Inkjet recording apparatus

Abstract

The invention provides an ink jet recording apparatus, and aims to detect electrical connection failure of a part of a plurality of signal lines between a control device and an ink jet unit and a wire harness. The plurality of terminal resistors are respectively connected with the plurality of second signal lines. The plurality of piezoelectric elements are supplied with a plurality of drive signals corresponding to the plurality of control signals received by the plurality of reception circuits, respectively. In the control device, a plurality of test resistors are supplied with a test voltage from a test voltage output circuit, and each of the plurality of test resistors and a plurality of termination resistors constitute a plurality of voltage division circuits. The partial voltage detection circuit detects an output voltage of each of the plurality of voltage division circuits. The control circuit controls the working voltage output circuit, the plurality of control signal output circuits and the test voltage output circuit to be in a test state, and determines whether the electrical connection state is normal or abnormal according to the detection result of the sub-voltage detection circuit in the test state.

Description

Technical Field

[0001] The present invention relates to an inkjet recording device having a function of testing a connection state between a control device and an inkjet unit. Background Art

[0002] The inkjet recording device includes an inkjet unit and a control device for controlling the inkjet unit.

[0003] The ink ejection unit includes: a plurality of piezoelectric elements to which driving signals are supplied respectively; and a plurality of nozzles to eject ink pressurized by the plurality of piezoelectric elements.

[0004] When executing the printing process, the control device outputs an operating voltage and a plurality of control signals generated based on data of an output target image to the inkjet unit. In the inkjet unit, a plurality of receiving circuits receive the plurality of control signals and supply a plurality of driving signals corresponding to the plurality of control signals to the plurality of piezoelectric elements.

[0005] The control device and the inkjet unit are connected via a wiring harness having a plurality of electric wires for transmitting the operating voltage and a plurality of control signals supplied to the inkjet unit.

[0006] A first end portion of the wire harness is connected to a first connector provided in the control device, and a second end portion of the wire harness is connected to a second connector provided in the inkjet unit.

[0007] Sometimes, the electrical connection between the first connector and the second connector and the wiring harness is poor. In this case, if the control device outputs the operating voltage and the plurality of control signals, various problems may occur.

[0008] For example, a technique is known in which a plurality of terminals of a flexible cable include an input terminal for inputting a test signal and an output terminal corresponding to the input terminal, and whether a signal identical to the test signal is detected at the output terminal is checked.

[0009] When the output terminal does not detect a signal identical to the test signal, it is determined that the flexible cable is obliquely inserted into the connector. The flexible cable is an example of a wiring harness.

[0010] However, in addition to the oblique insertion of the connector, poor electrical connection between the control device and the inkjet unit and the wiring harness may occur individually at each of the plurality of terminals.

[0011] For example, it is conceivable that foreign matter is caught in some of the plurality of terminals, or some of the plurality of electric wires of the wiring harness are disconnected. Summary of the invention

[0012] An object of the present invention is to provide an inkjet recording apparatus capable of detecting electrical connection failure of some of a plurality of signal lines between a control device and an inkjet unit and a wiring harness.

[0013] An inkjet recording device according to one aspect of the present invention includes a control device and an inkjet unit connected by a harness. The control device includes an operating voltage output circuit, a plurality of control signal output circuits, and a first connector. The operating voltage output circuit is capable of outputting an operating voltage. The plurality of control signal output circuits are capable of outputting a plurality of control signals, respectively. The first connector includes a plurality of first terminals connected to a first voltage line transmitting the operating voltage and a plurality of first signal lines transmitting the plurality of control signals, and is connected to a first end of the harness. The inkjet unit includes a second connector, a plurality of receiving circuits, a plurality of terminal resistors, a plurality of piezoelectric elements, and a plurality of nozzles. The second connector includes a plurality of second terminals, and is connected to a second end of the harness. The plurality of receiving circuits are supplied with the operating voltage and the plurality of control signals, respectively, through a second voltage line connected to the plurality of second terminals and a plurality of second signal lines. The plurality of terminal resistors are connected to the plurality of second signal lines, respectively. The plurality of piezoelectric elements are supplied with a plurality of drive signals corresponding to the plurality of control signals received by the plurality of receiving circuits, respectively. The plurality of nozzles eject ink pressurized by the plurality of piezoelectric elements. The control device includes a test voltage output circuit, a plurality of test resistors, a voltage division detection circuit, and a control circuit. The test voltage output circuit is capable of outputting a test voltage. The test resistors are supplied with the test voltage from the test voltage output circuit, and respectively form a plurality of voltage divider circuits with the plurality of terminal resistors. The voltage divider detection circuit detects the output voltage of each of the plurality of voltage divider circuits. The control circuit controls the working voltage output circuit, the plurality of control signal output circuits, and the test voltage output circuit. The control circuit performs a test process, in which the working voltage output circuit, the plurality of control signal output circuits, and the test voltage output circuit are controlled to be in a test state, and according to the detection result of the voltage divider detection circuit in the test state, it is determined whether the electrical connection state between the plurality of first terminals and the plurality of second terminals is normal or abnormal, and the control circuit performs inkjet control after determining that the electrical connection state is normal through the test process, in which the working voltage output circuit is made to output the working voltage and part or all of the plurality of control signal output circuits are made to output part or all of the plurality of control signals.

[0014] According to the present invention, it is possible to provide an inkjet recording apparatus capable of detecting electrical connection failure in some of a plurality of signal lines between a control device and an inkjet unit and a wiring harness.

[0015] This specification is presented in a simplified form, with appropriate reference to the accompanying drawings, to summarize the concepts described in the following detailed description. This specification is not intended to limit the important features and essential features of the subject matter described in the claims, nor is it intended to limit the scope of the subject matter described in the claims. In addition, the subject matter described in the claims is not limited to implementations that solve some or all of the disadvantages described in any part of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural diagram of the inkjet recording apparatus according to the first embodiment.

[0017] Figure 2 This is a block diagram showing the configuration of a control device for the inkjet recording apparatus according to the first embodiment.

[0018] Figure 3 This is a cross-sectional view of a part of the ink jet unit of the ink jet recording apparatus according to the first embodiment.

[0019] Figure 4 It is a configuration diagram of an electrical system of a control device and an inkjet unit of the inkjet recording apparatus according to the first embodiment.

[0020] Figure 5 This is a flowchart showing an example of a procedure of a test process of the inkjet recording apparatus according to the first embodiment.

[0021] Figure 6 This is a flowchart showing an example of the procedure of the connector connection test process of the inkjet recording apparatus according to the first embodiment.

[0022] Figure 7 This is a flowchart showing an example of the procedure of the line insulation test process of the inkjet recording apparatus according to the first embodiment.

[0023] Figure 8 This is a flowchart showing an example of the procedure of the line ground test process of the inkjet recording apparatus according to the first embodiment.

[0024] Fig. 9 It is a structural diagram of a portion related to the connector connection test process of the inkjet recording apparatus according to the first embodiment.

[0025] Fig.10 This is a graph showing the relationship between the target line resistance and the target detection voltage in the inkjet recording apparatus according to the first embodiment.

[0026] Fig.11 It is a structural diagram of a portion related to the line insulation test process of the inkjet recording apparatus according to the first embodiment.

[0027] Fig.12It is a structural diagram of a portion related to a line ground test process of the inkjet recording apparatus according to the first embodiment.

[0028] Fig.13 It is a structural diagram of a portion related to a connector connection test process of an inkjet recording apparatus according to a second embodiment.

[0029] Fig.14 This is a graph showing the relationship between the elapsed time from the start of output of the test voltage and the first object detection voltage in the inkjet recording apparatus according to the second embodiment.

[0030] Fig.15 This is a connection diagram between a control device and a plurality of ink jet units of an ink jet recording apparatus according to a third embodiment. DETAILED DESCRIPTION

[0031] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the following embodiment is an example of embodying the present invention and does not limit the technical scope of the present invention.

[0032] [First embodiment] The inkjet recording device 10 of the embodiment is an image forming device capable of executing a printing process using an inkjet method. For example, the inkjet recording device 10 is a printer, a facsimile machine, a copier, or a multifunction peripheral.

[0033] The printing process is a process of forming an image on a recording medium. In the present embodiment, the recording medium is a sheet 9 such as paper or a resin film. The sheet 9 is an example of the recording medium.

[0034] [Structure of Inkjet Recording Device 10] like Figure 1 As shown, the inkjet recording device 10 includes a sheet storage unit 1, a sheet conveying device 2, a printing device 5, and a control device 8 (see Figure 1 ). The inkjet recording device 10 further includes an operating device 801 and a display device 802 .

[0035] The control device 8 controls the sheet conveying device 2 and the printing device 5 . The control device 8 constitutes a part of the sheet conveying device 2 and a part of the printing device 5 .

[0036] The operating device 801 is a device that accepts human operation and includes, for example, operating buttons and a touch panel.

[0037] The display device 802 is a device that displays information and includes, for example, a panel display device such as a liquid crystal display unit.

[0038] The sheet conveying device 2 conveys the sheets 9 accommodated in the sheet accommodating portion 1 one by one. The sheet conveying device 2 includes a front-stage conveying device 21 , a belt conveying device 3 , and a rear-stage conveying device 22 .

[0039] The front-stage conveyance device 21 conveys the sheets 9 from the sheet storage unit 1 to the primary conveyance path 201 . The primary conveyance path 201 is a conveyance path for the sheets 9 formed between the sheet storage unit 1 and the belt conveyance device 3 .

[0040] The front-stage conveyance device 21 further conveys the sheet 9 along the primary conveyance path 201 , and sends the sheet 9 out from the primary conveyance path 201 to the belt conveyance device 3 .

[0041] The belt conveyor 3 continues conveying the sheet 9 from the preceding conveyor 21. The belt conveyor 3 conveys the sheet 9 along a flat path, and further sends the sheet 9 out from the flat path to the secondary conveyance path 202.

[0042] The secondary conveyance path 202 is a conveyance path for the sheet 9 formed in the rear stage of the belt conveyor 3 .

[0043] The rear conveyor 22 continues conveying the sheet 9 from the belt conveyor 3. The rear conveyor 22 conveys the sheet 9 along the secondary conveying path 202 and sends the sheet 9 from the secondary conveying path 202 to a rear section (not shown). For example, the rear section is a discharge tray, a post-processing device, or a transfer conveyor.

[0044] The printing device 5 executes the above-described printing process on the sheet 9 conveyed by the belt conveyor device 3 .

[0045] exist Figure 1 In the example shown, the printing device 5 includes a plurality of ink ejecting units 51 and a plurality of ink supply sections 52 corresponding to a plurality of colors, respectively.

[0046] The plurality of ink supply sections 52 supply ink to the plurality of ink ejecting units 51 , respectively. Each of the ink ejecting units 51 ejects ink droplets toward the sheet 9 , thereby forming an image on the sheet 9 .

[0047] [Structure of the control device 8] The control device 8 includes a CPU (Central Processing Unit) 81, a RAM (Random Access Memory) 82, an auxiliary storage device 83, a signal interface 84, a communication device 85, and an inkjet control device 4 (see Figure 2 ).

[0048] The auxiliary storage device 83 is a non-volatile storage device that can be read by a computer. The auxiliary storage device 83 can store and update computer programs and various data. For example, one or both of a flash memory and a hard disk drive are used as the auxiliary storage device 83.

[0049] The signal interface 84 converts the signals output by various sensors into digital data, and transmits the converted digital data to the CPU 81. The signal interface 84 also converts the control instructions output by the CPU 81 into control signals, and transmits the control signals to the device to be controlled.

[0050] The communication device 85 performs communication with other devices such as a host device (not shown). The CPU 81 communicates with the other devices via the communication device 85 .

[0051] The inkjet control device 4 generates a control signal SC1 and supplies the control signal SC1 to each inkjet unit 51. The control signal SC1 is a command signal indicating the type of the drive signal SD1 supplied to one or more drive piezoelectric elements periodically selected from the plurality of piezoelectric elements 531 (see Figure 2 , Figure 3 For example, the inkjet drive device 4 generates a control signal SC1 indicating the level of the drive signal SD1 according to the droplet size. The droplet size is the size of the ink droplets ejected onto the sheet 9.

[0052] The CPU 81 is a processor that executes various data processing and control by executing the computer program. The control device 8 including the CPU 81 controls the sheet conveying device 2, the printing device 5, and the like.

[0053] The RAM 82 is a computer-readable volatile storage device and temporarily stores the computer programs executed by the CPU 81 and data output and referenced by the CPU 81 during the execution of various processes.

[0054] The CPU 81 includes a plurality of processing modules realized by executing the computer program, including a main processing unit 8a and a print control unit 8b.

[0055] The main processing unit 8a executes processes for starting various processes in response to occurrence of various processing events and controls the display device 802. The processing events include operation events and reception events.

[0056] The operation event is an event in which an operation on the operation device 801 is detected. The reception event is an event in which various processing requests are received through the communication device 85. The processing request includes a print request requesting execution of the print process.

[0057] The print control unit 8 b controls the sheet conveying device 2 and the printing device 5 . The print control unit 8 b controls conveyance of the sheet 9 by controlling the sheet conveying device 2 .

[0058] The print control unit 8b also controls the printing device 5 by controlling the inkjet control device 4. The print control unit 8b causes the printing device 5 to execute the above-described printing process in synchronization with the conveyance of the sheet 9 by the sheet conveyance device 2.

[0059] For example, when the communication device 85 receives the print request, the print control unit 8 b causes the sheet conveying device 2 to convey the sheet 9 and causes the printer 5 to execute the print process.

[0060] [Structure of the Multiple Inkjet Units 53] Each inkjet unit 51 has a plurality of inkjet sections 53 (see Figure 1 , Figure 3 ). The plurality of inkjet units 53 are arranged opposite to the upper surface of the conveyor belt 31 .

[0061] Each ink ejection unit 53 includes a piezoelectric element 531, a nozzle 532, a vibration plate 533, and a pressure chamber 534. That is, each ink ejection unit 51 includes a plurality of piezoelectric elements 531, a plurality of nozzles 532, a plurality of vibration plates 533, and a plurality of pressure chambers 534.

[0062] Each pressure chamber 534 communicates with each nozzle 532. Each vibration plate 533 forms a part of a diaphragm of each pressure chamber 534. Each piezoelectric element 531 pressurizes the ink in the pressure chamber 534 via the vibration plate 533 by being supplied with each drive signal SD1 corresponding to each control signal SC1.

[0063] The inkjet control device 4 can supply a plurality of control signals SC1 to each inkjet unit 51, and the plurality of control signals SC1 indicate the types of the plurality of drive signals SD1 to be supplied to the plurality of piezoelectric elements 531. Each piezoelectric element 531 is supplied with each drive signal SD1, thereby pressurizing the ink inside the plurality of pressure chambers 534 and the plurality of nozzles 532. Thus, the plurality of nozzles 532 ejects the ink pressurized by the plurality of piezoelectric elements 531. Each piezoelectric element 531 is, for example, a piezoelectric element.

[0064] [Structure of Inkjet Control Device 4 and Inkjet Unit 51] The inkjet recording device 10 further includes a plurality of wiring harnesses 6 (see Figure 4 ). That is, the inkjet control device 4 and each inkjet unit 51 are connected via the wiring harness 6.

[0065] The inkjet control device 4 includes an operating voltage output circuit 41, a plurality of control signal output circuits 42, a control circuit 43, and a first connector 44 (see Figure 4 The control circuit 43 controls the operating voltage output circuit 41 and the plurality of control signal output circuits 42.

[0066] The operating voltage output circuit 41 can output the operating voltage VO1 according to the operating instruction of the control circuit 43. The plurality of control signal output circuits 42 can respectively output the plurality of control signals SC1 according to the driving instruction of the control circuit 43.

[0067] The inkjet control device 4 further includes a first voltage line 401 for transmitting an operating voltage VO1 and a plurality of first signal lines 402 for transmitting a plurality of control signals SC1 .

[0068] The first connector 44 includes a plurality of first terminals 44a connected to the first voltage line 401 and the plurality of first signal lines 402. The first connector 44 is connected to a first harness connector 6a which is a first end portion of the harness 6.

[0069] The inkjet unit 51 further includes a plurality of receiving circuits 54, a plurality of terminal circuits 55, and a second connector 56 (see Figure 4 ). The plurality of receiving circuits 54 and the plurality of terminal circuits 55 correspond to the plurality of piezoelectric elements 531, respectively.

[0070] The second connector 56 includes a plurality of second terminals 56 a corresponding to the plurality of first terminals 44 a. The second connector 56 is connected to a second harness connector 6 b which is a second end portion of the harness 6 .

[0071] The harness 6 includes a plurality of electric wires 6c extending from the first harness connector 6a to the second harness connector 6b. When the harness 6 is normally connected to the first connector 44 and the second connector 56, the plurality of electric wires 6c electrically connect the plurality of first terminals 44a and the plurality of second terminals 56a.

[0072] The ink ejection unit 51 further includes a second voltage line 501 and a plurality of second signal lines 502 connected to the plurality of second terminals 56 a .

[0073] The second voltage line 501 transmits the operating voltage VO1 supplied to the ink ejecting unit 51 through the first voltage line 401 and the harness 6. The plurality of second signal lines 502 transmits the plurality of control signals SC1 supplied to the ink ejecting unit 51 through the plurality of first signal lines 402 and the harness 6.

[0074] The operating voltage VO1 and the plurality of control signals SC1 are respectively supplied to the plurality of receiving circuits 54 through the second voltage line 501 and the plurality of second signal lines 502. The plurality of receiving circuits 54 receive the plurality of control signals SC1 respectively. Each receiving circuit 54 extracts a specific signal component from each control signal SC1. The specific signal component indicates the type of the drive signal SD1 supplied to each piezoelectric element 531 electrically connected to each receiving circuit 54.

[0075] The inkjet unit 51 further includes a driving circuit (not shown) connected to the plurality of receiving circuits 54 and the plurality of piezoelectric elements 531. The driving circuit generates driving signals SD1 corresponding to the specific signal components extracted by the receiving circuits 54, and supplies the generated driving signals SD1 to the piezoelectric elements 531.

[0076] That is, a plurality of driving signals SD1 corresponding to the plurality of control signals SC1 received by the plurality of receiving circuits 54 are supplied to the plurality of piezoelectric elements 531 , respectively.

[0077] The plurality of terminal circuits 55 are respectively connected to the plurality of second signal lines 502. The plurality of terminal circuits 55 include a plurality of first terminal resistors 551 and a plurality of second terminal resistors 552.

[0078] The plurality of first terminal resistors 551 are connected to the plurality of second signal lines 502 and the ground line, respectively. The plurality of second terminal resistors 552 are connected to the second voltage line 501 and the plurality of second signal lines 502, respectively.

[0079] A plurality of terminal circuits 55 are provided to prevent reflection of signals in the plurality of second signal lines 502 .

[0080] In addition, the ink ejection control device 4 also includes a plurality of terminal resistors 45 connected to the plurality of first signal lines 402. The plurality of terminal resistors 45 are connected to the plurality of first signal lines 402 near output ends of the ink ejection control device 4, respectively.

[0081] However, there may be a case where the electrical connection between the first connector 44 and the second connector 56 and the harness 6 is poor. In this case, if the inkjet control device 4 outputs the operating voltage VO1 and the plurality of control signals SC1, various problems may occur.

[0082] In addition to the oblique insertion of the connectors 6a and 6b of the harness 6, poor electrical connection between the inkjet control device 4 and the inkjet unit 51 and the harness 6 may occur individually at each first terminal 44a or each second terminal 56a.

[0083] For example, it is conceivable that foreign matter is caught in part of the plurality of first terminals 44 a or the plurality of second terminals 56 a , or that part of the plurality of electric wires 6 c of the wire harness 6 is disconnected.

[0084] The inkjet control device 4 includes a structure for detecting electrical connection failure in a part of the plurality of first terminals 44a or the plurality of second terminals 56a. This structure will be described below.

[0085] The inkjet control device 4 further includes a test voltage output circuit 47, a plurality of test resistors 46, and a divided voltage detection circuit 48 (see Figure 4 ).

[0086] The test voltage output circuit 47 can output the test voltage VT1 to each of the plurality of test resistors 46 according to the test output command of the control circuit 43 .

[0087] The test voltage VT1 is supplied from the test voltage output circuit 47 to the plurality of test resistors 46 , and the plurality of test resistors 46 respectively form a plurality of voltage dividing circuits together with the plurality of first terminal resistors 551 .

[0088] like Figure 4 As shown, the ink ejection control device 4 has a plurality of test signal lines 403 connected to the test voltage output circuit 47 and the plurality of first signal lines 402. The plurality of test resistors 46 are disposed on the plurality of test signal lines 403, respectively.

[0089] Therefore, the test resistors 46 and the first terminal resistors 551 are electrically connected in series by the test signal lines 403 , the first signal lines 402 , a part of the electric wires 6 c of the harness 6 , and the second signal lines 502 .

[0090] The plurality of test resistors 46 and the plurality of first terminal resistors 551 electrically connected in series constitute the plurality of voltage dividing circuits.

[0091] The test voltage output circuit 47 can selectively output the test voltage VT1 to a part or all of the plurality of test signal lines 403. That is, the test voltage output circuit 47 can selectively output the test voltage VT1 to a part or all of the plurality of voltage dividing circuits.

[0092] The divided voltage detection circuit 48 detects the output voltage of each of the plurality of divided voltage circuits. That is, when the test voltage VT1 is output to the plurality of divided voltage circuits, the divided voltage detection circuit 48 detects the voltages of the test voltage VT1 divided by the plurality of test resistors 46 and the plurality of first terminal resistors 551 .

[0093] The output voltages of the plurality of voltage-dividing circuits are input to a divided voltage detection circuit 48 through a plurality of detection lines 404. The divided voltage detection circuit 48 includes a switch circuit 48a and a detection circuit 48b.

[0094] The switch circuit 48a electrically connects one detection target line selected from the plurality of detection lines 404 to the detection circuit 48b in accordance with a selection instruction of the control circuit 43. The detection circuit 48b detects a voltage of the detection target line.

[0095] exist Figure 4 In the illustrated example, the plurality of detection lines 404 electrically connect the divided voltage detection circuit 48 to portions of the plurality of first signal lines 402 between the plurality of terminal resistors 45 and the plurality of control signal output circuits 42 .

[0096] exist Figure 4 In the example shown, the output voltages of the plurality of voltage divider circuits are input to the divided voltage detection circuit 48 at levels dropped by the plurality of terminal resistors 45. However, since the resistance value of each terminal resistor 45 is small, the voltage drop amount at each terminal resistor 45 is small.

[0097] The detection circuit 48b transmits a voltage detection signal indicating the detected voltage level to the control circuit 43. The control circuit 43 determines the level of the voltage detection signal in consideration of the voltage drop amount in each terminal resistor 45.

[0098] In addition, the control circuit 43 may also serve as the detection circuit 48 b. In addition, the control circuit 43 may also serve as the divided voltage detection circuit 48 .

[0099] The control circuit 43 controls the operating voltage output circuit 41 , the plurality of control signal output circuits 42 , the test voltage output circuit 47 , and the switch circuit 48 a of the divided voltage detection circuit 48 .

[0100] For example, the control circuit 43 is implemented by an MPU (Micro Processing Unit), an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), etc. In addition, the CPU 81 may also serve as part or all of the control circuit 43 .

[0101] The control circuit 43 performs a test process of determining whether the electrical connection state between the plurality of first terminals 44 a and the plurality of second terminals 56 a is normal or abnormal.

[0102] In the test process, the control circuit 43 controls the operating voltage output circuit 41, the plurality of control signal output circuits 42 and the test voltage output circuit 47 to a predetermined test state. The control circuit 43 determines whether the electrical connection state is normal or abnormal based on the detection result of the divided voltage detection circuit 48 in the test state.

[0103] After determining that the electrical connection state is normal through the test process, the control circuit 43 executes the ink ejection control. In other words, the control circuit 43 allows the ink ejection control to be executed on the condition that the electrical connection state is normal through the test process.

[0104] In the ink ejection control, the control circuit 43 causes the operating voltage output circuit 41 to output the operating voltage VO1 and causes a part or all of the plurality of control signal output circuits 42 to output a part or all of the plurality of control signals SC1 .

[0105] For example, the control circuit 43 executes the test process when the inkjet recording device 10 is activated. Alternatively, the control circuit 43 may execute the test process each time the control circuit 43 receives a new print request.

[0106] [Test Processing] Below, refer to Figure 5 The flowchart shown in FIG. 1 illustrates an example of the steps of the test process.

[0107] In the following description, S101, S102, ... denote reference numerals of a plurality of steps in the test process. In the test process, the process of step S101 is first executed.

[0108] <Step S101> In step S101, the control circuit 43 executes a connector connection test process. The connector connection test process is a first example of a process for determining whether the electrical connection state is normal or abnormal (see Figure 6 ).

[0109] The connector connection test process will be described in detail later. When it is determined in the connector connection test process that the electrical connection state is abnormal, the control circuit 43 executes the process of step S102.

[0110] On the other hand, when it is determined in the connector connection test process that the electrical connection state is normal, the control circuit 43 executes the process of step S103 .

[0111] <Step S102> In step S102 , the control circuit 43 outputs a first error notification to the CPU 81 .

[0112] The first error notification indicates that the electrical connection state is determined to be abnormal by the connector connection test process.

[0113] Upon receiving the first error notification from the control circuit 43 , the main processing unit 8 a of the CPU 81 notifies the user of a first error message indicating the content of the first error notification.

[0114] For example, the main processing unit 8a causes the display device 802 to display the first error message. Alternatively, the main processing unit 8a transmits the first error message to the host device via the communication device 85.

[0115] After executing the process of step S102 , the control circuit 43 executes the process of step S107 .

[0116] <Step S103> In step S103, the control circuit 43 performs a line insulation test process. The line insulation test process is a second example of a process for determining whether the electrical connection state is normal or abnormal (see Figure 7 ).

[0117] The details of the line insulation test process will be described later. When it is determined that the electrical connection state is abnormal by the line insulation test process, the control circuit 43 executes the process of step S104.

[0118] On the other hand, when it is determined by the line insulation test process that the electrical connection state is normal, the control circuit 43 executes the process of step S105 .

[0119] <Step S104> In step S104 , the control circuit 43 outputs a second error notification to the CPU 81 .

[0120] The second error notification indicates that it is determined that the electrical connection state is abnormal through the line insulation test process.

[0121] Upon receiving the second error notification from the control circuit 43 , the main processing unit 8 a of the CPU 81 notifies the user of a second error message indicating the content of the second error notification.

[0122] For example, the main processing unit 8a causes the display device 802 to display the second error message. Alternatively, the main processing unit 8a transmits the second error message to the host device via the communication device 85.

[0123] After executing the process of step S104 , the control circuit 43 executes the process of step S107 .

[0124] <Step S105> In step S105, the control circuit 43 executes a wire grounding test process. The wire grounding test process is a third example of a process for determining whether the electrical connection state is normal or abnormal (see Figure 8 ).

[0125] The details of the wire ground test process will be described later. When it is determined that the electrical connection state is abnormal by the wire ground test process, the control circuit 43 executes the process of step S106.

[0126] On the other hand, when it is determined by the wire ground test process that the electrical connection state is normal, the control circuit 43 executes the process of step S108 .

[0127] <Step S106> In step S106 , the control circuit 43 outputs a third error notification to the CPU 81 .

[0128] The third error notification indicates that it is determined that the electrical connection state is abnormal through the wire ground test process.

[0129] Upon receiving the third error notification from the control circuit 43 , the main processing unit 8 a of the CPU 81 notifies the user of a third error message indicating the content of the third error notification.

[0130] For example, the main processing unit 8a causes the display device 802 to display the third error message. Alternatively, the main processing unit 8a transmits the third error message to the host device via the communication device 85.

[0131] After executing the process of step S106 , the control circuit 43 executes the process of step S107 .

[0132] <Step S107> In step S107 , the control circuit 43 sets the print permission flag to disallow printing.

[0133] The control circuit 43 executes the ink ejection control on the condition that the print permission flag is set to permit printing. Therefore, the state in which the print permission flag is set to not permit printing is a state in which the ink ejection control is not permitted to be executed.

[0134] After executing the process of step S107 , the control circuit 43 ends the test process.

[0135] <Step S108> In step S108 , the control circuit 43 sets the print permission flag to permit printing.

[0136] A state in which the print permission flag is set to permit printing is a state in which execution of the ink ejection control is permitted.

[0137] After executing the process of step S108, the control circuit 43 ends the test process. Even after the test process ends, the state of the print permission flag is maintained.

[0138] [Connector connection test process] Next, refer to Figure 6 The flowchart shown in FIG. 1 illustrates an example of the steps of the connector connection test process.

[0139] In the following description, S201, S202, ... denote reference numerals of a plurality of steps in the connector connection test process. In the connector connection test process, the process of step S201 is first executed.

[0140] <Step S201> In step S201, the control circuit 43 selects one of the plurality of control signal output circuits 42 as the target output circuit 42x (see Fig. 9 ). Each time the process of step S201 is executed, each control signal output circuit 42 is sequentially selected as the target output circuit 42x.

[0141] Fig. 9 The structure of the inkjet control device 4 and the part related to the connector connection test process of the inkjet unit 51 are shown.

[0142] In the following description, one of the plurality of first signal lines 402 corresponding to the target output circuit 42x is referred to as a target first signal line 402x. Also, one of the plurality of test resistors 46 connected to the target first signal line 402x is referred to as a target test resistor 46x.

[0143] In addition, one of the plurality of second signal lines 502 corresponding to the target first signal line 402x is referred to as a target second signal line 502x. In addition, one of the plurality of first terminal resistors 551 corresponding to the target test resistor 46x is referred to as a target terminal resistor 551x.

[0144] Furthermore, one of the plurality of voltage dividing circuits including the target test resistor 46 x and the target terminal resistor 551 x is referred to as a target voltage dividing circuit.

[0145] After executing the process of step S201 , the control circuit 43 executes the process of step S202 .

[0146] <Step S202> In step S202 , the control circuit 43 controls the operating voltage output circuit 41 to be in an operating voltage OFF state, sets the target output circuit 42 x to a high impedance state, and controls the test voltage output circuit 47 to be in a first test voltage ON state.

[0147] The operating voltage disconnected state is a state in which the operating voltage output circuit 41 does not output the operating voltage VO1 .

[0148] The object output circuit 42x selectively switches between two states according to the instruction of the control circuit 43. The two states include an active state that outputs a signal of a level between a predetermined low level and a high level and a high impedance state. The object output circuit 42x outputs the control signal SC1 in the active state.

[0149] When the target output circuit 42 x is in the high impedance state, current does not flow backward to the target output circuit 42 x via the target first signal line 402 x.

[0150] The first test voltage-on state is a state in which the test voltage VT1 is supplied from the test voltage output circuit 47 to the target voltage dividing circuit.

[0151] Fig. 9 The control state of step S202 is shown. The control state of step S202 is a first example of the test state. When the control circuit 43 executes the process of step S202, it also executes the process of step S203.

[0152] <Step S203> In step S203, the control circuit 43 obtains information on the first target detection voltage VX1 from the divided voltage detection circuit 48. The first target detection voltage VX1 is the detection voltage detected by the divided voltage detection circuit 48 for the target voltage dividing circuit under the control state of step S202 (see Fig. 9 ).

[0153] After executing the process of step S203 , the control circuit 43 executes the process of step S204 .

[0154] <Step S204> In step S204 , the control circuit 43 determines whether the electrical connection state is normal or abnormal based on the level of the first object detection voltage VX1 .

[0155] exist Fig. 9 , the first voltage-dividing resistor R1 is the resistance value of the target test resistor 46x, and the second voltage-dividing resistor R2 is the resistance value of the target terminal resistor 551x.

[0156] exist Fig. 9 In FIG. 4 , the target connection resistor R3 is the resistance value of the target signal line from the target first signal line 402x to the target second signal line 502x. In addition, the resistance value of each terminal resistor 45 is negligibly small compared to the second voltage-dividing resistor R2.

[0157] The first object detection voltage VX1 is a voltage obtained by dividing the test voltage VT1 by the first voltage-dividing resistor R1 , the object connection resistor R3 , and the second voltage-dividing resistor R2 .

[0158] Fig.10is a graph showing the relationship between the object connection resistance R3 and the first object detection voltage VX1. Fig.10 As shown, when the object connection resistance R3 is zero, the first object detection voltage VX1 is a reference voltage V01 determined by the test voltage VT1, the first voltage dividing resistance R1 and the second voltage dividing resistance R2.

[0159] like Fig.10 As shown, as the target connection resistance R3 increases from zero, the first target detection voltage VX1 gradually increases from the reference voltage V01 and gradually approaches the test voltage VT1. When the connection state of the wiring harness 6 is normal, the target connection resistance R3 is extremely small.

[0160] exist Fig.10 In the example, the upper limit resistance HR3 is the upper limit value of the allowable range of the target connection resistance R3. The threshold voltage VS1 is the first target detection voltage VX1 when the target connection resistance R3 is the upper limit resistance HR3.

[0161] When the level of the first object detection voltage VX1 is lower than the threshold voltage VS1, the control circuit 43 determines that the electrical connection state of the object signal line is normal. On the other hand, when the level of the first object detection voltage VX1 exceeds the threshold voltage VS1, the control circuit 43 determines that the electrical connection state of the object signal line is abnormal.

[0162] For example, the abnormality in the electrical connection state of the target signal line is caused by a non-conductive foreign object being caught between the terminals of the first connector 44 or the second connector 56 .

[0163] When the control circuit 43 determines that the electrical connection state of the target signal line is abnormal, the control circuit 43 executes the processing of step S205. On the other hand, when the control circuit 43 determines that the electrical connection state of the target signal line is normal, the control circuit 43 executes the processing of step S206.

[0164] <Step S205> In step S205 , the control circuit 43 records abnormality data indicating that the electrical connection state of the target signal line is abnormal in a predetermined storage device.

[0165] After executing the process of step S205 , the control circuit 43 executes the process of step S206 .

[0166] <Step S206> In step S206 , the control circuit 43 determines whether or not the target output circuit 42 x has been selected in step S201 for all the control signal output circuits 42 .

[0167] When the control circuit 43 determines that the target output circuit 42x has not been selected for all the control signal output circuits 42, the control circuit 43 repeats the processing after step S201. Thus, a new target output circuit 42x is selected and the processing after step S202 corresponding to the new target output circuit 42x is executed.

[0168] That is, the control circuit 43 executes the processing of steps S202 to S205 for each of the plurality of control signal output circuits 42 as a target output circuit 42 x.

[0169] On the other hand, when the control circuit 43 determines that the target output circuit 42 x has been selected for all the control signal output circuits 42 , the connector connection test process ends.

[0170] When the connector connection test process is completed, the presence or absence of the abnormal data record indicates whether the electrical connection state is determined to be normal or abnormal. In addition, the content of the abnormal data indicates the content of the abnormal electrical connection state determined by the connector connection test process.

[0171] [Line insulation test process] Next, refer to Figure 7 The flowchart shown in FIG. 1 illustrates an example of the steps of the line insulation test process.

[0172] In the following description, S301, S302, ... denote reference numerals for a plurality of steps in the inter-line insulation test process. In the inter-line insulation test process, the process of step S301 is first executed.

[0173] <Step S301> In step S301, the control circuit 43 selects two of the plurality of control signal output circuits 42 as the target output circuit 42x and the associated output circuit 42y (see Fig.11 ).

[0174] Each time the process of step S301 is executed, each of the control signal output circuits 42 is sequentially selected as the target output circuit 42x. Here, one of the plurality of first terminals 44a electrically connected to the target output circuit 42x is referred to as a target terminal.

[0175] The associated output circuit 42y is one of the plurality of control signal output circuits 42 that is electrically connected to a nearby terminal of the plurality of first terminals 44a that is arranged in a predetermined proximity to the target terminal. For example, the nearby terminal is a terminal adjacent to the target terminal.

[0176] Fig.11The structure of the portion of the ink ejection control device 4 related to the above-mentioned inter-line insulation test process of the ink ejection unit 51 is shown.

[0177] In the following description, one of the plurality of first signal lines 402 corresponding to the associated output circuit 42y is referred to as an associated first signal line 402y. Also, one of the plurality of second signal lines 502 corresponding to the associated first signal line 402y is referred to as an associated second signal line 502y.

[0178] Furthermore, one of the plurality of test resistors 46 connected to the associated first signal line 402y is referred to as an associated test resistor 46y. Furthermore, one of the plurality of first terminal resistors 551 corresponding to the associated test resistor 46y is referred to as an associated terminal resistor 551y.

[0179] Furthermore, one voltage dividing circuit including the associated test resistor 46 y and the associated terminal resistor 551 y among the plurality of voltage dividing circuits is referred to as an associated voltage dividing circuit.

[0180] After executing the process of step S301 , the control circuit 43 executes the process of step S302 .

[0181] <Step S302> In step S302, the control circuit 43 controls the working voltage output circuit 41 to the state where the working voltage is disconnected, sets the object output circuit 42x to the high impedance state, enables the associated output circuit 42y to output a high level signal, and controls the test voltage output circuit 47 to the state where the second test voltage is connected.

[0182] The second test voltage-on state is a state in which the test voltage VT1 is supplied from the test voltage output circuit 47 to the target voltage dividing circuit and the associated voltage dividing circuit.

[0183] Fig.11 The control state of step S302 is shown. The control state of step S302 is a second example of the test state. When the control circuit 43 executes the process of step S302, it also executes the process of step S303.

[0184] <Step S303> In step S303, the control circuit 43 obtains information on the second target detection voltage VX2 from the divided voltage detection circuit 48. The second target detection voltage VX2 is the detection voltage detected by the divided voltage detection circuit 48 for the target voltage dividing circuit under the control state of step S302 (see Fig.11 ).

[0185] After executing the process of step S303 , the control circuit 43 executes the process of step S304 .

[0186] <Step S304> In step S304 , the control circuit 43 determines whether the electrical connection state is normal or abnormal based on the level of the second object detection voltage VX2 .

[0187] Usually, the second target detection voltage VX2 is the same as the first target detection voltage VX1 , that is, a voltage obtained by dividing the test voltage VT1 by the first voltage-dividing resistor R1 , the target connection resistor R3 , and the second voltage-dividing resistor R2 .

[0188] However, there may be a case where a line short circuit occurs between the target signal line and the associated signal line from the associated first signal line 402y to the associated second signal line 502y. The target signal line is a signal line from the target first signal line 402x to the target second signal line 502x.

[0189] For example, the short circuit between the wires may be caused by a conductive foreign object being caught between the terminals of the first connector 44 or the second connector 56 .

[0190] When the line short circuit occurs, a voltage equivalent to the high level signal output from the associated output circuit 42y is detected as the second target detection voltage VX2. That is, when the line short circuit occurs, the second target detection voltage VX2 is higher than the threshold voltage VS1.

[0191] When the level of the second target detection voltage VX2 is lower than the threshold voltage VS1, the control circuit 43 determines that the electrical connection state is normal. On the other hand, when the level of the second target detection voltage VX2 exceeds the threshold voltage VS1, the control circuit 43 determines that the electrical connection state is abnormal.

[0192] The electrical connection state determined in step S304 is a state indicating whether electrical insulation between the target signal line and the relevant signal line is sufficiently ensured.

[0193] When the control circuit 43 determines that the electrical connection state in step S304 is abnormal, the control circuit 43 executes the process of step S305. On the other hand, when the control circuit 43 determines that the electrical connection state in step S304 is normal, the control circuit 43 executes the process of step S306.

[0194] <Step S305> In step S305 , the control circuit 43 records abnormality data indicating that the electrical connection state in step S304 is abnormal in a predetermined storage device.

[0195] After executing the process of step S305 , the control circuit 43 executes the process of step S306 .

[0196] <Step S306> In step S306 , the control circuit 43 determines whether the selection of the target output circuit 42 x and the related output circuit 42 y in step S301 has been completed for all predetermined selection candidates.

[0197] When the control circuit 43 determines that the target output circuit 42x and the associated output circuit 42y have not been selected for all selection candidates, the control circuit 43 repeats the processing after step S301 to select a new combination of the target output circuit 42x and the associated output circuit 42y and executes the processing after step S302 corresponding to the new combination.

[0198] That is, the control circuit 43 executes the processing of steps S302 to S305 for each of the plurality of control signal output circuits 42 as a target output circuit 42 x.

[0199] On the other hand, when the control circuit 43 determines that the target output circuit 42x and the related output circuit 42y have been selected for all the selection candidates, the control circuit 43 ends the line insulation test process.

[0200] When the line insulation test process is completed, the presence or absence of the abnormal data record indicates whether the electrical connection state is determined to be normal or abnormal. In addition, the content of the abnormal data indicates the content of the electrical connection state abnormality determined by the line insulation test process.

[0201] [Wire grounding test processing] Next, refer to Figure 8 The flowchart shown in FIG. 1 illustrates an example of the steps of the wire ground test process.

[0202] In the following description, S401, S402, ... denote reference numerals for a plurality of steps in the wire ground fault test process. In the wire ground fault test process, the process of step S401 is first executed.

[0203] <Step S401> In step S401, the control circuit 43 selects one of the plurality of control signal output circuits 42 as the target output circuit 42x (see Fig.12 ) Each time the process of step S401 is executed, each of the control signal output circuits 42 is sequentially selected as the target output circuit 42x.

[0204] Fig.12 The structure of the portion of the ink ejection control device 4 related to the line grounding test process of the ink ejection unit 51 is shown.

[0205] After executing the process of step S401 , the control circuit 43 executes the process of step S402 .

[0206] <Step S402> In step S402 , the control circuit 43 controls the test voltage output circuit 47 to be in a test voltage OFF state, causes the target output circuit 42 x to output a high level signal, and controls the operating voltage output circuit 41 to be in an operating voltage ON state.

[0207] The test voltage off state is a state in which the test voltage output circuit 47 does not output the test voltage VT1.

[0208] The state in which the operating voltage is turned on is a state in which the operating voltage output circuit 41 outputs the operating voltage VO1. In the state in which the operating voltage is turned on, the operating voltage VO1 is supplied to the first voltage line 401.

[0209] Fig.12 The control state of step S402 is shown. The control state of step S402 is a third example of the test state. When the control circuit 43 executes the process of step S402, it also executes the process of step S403.

[0210] <Step S403> In step S403, the control circuit 43 obtains information on the third target detection voltage VX3 from the divided voltage detection circuit 48. The third target detection voltage VX3 is the detection voltage detected by the divided voltage detection circuit 48 for the target voltage dividing circuit in the control state of step S402 (see Fig.12 ).

[0211] After executing the process of step S403 , the control circuit 43 executes the process of step S404 .

[0212] <Step S404> In step S404 , the control circuit 43 determines whether the electrical connection state is normal or abnormal based on the level of the third object detection voltage VX3 .

[0213] Normally, the third object detection voltage VX3 is a voltage equivalent to the voltage of the high-level signal output from the object output circuit 42 x .

[0214] However, when the target signal line is grounded, a voltage close to the ground potential is detected as the third target detection voltage VX3. Here, the allowable lower limit value of the voltage level of the high-level signal is referred to as a high-level lower limit value.

[0215] When the level of the third object detection voltage VX3 is greater than the high level lower limit value, the control circuit 43 determines that the electrical connection state of the object signal line is normal. On the other hand, when the level of the third object detection voltage VX3 is less than the high level lower limit value, the control circuit 43 determines that the electrical connection state of the object signal line is abnormal.

[0216] The electrical connection state determined in step S404 is a state indicating whether or not electrical insulation between the target signal line and the ground portion is sufficiently ensured.

[0217] For example, the target signal line is grounded due to conductive foreign matter being caught between terminals of the first connector 44 or the second connector 56 .

[0218] When the control circuit 43 determines that the electrical connection state in step S404 is abnormal, the control circuit 43 executes the process of step S405. On the other hand, when the control circuit 43 determines that the electrical connection state in step S404 is normal, the control circuit 43 executes the process of step S406.

[0219] <Step S405> In step S405 , the control circuit 43 records abnormality data indicating that the electrical connection state in step S404 is abnormal in a predetermined storage device.

[0220] After executing the process of step S405 , the control circuit 43 executes the process of step S406 .

[0221] <Step S406> In step S406 , the control circuit 43 determines whether or not the target output circuit 42 x has been selected for all the control signal output circuits 42 in step S401 .

[0222] When the control circuit 43 determines that the target output circuit 42x has not been selected for all the control signal output circuits 42, the control circuit 43 repeats the processing after step S401. Thus, a new target output circuit 42x is selected and the processing after step S402 corresponding to the new target output circuit 42x is executed.

[0223] That is, the control circuit 43 executes the processing of steps S402 to S405 for each of the plurality of control signal output circuits 42 as a target output circuit 42 x.

[0224] On the other hand, when the control circuit 43 determines that the target output circuit 42 x has been selected for all the control signal output circuits 42 , the control circuit 43 ends the line ground test process.

[0225] When the wire grounding test process is completed, the presence or absence of the abnormal data record indicates whether the electrical connection state is determined to be normal or abnormal. In addition, the content of the abnormal data indicates the content of the abnormal electrical connection state determined by the wire grounding test process.

[0226] By using the inkjet recording device 10 , it is possible to detect electrical connection failure of some of the plurality of signal lines between the inkjet control device 4 , the inkjet unit 51 , and the harness 6 .

[0227] [Second embodiment] Next, refer to Fig.13 , Fig.14 Next, an inkjet recording apparatus 10A according to a second embodiment will be described. The inkjet recording apparatus 10A is a modified example of the inkjet recording apparatus 10 .

[0228] exist Fig.13 In, with Figure 1 to Figure 4 , Fig. 9 The same components are denoted by the same reference numerals. The following describes the technical features of the inkjet recording apparatus 10A that are different from the inkjet recording apparatus 10.

[0229] The inkjet recording device 10A includes a plurality of inkjet units 51A instead of the plurality of inkjet units 51. Each inkjet unit 51A includes a plurality of terminal circuits 55A instead of the plurality of terminal circuits 55.

[0230] Each terminal circuit 55A has a structure in which a capacitor 553 is added to each terminal circuit 55. That is, the ink ejection unit 51A includes a plurality of capacitors 553 connected in series with the plurality of first terminal resistors 551, respectively.

[0231] Each capacitor 553 is provided to reduce power consumption of each terminal circuit 55A.

[0232] Fig.13 The structure of the portion of the inkjet control device 4 related to the connector connection test process of the inkjet unit 51A is shown. Fig.13 The control state of step S202 in the case where the ink jet unit 51A is used is shown.

[0233] Fig.14 The graph of φ represents the relationship between the test voltage output time and the first target detection voltage VX1 when the inkjet recording device 10A is in the control state of step S202. The test voltage output time is the elapsed time from the start of output of the test voltage VT1.

[0234] exist Fig.14 The first graph G1 shows the change of the first object detection voltage VX1 when the object connection resistance R3 is the upper limit resistance HR3. The second graph G2 shows the change of the first object detection voltage VX1 when the object connection resistance R3 is greater than the upper limit resistance HR3.

[0235] like Fig.14As shown, when the capacitor 553 is connected to the target voltage dividing circuit, as the test voltage output time elapses, the first target detection voltage VX1 gradually increases to the test voltage VT1.

[0236] Furthermore, when the target connection resistance R3 is large, the rising speed of the first target detection voltage VX1 is faster than when the target connection resistance R3 is small.

[0237] The control circuit 43 of this embodiment acquires information of the first target detection voltage VX1 at a specific time point T1 after a predetermined time has passed since the time point when the test voltage VT1 is output to the target voltage dividing circuit in step S203 (see Fig.14 ).

[0238] Then, the control circuit 43 determines whether the electrical connection state is normal or abnormal based on the level of the first target detection voltage VX1 at the specific time point T1 in step S204 .

[0239] Specifically, when the level of the first object detection voltage VX1 at the specific time point T1 is less than the threshold voltage VS2, the control circuit 43 determines that the electrical connection state is normal. On the other hand, when the level of the first object detection voltage VX1 at the specific time point T1 exceeds the threshold voltage VS2, the control circuit 43 determines that the electrical connection state is abnormal.

[0240] For example, the threshold voltage VS2 is the first target detection voltage VX1 at a specific time point T1 when the target connection resistance R3 is the allowable upper limit resistance HR3 .

[0241] Similarly, the control circuit 43 of this embodiment acquires information of the second target detection voltage VX2 at a specific time point T1 when a predetermined time has elapsed since the time point when the test voltage VT1 was output to the target voltage dividing circuit and the associated voltage dividing circuit in step S303 .

[0242] Then, the control circuit 43 determines whether the electrical connection state is normal or abnormal based on the level of the second target detection voltage VX2 at the specific time point T1 in step S304 .

[0243] Also in the case of adopting the second embodiment, the same effects as those in the case of adopting the first embodiment can be obtained.

[0244] [Third Embodiment] Next, refer to Fig.15 Next, an inkjet recording apparatus 10B according to a third embodiment will be described. The inkjet recording apparatus 10B is a modified example of the inkjet recording apparatus 10 .

[0245] exist Fig.15 In, with Figure 1 to Figure 4 , Fig. 9 The same components are denoted by the same reference numerals. The following describes the technical features of the inkjet recording apparatus 10B that are different from the inkjet recording apparatus 10.

[0246] The inkjet recording device 10B includes an inkjet control device 4x instead of the inkjet control device 4. The inkjet control device 4x has a configuration in which one or more display units 49 are added to the inkjet control device 4. The display unit 49 is disposed corresponding to the first connector 44.

[0247] exist Fig.15 In the example shown, the ink ejection control device 4x is electrically connected to the plurality of ink ejection units 51 via the plurality of harnesses 6. In this case, the ink ejection control device 4x includes a plurality of first connectors 44 corresponding to the plurality of harnesses 6.

[0248] exist Fig.15 In the illustrated example, the inkjet control device 4x includes a plurality of display units 49 that are arranged corresponding to the plurality of first connectors 44. Each display unit 49 can recognize and display at least two states.

[0249] In the present embodiment, each display unit 49 is an LED (Light Emitting Diode). For example, the LED can identify and display two states by turning on or off. In addition, the LED can identify and display two states by turning on or flashing. In addition, each display unit 49 can also be a two-color LED that can emit light of two colors.

[0250] The control circuit 43 controls the output state of the lighting signal to each display unit 49. The control circuit 43 controls each display unit 49 to a display state indicating the determination result of the electrical connection state determined by the test process by controlling the lighting signal.

[0251] Here, one or more connectors among the plurality of first connectors 44 that have obtained the determination result of abnormal electrical connection state are referred to as abnormal connectors. In addition, one or more connectors among the plurality of first connectors 44 that have not obtained the determination result of abnormal electrical connection state are referred to as normal connectors.

[0252] For example, the control circuit 43 controls one or more first display units corresponding to the normal connector among the plurality of display units 49 to the first display state. On the other hand, the control circuit 43 controls one or more second display units corresponding to the abnormal connector among the plurality of display units 49 to the second display state.

[0253] For example, the first display state is a light-off state, and the second display state is a light-on state. In addition, the first display state is a state of continuous light-on, and the second display state is a flashing state. In addition, the first display state is a state of light-on in a first color, and the second display state is a state of light-on in a second color.

[0254] In step S108 of the test process, the control circuit 43 controls the first display unit to be in the first display state.

[0255] On the other hand, the control circuit 43 controls the second display unit to the second display state as the first error notification in step S102 , the second error notification in step S104 , and the third error notification in step S106 of the test process.

[0256] In addition, the control circuit 43 may control the second display unit to a display state corresponding to the type of the electrical connection state abnormality. That is, the control circuit 43 may control the second display unit to a different display state in the first error notification, the second error notification, and the third error notification.

[0257] For example, the control circuit 43 causes the second display unit to blink in different blinking patterns in the first error notification, the second error notification, and the third error notification.

[0258] In addition, each display unit 49 may be a 7-segment LED capable of displaying a numerical value. In this case, the control circuit 43 causes the second display unit to display a different numerical value in the first error notification, the second error notification, and the third error notification.

[0259] When this embodiment is adopted, the same effect as that of the first embodiment can be obtained. By adopting this embodiment, it is easy to identify each of the normal connectors and the abnormal connectors in the inkjet control device 4x. In addition, this embodiment can also be applied to the second embodiment.

[0260] [Additional Notes on the Invention] Hereinafter, the summary of the invention extracted from the above-mentioned embodiment will be described in the supplementary notes. In addition, each structure and each processing function described in the following supplementary notes can be selected and combined arbitrarily.

[0261] <Additional Note 1> An inkjet recording device, which includes a control device and an inkjet unit connected by a wiring harness, the control device including: an operating voltage output circuit capable of outputting an operating voltage; a plurality of control signal output circuits capable of outputting a plurality of control signals respectively; and a first connector including a plurality of first terminals connected to a first voltage line transmitting the operating voltage and a plurality of first signal lines transmitting the plurality of control signals, and connected to a first end of the wiring harness, the inkjet unit including: a second connector including a plurality of second terminals, and connected to a second end of the wiring harness; a plurality of receiving circuits, which are respectively supplied with the operating voltage and the plurality of control signals through a second voltage line and a plurality of second signal lines connected to the plurality of second terminals; a plurality of terminal resistors, which are respectively connected to the plurality of second signal lines; a plurality of piezoelectric elements, which are respectively supplied with a plurality of drive signals corresponding to the plurality of control signals received by the plurality of receiving circuits; and a plurality of nozzles, which eject ink pressurized by the plurality of piezoelectric elements, the control device also including: a test voltage output circuit capable of outputting output a test voltage; a plurality of test resistors, to which the test voltage is supplied from the test voltage output circuit, respectively forming a plurality of voltage-dividing circuits with the plurality of terminal resistors; a voltage-dividing detection circuit, for detecting the output voltages of the respective voltage-dividing circuits; and a control circuit, for controlling the working voltage output circuit, the plurality of control signal output circuits and the test voltage output circuit, wherein the control circuit performs a test process, in which the working voltage output circuit, the plurality of control signal output circuits and the test voltage output circuit are controlled to be in a test state, and based on the detection result of the voltage-dividing detection circuit in the test state, it is determined whether the electrical connection state between the plurality of first terminals and the plurality of second terminals is normal or abnormal, and the control circuit performs inkjet control after determining that the electrical connection state is normal through the test process, in which the working voltage output circuit is made to output the working voltage and a part or all of the plurality of control signal output circuits are made to output a part or all of the plurality of control signals.

[0262] <Note 2> According to the inkjet recording device recorded in Note 1, the test process includes a connector connection test process, and the connector connection test process includes: the control circuit makes the working voltage output circuit not output the working voltage, and sets the multiple control signal output circuits to a high impedance state, and makes the test voltage output circuit output the test voltage to the multiple voltage divider circuits respectively; the control circuit determines whether the electrical connection state is normal or abnormal based on the levels of the detection voltages detected by the voltage divider detection circuit on the multiple voltage divider circuits respectively.

[0263] <Addendum 3> According to the inkjet recording device described in Note 2, the inkjet unit includes a plurality of capacitors respectively connected in series with the plurality of terminal resistors, and the control circuit determines whether the electrical connection state is normal or abnormal based on the levels of the detection voltages detected by the voltage-dividing detection circuits on the plurality of voltage-dividing circuits at a point in time when a predetermined time has passed since the test voltage was output to the plurality of voltage-dividing circuits.

[0264] <Addendum 4> According to the inkjet recording device described in Note 1, the test process includes a line insulation test process, and the line insulation test process includes: the control circuit selects an object output circuit and an associated output circuit from the multiple control signal output circuits, so that the working voltage output circuit does not output the working voltage, and sets the object output circuit to a high impedance state, and makes the associated output circuit output a high level signal, so that the test voltage output circuit outputs the test voltage to two of the multiple voltage divider circuits corresponding to the object output circuit and the associated output circuit; the control circuit determines whether the electrical connection state is normal or abnormal based on the level of the detection voltage detected by the voltage divider detection circuit on the object voltage divider circuit corresponding to the object output circuit among the multiple voltage divider circuits.

[0265] <Addendum 5> According to the inkjet recording device described in Note 4, the inkjet unit includes a plurality of capacitors respectively connected in series with the plurality of terminal resistors, and the control circuit determines whether the electrical connection state is normal or abnormal based on the levels of detection voltages detected by the voltage-dividing detection circuits on the plurality of voltage-dividing circuits at a point in time when a predetermined time has passed since the test voltage was output to the plurality of voltage-dividing circuits.

[0266] <Addendum 6> According to the inkjet recording device recorded in any one of Notes 2 to 5, the test process includes a line grounding test process, and the line grounding test process includes: the control circuit makes the test voltage output circuit not output the test voltage, and makes the working voltage output circuit output the working voltage, and makes the multiple control signal output circuits output high-level signals respectively; the control circuit determines whether the electrical connection state is normal or abnormal based on the levels of the detection voltages detected by the voltage-dividing detection circuit on the multiple voltage-dividing circuits respectively.

[0267] <Addendum 7> According to the inkjet recording device recorded in any one of Notes 1 to 6, the control device includes a display unit configured corresponding to the first connector, and the control circuit controls the display unit to display the determination result of the electrical connection status determined by the test process.

[0268] The scope of the present invention is not limited to the above content, but is defined by the description of the claims, so it can be considered that the embodiments described in this specification are only illustrative, not limiting. Therefore, all changes that do not depart from the scope and limits of the claims, as well as contents that are equivalent to the scope and limits of the claims, are included in the scope of the claims.

Claims

1. An inkjet recording device, characterized in that It includes a control device and an inkjet unit connected by a wiring harness. The control device comprises: A working voltage output circuit capable of outputting a working voltage; a plurality of control signal output circuits, each capable of outputting a plurality of control signals; and The first connector includes a plurality of first terminals connected to a first voltage line transmitting the working voltage and a plurality of first signal lines transmitting the plurality of control signals, and is connected to a first end of the wiring harness. The inkjet unit comprises: A second connector including a plurality of second terminals and connected to a second end portion of the wiring harness; a plurality of receiving circuits, which are respectively supplied with the operating voltage and the plurality of control signals through second voltage lines and a plurality of second signal lines connected to the plurality of second terminals; A plurality of terminal resistors, respectively connected to the plurality of second signal lines; a plurality of piezoelectric elements to which a plurality of driving signals corresponding to the plurality of control signals received by the plurality of receiving circuits are respectively supplied; and The plurality of nozzles eject ink pressurized by the plurality of piezoelectric elements. The control device also includes: A test voltage output circuit capable of outputting a test voltage; a plurality of test resistors, to which the test voltage is supplied from the test voltage output circuit, and which respectively form a plurality of voltage dividing circuits with the plurality of terminal resistors; A voltage division detection circuit, detecting the output voltage of each of the plurality of voltage division circuits; and a control circuit, controlling the working voltage output circuit, the plurality of control signal output circuits and the test voltage output circuit, The control circuit performs a test process in which the operating voltage output circuit, the plurality of control signal output circuits, and the test voltage output circuit are controlled to be in a test state, and determines whether the electrical connection state between the plurality of first terminals and the plurality of second terminals is normal or abnormal based on a detection result of the divided voltage detection circuit in the test state. Moreover, the control circuit performs inkjet control after determining that the electrical connection state is normal through the test process, and in the inkjet control, the working voltage output circuit is made to output the working voltage and a part or all of the multiple control signal output circuits are made to output a part or all of the multiple control signals.

2. The inkjet recording device according to claim 1, wherein The test process includes a connector connection test process, The connector connection test process comprises: The control circuit causes the working voltage output circuit not to output the working voltage, sets the plurality of control signal output circuits to a high impedance state, and causes the test voltage output circuit to output the test voltage to the plurality of voltage divider circuits; as well as The control circuit determines whether the electrical connection state is normal or abnormal based on the levels of the detection voltages detected by the divided voltage detection circuit for each of the plurality of voltage dividing circuits.

3. The inkjet recording device according to claim 2, wherein: The inkjet unit includes a plurality of capacitors respectively connected in series with the plurality of terminal resistors. The control circuit determines whether the electrical connection state is normal or abnormal based on the levels of detection voltages detected by the divided voltage detection circuits for the plurality of voltage dividing circuits at a time point when a predetermined time has passed since the test voltages were output to the plurality of voltage dividing circuits.

4. The inkjet recording device according to claim 1, wherein: The test process includes a line insulation test process, The line insulation test process comprises: The control circuit selects a target output circuit and an associated output circuit from the plurality of control signal output circuits, causes the operating voltage output circuit not to output the operating voltage, sets the target output circuit to a high impedance state, causes the associated output circuit to output a high level signal, and causes the test voltage output circuit to output the test voltage to two of the plurality of voltage divider circuits corresponding to the target output circuit and the associated output circuit; as well as The control circuit determines whether the electrical connection state is normal or abnormal based on the level of the detection voltage detected by the divided voltage detection circuit for the target voltage dividing circuit corresponding to the target output circuit among the plurality of voltage dividing circuits.

5. The inkjet recording device according to claim 4, characterized in that The inkjet unit includes a plurality of capacitors respectively connected in series with the plurality of terminal resistors. The control circuit determines whether the electrical connection state is normal or abnormal based on the levels of detection voltages detected by the divided voltage detection circuits for the plurality of voltage dividing circuits at a time point when a predetermined time has passed since the test voltages were output to the plurality of voltage dividing circuits.

6. The inkjet recording device according to claim 2 or 4, characterized in that: The test process includes a line grounding test process, The wire grounding test process comprises: The control circuit causes the test voltage output circuit not to output the test voltage, causes the working voltage output circuit to output the working voltage, and causes the multiple control signal output circuits to respectively output high-level signals; as well as The control circuit determines whether the electrical connection state is normal or abnormal based on the levels of the detection voltages detected by the divided voltage detection circuit for each of the plurality of voltage dividing circuits.

7. The inkjet recording device according to any one of claims 1 to 5, characterized in that: The control device includes a display unit configured corresponding to the first connector, The control circuit controls the display unit to display a determination result of the electrical connection state determined by the test process.

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