Ink receiving device and ink jet recording device

Abstract

To provide an ink receiving device which can detect contact abnormality of a temperature detection part to a waste bucket or a heating part when the heating part is controlled on the basis of a detection result of the temperature detection part.SOLUTION: An ink receiving device includes a waste bucket having a receiving part for receiving waste ink, a heating part which heats the receiving part, a temperature detection part which detects a temperature of the receiving part, and a control part which controls the heating part on the basis of a detection result of the temperature detection part. The temperature detection part is structured of a pair of temperature detection elements. The one temperature detection element is mounted on a first surface side of the heating part opposite to a lower surface of the receiving part. The other temperature detection element is mounted on a second surface side of the heating part. The control part detects contact abnormality of the temperature detection part to the waste bucket or the heating part on the basis of the detection result of the pair of temperature detection elements.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an ink receiving device and an ink jet recording apparatus. [Background technology]

[0002] Inkjet recording devices are known as one type of image forming device. Inkjet recording devices form images by ejecting ink droplets from the nozzles of an inkjet head onto a recording medium that is conveyed thereto. Inkjet recording devices cannot eject ink well if foreign matter adheres to the nozzles of the inkjet head, ink remains, air bubbles are mixed in, or the like. For this reason, in inkjet recording devices, head cleaning (hereinafter also referred to as "head maintenance") is performed as a form of maintenance to maintain good ink ejection conditions.

[0003] Patent Document 1 discloses an ink receiving device that includes a receiving section, a heating section, a temperature detection section, and a control section. The receiving section receives waste ink ejected from the nozzles. The receiving section constitutes part of a waste bucket. The heating section heats the receiving section. The temperature detection section detects the temperature of the receiving section. The control section controls the heating section based on the detection result of the temperature detection section, thereby adjusting the temperature of the receiving section to a target temperature (hereinafter also referred to as "temperature control"). In the inkjet recording device described in Patent Document 1, a temperature detection section is attached to one surface of the receiving section of the waste bucket, and a heating section is attached to one surface of the receiving section so as to cover the temperature detection section. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-30453 Summary of the Invention [Problem to be solved by the invention]

[0005] When attaching the heating unit to the receiving part of the waste bucket, the heating unit may float away from the receiving part of the waste bucket due to, for example, insufficient pressure to press the heating unit against the receiving part, deterioration of the heating unit over time after attachment, etc. In that case, as shown in Figures 16 and 17, the temperature detection unit 101 may float away from the receiving part 103 together with the heating unit 102, or may be left behind in the receiving part 103. In other words, an abnormal contact of the temperature detection unit with the waste bucket or the heating unit occurs.

[0006] In order to realize appropriate temperature control in an inkjet recording device, it is necessary to detect contact abnormality of the temperature detection unit with the waste bucket or the heating unit. However, the technology described in Patent Document 1 does not take into consideration the detection of contact abnormality of the temperature detection unit. Furthermore, when a contact abnormality of the temperature detection unit occurs as shown in FIG. 16, the temperature control may continue without detecting the occurrence of the contact abnormality.

[0007] An object of the present invention is to provide an ink receiving device and an ink jet recording device that can detect abnormal contact of the temperature detection unit with the waste bucket or the heating unit when controlling the heating unit based on the detection results of the temperature detection unit. [Means for solving the problem]

[0008] The ink receiving device of the present invention comprises a waste bucket having a receiving portion for receiving waste ink, a heating portion for heating the receiving portion, a temperature detection portion for detecting the temperature of the receiving portion, and a control portion for controlling the heating portion based on the detection results of the temperature detection portion, wherein the temperature detection portion is composed of a pair of temperature detection elements, one temperature detection element being attached to a first surface side of the heating portion facing the underside of the receiving portion, and the other temperature detection element being attached to a second surface side of the heating portion, and the control portion detecting abnormal contact of the temperature detection portion with the waste bucket or the heating portion based on the detection results of the pair of temperature detection elements.

[0009] An inkjet recording apparatus according to the present invention includes a head unit that ejects ink from nozzles to form an image on a recording medium, and the ink receiving device that receives waste ink ejected from the nozzles. Effect of the Invention

[0010] According to the present invention, when the heating section is controlled based on the detection result of the temperature detection section, it is possible to detect abnormal contact of the temperature detection section with the waste bucket or the heating section. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the overall configuration of an inkjet recording apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing the configuration of the head unit. [Diagram 3] FIG. 3 is a block diagram showing the main functional configuration of an inkjet recording apparatus according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram of an ink receiving device according to one embodiment of the present invention. [Diagram 5] FIG. 5 is a cross-sectional view of a main part showing the arrangement of the heating unit and the temperature detection unit relative to the waste bucket receiving unit. [Figure 6] FIG. 6 is a cross-sectional view of a main part showing a first contact abnormality as a contact abnormality of the temperature detection portion. [Figure 7] FIG. 7 is a cross-sectional view of a main part showing a second contact abnormality as a contact abnormality in the temperature detection portion. [Figure 8] FIG. 8 is a cross-sectional view of a main part showing a third contact abnormality as a contact abnormality in the temperature detection portion. [Figure 9] FIG. 9 is a cross-sectional view of a main part showing a fourth contact abnormality as a contact abnormality of the temperature detection portion. [Figure 10] FIG. 10 is a diagram showing the relationship between the arrangement of the temperature detectors, the first detected temperature, the second detected temperature, and the temperature rise time. [Figure 11] FIG. 11 is a diagram showing changes over time in the first detected temperature and the second detected temperature when a first contact abnormality occurs in the temperature detection unit. [Figure 12] FIG. 12 is a diagram showing changes over time in the first detected temperature and the second detected temperature when a second contact abnormality occurs in the temperature detection unit. [Figure 13] FIG. 13 is a diagram showing changes over time in the first detected temperature and the second detected temperature when the third contact abnormality occurs in the temperature detection unit. [Figure 14] FIG. 14 is a diagram showing changes over time in the first detected temperature and the second detected temperature when a fourth contact abnormality occurs in the temperature detection unit. [Figure 15] FIG. 15 is a flowchart showing an example of a control process performed by the control unit 40 during head maintenance. [Figure 16] FIG. 16 is a cross-sectional view of a main part showing a first example of contact abnormality in the temperature detection portion. [Figure 17] FIG. 17 is a cross-sectional view of a main part showing a second example of contact abnormality in the temperature detection portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In this specification and the drawings, elements having substantially the same functions or configurations are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the following description and drawings are examples for explaining the present invention, and may be omitted or simplified for convenience of explanation. Each component may be singular or plural unless otherwise limited. In addition, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0013] The overall configuration of the inkjet recording apparatus will be described. FIG. 1 is a diagram showing the overall configuration of an inkjet recording apparatus according to an embodiment of the present invention. As shown in FIG. 1, the inkjet recording device 1 has a paper feed section 10, an image forming section 20, a paper discharge section 30, an ink receiving device 100, and a control section 40. The inkjet recording device 1 operates under the control of the control section 40 as follows. First, the recording medium P stored in the paper feed section 10 is conveyed to the image forming section 20. Next, an image is formed on the recording medium P in the image forming section 20. Next, the recording medium P on which the image has been formed is discharged to the paper discharge section 30. As the recording medium P, in addition to paper such as plain paper or coated paper, various media capable of fixing the ink that has landed on the surface, such as fabric or sheet-like resin, can be used. In the present embodiment, as an example, it is assumed that the recording medium P is paper.

[0014] The paper feed section 10 includes a paper feed tray 11 and a transport section 12. The paper feed tray 11 stores a recording medium P. The transport section 12 transports the recording medium P from the paper feed tray 11 to the image forming section 20.

[0015] The paper feed tray 11 supports one or more recording media P placed thereon. The paper feed tray 11 is configured to move up and down depending on the amount of recording media P placed on the paper feed tray 11. The paper feed tray 11 holds the topmost recording medium P at a transport position so that the recording media P are transported by the transport unit 12 in order starting from the topmost recording medium P.

[0016] The conveying unit 12 has two rollers 121 and 122 and a loop-shaped belt 123. The belt 123 is supported with a predetermined tension by the two rollers 121 and 122. The belt 123, with the recording medium P placed on it, moves in a circular motion in accordance with the rotation of the rollers 121 and 122, thereby conveying the recording medium P to the image forming unit 20.

[0017] The image forming section 20 includes an image forming drum 21 , a delivery unit 22 , a paper heating section 23 , a head unit 24 , a fixing section 25 , a delivery section 26 , and an image reading sensor 27 .

[0018] The image forming drum 21 is composed of a cylindrical member. The image forming drum 21 is rotated counterclockwise by a drive motor (not shown). The image forming drum 21 has a cylindrical outer peripheral surface, and supports the recording medium P along this outer peripheral surface. The image forming drum 21 transports the recording medium P by the rotation of the image forming drum 21. The outer peripheral surface of the image forming drum 21 faces the paper heating section 23, the head unit 24, and the fixing section 25.

[0019] The delivery unit 22 delivers the recording medium P transported by the transport section 12 to the image forming drum 21. The delivery unit 22 is provided between the transport section 12 and the image forming drum 21. The delivery unit 22 has a claw portion 221 and a delivery drum 222. The claw portion holds one end of the recording medium P transported by the transport section 12. The delivery drum 222 receives the recording medium P held by the claw portion 221 from the claw portion 221 and delivers it to the image forming drum 21.

[0020] The paper heating section 23 heats the recording medium P so that the recording medium P conveyed by the image forming drum 21 reaches a predetermined temperature. The paper heating section 23 is disposed downstream of the delivery drum 222 and upstream of the head unit 24 in the rotation direction of the image forming drum 21.

[0021] The head units 24 form an image on the recording medium P by ejecting ink onto the recording medium P supported on the image forming drum 21. In the inkjet recording device 1 of this embodiment, four head units 24 are provided corresponding to four colors of ink: Y (yellow), M (magenta), C (cyan), and K (black). The four head units 24 are lined up in the order of Y, M, C, and K from the upstream side in the rotation direction of the image forming drum 21.

[0022] The configuration of the head unit will be described. 2 is a schematic diagram showing the configuration of the head unit, showing the surface of the head unit that faces the outer circumferential surface of the image forming drum 21. The head unit 24 includes four image forming heads 242. The four image forming heads 242 are attached to a mounting member 244. The four image forming heads 242 are arranged in a staggered pattern so that the nozzle rows are connected seamlessly in the X direction. Each of the image forming heads 242 is provided with a plurality of image forming elements. Each of the image forming elements has a plurality of pressure chambers, a plurality of piezoelectric elements, and a plurality of nozzles 243. When a drive signal is input to deform the piezoelectric elements, the pressure in the pressure chamber of each image forming element changes due to the deformation of the piezoelectric elements, and ink is ejected from the nozzles 243 communicating with the pressure chambers. The nozzles 243 eject ink droplets at a predetermined timing onto the recording medium P transported by the image forming drum 21.

[0023] Two nozzle rows are formed in the image forming head 242. The two nozzle rows are composed of nozzles 243 arranged at equal intervals in a direction (X direction in the figure) intersecting the transport direction of the recording medium P. The two nozzle rows are provided such that the positions of the nozzles 243 are shifted from each other in the X direction by half the arrangement interval of the nozzles 243 in each nozzle row.

[0024] The number of nozzle rows in the image forming head 242 may be one or three or more, instead of two. The number of image forming heads 242 in the head unit 24 may be three or less, or five or more, instead of four.

[0025] In the inkjet recording apparatus 1 according to this embodiment, the ink used for forming an image is, for example, an ultraviolet-curable ink. This ink is in a gel state at normal temperatures, including room temperature, and in a sol state when heated to a predetermined temperature or higher.

[0026] Returning to FIG. 1 for further explanation, the fixing unit 25 cures and fixes the ink ejected onto the recording medium P by the head unit 24 through irradiation with energy rays. In this embodiment, ultraviolet-curable ink is used. For this reason, the fixing unit 25 irradiates ultraviolet rays as the energy rays. The fixing unit 25 has, for example, a fluorescent tube such as a low-pressure mercury lamp, and irradiates the recording medium P with ultraviolet rays by emitting light from the fluorescent tube. The fixing unit 25 is disposed downstream of the head unit 24 in the rotation direction of the image forming drum 21.

[0027] The fixing unit 25 may have any configuration as long as it is capable of fixing an image by irradiating ultraviolet rays onto the recording medium P. For example, the fixing unit 25 may be configured with an ultraviolet laser light source, a metal halide lamp, a light emitting diode, or the like. In addition, the energy rays irradiated by the fixing unit 25 are not limited to ultraviolet rays, and may be any energy rays having a property of curing ink according to the properties of the ink.

[0028] The ink receiving device 100 receives and collects ink discharged from the nozzles of the inkjet head during head maintenance (hereinafter, also referred to as "waste ink"). The ink receiving device 100 will be described in detail later.

[0029] The delivery section 26 transports the recording medium P irradiated with ultraviolet light by the fixing section 25 from the image forming drum 21 to the paper discharge section 30. The delivery section 26 is disposed between the image forming drum 21 and the paper discharge section 30. The delivery section 26 has two rollers 261, 262, a ring-shaped belt 263, and a transfer drum 264. The belt 263 is supported by the two rollers 261, 262 with a predetermined tension. The belt 263 transports the recording medium P by moving in a circle in accordance with the rotation of each of the rollers 261, 262 with the recording medium P placed on the belt 263. The transfer drum 264 transfers the recording medium P from the image forming drum 21 to the belt 263.

[0030] The image reading sensor 27 reads an image on the recording medium P transported by the delivery unit 26. The image data read by the image reading sensor 27 is sent to the control unit 40.

[0031] The paper discharge section 30 stores the recording medium P transported by the delivery section 26. The paper discharge section 30 has a paper discharge tray 31. The paper discharge tray 31 stacks the recording media P transported by the delivery section 26 in order.

[0032] 3 is a block diagram showing the main functional configuration of an inkjet recording device according to an embodiment of the present invention. In addition to the above-mentioned paper heating section 23, head unit 24, fixing section 25, control section 40, and ink receiving device 100, the inkjet recording device 1 includes a transport drive section 51, an operation display section 52, an input / output interface 53, and the like. The head unit 24 includes a head drive section 241 and an image forming head 242. The head drive section 241 supplies a drive signal for deforming a piezoelectric element to an image forming element of the image forming head 242 at an appropriate timing, thereby causing an appropriate amount of ink to be ejected from a nozzle 243 of the image forming head 242.

[0033] The control unit 40 includes a CPU 41 (Central Processing Unit), a RAM 42 (Random Access Memory), a ROM 43 (Read Only Memory), and a storage unit 44.

[0034] The CPU 41 loads various control programs and setting data stored in the ROM 43 into the RAM and executes the programs, thereby centrally controlling the operation of the entire inkjet recording apparatus 1. The RAM 42 provides a working memory space for the CPU 41 and temporarily stores data. The RAM 42 may include a non-volatile memory. The ROM 43 stores various control programs and setting data executed by the CPU 41.

[0035] The storage unit 44 stores print jobs input from the external device 2 via the input / output interface 53, image data related to the print jobs, and the like. The print job includes information specifying the image data related to the image to be formed, as well as information related to the type of recording medium P on which the image is to be formed. The information related to the type of recording medium P is, for example, the size and thickness of the recording medium P. For example, an HDD (Hard Disk Drive) is used as the storage unit 44.

[0036] The transport drive unit 51 supplies a drive signal to a motor for rotating the image forming drum 21 based on a control signal supplied from the control unit 40 .

[0037] Further, the transport drive unit 51 supplies drive signals to motors for operating the transport unit 12, the delivery unit 22, and the delivery unit 26 based on control signals supplied from the control unit 40.

[0038] The operation display unit 52 has a display unit and an input unit. The display unit is, for example, a liquid crystal display, an organic EL display, or the like. The input unit is, for example, a touch panel that is placed over the screen of the display unit. The operation display unit 52 has a function of displaying various information to the user and a function of accepting input of various information from the user. That is, the operation display unit 52 functions as a user interface.

[0039] The input / output interface 53 is an interface for transmitting and receiving data between the external device 2 and the control unit 40 .

[0040] The external device 2 is configured by, for example, a personal computer. The external device 2 supplies print jobs, image data, and the like to the control unit 40 via the input / output interface 53.

[0041] In the inkjet recording device 1, clogging of the nozzles 243 may occur due to an increase in the viscosity of the ink caused by drying, and due to the intrusion of foreign matter into the nozzles 243. Therefore, in the inkjet recording device 1, head maintenance is performed at a predetermined timing. Head maintenance is maintenance performed by operating the head unit 24 under the control of the control unit 40 in order to eliminate clogging of the nozzles 243. In this head maintenance, a purging process is performed to replace the ink in the nozzles 243. In the purging process, ink is forcibly ejected from the nozzles 243. Waste ink ejected from the nozzles 243 by the purging process during head maintenance is received in a waste bucket 60 (FIG. 4). Waste ink in the waste bucket 60 is discharged into a waste ink collection container.

[0042] The ink receiving device will now be described. FIG. 4 is a schematic diagram of an ink receiving device according to one embodiment of the present invention. 4, ink receiving device 100 includes waste bucket 60, heating unit 61, and temperature detection unit 62. Heating unit 61 is controlled by control unit 40. Therefore, control unit 40 functions as a control unit for ink receiving device 100. Waste bucket 60 includes receiving unit 65, wall unit 66, and discharge unit 67. Receiving unit 65 receives waste ink ejected from nozzles 243 of head unit 24 on an upper surface of receiving unit 65.

[0043] The receiving portion 65 has four receiving portions 65A, 65B, 65C, and 65D. Each of the receiving portions 65A, 65B, 65C, and 65D is formed in a generally triangular shape in a plan view. The four receiving portions 65A, 65B, 65C, and 65D have two sides connected to each other, and are generally formed in an inverted pyramid shape.

[0044] The wall portion 66 is formed to rise vertically from the outer circumferential edge of the receiving portion 65. The wall portion 66 has four wall portions 66A, 66B, 66C, and 66D corresponding to the four receiving portions 65A, 65B, 65C, and 65D. The wall portion 66 is provided to prevent waste ink from leaking from the receiving portion 65.

[0045] The discharge portion 67 is an opening for discharging the waste ink received by the receiving portion 65 to a waste ink recovery container (not shown). The discharge portion 67 is provided on the tops of the four receiving portions 65A, 65B, 65C, and 65D. The tops of the four receiving portions 65A, 65B, 65C, and 65D are the lowest parts of the upper surface of the receiving portion 65.

[0046] The heating unit 61 heats the receiving portion 65 of the waste pail 60. The heating unit 61 is attached to the lower surface of the receiving portion 65. The heating unit 61 has four heating units 61A, 61B, 61C, and 61D corresponding to the four receiving portions 65A, 65B, 65C, and 65D.

[0047] The configurations of the heating parts 61A, 61B, 61C, and 61D are basically the same, except for the corresponding receiving parts 65A, 65B, 65C, and 65D. For this reason, the configuration of the heating part 61A will be described here as an example. The heating part 61A is composed of a planar heater that is approximately triangular in plan view. The planar size of the planar heater is slightly smaller than the planar size of the receiving part 65A. The planar heater that constitutes the heating part 61A is, for example, a rubber heater. The heating part 61A is attached to the lower surface of the receiving part 65A.

[0048] The temperature detection unit 62 detects the temperature of the receiving part 65. The temperature detection unit 62 is disposed within the heating area of ​​the heating unit 61. The heating area is the area in the receiving part 65 where the heating unit 61 is disposed. The temperature detection unit 62 is attached to the lower surface side of the receiving part 65. The temperature detection unit 62 has four temperature detection units 62A, 62B, 62C, 62D corresponding to the four receiving parts 65A, 65B, 65C, 65D.

[0049] The configurations of the temperature detection units 62A, 62B, 62C, and 62D are basically the same, except that the corresponding receiving units 65A, 65B, 65C, and 65D are different. For this reason, the configuration of the temperature detection unit 62A will be described as an example here. As shown in FIG. 5, the temperature detection unit 62A is composed of a pair of temperature detection elements 62A-1 and 62A-2. In this embodiment, each of the temperature detection elements 62A-1 and 62A-2 is composed of a thermistor. The pair of temperature detection elements 62A-1 and 62A-2 are disposed within the heating area of ​​the heating unit 61A. The pair of temperature detection elements 62A-1 and 62A-2 are disposed approximately in the center of the heating area. In this embodiment, the heating unit 61A is composed of a rubber heater.

[0050] The pair of temperature detection elements 62A-1, 62A-2 are preferably arranged in a state where at least a part of the temperature detection elements (62A-1, 62A-2) overlap each other in the heating region of the heating unit 61A when the pair of temperature detection elements 62A-1, 62A-2 are viewed from a direction perpendicular to the lower surface of the receiving unit 65A (the direction indicated by the arrow in the figure). In addition, the pair of temperature detection elements 62A-1, 62A-2 are preferably arranged in a state where the whole of the temperature detection elements (62A-1, 62A-2) overlap each other in the heating region of the heating unit 61A when the pair of temperature detection elements 62A-1, 62A-2 are viewed from a direction perpendicular to the lower surface of the receiving unit 65A, that is, at the same position in the heating region. In other words, the pair of temperature detection elements 62A-1, 62A-2 are preferably arranged in the same position with the heating unit 61A between them.

[0051] The temperature detection element 62A-1 is attached to the lower surface of the receiving portion 65A. The temperature detection element 62A-1 is covered by the heating portion 61A. That is, the temperature detection element 62A-1 is attached to the lower surface of the receiving portion 65A while being covered by the heating portion 61A. As a result, the temperature detection element 62A-1 is attached to the lower surface of the receiving portion 65A while being sandwiched between the receiving portion 65A and the heating portion 61A.

[0052] On the other hand, the temperature detection element 62A-2 is attached to the lower surface of the heating section 61A. As a result, one temperature detection element 62A-1 is attached to the upper surface side of the heating section 61A, and the other temperature detection element 62A-2 is attached to the lower surface side of the heating section 61A. The upper surface side of the heating section 61A corresponds to the first surface side of the heating section 61A. The lower surface side of the heating section 61A corresponds to the second surface side of the heating section 61A. The first surface and the second surface of the heating section 61A are surfaces facing opposite each other in the thickness direction of the heating section 61A.

[0053] In the ink receiving device 100 having the above configuration, the control unit 40 controls the heating unit 61 based on the detection result of the temperature detection unit 62 so that the waste ink received in the receiving unit 65 is maintained in a fluid state. At that time, the control unit 40 controls the heating unit 61 so that the temperature of the receiving unit 65 detected by the temperature detection unit 62 becomes a target temperature. However, in the ink receiving device 100, if a contact abnormality occurs between the temperature detection unit 62 and the waste pail 60 or the heating unit 61, appropriate temperature control cannot be performed. For this reason, in the ink receiving device 100 according to this embodiment, the temperature detection unit 62A arranged in the heating area of ​​the heating unit 61A is composed of a pair of temperature detection elements 62A-1 and 62A-2, and the control unit 40 detects the above contact abnormality based on the detection result of the pair of temperature detection elements 62A-1 and 62A-2. A detailed description will be given below.

[0054] First, specific examples of contact abnormalities of the temperature detection unit 62A will be described. Contact abnormalities of the temperature detection unit 62A are classified into the following four types of contact abnormalities. The state in which no contact abnormality occurs in the temperature detection unit 62A, that is, the normal state, is the state shown in FIG. 5.

[0055] 6, the first contact abnormality is a state in which one temperature detection element 62A-1, together with the heating part 61A, is floating above the receiving part 65A of the waste pail 60. In the first contact abnormality, the other temperature detection element 62A-2 is in contact with the underside of the heating part 61A. 7, the second contact abnormality occurs when one temperature detection element 62A-1 is left behind in the receiving portion 65A of the waste pail 60, and the heating portion 61A is floating above the receiving portion 65. In the second contact abnormality, the other temperature detection element 62A-2 is in contact with the underside of the heating portion 61A. 8, the third contact abnormality is a state in which one temperature detection element 62A-1 is left behind in the receiving part 65A of the waste pail 60, and the heating part 61A is floating above the receiving part 65. In the third abnormal state, the other temperature detection element 62A-2 is floating above the underside of the heating part 61A. The fourth contact abnormality is a state in which one temperature detection element 62A-1 and heating portion 61A are in contact with the lower surface of receiving portion 65A, and the other temperature detection element 62A-2 is floating above the lower surface of heating portion 61A, as shown in FIG.

[0056] FIG. 10 is a diagram showing the relationship between the arrangement state of the temperature detection unit, the first detection temperature, the second detection temperature, and the temperature rise time. In FIG. 10, the arrangement state of the temperature detection unit 62A is shown as an example of the arrangement state of the temperature detection unit. The arrangement state of the temperature detection unit 62A is classified into the normal state described above, the first contact abnormality, the second contact abnormality, the third contact abnormality, and the fourth contact abnormality. The first detection temperature T1 (°C) is the temperature detected by the temperature detection element 62A-1. The second detection temperature T2 (°C) is the temperature detected by the temperature detection element 62A-2. The temperature rise time (seconds) is the time from when the heating unit 61A starts heating the receiving unit 65A until the temperature detected by the temperature detection unit 62A reaches the target temperature or a predetermined temperature lower than the target temperature. Note that the specific values ​​of the first detection temperature, the second detection temperature, and the temperature rise time shown in FIG. 10 are values ​​described as examples to understand the contents of the present invention, and may differ from the actual values.

[0057] As shown in FIG. 10, when the temperature detection unit 62A is in a normal state (FIG. 5), the first detection temperature is 82° C., the second detection temperature is 85° C., and the temperature rise time is 300 seconds. In this case, 82° C. corresponds to the target temperature corresponding to the first detection temperature, and 85° C. corresponds to the target temperature corresponding to the second detection temperature. The reason why the first detection temperature is lower than the second detection temperature is that a part of the heat generated by the heating unit 61A is taken by the receiving unit 65A or the waste ink. In contrast, when the temperature detection unit 62A has a first contact abnormality (FIG. 6), the first detection temperature is 85° C., the second detection temperature is 85° C., and the temperature rise time is 250 seconds. Also, when the temperature detection unit 62A has a second contact abnormality (FIG. 7), the first detection temperature is 75° C., the second detection temperature is 85° C., and the temperature rise time is 300 seconds. Furthermore, if the temperature detection unit 62A experiences a third contact abnormality (FIG. 8), the first detected temperature will be 75° C., the second detected temperature will be 75° C., and the temperature rise time will be 600 seconds. Furthermore, if the temperature detection unit 62A experiences a fourth contact abnormality (FIG. 9), the first detected temperature will be 82° C., the second detected temperature will be 75° C., and the temperature rise time will be 300 seconds.

[0058] Fig. 11 is a diagram showing the change over time of the first detected temperature T1 and the second detected temperature T2 when the first contact abnormality occurs in the temperature detection unit 62A. In Fig. 11, the change over time of the first detected temperature T1 and the second detected temperature T2 when the first contact abnormality occurs in the temperature detection unit 62A is shown by a solid line. Also, in Fig. 11, the change over time of the first detected temperature T1 and the second detected temperature T2 when the temperature detection unit 62A is in a normal state is shown by a dashed line. As shown in FIG. 11, when the first contact abnormality occurs, the first detection temperature T1 and the second detection temperature T2 reach the target temperature earlier than the temperature rise time (300 seconds) in a normal state.

[0059] FIG. 12 is a diagram showing changes over time in the first detected temperature T1 and the second detected temperature T2 when a second contact abnormality occurs in the temperature detection unit 62A. 12, when the second contact abnormality occurs in the temperature detection unit 62A, the difference between the first detection temperature T1 and the second detection temperature T2 exceeds the allowable value when the second detection temperature T2 reaches the target temperature. The allowable value is set to a value larger than the difference between the first detection temperature T1 and the second detection temperature T2 in a normal state.

[0060] FIG. 13 is a diagram showing changes over time in the first detected temperature T1 and the second detected temperature T2 when a third contact abnormality occurs in the temperature detection unit 62A. 13, when the third contact abnormality occurs in the temperature detection unit 62A, neither the first detection temperature T1 nor the second detection temperature T2 reaches the target temperature even after about 600 seconds have passed since the heating unit 61A started to generate heat. The allowable time in the figure is a time that is preset to detect the occurrence of the third contact abnormality.

[0061] FIG. 14 is a diagram showing changes over time in the first detected temperature T1 and the second detected temperature T2 when a fourth contact abnormality occurs in the temperature detection unit 62A. 14, when a fourth contact abnormality occurs in the temperature detection unit 62A, the difference between the first detection temperature T1 and the second detection temperature T2 exceeds the allowable value before the second detection temperature T2 reaches the target temperature. The allowable value is set to a value larger than the difference between the first detection temperature T1 and the second detection temperature T2 in a normal state.

[0062] Under these assumptions, an example of the control process performed by the control unit 40 during head maintenance will be described with reference to the flowchart in Fig. 15. Here, an example will be described in which the control unit 40 performs control process based on the detection result of the temperature detection unit 62A, which is composed of a pair of temperature detection elements 62A-1 and 62A-2. The control unit 40 also performs the same control process as in Fig. 15 when controlling the corresponding heating units 61B, 61C, and 61D based on the detection results of the temperature detection units 62B, 62C, and 62D.

[0063] First, the control unit 40 starts temperature adjustment control (step S1). Specifically, the control unit 40 switches the heating unit 61A from an OFF state to an ON state by energizing the heating unit 61A. This causes the heating unit 61A to start generating heat, and the heat is transferred to the receiving unit 65A, heating the receiving unit 65A.

[0064] Next, the control unit 40 starts acquiring the first detected temperature T1 and the second detected temperature T2 (step S2). The first detected temperature T1 is the temperature detected by the temperature detection element 62A-1. The second detected temperature T2 is the temperature detected by the temperature detection element 62A-2. Therefore, the control unit 40 acquires the first detected temperature T1 from the temperature detection element 62A-1 and the second detected temperature T2 from the temperature detection element 62A-2. The control unit 40 acquires the first detected temperature T1 and the second detected temperature T2 at a predetermined time interval until the temperature adjustment control is terminated.

[0065] Next, the control unit 40 judges whether the difference between the first detected temperature T1 and the second detected temperature T2 exceeds a preset allowable value (step S3). As described above, the allowable value is set to a value larger than the difference between the first detected temperature T1 and the second detected temperature T2 in a normal state. The allowable value is set to 5°C, for example.

[0066] If the determination in step S3 is "YES," the control unit 40 detects the occurrence of a fourth contact abnormality as a contact abnormality in the temperature detection unit 62A (step S4). Next, the control unit 40 controls the operation display unit 52 to execute an error display indicating that a fourth contact abnormality has occurred as a contact abnormality in the temperature detection unit 62A (step S14). Thereafter, the control unit 40 proceeds from step S14 to step S15 and ends the temperature adjustment control. When the control unit 40 ends the temperature adjustment control, the heating unit 61A is turned off.

[0067] If the determination in step S3 is "NO," the control unit 40 determines whether the elapsed time Ts from when the temperature adjustment control was started in step S1 above has exceeded a preset allowable time (step S5). The elapsed time Ts is measured by the control unit 40. The allowable time is set to a time longer than the temperature rise time (300 seconds) in a normal state (FIG. 13). For example, the allowable time is set to 400 seconds.

[0068] If the determination in step S5 is "YES," the control unit 40 detects the occurrence of a third contact abnormality as a contact abnormality in the temperature detection unit 62A (step S6). Next, the control unit 40 controls the operation display unit 52 to execute an error display indicating that a third contact abnormality has occurred as a contact abnormality in the temperature detection unit 62A (step S14), and then ends the temperature adjustment control (step S15).

[0069] If the determination in step S5 is "NO", the control unit 40 determines whether the second detection temperature T2 has reached the target temperature (step S7). If the determination in step S7 is "NO", the control unit 40 returns to the above step S3.

[0070] If the determination in step S7 is "YES", the control unit 40 continues the temperature adjustment control (step S8), whereby the control unit 40 controls the heating unit 61A so that the second detected temperature T2 is maintained at the target temperature.

[0071] Next, the control unit 40 judges whether the difference between the first detected temperature T1 and the second detected temperature T2 is within the above-mentioned allowable value (for example, 5° C.) (step S9). If the judgment in step S9 is "NO," the control unit 40 detects the occurrence of a second contact abnormality as a contact abnormality of the temperature detection unit 62A (step S10). Next, the control unit 40 controls the operation display unit 52 to execute an error display indicating that the second contact abnormality has occurred as a contact abnormality of the temperature detection unit 62A (step S14), and then ends the temperature adjustment control (step S15).

[0072] If the answer is "YES" in step S9, the control unit 40 judges whether the time Tt from when the temperature adjustment control is started in step S1 to when the second detected temperature T2 reaches the target temperature is shorter than a preset allowable range (step S11). The time Tt is measured by the control unit 40. The allowable range is set to a predetermined time width centered on the temperature rise time (300 seconds) in a normal state (FIG. 11). For example, the allowable range is set to a range of 280 seconds to 320 seconds.

[0073] If the determination in step S11 is "YES," the control unit 40 detects the occurrence of a first contact abnormality as a contact abnormality of the temperature detection unit 62A (step S12). Next, the control unit 40 controls the operation display unit 52 to execute an error display indicating that a first contact abnormality has occurred as a contact abnormality of the temperature detection unit 62A (step S14), and then ends the temperature adjustment control (step S15).

[0074] If the determination in step S11 is "NO," the control unit 40 repeatedly determines whether head maintenance is complete (step S13). If the determination in step S13 is "YES," the control unit 40 ends the temperature adjustment control (step S15). This ends a series of control processes related to head maintenance.

[0075] As described above, in the ink receiving device 100 of this embodiment, the temperature detection unit 62A that detects the temperature of the receiving unit 65A is composed of a pair of temperature detection elements 62A-1, 62A-2. Then, the control unit 40 detects contact abnormality of the temperature detection unit 62A with the waste pail 60 or the heating unit 61A based on the detection results of the pair of temperature detection elements 62A-1, 62A-2. This makes it possible to detect contact abnormality of the temperature detection unit 62A with the waste pail 60 or the heating unit 61A when controlling the heating unit 61A based on the detection results of the temperature detection unit 62A.

[0076] Furthermore, in the ink receiving device 100 according to this embodiment, if the control unit 40 detects a contact abnormality in the temperature detection unit 62A after starting the temperature control, the control unit 40 stops (ends) the temperature control. This makes it possible to avoid the temperature control being continued while the contact abnormality in the temperature detection unit 62A remains.

[0077] The invention according to this embodiment can also be obtained when controlling heating unit 61B based on the detection result of temperature detection unit 62B, when controlling heating unit 61C based on the detection result of temperature detection unit 62C, or when controlling heating unit 61D based on the detection result of temperature detection unit 62D.

[0078] The technical scope of the present invention is not limited to the above-described embodiment, and includes various modifications and improvements within the scope of the specific effects obtained by the constituent elements of the invention and their combinations.

[0079] For example, in the above embodiment, an example was shown in which the receiving portion 65 of the waste bucket 60 was formed into an inverted square pyramid shape, but the present invention is not limited to this, and the receiving portion 65 of the waste bucket 60 may also be formed into an inverted triangular pyramid shape or an inverted cone shape. [Explanation of symbols]

[0080] 1...Inkjet recording device. 24…Head unit 40...Control unit 60...waste bucket 61 (61A, 61B, 61C, 61D)...Heating part 61A-1, 61A-2...Temperature detection element 65 (65A, 65B, 65C, 65D)…Receiving part 100...Ink receiving device 243…Nozzle

Claims

1. a waste bucket having a receiving portion for receiving waste ink; A heating unit that heats the receiving unit; A temperature detection unit that detects the temperature of the receiving portion; a control unit that controls the heating unit based on a detection result of the temperature detection unit, the temperature detection unit is composed of a pair of temperature detection elements, one of which is attached to a first surface side of the heating unit facing the lower surface of the receiving portion, and the other of which is attached to a second surface side of the heating unit; The control unit detects a contact abnormality of the temperature detection unit with respect to the waste bucket or the heating unit based on a detection result of the pair of temperature detection elements. Ink receiving device.

2. The pair of temperature detection elements are disposed within the heating region of the heating unit, and are disposed in a state in which at least a portion of the temperature detection elements overlap with each other.

2. The ink receiving device according to claim 1.

3. The pair of temperature detection elements are disposed at the same position within the heating region of the heating unit.

2. The ink receiving device according to claim 1.

4. the control unit detects a first contact abnormality as a contact abnormality of the temperature detection unit when a time from when the heating unit starts to generate heat to when the temperature detected by the temperature detection unit reaches a target temperature is shorter than an allowable range, The first contact abnormality is a state in which the one temperature detection element is floating together with the heating portion from the receiving portion.

2. The ink receiving device according to claim 1.

5. the control unit detects a second contact abnormality as a contact abnormality of the temperature detection unit when a difference between the temperature detected by the one temperature detection element and the temperature detected by the other temperature detection element is not within a tolerance when the temperature detected by the temperature detection unit reaches a target temperature, The second contact abnormality is a state in which the one temperature detection element is left behind on the receiving portion and the heating portion is floating above the receiving portion.

2. The ink receiving device according to claim 1.

6. the control unit detects a third contact abnormality as a contact abnormality of the temperature detection unit when an elapsed time from when the heating unit starts to generate heat exceeds an allowable time before the temperature detected by the temperature detection unit reaches a target temperature, The third contact abnormality is a state in which the one temperature detection element is left behind on the receiving portion, the heating portion is floating from the receiving portion, and the other temperature detection element is floating from the heating portion.

2. The ink receiving device according to claim 1.

7. the control unit detects a fourth contact abnormality as a contact abnormality of the temperature detection unit when a difference between the temperature detected by the one temperature detection element and the temperature detected by the other temperature detection element exceeds a tolerance before the temperature detected by the temperature detection unit reaches a target temperature, The fourth contact abnormality is a state in which the one temperature detection element and the heating portion are in contact with the receiving portion, and the other temperature detection element is floating above the heating portion.

2. The ink receiving device according to claim 1.

8. When the control unit detects a contact abnormality in the temperature detection unit, the control unit executes an error display to that effect.

2. The ink receiving device according to claim 1.

9. The control unit starts a temperature adjustment control for controlling the heating unit so that the temperature of the receiving unit becomes a target temperature, and then stops the temperature adjustment control when a contact abnormality of the temperature detection unit is detected.

2. The ink receiving device according to claim 1.

10. a head unit that ejects ink from nozzles to form an image on a recording medium; an ink receiving device for receiving waste ink discharged from the nozzles; The ink receiving device is a waste bucket having a receiving portion for receiving waste ink; A heating unit that heats the receiving unit; A temperature detection unit that detects the temperature of the receiving portion; a control unit that controls the heating unit based on a detection result of the temperature detection unit, The temperature detection unit is composed of a pair of temperature detection elements, one of which is attached to a first surface side of the heating unit facing the lower surface of the receiving portion, and the other of which is attached to a second surface side of the heating unit, The control unit detects a contact abnormality of the temperature detection unit with respect to the waste bucket or the heating unit based on a detection result of the pair of temperature detection elements. Inkjet recording device.

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