than the currently set value. This makes it possible to eliminate excessive cleaning.

[0118] The CPU 520 may determine one or more of the above cleaning conditions. More specifically, the CPU 520 may determine the one or more cleaning conditions according to the difference between the detected length Lt of the contact area and the upper limit or lower limit of the target range. For example, when the length Lt of the contact area is different from the upper limit or lower limit of the target range to the same extent over the entire alternative surface 213, the CPU 520 may determine the cleaning conditions so that only the pressing amount of the wiping roller 200 against the head nozzle surface 222 is different from the currently set value (the pressing amount when the wiping roller 200 contacts the alternative surface 213). In this case, the CPU 520 may adjust the pressing amount of the wiping roller 200 against the alternative surface 213 in stages by repeating the detection operation until the length Lt of the contact area detected when the wiping roller 200 contacts the alternative surface 213 falls within the target range. Thereby, the pushing amount when the length Lt of the contact area falls within the target range can be used as the pushing amount of the wiping roller 200 against the head nozzle surface 222 when the cleaning operation is performed. Furthermore, the CPU 520 may determine the cleaning conditions such that the cleaning conditions (such as the rotation speed and movement speed of the wiping roller 200) other than the pushing amount when the cleaning operation is performed are the same as the conditions when the wiping roller 200 contacts the alternative surface 213.

[0119] Further, the CPU 520 may estimate that the pushing amount is excessive or insufficient so that the length Lt1 of the contact area falls outside the target range only in a part of the head nozzle surface 222. In this case, the CPU 520 may determine the cleaning conditions in addition to or instead of the pushing amount, so that the cleaning conditions are different from the conditions when the wiping roller 200 contacts the alternative surface 213, in addition to the pushing amount, only when the cleaning member 625 is caused to clean the part. The CPU 520 may determine the cleaning conditions when the cleaning member 625 is caused to clean the part other than the part, so that the cleaning conditions are the same as the conditions when the wiping roller 200 contacts the alternative surface 213. In this way, the CPU 520 determines the cleaning conditions based on the distribution of the first index value, so that the contact state between the head nozzle surface 222 and the wiping roller 200 can be appropriately maintained. As a result, an image is formed on the recording medium P in a state where the entire head nozzle surface 222 is not sufficiently cleaned (a state where some nozzles of the head nozzle surface 222 are not sufficiently cleaned), and a deterioration in image quality due to malfunction of the ink ejection from the nozzles can be suppressed.

[0120] [Verification results] The inventors conducted experiments to detect the distribution of the length Lt of the contact area on the replacement surface 213 in each of the cases where the wiping roller 200 has no circumferential (θ direction) indentation (Figure 7) and where the wiping roller 200 has a circumferential indentation 905 (Figure 9).

[0121] In the experiment, the wiping roller 200 used had a sponge, which was a porous member, formed on a rotating shaft. The diameter of the core metal of the wiping roller 200 was 16 mm. The thickness of the porous member constituting the wiping roller 200 was 7 mm. The diameter of the wiping roller 200 was 30 mm. In the wiping roller 200 having the recess 905 (FIG. 9), the width of the recess 905 was 12 mm. The lower half of the wiping roller 200 was immersed in a water tank 205 containing pure water as the cleaning liquid 207. The surface speed (circumferential speed) of the wiping roller 200 when the wiping roller 200 was rotating was 80 mm / s. The moving speed of the wiping roller 200 relative to the surface to be cleaned was 10 mm / s. The pressing amount of the wiping roller 200 relative to the replacement surface 213 was 1.5 mm. The target length was 2 mm, which was equal to the interval I between the line electrode 400 and the point electrode 500k. The width of the head on the head nozzle surface 222 was 57 mm. The amount of ink supplied per cycle in the head unit 105 was 0.1 mL.

[0122] In the experiment, when there was no dent in the circumferential direction (θ direction) of the wiping roller 200 (FIG. 7), the distribution of the detected second index values ​​was similar to the distribution 1100. That is, like the distribution 1100, this distribution indicated that there was no insufficient contact between the wiping roller 200 and the substitute member 212. The CPU 520 determined the cleaning conditions based on data registered in advance in the non-volatile memory 605.

[0123] On the other hand, when the wiping roller 200 has a circumferential recess 905 (FIG. 9), the distribution of the detected second index values ​​was similar to the distribution 1105. With regard to this distribution, the CPU 520 determined the cleaning conditions based on the fact that the length Lt of the contact area detected in each of the sections a1 to a6 during the time interval T3 was outside the threshold range. More specifically, during the time interval T3 during which the time that has elapsed since the wiping roller 200 came into contact with the head nozzle surface 222 and started to move in the direction of the arrow 830 (the distance traveled by the wiping roller 200 since coming into contact with the head nozzle surface 222 was v×t 23 ~v×t 34When the first index value falls outside the threshold range when the wiping roller 200 contacts a nozzle having the same y coordinate as each of the areas a1 to a6 during the period (while the wiping roller 200 is in the range of a1 to a6), the CPU 520 judges based on the distribution of the first index value estimated from the distribution 1105. The CPU 520 increased the pushing amount of the cleaning member 625 on the head nozzle surface 222 during the period from 1.5 mm to 2.0 mm, compared with the pushing amount outside the period. In addition, the CPU 520 determined the cleaning conditions while the wiping roller 200 was moving in the range, so as to lower the speed v from 10 mm / s to 8 mm / s and increase the rotation speed of the wiping roller 200 from 94 mm / s to 100 mm / s, compared with the cleaning conditions while the wiping roller 200 was not moving in the range. The cleaning conditions while the wiping roller 200 was moving in the range other than the range were the same as the cleaning conditions described above (pushing amount 1.5 mm, moving speed 10 mm / s, and rotation speed 94 mm / s).

[0124] Further, in order to check whether the degree of contact between the cleaning member 625 and the member to be cleaned 630 during the cleaning operation is appropriate or not, a sensor (not shown) is provided near each nozzle on the head nozzle surface 222. Each sensor is provided so that the CPU 520 detects the length Lt1 of the contact area between the wiping roller 200 and the head nozzle surface 222. The detection principle of the length Lt1 of the contact area is the same as that described with reference to FIG. 5, FIG. 6, and FIG. 8. Here, the detection result by the sensor is considered to be basically the same as the length Lt1 of the contact area of ​​each nozzle 310 when the wiping roller 200 contacts each nozzle during the cleaning operation. Therefore, when the length Lt1 of the contact area detected by the sensor provided near each nozzle is the target length, the degree of contact between each nozzle and the cleaning member 625 during the cleaning operation is appropriate. Therefore, in this case, it can be confirmed that the nozzle has been properly cleaned. In other words, by using the detection result by the sensor, it is possible to confirm that an appropriate cleaning operation has been performed based on the cleaning conditions determined from the distribution of the first index value.

[0125] After the cleaning operation was performed, the CPU 520 detected the length Lt1 of the contact area near each nozzle using each sensor. As a result, the length Lt1 of the contact area detected near each nozzle was all within the target range. That is, the length Lt1 of the contact area when the cleaning operation was performed was within the target range over the entire head nozzle surface 222. Therefore, the inventors were able to confirm that the entire head nozzle surface 222 was properly cleaned by performing the cleaning operation according to the cleaning conditions based on the distribution of the first index value estimated using the distribution of the second index value (the length Lt of the contact area).

[0126] A functional configuration of image forming apparatus 100 for detecting length Lt of the contact area will be described with reference to Fig. 12. Fig. 12 is a block diagram showing functions for explaining a process executed by cleaning device 135 in image forming apparatus 100.

[0127] The cleaning device 135 includes a replacement member 212 , a cleaning member 625 , a detection unit 1205 , a drive unit 1210 , and a control unit 1215 .

[0128] As described above, the cleaning member 625 comes into contact with the surface to be cleaned 1262 of the member to be cleaned 630 and cleans the surface to be cleaned 1262. The cleaning member 625 also comes into contact with the replacement surface 213 of the replacement member 212.

[0129] The detection unit 1205 detects a second index value indicating the degree of contact between the alternative member 212 and the cleaning member 625. The detection unit 1205 detects, for example, the length of the contact area 1207 of the alternative surface 213 where the alternative member 212 and the cleaning member 625 are in contact with each other in the direction in which the cleaning member 625 moves relative to the alternative surface 213 (i.e., the length Lt of the contact area) as the second index value. The direction may be the direction indicated by the arrow 830 (x direction). The detection unit 1205 is realized, for example, by the CPU 520 analyzing a signal output from the detection circuit 505. While the cleaning member 625 is moving relatively in the direction or rotating, the CPU 520 detects the length Lt of the contact area. Note that the second index value detected by the detection unit 1205 is not limited to the length Lt of the contact area, and may be, for example, a pressure value measured by a pressure sensor that may be provided in each of the sections a1 to a6.

[0130] The members 1208A and 1208B for the detection unit 1205 to detect the second index value are provided in the same plane as the alternative surface 213 in a certain aspect. This allows the detection unit 1205 to determine that the alternative surface 213 and the cleaning member 625 have come into contact with each other at the timing when the members 1208A and 1208B come into contact with the cleaning member 625. In the example of FIG. 3, the members 1208A and 1208B are the line electrode 400 and the point electrode 405 (point electrode 500 k ). In this way, by using an electrode as the member 1208, the member 1208 can be simplified and made smaller. As a result, the configuration of the cleaning device 135 that detects the second index value using the member 1208 and the detection circuit 505 can be applied to various types of cleaning devices and is highly versatile. Other components for detecting the presence or absence of contact, such as a pressure sensor, may be used as the members 1208A and 1208B instead of the electrodes.

[0131] In another aspect, when the second index value detected by the detection unit 1205 is a pressure value, the member 1208 may be a pressure sensor provided in each area of ​​the alternative surface 213. The pressure sensor is different in its purpose of use, that is, to detect a pressure value, from the above-mentioned pressure sensor intended to be used for detecting the presence or absence of contact.

[0132] The driving unit 1210 moves the cleaning member 625 relatively to the alternative surface 213. The driving unit 1210 also moves the cleaning member 625 relatively to the surface to be cleaned 1262 of the member to be cleaned 630. In one aspect, the driving unit 1210 is realized by a driving circuit such as a motor driver 620. In another aspect, the driving unit 1210 may be realized by the CPU 520 operating in accordance with a program stored in the non-volatile memory 605.

[0133] Control unit 1215 controls the overall operation of cleaning device 135. More specifically, control unit 1215 includes a distribution generating unit 1218, a distribution estimating unit 1220, a discriminating unit 1240, an output unit 1245, and a determining unit 1250. In one aspect, the functions of control unit 1215 may be realized by CPU 520 operating in accordance with a program stored in non-volatile memory 605. In another aspect, the above functions may be realized by a so-called cloud service in which at least one server executes all or part of the processing of the program.

[0134] The distribution generating unit 1218 generates a distribution of the second index values ​​detected in each section (e.g., sections a1 to a6) on the alternative surface 213 based on the second index values ​​detected by the detecting unit 1205. The distribution generating unit 1218 generates a distribution of the second index values ​​according to at least one of the time t at which the second index values ​​were detected or the positions at which the second index values ​​were detected (e.g., the x coordinate or y coordinate of each section a1 to a6). The distribution of the second index values ​​includes a distribution (e.g., distribution 1100 or 1105) according to the positions (sections) in the y direction perpendicular to the x direction in which the driving unit 1210 moves the cleaning member 625 relatively to the alternative surface 213. Note that the distribution of the second index values ​​generated by the distribution generating unit 1218 does not have to be displayed on the screen of the display unit 635 as in the example of FIG. 11. Information associating the second index value with at least one of the time t at which the second index value was detected or the position at which the second index value was detected may also be a distribution of the second index values ​​generated by the distribution generation unit 1218.

[0135] Furthermore, when the cleaning member 625 is configured to be rotatable like the wiping roller 200, the distribution of the second index values ​​may be a distribution of the second index values ​​detected when the wiping roller 200 is rotating. More specifically, the distribution may include a distribution that represents a change in the second index value according to the amount of rotation of the wiping roller 200 when the cleaning member 625 is rotating in contact with the alternative surface 213.

[0136] The distribution estimation unit 1220 estimates the distribution of the first index value indicating the degree of contact between the member to be cleaned 630 and the cleaning member 625 on the surface to be cleaned 1262. More specifically, the distribution estimation unit 1220 estimates the distribution of the first index value based on the distribution of the second index value generated by the distribution generation unit 1218. When the distribution of the second index value is a distribution according to the position in the y direction, the distribution of the second index value may also be a distribution according to the position in the y direction. Furthermore, when the distribution of the second index value is a distribution according to the amount of rotation of the cleaning member 625, the distribution of the first index value may also be a distribution according to the amount of rotation of the cleaning member 625.

[0137] The first index value includes, but is not limited to, the length Lt1 in the x direction of the movement of the cleaning member 625 relative to the surface to be cleaned 1262 in a contact area 1265 where the member to be cleaned 630 and the cleaning member 625 come into contact with each other. In other aspects, the first index value may be other values, such as pressure values ​​that would be measured by pressure sensors provided in each area in the surface to be cleaned 1262.

[0138] The distribution estimation unit 1220 estimates the distribution of the first index values ​​before the cleaning member 625 cleans the surface to be cleaned 1262 (before the cleaning operation is performed) by the driving unit 1210 moving the cleaning member 625 relatively to the surface to be cleaned 1262. That is, a series of processes including detection of the second index value by the detection unit 1205, generation of the distribution of the second index values ​​by the distribution generation unit 1218, and estimation of the distribution of the first index values ​​by the distribution estimation unit 1220 are performed before the cleaning member 625 cleans the surface to be cleaned 1262. This series of processes may be performed, for example, while the nozzles 300 of the head unit 105 are ejecting ink.

[0139] Note that the distribution generation unit 1218 differs from the distribution generation unit 1218 in that while the distribution generation unit 1218 generates a distribution of second index values ​​indicating the degree of contact between the cleaning member 625 and the substitute member 212, the distribution estimation unit 1220 estimates a distribution of first index values ​​indicating the degree of contact between the cleaning member 625 and the member to be cleaned 630.

[0140] In this embodiment, the distribution estimation unit 1220 estimates the distribution of the first index values ​​based on the distribution of the second index values ​​generated by the distribution generation unit 1218. When the first index values ​​are pressure values ​​detected in each zone (e.g., a1 to a6) on the head nozzle surface 222, the distribution estimation unit 1220 may estimate the distribution of pressure values ​​detected in each zone when a pressure sensor is provided in each zone on the head nozzle surface 222.

[0141] The discrimination unit 1240 discriminates the position of a portion of the cleaning member 625 whose second index value is outside a predetermined range, based on the distribution of the second index values ​​generated by the distribution generation unit 1218. In the example of FIG. 11, the portion of the cleaning member 625 is a portion where the cleaning member 625 contacted the areas a1 to a6 during the time interval T3. The y coordinates of the portion are y0 to y6. The θ coordinate of the portion is θ0+ωt (θ0 is the θ coordinate of the cleaning member 625 when the cleaning member 625 contacted the alternative surface 213, ω is the angular velocity of the cleaning member 625, t 23 ≦t≦t 34 ) is determined.

[0142] 11, the output unit 1245 outputs the result of the discrimination by the discrimination unit 1240. In the example of Fig. 11, the output unit 1245 outputs the y coordinate of the part of the cleaning member 625 where the second index value is outside the predetermined range by displaying the distribution 1100 or the distribution 1105 on the display unit 635. In another aspect, the output unit 1245 may output the position of the part of the cleaning member 625 where the second index value is outside the predetermined range by voice via a microphone (not shown).

[0143] The determination unit 1250 determines the cleaning conditions when the cleaning member 625 cleans the surface 1262 to be cleaned, based on the distribution of the first index values ​​estimated by the distribution estimation unit 1220. More specifically, the determination unit 1250 determines the cleaning conditions based on the position of a portion in the distribution of the first index values ​​where the first index value is outside the threshold range. In the example of FIG. 11, the position is the position of a hatched cell, and is specified by the areas a1 to a6 and the time intervals T1 to T12. The position may be expressed by the coordinates of the y axis and the coordinates of the t axis. The determination unit 1250 determines the cleaning conditions based on the position on the head nozzle surface 222 corresponding to the position, and the time when the cleaning member 625 contacts the position. As described above, the cleaning conditions include the number of times N (N is a natural number) that the cleaning member 625 cleans the surface to be cleaned 1262, the amount of pressure of the cleaning member 625 against the surface to be cleaned 1262, the relative movement speed of the cleaning member 625 with respect to the surface to be cleaned 1262, and the rotational speed of the cleaning member 625.

[0144] When the cleaning operation is performed multiple times (when the number of times N is 2 or more), the cleaning conditions do not have to be the same each time. That is, the determination unit 1250 may determine at least one other cleaning condition (such as the above-mentioned pushing amount, rotation speed, and movement speed) in the n-th (1≦n≦N) cleaning operation so as to be different from the at least one other cleaning condition in the m-th (1≦m≦N and n≠m) cleaning operation. For example, the determination unit 1250 may determine the cleaning conditions so that the pushing amount in the first cleaning operation is different from the pushing amount in the second cleaning operation.

[0145] In another aspect, at least one of the detection unit 1205 , the drive unit 1210 , and the control unit 1215 may be realized as a function of a component different from the cleaning device 135 in the image forming apparatus 100 .

[0146] FIG. 13 is a timing chart for explaining an example of a series of cleaning operations performed when the cleaning member 625 is a roller-shaped member such as the wiping roller 200. In FIG.

[0147] The CPU 520 starts a movement process for the substrate 106 and the wiping roller 200 fixed to the head unit 105. More specifically, the movement process is executed as follows. First, the CPU 520 starts a movement process for the substrate 106 and the wiping roller 200 fixed to the head unit 105. A ), the CPU 520 causes each nozzle provided on the head nozzle surface 222 to eject ink. B At time t3 after the elapse of time, the wiping roller 200 is rotated via the drive unit 1210, and a movement process for moving the head unit 105 relative to the wiping roller 200 is started.

[0148] Between time t3 and time t4, the CPU 520 causes the head unit 105 to descend relative to the wiping roller 200 (in the example of FIG. 2, to move in the -z direction) via the drive unit 1210. The descending distance is regulated by a microswitch (not shown) provided on the head nozzle surface 222 for detecting the position of the wiping roller 200 relative to the head nozzle surface 222, and is set to a predetermined pushing amount. Data indicating the pushing amount is stored in the non-volatile memory 605.

[0149] The CPU 520 references the timer 610 to start the period T CAt time t5 after the elapse of time, the wiping roller 200 starts wiping the head nozzle surface 222 (scanning of the head unit 105). The CPU 520 outputs a signal as a control command to the motor driver 620 to move the wiping roller 200 in the +x direction relative to the head nozzle surface 222 by moving the substrate 106 to which the head unit 105 is fixed in the scanning direction (the -x direction in the example of FIG. 2). The motor driver 620 moves the wiping roller 200 in the +x direction relative to the head nozzle surface 222. As the substrate 106 moves in this direction, the wiping roller 200 wipes off the ink adhering to the nozzles 310 on the head nozzle surface 222. The distance that the substrate 106 moves in that direction is regulated by the above-mentioned microswitch provided on the substrate 106 so that the head nozzle surface 222 is wiped by the wiping roller 200 from one end (the end in the -x direction of the head unit 105) to the other end (the end in the +x direction of the head unit 105).

[0150] At time t6, the microswitch detects that the wiping roller 200 has finished wiping the end of the head nozzle surface 222 in the +x direction. D At time t7, after the elapse of time, the CPU 520 starts to raise the substrate 106 to which the head unit 105 is fixed in the +z direction. This causes the wiping roller 200 to separate from the head nozzle surface 222. The CPU 520 raises the substrate 106 to which the head unit 105 is fixed until the time reaches time t8. The CPU 520 also stops the rotation of the wiping roller 200 at time t8.

[0151] Time t8 to period T E At time t9 after the time t has elapsed, the CPU 520 moves the substrate 106 to which the head unit 105 is fixed in the direction opposite to the main scanning direction (the +x direction in the example of FIG. 2) to return it to the initial position. 10At this point, the CPU 520 stops the movement of the head unit 105, and discards the cleaning liquid 207 contained in the water tank 205 via a drive mechanism (not shown), replacing it with new cleaning liquid.

[0152] 13 shows an example of the operation of the cleaning device 135 when the wiping roller 200 moves relatively to the head nozzle surface 222. The operation of the cleaning device 135 when the CPU 520 brings the wiping roller 200 into contact with the alternative surface 213 and moves it relatively to the alternative surface 213 in order to estimate the distribution of the first index values ​​may also be similar to the operation shown in FIG.

[0153] For example, the CPU 520 starts the rotation of the wiping roller 200 and starts a movement process for moving the replacement member 212 relatively to the wiping roller 200 (time t3). The CPU 520 lowers the replacement member 212 relative to the wiping roller 200 via the motor driver 620 (time t3 to time t4), and brings the cleaning member 625 into contact with the replacement surface 213. While the CPU 520 rotates the wiping roller 200 in a state of contact with the replacement surface 213 and moves it relatively (time t5 to time t6), the CPU 520 detects the second index value in each area (e.g., a1 to a6) on the replacement surface 213 until the wiping roller 200 makes one rotation. As a result, a distribution of the second index values ​​is generated, and a distribution of the first index values ​​is estimated.

[0154] In another aspect, the CPU 520 may rotate the wiping roller 200 without moving the wiping roller 200 relative to the alternative surface 213, and detect the second index value in each area on the alternative surface 213 until the wiping roller 200 rotates once.

[0155] After time t6, the CPU 520 separates the wiping roller 200 from the replacement surface 213 (time t7), raises the replacement member 212 (time t7 to time t8), and stops the rotation of the wiping roller 200 (time t8). The CPU 520 moves the replacement member 212 to the position before the start of the above-mentioned movement process (time t8 to time t9). The above series of operations is performed to estimate the distribution of the first index value before the cleaning operation is performed. Hereinafter, the above series of operations is also referred to as a "distribution estimation operation."

[0156] A procedure for performing a cleaning operation in image forming apparatus 100 of embodiment 1 will be described with reference to Fig. 14 and Fig. 15. Fig. 14 is a flowchart showing an example of a procedure for image forming apparatus 100 of embodiment 1 to perform a cleaning operation. Fig. 15 is a diagram showing an example of a screen displayed on display 635 in step S1430.

[0157] 14 is realized by CPU 520 executing a program stored in non-volatile memory 605. In another aspect, the above-described process may be performed by using at least one application specific integrated circuit (ASIC), at least one field programmable gate array (FPGA), other circuit elements configured to perform the process, or a combination of these, instead of CPU 520.

[0158] In step S1405, the CPU 520 starts a movement process for moving the replacement member 212 relatively to the wiping roller 200. The CPU 520 brings the cleaning member 625 into contact with the replacement surface 213. The CPU 520 can start this process based on an instruction from a user received via an input device (not shown) included in the image forming apparatus 100.

[0159] In step S1410, while the wiping roller 200 is rotating while moving relatively to the replacement surface 213, or while the wiping roller 200 is rotating without moving relatively to the replacement surface 213, the CPU 520 detects the detection circuit 505 (partial circuit 506 k ) to obtain the signal output from

[0160] In step S1415, the CPU 520 stores the acquired signal in the volatile memory 607. More specifically, the CPU 520 stores the signal in the volatile memory 607 as a binary code.

[0161] In step S1420, the CPU 520, functioning as the detection unit 1205, detects a second index value based on the acquired signal. In one aspect, the CPU 520 detects the length Lt of the contact area in each of the sections a1 to a6 when the wiping roller 200 is in contact with the replacement surface 213 as the second index value. In another aspect, the CPU 520 may detect the length Lt of the contact area by a predetermined arithmetic process. A case in which the CPU 520 detects the length Lt of the contact area by arithmetic process will be described in the fifth embodiment.

[0162] In step S1422, CPU 520, functioning as distribution generating section 1218, generates a distribution of second index values ​​based on the detected second index values.

[0163] In step S1424, CPU 520, functioning as distribution estimation section 1220, estimates the distribution of the first index values ​​based on the distribution of the second index values.

[0164] In step S1425, CPU 520 determines whether or not there is a position in the distribution of the second index values ​​where the second index value is outside the target range. If there is a position where the second index value is outside the target range (YES in step S1425), CPU 520, as discrimination unit 1240, discriminates the position of the part of the cleaning member where the second index value is outside the target range, and proceeds to step S1430. If not (NO in step S1425), CPU 520 proceeds to step S1440.

[0165] In step S1430, CPU 520 displays the position where the contact failure occurred in the cleaning member on display 635. That is, CPU 520 outputs the result of the above determination as output unit 1245, and displays the position of the part of the cleaning member where the second index value is outside the target range on display 635. Screen 1500 in FIG. 15 is an example of a screen displayed on display 635 when sensor 320 provided on substitute surface 213 is divided into m zones in the y direction and a distribution estimation operation is performed. Screen 1500 shows p-th zone and q-th zone a from the left among the m zones. p ,a q , the second index value is outside the target range, indicating that a contact failure has occurred. By displaying screen 1500 on display 635, when a contact failure has occurred between cleaning member 625 and alternative member 212, the user can be notified of the position of the part of cleaning member 625 where the contact failure has occurred. As a result, when a cleaning operation is performed, the position (e.g., area a p ,a q It is possible to inform the user that a cleaning defect may occur in a nozzle provided at a position on the head nozzle surface 222 corresponding to the y coordinate of the nozzle having the y coordinate of the head nozzle surface 222. This can provide the user with an incentive to perform maintenance or replace the cleaning member 625 in order to avoid the cleaning defect. As a result, it is possible to prevent a breakdown of the member to be cleaned 630 due to a cleaning defect, such as clogging of the nozzle.

[0166] In step S1435, CPU 520 calculates cleaning conditions (in FIG. 14, "CL" corresponds to cleaning) based on conditions registered in advance in data stored in non-volatile memory 605. More specifically, the cleaning conditions are calculated based on the distribution of the first index value and the conditions.

[0167] In step S1440, CPU 520 determines cleaning conditions as determining unit 1250. More specifically, CPU 520 determines cleaning conditions when cleaning member 625 cleans surface 1262 to be cleaned, based on the position of a portion where the first index value is outside the threshold range in the distribution of the first index values.

[0168] In step S1445, CPU 520 starts the cleaning operation based on the determined cleaning conditions. More specifically, the series of operations described with reference to Fig. 13 starts. For example, CPU 520 outputs a control command to motor driver 620 as driving unit 1210 to move cleaning member 625 relative to surface to be cleaned 1262. Motor driver 620 moves cleaning member 625 relative to surface to be cleaned 1262 based on the command.

[0169] In step S1450, CPU 520 ends the cleaning operation, and then ends the series of processes.

[0170] [Effects of the first embodiment] Before a cleaning operation is performed, the cleaning device 135 according to the embodiment estimates a distribution of first index values ​​indicating the degree of contact between the cleaning member 625 and the member to be cleaned 630. More specifically, the cleaning device 135 estimates the distribution of the first index values ​​by detecting a second index value indicating the degree of contact between the cleaning member 625 and the substitute member 212. This makes it possible to estimate in advance the contact state between the cleaning member 625 and the member to be cleaned 630, which may change when the cleaning operation is performed. In other words, it is possible to estimate the position and time at which a cleaning defect may occur on the surface to be cleaned 1262.

[0171] Moreover, the cleaning device 135 determines the cleaning conditions based on the distribution of the first index value. This allows the contact state between the cleaning member 625 and the surface to be cleaned 1262 to be kept appropriate. As a result, it is possible to reduce the frequency of performing the cleaning operation again due to the surface to be cleaned 1262 not being sufficiently cleaned even though the cleaning operation has been performed. In particular, even if the cleaning member is made of a porous body that has absorbed the cleaning liquid and the shape of the member changes during operation, causing the contact state between the cleaning member 625 and the surface to be cleaned 630 to change, the contact state between the cleaning member 625 and the surface to be cleaned 630 can be stably and appropriately maintained. Therefore, the cleaning device 135 can also solve the above-mentioned problems specific to cleaning of inkjet heads.

[0172] Furthermore, the cleaning device 135 can detect the length Lt of the contact area between the cleaning member 625 and the alternative surface 213 as the second index value using the electrodes (the line electrode 400 and the point electrode 500). This allows the cleaning device 135 to reliably detect insufficient or excessive contact between the cleaning member 625 and the alternative surface 213 even when the cleaning member 625, which has absorbed cleaning liquid and has low hardness, such as a porous body, comes into contact with the alternative surface 213 at low pressure. As a result, the accuracy in estimating the contact state (distribution of the first index value) between the cleaning member 625 and the member to be cleaned 630 can be improved.

[0173] [Variations] 16 and 17, the distribution of the first index value and the distribution of the second index value in the case where the cleaning member 625 has a dent or has foreign matter attached in only a small portion thereof will be described.

[0174] Fig. 16 is a diagram showing a wiping roller 200 having a recess 1600 in a small portion. Fig. 17 is a diagram showing a distribution 1700 of the second index value when the wiping roller 200 having the recess 1600 comes into contact with the substitute member 212.

[0175] The CPU 520 performed the distribution estimation operation using the wiping roller 200 having the recess 1600 and the alternative member 212. More specifically, the CPU 520 detected the length Lt of the contact area when the wiping roller 200 having the recess 1600 and the alternative member 212 came into contact with each other as the second index value.

[0176] The CPU 520 generates a distribution 1700 of the length Lt of the contact area when the period T has elapsed since the wiping roller 200 came into contact with the alternative surface 213, based on the second index value. The distribution 1700 is a distribution showing the change over time of the length Lt of the contact area detected in the sections a1 to a6. More specifically, the distribution 1700 shows that the length Lt of the contact area detected in the sections a1 to a4, a6 in the time interval T1 to T12 and the length Lt of the contact area detected in the section a5 in the time interval T1 to T2, T6 to T12 are equal to or greater than the target length. On the other hand, the distribution 1700 shows that the length Lt of the contact area detected in the section a5 in the time interval T3 to T5 is shorter than the target length. This is because, as shown in FIG. 16, only a part of the wiping roller 200 (the area with the y coordinate y 45 ~y 56 and the portion having an angle θ1 in the xz plane) is consistent with the presence of a recess 1600. Note that the cells (cells specified by area a5 and times T3 to T4) in which the length Lt of the contact area is less than the target length are hatched.

[0177] CPU 520 estimates the distribution of the first index values ​​based on distribution 1700 as the distribution of the second index values. In the example of Fig. 17, CPU 520 estimates a distribution in which distribution 1700 is repeated as the distribution of the first index values. Therefore, CPU 520 determines that a cleaning defect may occur in a nozzle (such as nozzle 310G) having a y coordinate corresponding to area a5 during the time interval T3 to T5 when a cleaning operation is performed.

[0178] The CPU 520 determines the cleaning conditions based on the result of the determination. For example, the CPU 520 determines the cleaning conditions so that the wiping roller 200 is rotated in the θ direction and temporarily waits without moving in the x direction during the period when the part having the angle θ1 in the xz plane (the part represented by the dotted line in FIG. 16(A)) is in contact with the head nozzle surface 222 (the period designated by the time interval T3 to T5 after the contact time and the time when the period T×n has elapsed (n is the number of rotations of the wiping roller 200)). The CPU 520 determines the cleaning conditions so that the wiping roller 200 starts to move in the x direction after the period has elapsed. This makes it possible to avoid poor cleaning on the surface to be cleaned 1262 due to the recess 1600, and the entire surface to be cleaned 1262 can be properly cleaned.

[0179] In the above description, the case where the recess 1600 is located at a very small portion of the cleaning member 625 has been described, but this modified example can also be applied to the case where foreign matter is attached at a similar position. In that case, instead of insufficient contact caused by the recess 1600, excessive contact occurs due to the attached foreign matter. For example, the CPU 520 can determine the cleaning conditions so that the position of the wiping roller 200 in the y direction relative to the head nozzle surface 222 is changed from a predetermined position so that the wiping roller 200 is shifted in the +y direction or the -y direction so that the portion to which the foreign matter is attached does not contact the surface to be cleaned 1262. The CPU 520 causes the wiping roller 200 to clean the surface to be cleaned 1262 based on the conditions. Note that this modified example can also be applied to the case where the cleaning member 625 other than the wiping roller 200, for example, a blade, has chips or foreign matter.

[0180] <Embodiment 2> In the first embodiment, the cleaning device 135 has been mainly described in the case where the cleaning member 625 is the wiping roller 200. In the second embodiment, the cleaning device 135 will be described in the case where the cleaning member 625 is a blade.

[0181] 1 to 6, 8, and 12 to 15, the configuration and operation of cleaning device 135 of embodiment 2 are basically the same as the configuration and operation of cleaning device 135 of embodiment 1, and therefore will not be described repeatedly.

[0182] With reference to FIG. 18(A) and FIG. 18(B), blades 1800 and 1802 used as cleaning members 625 will be described. FIG. 18(A) is a diagram showing blade 1800 when the free length Lf is uniform. In FIG. 18(A), the upper surface of blade 1800 is parallel to head nozzle surface 222 parallel to the xy plane. The width of blade 1800 in the x direction is Lw. FIG. 18(B) is a diagram showing blade 1802 when the free length Lf is not uniform. In FIG. 18(B), the upper surface of blade 1802 is not parallel to head nozzle surface 222. In each of FIG. 18(A) and FIG. 18(B), support members 1805A and 1805B support plate-shaped blades 1800 and 1802. In the example of FIG. 18, blades 1800 and 1802 may be made of sponge, which is a porous member. In another aspect, blades 1800, 1802 may be configured by bonding a porous member to a member made of a different material, such as solid rubber, than the porous member.

[0183] FIG. 19(A) shows an example of a signal output from the detection circuit 505 when a blade 1800 with a uniform free length Lf is in contact with the alternative surface 213.

[0184] When the wiping roller 200 comes into contact with the replacement surface 213, the line electrode 400 and the point electrode 500 k-1 ,500 k ,500 k+1 Assume that the person comes into contact with 21 While the blade 1800 is in contact with the alternative surface 213, each of the subcircuits 506 in the detection circuit 505 k-1 ,506 k ,506 k+1 outputs a high signal (at time t 21~time t 22 When the blade 1800 moves away from the alternate surface 213, each of the subcircuits 506 k-1 ,506 k ,506 k+1 stops outputting the high signal (at time t 22 ).

[0185] FIG. 19(A) shows the arrangement of point electrodes 500k-1,500 k ,500 k+1 19(A) shows that in each of the regions (regions a1 to a6) where the contact area length Lt is provided, the contact area length Lt is equal to or longer than the target length. That is, FIG. 19(A) shows that there is no insufficient contact in each region, which is consistent with the fact that the free length Lf is uniform.

[0186] FIG. 19(B) shows an example of a signal output from the detection circuit 505 when a blade 1802 with a non-uniform free length Lf is in contact with the alternative surface 213.

[0187] Referring to FIG. 19(B), when the blade 1802 contacts the alternative surface 213, the wire electrode 400 and the point electrode 500 are connected. k ,500 k+1 On the other hand, the point electrode 500 k-1 Therefore, the partial circuit 506 k ,506 k+1 outputs a High signal, while the subcircuit 506 k-1 does not output a high signal (time t 21 ).

[0188] While the blade 1802 is in contact with the alternate surface 213, each of the subcircuits 506 k ,506 k+1 outputs a high signal (at time t 21 ~time t 22 When the blade 1802 moves away from the alternate surface 213, each of the subcircuits 506 k ,506 k+1 stops outputting the high signal (at time t 22 ).

[0189] FIG. 19B shows a point electrode 500 on the alternative surface 213. k ,500 k+1 19(B) shows that the length Lt of the contact area is equal to or greater than the target length in each of the areas where the point electrode 500 is provided on the alternative surface 213. k-1 It also shows that the length Lt of the contact area is less than the target length in the area where the point electrode 500 is provided. k+1 y coordinate of point electrode 500 k y coordinate of the electrode, and point 500 k-1 The y coordinates of the blade 1802 decrease in this order. This is consistent with the fact that, as the y coordinate decreases, the z coordinate of the upper surface of the blade 1802 decreases (the free length Lf is not uniform, and the degree of contact with the surface 1262 to be cleaned decreases) as shown in FIG. 18(B).

[0190] 20(A) is a diagram showing a distribution 2000 of the contact area lengths Lt detected while the blade 1800 is in contact with the alternative surface 213 when the free length Lf is uniform. The result is displayed on the display 635.

[0191] A distribution 2000 shows a distribution of the contact area lengths Lt as second index values ​​detected in each of the time intervals T1 to T12 in the sections a1 to a6 divided in the y direction by the alternative surface 213. In a certain aspect, the sum of the time intervals T1 to T12 is the time T t The blade 1800 may move in the +z direction with a velocity v until it contacts the alternative surface 213 and then moves away from it. t may be, for example, the width Lw of blade 1800 in the x direction divided by the velocity v. In other aspects, blade 1800 may not move in the +x direction while in contact with alternative surface 213.

[0192] According to distribution 2000, the lengths Lt of the contact regions are all within the target range. Therefore, distribution 2000 indicates that there was no insufficient contact between blade 1800 and replacement member 212. This result is consistent with the uniformity of free length Lf, as shown in FIG. 18(A).

[0193] 20(B) is a diagram showing a distribution 2005 of the contact area lengths Lt detected while the blade 1802, which has a non-uniform free length Lf, is in contact with the alternative surface 213. The result is displayed on the display 635.

[0194] A distribution 2005 shows the distribution of the contact area lengths Lt detected in the areas a1 to a6 during each of the time intervals T1 to T12. Among the cells designated by the areas ai (i=1, 2, ..., 6) and T (j=1, 2, ..., 12), the cells whose contact area lengths Lt are less than the target length are hatched.

[0195] According to the distribution 2005, the length Lt of the contact area detected in the area a1 during the time interval T1 to T8 is less than the target length. The length Lt of the contact area detected in the area a2 during the time interval T1 to T7 is also less than the target length. Furthermore, the length Lt of the contact area detected in the areas a3 to a6 during the time interval T1 to T12 is within the target range. That is, the distribution 2005 indicates that insufficient contact occurs in the areas a1 and a2 with relatively small y coordinates. Therefore, the distribution 2005 is consistent with the fact that the free length Lf is not uniform in the y direction as shown in FIG. 18(B), that is, as the y coordinate decreases, the z coordinate of the upper surface of the blade 1802 decreases, and the degree of contact with the surface to be cleaned 1262 decreases.

[0196] The distribution 2000 or 2005 is a distribution showing the change over time in the length Lt of the contact area in the areas a1 to a6 specified by the y coordinate. In another aspect, the distribution 2000 or 2005 may be represented by the area specified by the y coordinate as described above and the x coordinate of the upper surface of the blade 1800, 1802. In the case of FIG. 19, if the moving speed of the blade 1800, 1802 in the +x direction is v, the x axis showing the x coordinate calculated according to the conversion formula x=v×t may be used instead of the t axis. In other words, the distribution 2000 or 2005 may be a distribution of the second index value according to the two-dimensional coordinate.

[0197] For example, the CPU 520 generates a distribution of the second index values ​​from when the blade 1800, 1802 contacts the alternative surface 213 until it moves by the width Lw as the distribution 2000 or the distribution 2005. The CPU 520 estimates the distribution of the first index values ​​from the distribution of the second index values. For example, the CPU 520 can determine the area where the insufficient contact occurred (for example, at least one of the areas a1 to a6) and the time when the insufficient contact occurred in the area from the distribution of the second index values ​​obtained while the blade 1800 moves in the x direction with respect to the alternative surface 213 at a speed v. The CPU 520 estimates the distribution of the first index values ​​indicating that cleaning due to poor contact may occur at a specific position on the head nozzle surface 222 having the same y coordinate as the area where the poor contact occurred on the alternative surface 213, based on the result of the above determination.

[0198] When the CPU 520 determines that a cleaning failure due to poor contact may occur at the specific position on the head nozzle surface 222, the CPU 520 determines the cleaning conditions as follows. For example, from the distribution 2005, the CPU 520 determines that a cleaning failure may occur at a position on the head nozzle surface 222 that has the same y coordinate as the y coordinate of the areas a1 and a2 when a cleaning operation is performed using the blade 1802 with the cleaning count set to one. Based on the determination result, the CPU 520 determines the cleaning conditions so that the cleaning count is two or more. In the example of FIG. 20, the CPU 520 determines the cleaning conditions so that the cleaning count is two.

[0199] The CPU 520 determines the cleaning conditions for the first cleaning operation based on the conditions registered in advance in the non-volatile memory 605.

[0200] The CPU 520 determines the cleaning conditions in the second cleaning operation so that cleaning defects that may occur after the first cleaning operation are eliminated. More specifically, the CPU 520 determines the cleaning conditions so that the relative positions of the blade 1802 and the head nozzle surface 222 in the first cleaning operation are different from the relative positions in the second cleaning operation. In the example of FIG. 22, the CPU 520 determines the cleaning conditions so that the blade 1802 cleans the head nozzle surface 222 in the second cleaning operation in a state in which the blade 1802 is moved (shifted) a predetermined distance in the y direction from the position of the blade 1802 in the first cleaning operation. This makes it possible to eliminate the cleaning defects in the second cleaning operation even if a cleaning defect may occur in the first cleaning operation.

[0201] [Verification results] 19 and 20, the results of verifying the presence or absence of cleaning defects based on the length Lt of the contact area as the second index value will be described. The inventors conducted an experiment to verify whether cleaning defects can be eliminated under cleaning conditions determined based on the distribution of the first index value, using a blade 1800 with a uniform free length Lf and a blade 1802 with an uneven free length Lf. In order to inspect whether the degree of contact between the cleaning member 625 and the member to be cleaned 630 is appropriate, a sensor (not shown) was provided near each nozzle on the head nozzle surface 222, as in the first embodiment.

[0202] In each of the cases of FIG. 18(A) and FIG. 18(B), the blades 1800 and 1802 were used with their tips containing pure water as the cleaning liquid 207. The thickness of the blades 1800 and 1802 in the x direction was 5 mm. The length of the blades 1800 and 1802 in the y direction was 50 mm. The thickness of the porous material constituting the blades 1800 and 1802 was 5 mm. The speed at which the blade 1800 moved (slid) in the x direction was 10 mm. The amount of pressing of the blade 1800 against the head nozzle surface 222 was 1.5 mm. The reference for the amount of pressing is the upper surface of the blade 1800 in the case of FIG. 18(A), and the left end of the upper surface of the blade 1802 in the case of FIG. 18(B). In FIG. 18(A), the free length Lf was 15 mm. The distribution of the second index values ​​obtained when the cleaning device 135 performed the distribution estimation operation using the blade 1800 was distribution 2000. The distribution of the second index values ​​obtained when the cleaning device 135 performed the distribution estimation operation using the blade 1802 was distribution 2005.

[0203] When the blade 1800 was used, the CPU 520 estimated the distribution of the first index value based on the distribution 2000. In the distribution, all of the lengths Lt of the contact area as the first index value were within the threshold range. The CPU 520 performed the cleaning operation based on the cleaning conditions stored in advance in the non-volatile memory. After the cleaning operation was completed, the CPU 520 detected the length Lt1 of the contact area between the cleaning member 625 and the head nozzle surface 222 based on the output signal from the sensor provided in the vicinity of each nozzle. As a result, all of the detected lengths Lt1 of the contact area were within the target range over the entire head nozzle surface 222.

[0204] On the other hand, in the case where the blade 1802 was used, the CPU 520 estimated the distribution of the first index value based on the distribution 2005. The CPU 520 judged that in the distribution of the first index value, insufficient contact may occur in the nozzles on the head nozzle surface 222 having the same y coordinate as the areas a1 and a2 with a relatively small y coordinate in the first cleaning operation. Therefore, the CPU 520 determined the cleaning conditions so that the blade 1802 was moved (shifted) further 5 mm in the sub-scanning direction (-y direction) in the second cleaning operation to make the blade 1802 clean the surface to be cleaned 1262. After that, the CPU 520 made the blade 1802 clean the surface to be cleaned 1262 based on the determined conditions. In the second cleaning operation, the cleaning conditions (such as the pressing amount and moving speed of the blade 1802 against the head nozzle surface 222) other than the shifting of the blade 1802 in the -y direction were the same as those in the first cleaning operation.

[0205] After the second cleaning operation was completed, the CPU 520 detected, based on the output signal from the sensor provided near each nozzle, the length Lt1 of the contact area between the cleaning member 625 and the head nozzle surface 222. As a result, the detected contact area lengths Lt1 were all within the target range over the entire head nozzle surface 222.

[0206] From the above, the inventors have confirmed that the blade 1802 can properly clean the nozzles 310 over the entire head nozzle surface 222 by the CPU 520 determining the cleaning conditions based on the distribution of the first index value estimated before the cleaning operation is performed.

[0207] In addition, when the blade 1802 with an inconstant free length Lf is used as the cleaning member 625, unlike the above example, excessive contact may occur uniformly in the +y direction in the first cleaning operation. For example, in FIG. 20, instead of insufficient contact occurring in the time interval T1 to T7 (T8) in the sections a1 and a2, excessive contact may occur in the sections a5 and a6 at times T1 to T7. In this case, the CPU 520 may eliminate excessive cleaning due to excessive contact in the direction by making the pressing amount of the blade 1800 against the head nozzle surface 222 smaller than the pressing amount against the substitute surface 213 when the distribution estimation operation was performed.

[0208] [Effects of the second embodiment] As described above, even when the cleaning member 625 is the blade 1800 or 1802, the cleaning device 135 estimates the distribution of the first index value. The cleaning device 135 determines appropriate cleaning conditions based on the distribution of the first index value. In particular, the cleaning device 135 can eliminate cleaning defects caused by the free length Lf being not constant, such as in the case of the blade 1802, based on the appropriate cleaning conditions.

[0209] [Variations] In the above example, the case where CPU 520 estimates the distribution of the first index values ​​when free length Lf is not constant has been described. In the modified example, with reference to Figs. 21 and 22, the case where CPU 520 estimates the distribution of the first index values ​​when blade 1800 is partially chipped or has a foreign object will be described.

[0210] Fig. 21 is a diagram showing a blade 2100 having a chip 2102 in a portion thereof. Fig. 22 is a diagram showing a distribution 2200 of the length Lt of the contact region obtained when the blade 2100 having the chip 2102 comes into contact with the alternative surface 213.

[0211] CPU 520 detects time T tA distribution of the second index values ​​over time is generated as distribution 2200. Distribution 2200 shows the change over time in length Lt of the contact area in sections a1 to a6. Distribution 2200 shows that the length Lt of the contact area detected in sections a1 to a4, a6 in time interval T1 to T12 was equal to or greater than the target length. In contrast, distribution 2200 shows that the length Lt of the contact area detected in section a5 in time interval T1 to T12 was less than the target length. This is because, as shown in FIG. 21(B) , when the y coordinate of blade 1800 is y 45 ~y 56 This is consistent with the presence of a chip 2102 at a position where the length Lt of the contact area is less than the target length (the cell designated by the area a5) is hatched.

[0212] The CPU 520 estimates the distribution of the first index values ​​based on the distribution 2200 as the distribution of the second index values. In the example of Fig. 22, the CPU 520 estimates that the distribution of the first index values ​​is a distribution in which the distribution 2200 is repeated. The CPU 520 determines, based on the distribution, that a cleaning defect may occur in a nozzle (such as the nozzle 3100G) having a y coordinate corresponding to the area a5 when a cleaning operation is performed.

[0213] The CPU 520 determines the cleaning conditions based on the result of the determination. For example, the CPU 520 determines from the distribution of the first index value that when the cleaning operation is performed only once, insufficient cleaning due to insufficient contact may occur in a specific nozzle on the head nozzle surface 222 having the same y coordinate as the area a5. The CPU 520 determines the cleaning conditions so that the number of cleaning times is two or more based on the result of the determination. As an example, the CPU 520 may determine the cleaning conditions so that the blade 2100 is moved (shifted) further by 5 mm in the sub-scanning direction (+y direction) in the second cleaning operation to make the blade 2100 clean the head nozzle surface 222. As a result, even if a cleaning defect may occur in the specific nozzle after the first cleaning operation is performed, the specific nozzle can be properly cleaned by performing the second cleaning operation. As a result, the entire head nozzle surface 222 can be properly cleaned.

[0214] <Embodiment 3> In the first and second embodiments, the CPU 520 detects the line electrode 400 and the point electrode 500. k On the other hand, in the third embodiment, the CPU 520 determines that the cleaning member 625 has come into contact with the alternative surface 213 based on a change in impedance between the electrodes (the line electrode 400 and the point electrode 500) as the member 1208 with which the cleaning member 625 is in contact.

[0215] 1 to 4 and 6 to 22, the configuration and operation of cleaning device 135 of embodiment 3 are basically the same as the configuration and operation of cleaning device 135 of embodiments 1 and 2, respectively, and therefore will not be described repeatedly.

[0216] 23 to 25, the principle of detecting the length Lt of the contact area between the cleaning member 625 and the alternative member 212 on the alternative surface 213 will be described.

[0217] 23 is a diagram showing the configuration of a circuit for detecting the length Lt of the contact area based on the change in impedance between the adjacent line electrode 400 and point electrode 500. The detection circuit 2300 includes a partial circuit 2305. k-1 ,2305 k and 2305 k+1 The partial circuit 2305 k is the resistive element R k and the amplification and absolute value circuit P k and capacitor C k and the comparator CP k The line electrode 400 and the point electrode 500 k The distance I in the x direction between the point electrodes 500 and 500 is set to 2 mm, which is equal to the target length. k and 500 point electrodes k+1 It is desirable that the interval Id in the y direction between the electrodes 11 and 12 is 1.2 times the interval I or more. Therefore, in this embodiment, the interval Id is set to 10 mm, which is 5 times the interval I.

[0218] A cleaning member 625, such as a wiping roller 200 or blade 1800, contacts the line electrode 400 and the point electrode 500 on the alternate surface 213. k When the AC signal from the oscillator 2303 contacts both the line electrode 400, the cleaning member 625, and the point electrode 500, k and via the partial circuit 2305 k is entered into

[0219] Amplification and absolute value circuits P k The comparator CP amplifies a very small AC signal that is input, then amplifies, rectifies and smooths the signal before outputting it. k The output signal value is a predetermined voltage value V R It judges whether it is equal to or greater than the value. Comparator CP k The voltage value of the output signal is V R If it is equal to or greater than this, the comparator CP k The voltage value of the output signal is V RIf it is less than this, it does not output a high signal (it outputs a low signal). k The voltage value of the output signal is V R Only when the level is equal to or higher than this, the PIO 510 outputs a High signal. The output signal is transmitted to the CPU 520 via the PIO 510.

[0220] Based on the signal, the CPU 520 determines whether the line electrode 400 and the point electrode 500 are k The CPU 520 determines that the cleaning member 625 has come into contact with both of the partial circuit 506. k Point electrode 500 connected to k The CPU 520 determines that the wiping roller 200 has come into contact with the alternative surface 213 in a region (for example, any of the regions a1 to a6) where the contact area is provided. The CPU 520 detects that the length Lt of the contact area in the region is equal to or greater than the interval I equal to the target length. The CPU 520 generates a distribution of the second index values ​​based on the detected length Lt of the contact area (second index value). The CPU 520 estimates the distribution of the first index values ​​based on the distribution of the second index values.

[0221] FIG. 24 illustrates the effect of the cleaning member 625 on the adjacent electrodes 400 and 500 when the cleaning member 625 contacts the insulating layer on the alternative surface 213. k FIG. 13 is a diagram showing a current flowing through the

[0222] In FIG. 24, a line electrode 400 and a point electrode 500 are provided on the alternative surface 213. k An insulating layer 2400 is formed on the line electrode 400 and the point electrode 500. k The interval I between the line electrodes 400 and the point electrodes 500 is set to 2 mm, which is the target length. The insulating layer 2400 is made of a common material such as polyimide, epoxy resin, or silicon dioxide. In the example of FIG. 24, a tape made of polyimide is used to cover the line electrodes 400 and the point electrodes 500. k 2400 is attached on top of the insulating layer 2400 .

[0223] FIG. 25 shows the line electrode 400 and the point electrode 500 when the cleaning member 625 contacts the insulating layer 2400.k FIG. 13 is a diagram showing how the impedance changes between

[0224] The cleaning member 625 is connected to the line electrode 400 and the point electrode 500. k When not in contact with the wire electrode 400 and the point electrode 500 k Between the dielectric component C of the insulating layer 2400 A ,C B and dielectric components such as air, C C (stray capacitance) forms a series circuit having impedance Z (state 1). Here, the cleaning member 625 has a capacitance component and a resistance component. The capacitance component of the cleaning member 625 is the capacitance component C of the air layer. C The resistance component of the cleaning member 625 is higher than that of the air layer. Therefore, the cleaning member 625 is k When the cleaning member 625 contacts both the line electrode 400 and the point electrode 500 (second electrode), the capacitance and resistance components of the impedance between those electrodes become larger and smaller, respectively, than the capacitance and resistance components when the cleaning member 625 is not in contact with both of those electrodes. k When the insulating layer 2600 contacts both the A ,C B and the resistance component R of the cleaning member 625 A When the cleaning member 625 comes into contact with the replacement surface 213 (when state 1 changes to state 2), the line electrode 400 and the point electrode 500 form a series circuit (state 2). k The impedance Z between the cleaning member 625 and the replacement surface 213 changes to impedance Z1. The detection circuit 2300 in FIG. 23 detects this change and outputs a signal. The CPU 520 determines that the cleaning member 625 is in contact with the replacement surface 213 based on the signal.

[0225] In the above description, the CPU 520 detects the linear electrodes 400 and the point electrodes 500 adjacent to each other based on the output signal from the detection circuit 2300. kIt is detected that the impedance Z between the first and second terminals changes to the impedance Z1. Here, the change in the impedance Z may be a change in the resistance component of the impedance Z or a change in the capacitance component of the impedance Z.

[0226] For example, when the frequency of the AC signal from the oscillator 2303 is sufficiently high, the CPU 520 is unlikely to detect a change in impedance Z due to the capacitance component of the cleaning member 625, while the CPU 520 is unlikely to detect a change in impedance Z due to the capacitance component of the cleaning member 625. A As described above, the change in impedance Z caused by the cleaning member 625 is easily detected. k When the cleaning member 625 is in contact with both of the electrodes, the resistance component between those electrodes is smaller than the resistance component when the cleaning member 625 is not in contact with both of the electrodes. Therefore, a current easily flows between those electrodes. The CPU 520 detects a current flowing between the electrodes and outputs a current to the comparator CP k Based on the signal output from R A The change in impedance Z caused by the change in the impedance Z is detected by the CPU 520. As a result, the CPU 520 determines that the cleaning member 625 has come into contact with the surface 1262 to be cleaned.

[0227] On the other hand, if the frequency of the AC signal from oscillator 2303 is sufficiently low, CPU 520 A On the other hand, it is easy to detect a change in impedance Z due to the capacitance component of the cleaning member 625. k When the cleaning member 625 is in contact with both of the electrodes, the capacitance component between those electrodes becomes larger than the capacitance component when the cleaning member 625 is not in contact with both of the electrodes. Therefore, a displacement current easily flows between those electrodes. The CPU 520 detects the displacement current flowing between the electrodes and outputs it to the comparator CP kBased on the signal output from the sensor 520, the sensor 520 detects a change in impedance Z due to the capacitance component of the cleaning member 625. This enables the CPU 520 to determine that the cleaning member 625 has come into contact with the alternative surface 213.

[0228] The inventors conducted an experiment using a wiping roller 200 (FIG. 7) without a circumferential recess and a wiping roller 200 (FIG. 9) with a circumferential recess as the cleaning member 625 to verify whether or not there is a contact failure between the cleaning member 625 and the substitute member 212 can be determined based on a change in the impedance Z between the electrodes. The diameter, moving speed, and rotation speed of the wiping roller 200 used in the experiment were the same as those in the first embodiment.

[0229] As in the first embodiment, a sensor (not shown) is provided near each nozzle on the head nozzle surface 222 to check whether the degree of contact between the cleaning member 625 and the member to be cleaned 630 is appropriate.

[0230] When the wiping roller 200 without any recesses in the circumferential direction was used as the cleaning member 625, the CPU 520 found that no contact failure occurred over the entire replacement surface 213. More specifically, the distribution of the second index values ​​was similar to the distribution 1100. The CPU 520 estimated the distribution of the first index values ​​based on the obtained distribution of the second index values. The CPU 520 determined cleaning conditions based on the distribution of the first index values ​​and performed the cleaning operation. The CPU 520 determined that the degree of contact between the cleaning member 625 and the member to be cleaned 630 over the entire head nozzle surface 222 was appropriate based on a signal output from a sensor in the vicinity of each nozzle.

[0231] On the other hand, when the wiping roller 200 having a circumferential recess was used as the cleaning member 625, insufficient contact occurred in a part of the replacement surface 213. More specifically, the distribution of the second index values ​​was similar to the distribution 1105. The CPU 520 estimated the distribution of the first index values ​​based on the distribution 1105 as the distribution of the second index values.

[0232] For example, the CPU 520 calculates the time interval T3 from the time the wiping roller 200 contacts the head nozzle surface 222 and starts to move in the direction of the arrow 830 (the time interval T3 is v×t 23 ~v×t 34 It is estimated that the length Lt1 of the contact area (first index value) will be less than the lower limit of the target range while the wiping roller 200 is in a range moved by a distance of n×v×T in the +x direction from the position. In addition, if n is the number of rotations of the wiping roller 200 and the rotation period of the wiping roller 200 is a period T, it is determined that the length Lt1 of the contact area may be less than the target range even at a position away from the position by a distance of n×v×T in the +x direction.

[0233] That is, the CPU 520 judges that insufficient cleaning may occur at these positions due to insufficient contact between the wiping roller 200 and the head unit 105. Based on the result of this judgment, the CPU 520 judges that the insufficient cleaning cannot be resolved if the cleaning operation is performed only once, and determines the cleaning conditions so that the number of cleaning operations is two or more.

[0234] In the embodiment, the CPU 520 determines the cleaning conditions for the second cleaning operation such that the amount of pressure is increased from 1.5 mm to 2.0 mm, the relative movement speed is decreased from 10 mm / s to 8 mm / s, and the rotation speed of the wiping roller 200 is increased from 94 mm / s to 100 mm / s, compared to the cleaning conditions for the first cleaning operation. After the first and second cleaning operations are performed, the CPU 520 acquires the length Lt1 of the contact area detected in the vicinity of each nozzle while the cleaning operation is being performed based on the signal output from the sensor provided in the vicinity of each nozzle as described above. As a result, it was confirmed that the cleaning operation was performed in a state where the length Lt1 of the contact area was equal to or longer than the target length over the entire head nozzle surface 222. That is, the inventors confirmed that the cleaning failure was eliminated by the CPU 520 determining the cleaning conditions based on the distribution of the first index value.

[0235] [Effects of the third embodiment] The cleaning device 135 detects the length Lt of the contact area as a second index value based on the change in the impedance Z between the electrodes provided on the replacement surface 213. By detecting the change in the capacitance component of the impedance between the electrodes, the CPU 600 determines whether the resistance value of the cleaning member 625 or the insulating layer 2600 is high or the electrodes 400, 500 are low. k Even if a coating layer is formed to coat the surface, it is possible to determine that the cleaning member 625 has come into contact with the surface 1262 to be cleaned.

[0236] <Embodiment 4> In the first to fourth embodiments, the detection unit 1205 detects the line electrode 400 and the point electrode 500 on the replacement surface 213. k In the above description, the length Lt of the contact area is detected as the second index value based on the interval I. In the fourth embodiment, a case will be described with reference to Figs. 26 to 29 in which the detection unit 1205 detects the length Lt of the contact area based on the detection time of the contact between the cleaning member 625 and the alternative surface 213.

[0237] As for other points in Figures 1 to 3, 6, 7, and 12 to 15, the configuration and operation of cleaning device 135 of embodiment 5 are basically the same as the configuration and operation of cleaning device 135 of embodiment 1, and therefore the description will not be repeated.

[0238] 26 and 27 are diagrams for explaining the principle of detecting the length Lt of the contact area. k 13 is a diagram showing an example of a circuit for allowing a CPU 520 to detect a length Lt of a contact area based on a detection time detected when the touch panel 50 is in contact with the touch panel.

[0239] 26, the speed v of the cleaning member 625 moving relative to the alternative surface 213, the point electrode pair 2600 k diameter d, length of contact area Lt and detection time T k The relationship between T k =(Lt+d) / v. The cleaning member 625 is a point electrode pair 2600. k When in contact with the point electrode pair 2600 k Thus, the CPU 520 detects whether the cleaning member 625 is in the point-electrode pair 2600. k The length of the contact area Lt when in contact with the object is detected during the detection time T k The function of the detector 1205 is realized, for example, by the CPU 520 analyzing a signal output from a detector circuit 2700 in FIG.

[0240] 27, along the relative movement direction (+x direction) of the cleaning member 625 with respect to the alternative surface 213, the point electrode pair 2600 as the member 1208 is k ,2600 k+1 , ... are provided. The point electrode pair 2600 includes a point electrode 2600A k ,2600B k The number of point-electrode pairs 2600 was 6. The distance Is between each point-electrode pair in the x direction was 3 mm.

[0241] Point electrode 2600A k , 2600A k+1 ... is provided on the alternative surface 213. A point electrode 2600A on the alternative surface 213 k , 2600A k+1 The area where the point electrodes 2600A are provided may correspond to the areas ai (i=1, 2, ... 6). k and point electrode 2600B k A through hole is provided in the substrate 401 so that a current flows between the TTL element TT k The signal is transmitted to the CPU 520 via the

[0242] In addition, the cleaning member 625 is connected to the point electrode pair 2600 k ,2600 k+1 2600 point electrode pairs in the x direction so as not to contact more than two at the same time. k ,2600 k+1 It is desirable that the interval Is be 1.2 times or more the target length. Therefore, in the example of Fig. 28, the interval is set to 3 mm, which is 1.5 times the target length.

[0243] The detection circuit 2700 includes a resistive element R k and the TTL element TT k and binary counter 2805 k The TTL element TT k 2600 point electrodes k The cleaning member 625 converts the signal input from the point electrode pair 2600 into a TTL signal. k While in contact with both electrodes (point electrodes 2600 k While the cleaning member 625 moves within a range of width 2Lt+d in the x direction with the center at the center, a signal from the signal source DC1 is input to the TTL element TT k The TTL element TT k outputs a High signal (time t 31 ). Binary counter circuit 2805 k is the TTL element TT kThe high signal output from is counted using the reference pulse.

[0244] The cleaning member 625 is a point electrode pair 2600 k Apart from the point electrode pair 2600 k When the contact is lost (time t 32 ), the signal from the signal source DC1 is input to the TTL element TT k The TTL element TT k The CPU 520 acquires the count value via the PIO 510. The count value, which is expressed in binary, corresponds to the detection time T k (The cleaning member 625 is a point electrode pair 2600 k The CPU 520 calculates (detects) the length Lt of the contact area based on the acquired count value. More specifically, the CPU 520 calculates (detects) the length Lt of the contact area based on the detection time T k Based on this, the length Lt of the contact area is detected from the above-mentioned relational expression.

[0245] The CPU 520 determines whether the length Lt of the detected contact area is within the target range. k If the length Lt of the contact area based on is greater than the upper limit of the target range, the point electrode 2600 k The CPU 520 determines that an excessive contact has occurred in an area (for example, any of areas a1 to a6) where the detection time T k If the length Lt of the contact area based on is smaller than the lower limit of the target range, the CPU 520 determines that a lack of contact has occurred in the area where the point-electrode 2600k is provided.

[0246] Referring to FIG. 29, CPU 520 detects the detection time T k FIG. 29 illustrates the distribution of the length Lt of the contact area when the length Lt of the contact area is detected based on the detection time T k FIG. 29 shows a distribution 2900 of lengths Lt of contact areas detected based on the above.

[0247] CPU 520 performs a distribution estimation operation using blade 1800, and generates distribution 2000 as a distribution of the second index values. CPU 520 estimates, for example, the distribution of the first index values ​​as a distribution in which the distribution of the second index values ​​is repeated. CPU 520 determines that the same cleaning conditions as the conditions, such as the amount of pressing and the rotation speed of blade 1800 against replacement surface 213, when the distribution estimation operation was performed can be applied to the cleaning operation. CPU 520 performs the cleaning operation under the same conditions.

[0248] Furthermore, the CPU 520 performed a distribution estimation operation using the blade 1802. The CPU 520 generates, for example, a distribution 2900 as a distribution of the second index value. According to the distribution 2900, in the area a1 during the time interval T1 to T8, there is insufficient contact between the cleaning member 625 and the alternative member 212. In addition, in the area a2 during the time interval T1 to T7, there is insufficient contact between the cleaning member 625 and the alternative member 212. Furthermore, in the area a6 during the time interval T1 to T3, there is excessive contact between the cleaning member 625 and the alternative member 212.

[0249] The CPU 520 estimates the distribution of the first index value from the distribution 2900. The CPU 520 determines, based on the distribution of the first index value, that insufficient contact may occur in the time interval T1 to T7 (T8) at positions on the head nozzle surface 222 having the same y coordinate as the areas a1 and a2 when the cleaning operation is performed only once. The CPU 520 also determines that excessive contact may occur in the area a6. Therefore, the CPU 520 determines the cleaning conditions so that the number of cleanings is two or more. In the example of FIG. 20, the CPU 520 determines the cleaning conditions so that the number of cleanings is two.

[0250] The CPU 520 determines the cleaning conditions for the first cleaning operation based on the conditions registered in advance in the non-volatile memory 605. The CPU 520 also determines the cleaning conditions for the second cleaning operation so as to eliminate cleaning defects that may occur after the first cleaning operation. For example, the CPU 520 determines the cleaning conditions so that the blade 1802 cleans the surface to be cleaned 1262 in the second cleaning operation in a state in which the blade 1802 is moved (shifted) a predetermined distance in the sub-scanning direction (-y direction) from the relative position of the blade 1802 with respect to the head nozzle surface 222 in the first cleaning operation.

[0251] [Verification results] The inventors conducted an experiment to verify whether or not cleaning defects can be eliminated under cleaning conditions determined based on the distribution of the contact area length Lt, using a blade 1800 with a uniform free length Lf and a blade 1802 with a non-uniform free length Lf. In addition, to check whether the degree of contact between the cleaning member 625 and the member to be cleaned 630 is appropriate, a sensor (not shown) was provided near each nozzle on the head nozzle surface 222, as in the first embodiment.

[0252] When CPU 520 performed the distribution estimation operation using blade 1800, the distribution of the second index values ​​was similar to distribution 2000. CPU 520 estimated a distribution in which distribution 2000 was repeated as the distribution of the first index values. CPU 520 applied to the cleaning operation the same cleaning conditions as those conditions, such as the pressing amount and rotation speed of blade 1800 against replacement surface 213, when the distribution estimation operation was performed. CPU 520 performed the cleaning operation under those cleaning conditions.

[0253] After the cleaning operation was performed, the CPU 520 detected the length Lt1 of the contact area near each nozzle based on the output signal from the sensor provided near each nozzle. As a result, the detected contact area lengths Lt1 were all within the target range over the entire head nozzle surface 222.

[0254] On the other hand, CPU 520 performed a distribution estimation operation using blade 1802. The distribution of second index values ​​generated in the distribution estimation operation was a distribution similar to distribution 2900. CPU 520 estimated the distribution in which distribution 2900 was repeated as the distribution of first index values.

[0255] From this distribution, CPU 520 determined cleaning conditions so as to prevent insufficient cleaning during the time interval T1 to T7 (T8) in the nozzles on head nozzle surface 222 having the same y coordinate as areas a1, a2, and so as to prevent over-cleaning in the nozzles on head nozzle surface 222 having the same y coordinate as area a6.

[0256] More specifically, the CPU 520 determined the cleaning conditions so that the number of cleaning operations would be two, and determined other cleaning conditions in the second cleaning operation so as to eliminate cleaning defects that may occur after the first cleaning operation. In the above verification, the CPU 520 determined the cleaning conditions so that the blade 1802 was moved (shifted) an additional 5 mm in the sub-scanning direction (+y direction) in the second cleaning operation to clean the surface to be cleaned 1262. After that, the CPU 520 caused the blade 18002 to clean the head nozzle surface 222 based on the determined conditions. In the second cleaning operation, the cleaning conditions (such as the pressing amount and movement speed of the blade 1900 against the head nozzle surface 222) other than the shifting of the blade 1802 in the +y direction were the same as those in the first cleaning operation.

[0257] After the second cleaning operation was completed, the CPU 520 detected, based on the output signal from the sensor provided near each nozzle, the length Lt1 of the contact area between the cleaning member 625 and the head nozzle surface 222. As a result, the detected contact area lengths Lt1 were all within the target range over the entire head nozzle surface 222.

[0258] As described above, the inventors have confirmed that by having the CPU 520 determine the cleaning conditions based on the distribution of the first index values, it is possible to avoid insufficient cleaning and excessive cleaning, and to properly clean the entire head nozzle surface 222.

[0259] [Effects of the fourth embodiment] The cleaning device 135 detects the length Lt of the contact area as a second index value based on the detection time of the contact between the cleaning member 625 and the replacement surface 213. k As the width of the reference pulse for counting is set smaller, the sensitivity when detecting the length Lt of the contact area can be increased. This improves the accuracy when detecting the second index value. Therefore, the accuracy of estimating the position where insufficient or excessive contact between the cleaning member 625 and the member to be cleaned 630 may occur on the surface to be cleaned 1262 can be improved based on the distribution of the first index values. As a result, the optimal cleaning conditions can be determined based on the results of the estimation, and a more appropriate cleaning operation can be performed.

[0260] <Embodiment 5> In the first and second embodiments, the detection unit 1205 detects the line electrode 400 and the point electrode 500 as the member 1208 with which the cleaning member 625 is in contact. k In the third embodiment, the detection unit 1205 detects the length Lt of the contact area 1207 based on the presence or absence of contact between the replacement surface 213 and the cleaning member 625 at multiple points in the contact area 1207.

[0261] As for other points in Figures 1 to 3, 5 to 7, 9, and 12 to 15, the configuration and operation of cleaning device 135 of embodiment 3 are basically the same as the configuration and operation of cleaning device 135 of embodiments 1 and 2, respectively, and therefore will not be described repeatedly.

[0262] The principle of detecting the length Lt of the contact area will be described with reference to Fig. 30. Fig. 30 is a diagram showing an example of the hardware configuration of a sensor 320 for detecting the length Lt of the contact area in the fifth embodiment.

[0263] 30, the sensor 320 is divided into n sections a1 to an. The sensor 320 includes a substrate 3005 and a line electrode 400 in each section ai (i=1, 2, . . . n). i and 500 point electrodes i1 ,…,500 ik-1 ,500 ik ,…500 ih (k=1, 2, ... h). The substrate 3005 is used in place of the substrate 401 in FIG. 4 so that the CPU 520 can detect the length Lt of the contact area. i1 ,…,500 ik-1 ,500 ik ,…500 ih are provided in this order along the x direction in which the cleaning member 625 moves.

[0264] The substrate 3005 has a plurality of point electrodes 500 ik A plurality of through holes (not shown) are provided corresponding to the line electrodes 400. i and 500 point electrodes ik The line electrode 400 is provided to allow a current to flow between the line electrode 400 and the detection circuit. i and 500 point electrodes ik When the electrodes come into contact with the cleaning member 625, a signal indicating that the electrodes come into contact with the cleaning member 625 is transmitted to the detection circuit. Here, the detection circuit is a circuit in which the x-direction and the y-direction are interchanged in the detection circuit 505 of FIG. 5.ik In the circuit, the point electrode 500 in FIG. k It can correspond to.

[0265] In the fifth embodiment, a point electrode 500 in the x direction ik and 500 point electrodes ik+1 The point electrode 500 is provided so that the distance Ix between the point electrode 500 and the target length is less than the target length (for example, less than 1 / 2 of the target length). ik The diameter of is d.

[0266] In FIG. 30, the cleaning member 625 is i and 500 point electrodes ik When touching the point electrode 500 ik The partial circuit connected to is the partial circuit 506 in FIG. k In the same manner as above, the CPU 520 outputs a high signal. i and 500 point electrodes ik It can be determined that the person is in contact with

[0267] Here, the cleaning member 625 is in contact with the line electrode 400 in the area ai. i and 500 for each electrode i1 ,,…500 ik-1 ,500 ik When the cleaning member 625 comes into contact with these electrodes, each of the subcircuits connected to these point electrodes outputs a high signal. i and 500 point electrodes i1 ,…500 ik-1 ,500 ik It can be determined that the person is in contact with

[0268] In the above case, each electrode 500 ik+1 ,…,500 ih Therefore, the CPU 520 detects that the cleaning member 625 is in contact with the line electrode 400. i and 500 point electrodes ik+1,…,500 ih In this way, the CPU 520 can determine whether or not the contact area 1207 is in contact with the point electrode 500 as the member 1208 in the x direction based on whether or not a high signal has been received from each partial circuit. i1 ,…500 ik ,…500 ih The presence or absence of contact between the alternative surface 213 and the cleaning member 625 at each of the positions (where the position is provided) is determined.

[0269] The CPU 520 detects the length Lt of the contact area as a second index value based on the presence or absence of contact between the replacement surface 213 and the cleaning member 625 at the plurality of points. i and 500 for each electrode i1 ,,…,500 ik When the object is in contact with the object, the CPU 520 detects the length Lt of the contact area by a predetermined calculation process according to the formula (k-1)×Ix+(k-2)×d. The values ​​of the distance Ix and the diameter d are stored in the non-volatile memory 605.

[0270] The CPU 520 determines whether the length Lt of the contact area is within a threshold range based on the detected length Lt of the contact area. When the length Lt of the contact area is less than the threshold range, the CPU 520 determines that the degree of contact between the cleaning member 625 and the alternative member 212 is insufficient. When the length Lt of the contact area is equal to or greater than the threshold range, the CPU 520 determines that the degree of contact between the cleaning member 625 and the alternative member 212 is excessive.

[0271] The CPU 520 generates a distribution of the second index value based on the length Lt of the detected contact area, and estimates the distribution of the first index value. The subsequent processing is similar to the processing described in the first embodiment. Therefore, detailed description will not be repeated.

[0272] [Effects of the fifth embodiment] The cleaning device 135 detects the length Lt of the contact area as a second index value based on the presence or absence of contact at multiple points along the x direction in which the cleaning member 625 moves. ik and 500 ik+1 The smaller the interval Ix) between the cleaning member 625 and the cleaning member 630 is set, the higher the sensitivity when detecting the length Lt of the contact area. This improves the accuracy when detecting the second index value. Therefore, the accuracy of estimating the position where insufficient or excessive contact may occur between the cleaning member 625 and the cleaning member 630 on the cleaning surface 1262 can be improved based on the distribution of the first index values. As a result, the optimal cleaning conditions can be determined based on the results of the estimation, and a more appropriate cleaning operation can be performed.

[0273] <Embodiment 6> The cleaning device 135 in the first to fifth embodiments estimates the distribution of the first index values ​​based on the second index values ​​detected when the cleaning member 625 comes into contact with the alternative member 212. The cleaning device 135 in the sixth embodiment estimates the distribution of the first index values ​​indicating the degree of contact between the cleaning member 625 and the member to be cleaned 630 without bringing the cleaning member 625 into contact with the alternative member 212.

[0274] The principle of estimating the distribution of the first index values ​​in the sixth embodiment will be described with reference to Figures 31(A) and 31(B). Figures 31(A) and 31(B) are diagrams for explaining that the CPU 520 estimates the distribution of the first index values ​​without using the cleaning member 625 or the alternative member 212.

[0275] The cleaning device 135 includes a distribution estimation member 3100. The distribution estimation member 3100 is a member for estimating the distribution of the first index value, and is a conceptual member including the alternative member 212. The distribution estimation member 3100 does not necessarily need to be contacted by the cleaning member 625, unlike the alternative member 212. The distribution estimation member 3100 includes a reference member 3103 having a reference surface 3101 whose distance in the z direction with respect to the head nozzle surface 222 is known. The distribution estimation member 3100 includes an optical sensor 3102 as a member 1208 for measuring a distance Lz between the reference surface 3101 and the cleaning member 625.

[0276] The optical sensor 3102 measures the distance Lz to optically read (scan) the shape of the cleaning member 625. For example, the distance Lz when the cleaning member 625 has a dent 905, a chip 1600, a foreign object, or the like differs from the distance Lz when the cleaning member 625 does not have these. Therefore, the optical sensor 3102 can optically read the shape of the cleaning member 625 based on the measured distance Lz.

[0277] The CPU 520 acquires the shape of the cleaning member 625 based on the result of the reading. The CPU 520 estimates the distribution of the first index value (for example, the length Lt1 of the contact area) detected when the cleaning member 625 contacts the surface to be cleaned 1262 based on the acquired shape (distance Lz). More specifically, the CPU 520 estimates the distribution of the first index value detected when a sensor is provided on the surface to be cleaned 1262 when the cleaning member 625 having the read shape contacts the surface to be cleaned 1262 under a condition of a predetermined amount of pushing. For example, the CPU 520 converts the measured distance Lz into a first index value based on a data table that has been determined in advance by experiment or the like to show the relationship between the first index value and the distance Lz under the condition of the predetermined amount of pushing. The data table is stored in a non-volatile memory. The CPU 520 estimates the distribution of the first index value based on the converted first index value. In this manner, the CPU 520 (distribution estimation unit 1220) may estimate the distribution of the first index value by using the distribution estimation member 3100 without using the alternative member 212 for contacting the cleaning member 625.

[0278] 31(A), the optical sensor 3102 does not have to be provided integrally with the reference member 3103. For example, as shown in FIG 31(B), the light emitting unit 3102A and the light receiving unit 3102B constituting the optical sensor 3102 may be provided separately from the reference member 3103.

[0279] Referring to FIG. 31(B), the reference surface 3101 was provided at a position 2 mm away from the head nozzle surface 222 in the -z direction. A resin block made of black-painted PP (Polypropylene) was used as the reference member 3103. A light-emitting unit 3102A including six light-emitting elements (photodiodes) was provided so that light could pass through the gap between the cleaning member 625 and the reference surface 3101. The six light-emitting elements were provided along the z direction. In addition, a light-receiving unit 3102B including six light-receiving elements for measuring the amount of transmitted light was provided at a position facing the light-emitting unit 3102A across the cleaning member 625. The six light-emitting elements were also provided along the z direction, similar to the six light-emitting elements. The light-emitting unit 3102A and the light-receiving unit 3102B may correspond to the member 1208.

[0280] The CPU 520 calculates the distance Lz based on the amount of light emitted by the light emitting unit 3102A and the amount of transmitted light measured by the light receiving unit 3102B. For example, the CPU 520 calculates the distance Lz based on a data table that defines the relationship between the amount of received light, the amount of transmitted light, and the distance Lz in advance through experiments or the like. The CPU 520 estimates the distribution of the first index value based on the calculated distance Lz, similar to the case of FIG. 31(A).

[0281] For example, when the cleaning member 625 is a rotating body such as the wiping roller 200, the optical sensor 3102 may measure the change in the distance Lz while the cleaning member 625 is rotating. When the cleaning member 625 is the blade 1800, the optical sensor 3102 may measure the change in the distance Lz while the cleaning member 625 is moving on the xy plane.

[0282] [Verification results] The inventors conducted an experiment to verify whether a cleaning operation performed according to cleaning conditions based on the distribution of the first index value estimated using the distribution estimation member 3100 is appropriate. A wiping roller 200 without a circumferential recess (FIG. 7) and a wiping roller 200 with a circumferential recess (FIG. 9) were used as the cleaning member 625. The diameter, moving speed, and rotation speed of the wiping roller 200 used in the experiment were the same as those in the first embodiment.

[0283] As in the first embodiment, a sensor (not shown) is provided near each nozzle on the head nozzle surface 222 to check whether the degree of contact between the cleaning member 625 and the member to be cleaned 630 is appropriate.

[0284] When the wiping roller 200 without any recesses in the circumferential direction was used as the cleaning member 625, the distribution of the estimated first index values ​​was similar to the distribution estimated in the verification using the roller in the first embodiment. More specifically, the distribution of the first index values ​​was a distribution in which the distribution 1100 was repeated. The CPU 520 performed the cleaning operation according to the cleaning conditions based on the estimated distribution. The CPU 520 determined that the degree of contact between the cleaning member 625 and the member to be cleaned 630 over the entire head nozzle surface 222 was appropriate from the signal output from the sensor in the vicinity of each nozzle.

[0285] On the other hand, when the wiping roller 200 having a circumferential recess was used as the cleaning member 625, the distribution of the first index values ​​was similar to the distribution estimated in the verification using the roller in embodiment 1. Based on the distribution of the first index values, the CPU 520 determined that the insufficient cleaning could not be resolved if the cleaning operation was performed only once, and determined the cleaning conditions so that the number of cleaning operations would be two or more.

[0286] More specifically, the CPU 520 performed the cleaning operation under the second cleaning operation by increasing the pushing amount from 1.5 mm to 2.0 mm, lowering the relative movement speed from 10 mm / s to 8 mm / s, and increasing the rotation speed of the wiping roller 200 from 94 mm / s to 100 mm / s, as compared with the cleaning conditions under the first cleaning operation. After the first and second cleaning operations were performed, the CPU 520 acquired the length Lt1 of the contact area detected in the vicinity of each nozzle based on the signal output from the sensor provided in the vicinity of each nozzle as described above. As a result, it was confirmed that the cleaning operation was performed in a state in which the length Lt1 of the contact area was equal to or longer than the target length over the entire head nozzle surface 222. That is, the inventors confirmed that the cleaning failure was eliminated by the CPU 520 determining the cleaning conditions based on the distribution of the first index value.

[0287] [Effects of the sixth embodiment] The cleaning device 135 according to the sixth embodiment estimates the distribution of the first index values ​​by using the distribution estimation member 3100, without bringing the cleaning member 625 into contact with the alternative member 212. This allows the cleaning device 135 to estimate the distribution of the first index values ​​even when it is difficult to directly detect the second index value by bringing the cleaning member 625 into contact with the alternative member 212. Therefore, even in such a case, the cleaning device 135 can properly clean the entire surface to be cleaned 1262 under optimal cleaning conditions based on the estimated distribution of the first index values.

[0288] [Composition of porous elastomer and ink in the embodiment] The porous elastic material in each embodiment may include a foam structure formed by adding a foaming agent to urethane, olefin, etc. It is particularly desirable for the porous elastic material to have an open-cell structure in which minute cells are connected. The porous elastic material may be formed, for example, by an extraction method. The pore-forming material is kneaded and dispersed in the main material, and poured into a mold to remove the solvent and form the material, and then the pore-forming material is extracted to form a continuous porous body. The wiping roller 200 forms these porous elastic bodies on the rotation axis.

[0289] In addition, in each embodiment, a water-based pigment magenta ink was used. It is believed that any water-based ink can achieve the effect of this embodiment, but a pigment-based ink is likely to remain inside the porous member and is likely to achieve the effect. The ink used in the embodiment is a commercially available water-based magenta pigment ink, and the composition of the ink is general. In the ink, a quinacridone pigment is often used as a colorant, and water is used as a solvent. The ink further contains a dispersant for the colorant, a penetrant for penetrating the ink into the medium, a dihydric or trihydric alcohol as a drying prevention agent to prevent clogging, a PH (Power of Hydrogen) adjuster, and a preservative.

[0290] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0291] 100 image forming apparatus, 105 head unit, 135 cleaning device, 200 wiping roller, 212 alternative member, 213 alternative surface, 222 head nozzle surface, 320 sensor, 400 line electrode, 500 electrode, 625 cleaning member, 630 member to be cleaned, 1205 detection unit, 1207, 1265, 1210 drive unit, 1215 control unit, 1218 distribution generation unit, 1220 distribution estimation unit, 1240 discrimination unit, 1245 output unit, 1250 determination unit, 1262 surface to be cleaned, Lt, Lt1 length of contact area.

Claims

1. a cleaning member that comes into contact with a surface to be cleaned of a member to be cleaned to clean the surface to be cleaned; a drive unit that moves the cleaning member relative to the surface to be cleaned of the member to be cleaned; a distribution estimation unit that estimates a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by the driving unit moving the cleaning member relative to the surface to be cleaned; a replacement member having a replacement surface that is brought into contact with the cleaning member in place of the surface to be cleaned, The drive unit moves the cleaning member relative to the replacement surface, a detection unit that detects a second index value that indicates a degree of contact between the replacement member and the cleaning member, the distribution estimation unit estimates a distribution of the first index values ​​based on the second index values ​​detected by the detection unit; the second index value includes a length of a contact area of ​​the replacement surface where the cleaning member and the replacement member are in contact with each other in a direction in which the driving unit moves the cleaning member relative to the replacement surface, the member for detecting the second index value by the detection unit includes a plurality of electrodes provided on the alternative member, The detection unit determines whether the cleaning member has come into contact with the alternative surface based on the presence or absence of a current flowing between a first electrode and a second electrode among the plurality of electrodes.

2. a cleaning member that comes into contact with a surface to be cleaned of a member to be cleaned to clean the surface to be cleaned; a drive unit that moves the cleaning member relative to the surface to be cleaned of the member to be cleaned; a distribution estimation unit that estimates a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by the driving unit moving the cleaning member relative to the surface to be cleaned, The distribution estimation unit estimates a distribution of the first index value according to a position in a direction perpendicular to a direction in which the drive unit moves the cleaning member relatively to the surface to be cleaned.

3. a cleaning member that comes into contact with a surface to be cleaned of a member to be cleaned to clean the surface to be cleaned; a drive unit that moves the cleaning member relative to the surface to be cleaned of the member to be cleaned; a distribution estimation unit that estimates a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by the driving unit moving the cleaning member relative to the surface to be cleaned, The cleaning member is configured to be rotatable, The distribution estimation unit estimates a distribution of the first index value according to an amount of rotation of the cleaning member.

4. 4. The cleaning device according to claim 1, wherein the surface to be cleaned includes a nozzle surface of an inkjet head as the member to be cleaned.

5. 5. The cleaning device according to claim 1, wherein the cleaning member is made of a porous elastic body.

6. 6. The cleaning device according to claim 1, wherein the surface to be cleaned is wiped by the cleaning member in a state in which the cleaning liquid has been absorbed.

7. The cleaning device according to claim 1 , wherein the replacement member is provided in the vicinity of a position where the cleaning member waits before cleaning the surface to be cleaned.

8. The cleaning device according to claim 7 , wherein the surface to be cleaned and the alternative surface form a single plane.

9. a cleaning member that comes into contact with a surface to be cleaned of a member to be cleaned to clean the surface to be cleaned; a drive unit that moves the cleaning member relative to the surface to be cleaned of the member to be cleaned; a distribution estimation unit that estimates a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by the driving unit moving the cleaning member relative to the surface to be cleaned; a replacement member having a replacement surface that is brought into contact with the cleaning member in place of the surface to be cleaned, The drive unit moves the cleaning member relative to the replacement surface, a detection unit that detects a second index value that indicates a degree of contact between the replacement member and the cleaning member, the second index value includes a length of a contact area of ​​the replacement surface where the cleaning member and the replacement member are in contact with each other in a direction in which the driving unit moves the cleaning member relative to the replacement surface, the detection unit detects the second index value based on the presence or absence of contact between the cleaning member and the replacement surface at a plurality of points in the contact area along the direction, the member for detecting the second index value by the detection unit includes a plurality of electrodes provided on the alternative member, the plurality of electrodes include a line electrode provided along the direction in the contact area, and a plurality of point electrodes provided corresponding to the plurality of locations, The detection unit determines whether or not the cleaning member is in contact with the alternative surface at the multiple locations based on the presence or absence of current flowing between the line electrode and each of the multiple point electrodes.

10. a cleaning member that comes into contact with a surface to be cleaned of a member to be cleaned to clean the surface to be cleaned; a drive unit that moves the cleaning member relative to the surface to be cleaned of the member to be cleaned; a distribution estimation unit that estimates a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by the driving unit moving the cleaning member relative to the surface to be cleaned; a replacement member having a replacement surface that is brought into contact with the cleaning member in place of the surface to be cleaned, The drive unit moves the cleaning member relative to the replacement surface, a detection unit that detects a second index value that indicates a degree of contact between the replacement member and the cleaning member, the second index value includes a length of a contact area of ​​the replacement surface where the cleaning member and the replacement member are in contact with each other in a direction in which the driving unit moves the cleaning member relative to the replacement surface, The detection unit detects the second index value based on a detection time of contact between the cleaning member and the alternative surface.

11. a cleaning member that comes into contact with a surface to be cleaned of a member to be cleaned to clean the surface to be cleaned; a drive unit that moves the cleaning member relative to the surface to be cleaned of the member to be cleaned; a distribution estimation unit that estimates a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by the driving unit moving the cleaning member relative to the surface to be cleaned; a replacement member having a replacement surface that is brought into contact with the cleaning member in place of the surface to be cleaned, The drive unit moves the cleaning member relative to the replacement surface, a detection unit that detects a second index value that indicates a degree of contact between the replacement member and the cleaning member, the second index value includes a length of a contact area of ​​the replacement surface where the cleaning member and the replacement member are in contact with each other in a direction in which the driving unit moves the cleaning member relative to the replacement surface, the member for detecting the second index value by the detection unit includes a plurality of electrodes provided on the alternative member, The detection unit determines that the cleaning member has come into contact with the alternative surface based on a change in impedance between a first electrode and a second electrode among the plurality of electrodes.

12. the first electrode and the second electrode are adjacent to each other; The cleaning device according to claim 11 , wherein the change in impedance between the first electrode and the second electrode includes a change in a resistance component between the first electrode and the second electrode.

13. the first electrode and the second electrode are adjacent to each other; The cleaning device according to claim 11 , wherein the change in impedance between the first electrode and the second electrode comprises a change in a capacitance component between the first electrode and the second electrode.

14. a cleaning member that comes into contact with a surface to be cleaned of a member to be cleaned to clean the surface to be cleaned; a drive unit that moves the cleaning member relative to the surface to be cleaned of the member to be cleaned; a distribution estimation unit that estimates a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by the driving unit moving the cleaning member relative to the surface to be cleaned; a replacement member having a replacement surface that is brought into contact with the cleaning member in place of the surface to be cleaned, The drive unit moves the cleaning member relative to the replacement surface, a detection unit that detects a second index value that indicates a degree of contact between the replacement member and the cleaning member; a discrimination unit that discriminates a position of a portion of the cleaning member where the second index value is outside a predetermined range; The cleaning device further includes an output unit that outputs a determination result of the determination unit.

15. a cleaning member that comes into contact with a surface to be cleaned of a member to be cleaned to clean the surface to be cleaned; a drive unit that moves the cleaning member relative to the surface to be cleaned of the member to be cleaned; a distribution estimation unit that estimates a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by the driving unit moving the cleaning member relative to the surface to be cleaned; and a determination unit that determines cleaning conditions when the cleaning member cleans the surface to be cleaned, based on a position of a portion in the distribution of the first index values ​​where the first index value is outside a threshold range.

16. the cleaning condition includes a number of times N (N is a natural number) that the cleaning member cleans the surface to be cleaned and at least one other cleaning condition; The cleaning device according to claim 15, wherein the determination unit determines the at least one other cleaning condition when the cleaning member cleans the cleaned surface the nth time (1≦n≦N) so as to be different from the at least one other cleaning condition when the cleaning member cleans the cleaned surface the mth time (1≦m≦N, and n≠m).

17. an image forming unit that forms an image on a recording medium; An image forming apparatus comprising the cleaning device according to any one of claims 1 to 16.

18. 1. A cleaning method comprising the steps of: a step of moving a cleaning member, which comes into contact with a surface to be cleaned of a member to be cleaned and cleans the surface to be cleaned, relative to the surface to be cleaned; and estimating a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by moving the cleaning member relatively to the surface to be cleaned, the moving step includes moving the cleaning member relative to an alternative surface that is contacted by the cleaning member in place of the surface to be cleaned; The cleaning method further includes a step of detecting a second index value indicating a degree of contact between the replacement member having the replacement surface and the cleaning member; the step of estimating the distribution includes estimating a distribution of the first index values ​​based on the detected second index values; the second index value includes a length of a contact area of ​​the replacement surface where the cleaning member and the replacement member are in contact with each other in a direction in which the cleaning member moves relative to the replacement surface, the member for detecting the second index value includes a plurality of electrodes provided on the replacement member, The cleaning method, wherein the detecting step includes determining that the cleaning member has come into contact with the alternative surface based on the presence or absence of a current flowing between a first electrode and a second electrode among the plurality of electrodes.

19. a step of moving a cleaning member, which comes into contact with a surface to be cleaned of a member to be cleaned and cleans the surface to be cleaned, relative to the surface to be cleaned; and estimating a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by moving the cleaning member relatively to the surface to be cleaned, A cleaning method, wherein the step of estimating the distribution includes estimating a distribution of the first index value according to a position in a direction perpendicular to a direction in which the cleaning member is moved relatively to the surface to be cleaned.

20. a step of moving a cleaning member, which comes into contact with a surface to be cleaned of a member to be cleaned and cleans the surface to be cleaned, relative to the surface to be cleaned; and estimating a distribution of first index values ​​indicating a degree of contact between the cleaning member and the cleaning member on the surface to be cleaned before the cleaning member cleans the surface to be cleaned by moving the cleaning member relatively to the surface to be cleaned, The cleaning member is configured to be rotatable, A cleaning method, wherein the step of estimating the distribution includes estimating a distribution of the first index value according to an amount of rotation of the cleaning member.

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