WO2015019795A1 - Image recording device and abnormality detection method - Google Patents

Abstract

The present invention provides an image recording device and an abnormality detection method which detect transitional disconnection failure and contact failure of a transmission means disposed in a movable part. An image recording device (100) according to an aspect of the present invention is provided with a movement mechanism (170) for integrally moving a control unit and a recording head (132M, 132K, 132C, 132Y) relatively to a signal generation unit (122), and is provided with a communication test means (122, 136M, 136K, 136C, 136Y) which, while the recording head is relatively moved from a first position where a transmission means (140M, 140K, 140C, 140Y) comes into a first physical situation to a second position where the transmission means comes into a second physical situation, conducts a communication test between the signal generation unit and the control unit in a position between the first position and the second position.

Description

Image recording apparatus and abnormality detection method

The present invention relates to an image recording apparatus and an abnormality detection method, and more particularly to a technique for detecting an abnormality in a transmission means such as a cable arranged in a movable part.

In the image recording apparatus, the boards in the apparatus are connected by wiring. If this wiring is abnormal, the image recording apparatus cannot operate normally. However, there has been a problem that it takes a lot of time to identify a defective wiring portion.

In response to this problem, Patent Document 1 describes a technique for automatically detecting an abnormality in the wiring between a connection board in an image recording apparatus or between an image recording apparatus and an optional device. According to Patent Document 1, an operator can easily identify a defective part.

JP 2002-11927 A

∙ Cables and connecting parts (connectors) are subject to poor contact and metal fatigue in proportion to the years of use, and in particular, poor contact is likely to occur in movable parts. Also, in the transition period when the contact failure is completely disconnected, the physical condition changes due to movement, so temporary contact failure and good connection are often repeated irregularly. Is difficult to identify.

Conventionally, for such problems, it is expensive to make sure if the operator has inspected for defects by bending or stretching the cable with empirical intuition, or if contact failure occurs even once. A new cable replacement method was used, and there was a loss of time and replacement costs.

Further, Patent Document 1 does not solve such a problem.

The present invention has been made in view of such circumstances, and provides an image recording apparatus and an abnormality detection method capable of detecting a transient disconnection failure and contact failure of a transmission means arranged in a movable part. Objective.

In order to achieve the above object, one aspect of an image recording apparatus integrally supports a recording head having a recording element, a control unit that controls the recording element based on a control signal, and the recording head and the control unit. A support unit, a signal generation unit that generates a control signal, a transmission unit that transmits the control signal from the signal generation unit to the control unit, a moving unit that moves the recording head relative to the signal generation unit, and a transmission unit. While the transmission means relatively moves the recording head from the first position, which is the first physical condition, to the second position, which is the second physical condition, between the first position and the second position. Communication test means for performing a communication test between the signal generation unit and the control unit at the position is provided.

According to this aspect, while the recording unit is relatively moved from the first position where the transmission unit is in the first physical state to the second position where the transmission unit is in the second physical state, Since the communication test between the signal generation unit and the control unit is performed at a position between the position and the second position, it is possible to perform an inspection while changing the physical state of the transmission unit, and the transient of the transmission unit Disconnection failure and contact failure can be detected. Moreover, since it is not necessary to remove the transmission means for the inspection, the inspection time can be shortened.

The communication test means preferably performs the communication test while relatively moving the recording head. The communication test means may perform the communication test by stopping the recording head. Thereby, it is possible to perform inspection while appropriately changing the physical state of the transmission means.

The transmission means may include a cable having flexibility. The cable may be connected to the control unit via a connector, or may be connected to the signal generation unit via a connector. According to this aspect, disconnection failure of the cable and contact failure between the cable and the connector can be detected.

It is preferable to provide notification means for notifying the user when there is an abnormality in the result of the communication test. Thereby, recording defects can be reduced, and wasteful consumption of the recording medium can be reduced.

It is preferable that the communication test means repeatedly performs a communication test between the signal generation unit and the control unit at a plurality of positions between the first position and the second position. In addition, a communication test between the signal generation unit and the control unit may be performed in at least one of the first position and the second position. Thereby, the transmission means can be appropriately inspected.

The communication test means determines a success or failure of transmission means communication based on a test signal transmission section that transmits a test signal to the transmission means, a test signal reception section that receives the test signal via the transmission means, and the received test signal It is preferable to include a determination unit. In this case, the test signal transmission unit may be provided in the signal generation unit, and the test signal reception unit and the determination unit may be provided in the control unit. Thereby, the transmission means can be appropriately inspected.

The moving means is means for moving the recording head, and one of the first position and the second position is preferably an image recording position for recording an image on a recording medium. In this case, the other position is preferably a maintenance position for performing maintenance of the recording head. As described above, this aspect can be applied to an image recording apparatus in which the recording head can move between the image recording position and the maintenance position.

The recording head is an inkjet head, and may be provided with a moisture retention cap for retaining moisture on the nozzle surface of the inkjet head at the maintenance position. Thus, this aspect can also be applied to an image recording apparatus that includes an inkjet head and a moisture retention cap.

It is preferable that the recording apparatus includes a conveyance unit that conveys the recording medium and a synchronization signal output unit that outputs a synchronization signal synchronized with the conveyance unit, and the signal generation unit generates the control signal based on the synchronization signal. Thereby, the transport position of the recording medium is clarified, and an image can be recorded appropriately.

In order to achieve the above object, one aspect of the abnormality detection method is to integrally support a recording head having a recording element, a control unit that controls the recording element based on a control signal, and the recording head and the control unit. An image recording apparatus comprising: a support unit; a signal generation unit that generates a control signal; a transmission unit that transmits a control signal from the signal generation unit to the control unit; and a moving unit that moves the recording head relative to the signal generation unit In this abnormality detection method, the transmission means moves relative to the second position where the transmission means enters the second physical situation from the first position where the transmission means enters the first physical situation. A communication test between the signal generation unit and the control unit is performed at a position between the first position and the second position.

According to this aspect, while the recording unit is relatively moved from the first position where the transmission unit is in the first physical state to the second position where the transmission unit is in the second physical state, Since the communication test between the signal generation unit and the control unit is performed at a position between the position and the second position, it is possible to inspect while changing the physical state of the transmission means arranged in the movable unit Thus, it is possible to detect a transient disconnection failure or contact failure of the transmission means. Moreover, since it is not necessary to remove the transmission means for the inspection, the inspection time can be shortened.

According to the present invention, it is possible to inspect while changing the physical state of the transmission means arranged in the movable part, and it is possible to detect a transient disconnection failure or contact failure of the transmission means. Moreover, since it is not necessary to remove the transmission means for the inspection, the inspection time can be shortened.

FIG. 1 is a side view of the ink jet recording apparatus. FIG. 2 is a plan view of the ink jet recording apparatus. FIG. 3 is a front view (image recording position) of the ink jet recording apparatus. FIG. 4 is a front view (wiping position) of the ink jet recording apparatus. FIG. 5 is a front view (moisturizing position) of the ink jet recording apparatus. FIG. 6A is a plan perspective view showing an example of the structure of an inkjet head. FIG. 6B is an enlarged view of a part of FIG. 6A. FIG. 7A is a diagram illustrating an arrangement example of a plurality of head modules constituting the inkjet head. FIG. 7B is another diagram illustrating an arrangement example of a plurality of head modules constituting the ink jet head. FIG. 8 is a cross-sectional view showing a three-dimensional configuration of the droplet discharge element. FIG. 9 is a perspective view showing a connection form between the inkjet head and the control board. FIG. 10 is a block diagram showing an electrical configuration of the ink jet recording apparatus. FIG. 11 is a flowchart showing an example of processing in the stationary state cable test mode. FIG. 12 is a flowchart showing an example of processing in the movable state cable test mode.

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

[Overall configuration of inkjet recording apparatus]
FIG. 1 is a side view showing the ink jet recording apparatus according to the present embodiment. An ink jet recording apparatus 100 (an example of an image recording apparatus) is a single-pass line printer that records an image on a recording surface of a sheet 1 (an example of a recording medium), and includes a paper transport unit 110, an image recording unit 130, and the like. ing.

The paper transport unit 110 (an example of a transport unit) includes transport rollers 112 and 114, an annular transport belt (endless belt) 116, a rotary encoder 118, a paper sensor 120, a signal generation board 122, and the like.

The conveyance belt 116 is wound around a pair of conveyance rollers 112 and 114. The conveyance roller 112 is given a driving force from a conveyance motor (not shown) and rotates clockwise. The transport roller 114 is driven to rotate by the rotational force applied from the transport belt 116 as the transport roller 112 rotates. The transport belt 116 travels in the transport direction as the transport rollers 112 and 114 rotate, so that the paper 1 placed on the transport belt 116 is transported.

The transport roller 112 is provided with a rotary encoder 118 (an example of a synchronization signal output signal) that outputs an encoder signal (an example of a synchronization signal) accompanying the rotation of the transport roller 112. Further, the paper transport unit 110 includes a paper sensor 120 (an example of a synchronization signal output unit) that detects that the paper 1 has arrived and outputs a detection signal (an example of a synchronization signal).

The signal generation board 122 includes connectors 124E, 124S, 124M, 124K, 124C, 124Y and the like (in the following description, these connectors may be collectively referred to as “connector 124”). The encoder signal of the rotary encoder 118 is input from the cable 126E to the signal generation board 122 via the connector 124E. The detection signal of the paper sensor 120 is input to the signal generation board 122 from a cable (not shown) via the connector 124S.

The ink jet recording apparatus 100 can know the transport position of the paper 1 by this encoder signal and detection signal. Based on these signals, the signal generation board 122 outputs a print start signal and a print pixel clock described later.

The image recording unit 130 includes inkjet heads 132M, 132K, 132C, and 132Y, control boards 136M, 136K, 136C, and 136Y, connectors 138M, 138K, 138C, and 138Y, a head holding unit 142, and the like. In the following description, these inkjet head, control board, and connector may be collectively referred to as “inkjet head 132, control board 136, connector 138”.

The four inkjet heads 132M, 132K, 132C, 132Y (an example of a recording head) are sequentially arranged from the upstream side with a predetermined interval in the paper conveyance direction (Y direction) of the conveyance belt 116. The inkjet heads 132M, 132K, 132C, and 132Y include nozzle surfaces 134M, 134K, 134C, and 134Y that face the conveyor belt 116, respectively. The nozzle surfaces 134M, 134K, 134C, and 134Y include magenta ink and black, respectively. A plurality of nozzles 251 (see FIGS. 6A and 6B) for ejecting ink, cyan ink, and yellow ink are formed over the entire width of the paper 1.

Control boards 136M, 136K, 136C, and 136Y (an example of a control unit) are boards for controlling the inkjet heads 132M, 132K, 132C, and 132Y, and are provided with connectors 138M, 138K, 138C, and 138Y, respectively. ing.

The connectors 140M, 138K, 138C, and 138Y are connected to cables 140M, 140K, 140C, and 140Y (an example of transmission means) that are electrically connected to the connectors 124M, 124K, 124C, and 124Y of the signal generation board 122, respectively. Cables 140M, 140K, 140C, and 140Y have flexibility, and are composed of a conducting wire portion that transmits signals and a covering portion that covers the conducting wire portion. In FIG. 1, the cables 140M, 140K, and 140C are not shown.

The inkjet heads 132M, 132K, 132C, 132Y and the control boards 136M, 136K, 136C, 136Y are integrally held by a head holding portion 142 (an example of a support portion).

FIG. 2 is a plan view of the ink jet recording apparatus 100, and FIG. 3 is a front view. The ink jet recording apparatus 100 includes a maintenance unit 150 in the X direction orthogonal to the conveyance direction (Y direction) of the paper 1 by the paper conveyance unit 110.

The maintenance unit 150 includes nozzle surface wiping units 152M, 152K, 152C, and 152Y that clean the nozzle surfaces 134M, 134K, 134C, and 134Y of the inkjet heads 132M, 132K, 132C, and 132Y, and the nozzle surfaces 134M, 134K, and 134C, Moisturizing caps 154M, 154K, 154C, 154Y, etc. for moisturizing 134Y are provided.

The nozzle surface wiping units 152M, 152K, 152C, and 152Y are disposed between the paper transport unit 110 and the moisturizing caps 154M, 154K, 154C, and 154Y. Nozzle surface wiping units 152M, 152K, 152C, and 152Y are formed by wiping webs (not shown) to which the cleaning liquid is applied when the inkjet heads 132M, 132K, 132C, and 132Y pass over the nozzle surfaces 134M, 134K, 134C and 134Y are wiped and cleaned.

The moisturizing caps 154M, 154K, 154C, and 154Y are supplied with a pressurizing / suction mechanism (not shown) for pressurizing and sucking the inside of the nozzles, and for supplying cleaning liquid into the moisturizing caps 154M, 154K, 154C, and 154Y. The cleaning liquid supply mechanism (not shown) is provided. Further, a waste liquid tray 156 is disposed below the moisturizing caps 154M, 154K, 154C, and 154Y. The cleaning liquid supplied to the moisturizing caps 154M, 154K, 154C, and 154Y is discarded to the waste liquid tray 156, and is recovered from the waste liquid tray 156 to the waste liquid tank 160 through the waste liquid recovery pipe 158.

The head holding part 142 is configured to be movable in the X direction by a moving mechanism 170 (see FIG. 10). The moving mechanism 170 (an example of the moving means) includes the ink jet heads 132M, 132K, 132C, and 132Y, and the nozzle surface 134M, 134K, 134C, and 134Y shown in FIG. Wiping positions wiped and cleaned by 152M, 152K, 152C, and 152Y, and moisturizing positions where nozzle surfaces 134M, 134K, 134C, and 134Y shown in FIG. Can be moved to.

For example, when the inkjet recording apparatus 100 is stopped for a long time, the nozzle surfaces 134M, 134K, 132Y are moved by moving the inkjet heads 132M, 132K, 132C, 132Y from the image recording position to the moisturizing position via the wiping position. The ink adhering to 134C and 134Y can be removed, and drying of the nozzle 251 can be prevented.

Further, when recording an image, the head holding unit 142 moves the inkjet heads 132M, 132K, 132C, and 132Y from the moisturizing position to the image recording position.

As described above, the moving mechanism 170 moves the inkjet heads 132M, 132K, 132C, and 132Y from the first position with respect to the paper transport unit 110 (the control boards 136M, 136K, 136C, and 136Y with respect to the signal generation board 122) from the first position. Relative movement to a second position different from the first position is possible.

<Configuration example of inkjet head>
Next, the structure of the inkjet head will be described. Since the structures of the ink jet heads 132M, 132K, 132C, and 132Y corresponding to the respective colors are common, the ink jet head is represented by the reference numeral 250 in the following.

6A is a perspective plan view showing an example of the structure of the inkjet head 250, and FIG. 6B is an enlarged view of a part thereof. 7A and 7B are diagrams showing an example of the arrangement of a plurality of head modules constituting the ink jet head 250, and FIG. 8 shows a droplet discharge element (1 for one channel) that is a recording element unit (discharge element unit). FIG. 6 is a cross-sectional view (a cross-sectional view taken along line 6-6 in FIGS. 6A and 6B) showing a three-dimensional configuration of an ink chamber unit corresponding to one nozzle.

As shown in FIGS. 6A and 6B, the inkjet head 250 according to the present embodiment includes a plurality of inks including nozzles 251 (an example of a recording element) that are ink discharge ports and pressure chambers 252 corresponding to the nozzles 251. The chamber units (droplet ejection elements) 253 are arranged in a two-dimensional matrix, and are projected (orthographically projected) so as to be aligned along the head longitudinal direction (direction perpendicular to the paper feed direction). High density of substantial nozzle interval (projection nozzle pitch) is achieved.

In order to configure a nozzle row having a length corresponding to the entire width Wm of the drawing area of the paper 1 in the X direction orthogonal to the transport direction (Y direction) of the paper 1, for example, a plurality of nozzles as shown in FIG. Short head modules 250A in which 251 are two-dimensionally arranged are arranged in a staggered manner to constitute a long line type head. Alternatively, as shown in FIG. 7B, a mode in which the head modules 250B are connected in a line is also possible.

The pressure chamber 252 provided corresponding to each nozzle 251 has a substantially square planar shape (see FIGS. 6A and 6B), and the outlet to the nozzle 251 at one of the diagonal corners. And an ink inlet (supply port) 254 for the supply ink. Note that the shape of the pressure chamber 252 is not limited to this example, and the planar shape may have various forms such as a quadrangle (rhombus, rectangle, etc.), a pentagon, a hexagon, other polygons, a circle, and an ellipse.

As shown in FIG. 8, an inkjet head 250 ( head modules 250A and 250B) includes a nozzle plate 251A in which nozzles 251 are formed, a flow path plate 252P in which flow paths such as a pressure chamber 252 and a common flow path 255 are formed, and the like. It consists of the structure which laminated and joined. The nozzle plate 251A constitutes the nozzle surface 134 of the inkjet head 250, and a plurality of nozzles 251 communicating with the pressure chambers 252 are two-dimensionally formed.

The flow path plate 252P forms a side wall of the pressure chamber 252 and a flow path that forms a supply port 254 as a narrowed portion (most narrowed portion) of an individual supply path that guides ink from the common flow path 255 to the pressure chamber 252. It is a forming member. For convenience of explanation, the flow path plate 252P has a structure in which one or a plurality of substrates are stacked, although it is illustrated schematically in FIG.

The nozzle plate 251A and the flow path plate 252P can be processed into a required shape by a semiconductor manufacturing process using silicon as a material.

The common channel 255 communicates with an ink tank (not shown) as an ink supply source, and the ink supplied from the ink tank is supplied to each pressure chamber 252 via the common channel 255.

A piezoelectric actuator (piezoelectric element) 258 including an individual electrode 257 is joined to a diaphragm 256 constituting a part of the pressure chamber 252 (the top surface in FIG. 8). The diaphragm 256 of this example is made of silicon (Si) with a nickel (Ni) conductive layer functioning as a common electrode 259 corresponding to the lower electrode of the piezoelectric actuator 258, and is arranged corresponding to each pressure chamber 252. It also serves as a common electrode for the actuator 258. It is also possible to form the diaphragm with a non-conductive material such as resin. In this case, a common electrode layer made of a conductive material such as metal is formed on the surface of the diaphragm member. Moreover, you may comprise the diaphragm which serves as a common electrode with metals (conductive material), such as stainless steel (SUS).

By applying a driving voltage to the individual electrode 257, the piezoelectric actuator 258 is deformed and the volume of the pressure chamber 252 is changed, and ink is ejected from the nozzle 251 due to the pressure change accompanying this. When the piezoelectric actuator 258 returns to its original state after ink ejection, new ink is refilled into the pressure chamber 252 from the common flow channel 255 through the supply port 254.

As shown in FIG. 6B, the ink chamber unit 253 having such a structure is latticed in a fixed arrangement pattern along a row direction along the main scanning direction and an oblique column direction having a constant angle θ not orthogonal to the main scanning direction. The high-density nozzle head of this example is realized by arranging a large number in the shape. In this matrix arrangement, when the interval between adjacent nozzles in the sub-scanning direction is Ls, in the main scanning direction, each nozzle 251 is substantially equivalent to a linear arrangement with a constant pitch P = Ls / tan θ. It can be handled.

Further, in the practice of the present invention, the arrangement form of the nozzles 251 in the inkjet head 250 is not limited to the illustrated example, and various nozzle arrangement structures can be applied. For example, instead of the matrix arrangement described with reference to FIGS. 6A and 6B, a V-shaped nozzle arrangement, a zigzag nozzle arrangement (such as a W-shape) having a V-shaped arrangement as a repeating unit, etc. Is possible.

Note that means for generating discharge pressure (discharge energy) for discharging droplets from each nozzle in the inkjet head is not limited to a piezoelectric actuator (piezoelectric element), but various pressure generating elements (discharge) such as an electrostatic actuator. An energy generating element) can be applied. Corresponding energy generating elements are provided in the flow path structure according to the ejection method of the head.

FIG. 9 is a perspective view showing a connection form between the inkjet head 132 (132M, 132K, 132C, 132Y) and the control board 136 (136M, 136K, 137C, 136Y). Here, as an example, the connection form between the inkjet head 132Y and the control board 136Y is shown, but the connection form between the other inkjet heads 132M, 132K, 132C and the control boards 136M, 136K, 136C is the same.

As shown in FIG. 9, the control board 136Y is composed of boards 136Y-1, 136Y-2, and 136Y-3, and is arranged in the X direction and supported by the casing frame 200. The connector 138Y described above is provided on the board 136Y-1. The substrates 136Y-1 and 136Y-2 and the substrates 136Y-2 and 136Y-3 are connected to each other by wirings (not shown), so that signals input via the connector 138 are transmitted to the substrates 136Y-2 and 136Y-. 3 is transmitted.

Also, two flexible flat substrates 210A and 210B are led out from each head module 250A of the inkjet head 132Y. The flexible flat boards 210A and 210B are connected to the control board 136Y via connectors 212A and 212B (212B not shown). Control signals from the control board 136Y are transmitted to the inkjet head 132Y by the flexible flat boards 210A and 210B.

[Electrical configuration of inkjet recording apparatus]
FIG. 10 is a block diagram illustrating an electrical configuration of the inkjet recording apparatus 100. The ink jet recording apparatus 100 shown in the figure includes the signal generation board 122 and the control boards 136M, 136K, 136C, and 136Y described above, which are connected to the host control section 10 by a wired or wireless general-purpose protocol (such as LAN). ing.

As shown in FIG. 10, the signal generation board 122 (an example of a signal generation unit) includes a paper detection / encoder signal reception unit 20, a normal print setting unit 22, a test pulse setting unit 24, an operation mode setting unit 26, and a signal generation unit. 28 etc.

The paper detection / encoder signal receiving unit 20 receives the encoder signal of the rotary encoder 118 and the detection signal of the paper sensor 120 input via the connectors 124E and 124S.

The normal print setting unit 22 inputs setting conditions in a normal recording mode other than the test mode to the signal generation unit 28. The test pulse setting unit 24 inputs setting conditions such as a test pulse in a test mode to be described later to the signal generation unit 28.

The operation mode setting unit 26 determines the operation mode of the inkjet recording apparatus 100 in accordance with a command from the host control unit 10, and outputs the determined operation mode to the signal generation unit 28.

The signal generator 28 receives a print start signal and a print pixel clock (an example of a control signal) according to input signals from the paper detection / encoder signal receiver 20, the normal print setting unit 22, the test pulse setting unit 24, and the operation mode setting unit 26. ) And output to the control board 136.

The print start signal is normally at the H level, and is a signal that becomes the L level while the paper 1 passes through the recording area of each inkjet head 132 (about 1.2 seconds). The print pixel clock is a reference signal for driving each piezoelectric actuator 258 provided in the inkjet head 132, and repeats the H level / L level at about 25 kHz in synchronization with the encoder signal of the rotary encoder 118.

As described above, each of the cables 140M, 140K, 140C, and 140Y includes two wirings for a print start signal and a print pixel clock. The signal transmission between the signal generation board 122 and the control boards 136M, 136K, 136C, and 136Y using the cables 140M, 140K, 140C, and 140Y (signal transmission between the signal generation section 28 and the print signal reception section 30) LVDS (Low voltage differential signaling) system that is not easily affected by disturbance noise is adopted.

Further, as shown in FIG. 10, the control boards 136M, 136K, 136C, and 136Y include a print signal receiving unit 30, an operation mode setting unit 32, a test signal determination circuit 34, a normal print control unit 36, and the like.

The print signal receiving unit 30 receives the signal output from the signal generating unit 28 of the signal generating board 122 via the cable 140.

The operation mode setting unit 32 determines the operation mode of the ink jet recording apparatus 100 in accordance with a command from the host control unit 10 as in the operation mode setting unit 26 of the signal generation board 122, and the determination result is sent to the test signal determination circuit 34. Output.

The test signal determination circuit 34 determines pass / fail of the test signal based on the signal received by the print signal receiving unit 30 when the ink jet recording apparatus 100 is set to the test mode.

The normal printing control unit 36 controls the ink jet head 132 based on the signal received by the printing signal receiving unit 30 in the normal recording mode other than the test mode, thereby controlling image recording. The output signal of the normal print control unit 36 is input to the inkjet head 132 from the connectors 212A and 212B via the flexible flat substrates 210A and 210B.

Further, the host control unit 10 can move the inkjet heads 132M, 132K, 132C, and 132Y in the X direction by controlling the moving mechanism 170.

[Static cable test mode]
FIG. 11 is a flowchart illustrating an example of processing in the stationary state cable test mode. The cable test mode is a mode for inspecting whether there is an abnormality in a cable or a connector by performing communication (communication test) via a cable. Here, the inkjet heads 132M, 132K, 132C, 132Y are in a stationary state (for example, an image This is performed when the recording position is still).

In the present embodiment, the signal generation board 122 and the control boards 136M, 136K, 136C, and 136Y constitute communication test means. The communication contents of the communication test are defined in advance between the signal generation board 122 that transmits the test signal and the control boards 136M, 136K, 136C, and 136Y that receive the test signal.

When performing the communication test, the signal generation board 122 and the control boards 136M, 136K, 136C, and 136Y are synchronized to transmit and receive test signals. By judging the consistency of the transmitted and received test signals, the quality of the cable 140 and the connectors 124 and 138 can be determined.

(Step S1)
First, the upper level control unit 10 sets the inkjet recording apparatus 100 to a stationary state cable test mode. The operation mode setting section 26 of the signal generation board 122 and the operation mode setting section 32 of each control board 136M, 136K, 136C, 136Y are in the stationary cable test mode to the signal generation section 28 and the test signal determination circuit 34, respectively. The signal is output. Thereby, the signal generator 28 and the test signal determination circuit 34 are set to perform the operation in the stationary cable test mode.

(Step S2)
The signal generator 28 (an example of a test signal transmitter) transmits test data to the control boards 136M, 136K, 136C, and 136Y via the cables 140M, 140K, 140C, and 140Y. In this embodiment, a pulse signal is used as a signal to be transmitted (an example of a test signal), and the number of up edges of the pulse signal is used as test data. The test data is a unique value for each of the cables 140M, 140K, 140C, and 140Y. Here, as an example, it is assumed that the cable 140M is 4, the cable 140K is 3, the cable 140C is 2, and the cable 140Y is 1 as test data.

Specifically, when the stationary cable test mode is set, the signal generator 28 sets the potentials of the cables 140M, 140K, 140C, and 140Y to the L level, and then sets the H level / L level (pulse signal) to the test data. Repeat as many times as you like. For example, four pulse signals are transmitted to the cable 140M. In addition to the test data, a pulse signal indicating a start bit may be included. When the stationary cable test mode is canceled (when the normal recording mode is set), the potentials of the cables 140M, 140K, 140C, and 140Y are set to the H level.

In this embodiment, each of the cables 140M, 140K, 140C, and 140Y includes two wirings for a print start signal and a print pixel clock, but any wiring may be used for transmitting test data. Further, a mode in which one is used as a clock signal and the other is used as a data signal is also possible.

(Step S3)
Wait until the specified time has elapsed. The specified time may be longer than the time when the transmission of the test data by the signal generator 28 and the reception of the test data by the print signal receiver 30 are all completed. Within this specified time, the print signal receiving unit 30 (an example of the test signal receiving unit) of the control boards 136M, 136K, 136C, and 136Y transmits the test data transmitted from the signal generating unit 28 to the cables 140M, 140K, 140C, Receive via 140Y.

(Step S4)
The test signal determination circuit 34 of each control board 136M, 136K, 136C, 136Y confirms the test data received by the print signal receiving unit 30, respectively. Specifically, the number of times the H level / L level is repeated for the potentials of the cables 140M, 140K, 140C, and 140Y is counted and held as received test data.

(Step S5)
The test signal determination circuit 34 (an example of a determination unit) of each control board 136M, 136K, 136C, 136Y determines whether or not the received test data matches the specified data (success or failure). That is, the test signal determination circuit 34 of the control board 136M determines whether or not the received test data is 4, and the test signal determination circuit 34 of the control board 136K determines whether or not the received test data is 3. The test signal determination circuit 34 of the control board 136C determines whether or not the received test data is 2, and the test signal determination circuit 34 of the control board 136Y determines whether or not the received test data is 1. Determine whether or not.

If the received test data matches the specified data, the process proceeds to step S6. If they do not match, the process proceeds to step S7.

(Step S6)
Each cable 140M, 140K, 140C, 140Y is determined to be normal, and the process ends normally.

(Step S7)
For the cable 140 where the received test data does not match the specified data, it is determined that there is an abnormality in the wiring such as connector disconnection, poor contact, or internal disconnection of the cable (an example of an abnormal communication test result), and disconnection / connection failure It is notified and is finished. The disconnection / connection failure notification may be performed by the host control unit 10 (an example of a notification unit), or a warning lamp (not shown) mounted on the control board 136 may be turned on.

As described above, according to the stationary cable test mode, it is possible to inspect whether there is an abnormality in the cable or connector in the stationary state.

[Moving state cable test mode]
Next, the movable state cable test mode will be described. FIG. 12 is a flowchart illustrating an example of processing (abnormality detection method) in the movable state cable test mode. Detailed description of the same processing as in the stationary cable test mode is omitted.

As shown in FIGS. 3, 4, and 5, the cable 140 </ b> Y has a large bent shape when the inkjet head 132 </ b> Y is at the image recording position, at the wiping position, or at the moisturizing position. Change. Although not shown, the same applies to the other cables 140M, 140K, and 140C.

With such a change in the bent shape of the cables 140M, 140K, and 140C, the stress applied to the cable also changes, and the state of disconnection failure of the cable 140 due to metal fatigue changes. In addition, the stress applied to the connectors 124M, 124K, 124C, and 124Y and the connectors 138M, 138K, 138C, and 138Y also changes with the change in the bent shape, so that the contact failure status of the connectors 124 and 138 also changes.

Note that, here, the state of the bent shape of the cable and the state of stress applied to the cable and the connector accompanying the change in the bent shape are referred to as a physical state.

In the movable state cable test, the inkjet heads 132M, 132K, 132C, and 132Y (control board) are used when returning from the image recording position to the moisture retaining position, from the moisture retaining position to the image recording position, or from the moisture retaining position to the moisture retaining position again. 136M, 136K, 136C, 136Y) starts relative movement with respect to the signal generation substrate 122 from the first position, and reaches the second position and ends the relative movement (during the position movement). Then, communication (communication test) via the cable 140 is performed between the signal generation board 122 constituting the communication test means and the control boards 136M, 136K, 136C, and 136Y. By judging the consistency of the transmitted and received test signals, the quality of the cable 140 and the connectors 124 and 138 can be determined.

(Step S11)
The upper level control unit 10 sets the inkjet recording apparatus 100 to the movable state cable test mode. The operation mode setting section 26 of the signal generation board 122 and the operation mode setting sections 32 of the control boards 136M, 136K, 136C, and 136Y are in the movable cable test mode to the signal generation section 28 and the test signal determination circuit 34, respectively. Is output. Thereby, the signal generator 28 and the test signal determination circuit 34 are set to perform the operation in the movable state cable test mode.

(Step S12)
The host control unit 10 controls the moving mechanism 170 to start the position movement of the head holding unit 142 (ink jet heads 132M, 132K, 132C, 132Y, control boards 136M, 136K, 136C, 136Y). Here, as an example, the image recording position (an example of the first position) is moved (an example of the relative movement) from the moisturizing position (an example of the second position). By this position movement, the physical state of the connector 124Y, the cable 140Y, and the connector 138Y at the image recording position shown in FIG. 3 (first physical state; the cable 140Y is bent and folded) 5 until the physical state of the moisturizing liquid connector 124Y, the cable 140Y, and the connector 138Y shown in FIG. 5 (second physical state; the cable 140Y is closer to a straight line than the first physical state). To change. The same applies to the other connectors 124M, 124K, 124C, cables 140M, 140K, 140C, and connectors 138M, 138K, 138C.

In the present embodiment, the subsequent processing is performed without stopping the head holding unit 142 until the moisture retaining position is reached.

(Step S13)
When the head holding unit 142 starts to move and is at a position between the image recording position and the moisturizing position (that is, connectors 124M, 124K, 124C, 124Y, cables 140M, 140K, 140C, 140Y, connectors 138M, 138K). , 138C, and 138Y during the transition from the first physical state to the second physical state), the signal generating unit 28 sends the print signal receiving unit 30 of each control board 136M, 136K, 136C, and 136Y to the print signal receiving unit 30. Test data is transmitted via each cable 140M, 140K, 140C, 140Y. Here, as in the stationary cable test mode, a pulse signal is used as a signal to be transmitted, the number of up edges of the pulse signal is used as test data, and the test data of each cable 140M, 140K, 140C, 140Y is 4, 3 respectively. , 2,1.

(Step S14)
Wait until the specified time has elapsed. Within this specified time, the print signal receiver 30 of the control boards 136M, 136K, 136C, 136Y receives the test data transmitted from the signal generator 28 via the cables 140M, 140K, 140C, 140Y.

(Step S15)
The test signal determination circuit 34 of each control board 136M, 136K, 136C, 136Y confirms the test data received by the print signal receiving unit 30, respectively. Specifically, the number of up edges of the received pulse signal is held as received test data.

(Step S16)
The test signal determination circuit 34 of each control board 136M, 136K, 136C, 136Y determines whether or not the received test data matches the specified data.

If the received test data matches the specified data, the process proceeds to step S17. If they do not match, the process proceeds to step S19.

(Step S17)
Each cable 140M, 140K, 140C, 140Y is determined to be normal at the position where the test data is transmitted.

(Step S18)
It is determined whether or not the position movement of the inkjet heads 132M, 132K, 132C, and 132Y has been completed, that is, whether or not the head holding unit 142 has reached the moisture retention position. If it has not reached the moisturizing position, the process returns to step S13 and the same process (communication test) is repeated. When the moisture retaining position is reached, the movable state cable test mode is terminated.

(Step S19)
For the connector 124, the cable 140, and the connector 138 whose received test data does not match the specified data, it is determined that the internal disconnection of the cable 140 or the contact abnormality of the connectors 124, 138 is notified, and the disconnection / connection failure is notified and the process ends.

In this way, in order to detect a transient contact failure, it is moved with the cable attached in the ink jet recording apparatus, and the communication test is repeatedly performed when the control board is moved. As a result, a communication test can be performed while physically changing the cable status, and a transient disconnection failure or contact failure of the cable or connector can be detected. In addition, since it is not necessary to remove the cable for inspection, the inspection time can be shortened. Furthermore, when a disconnection failure or a contact failure is detected, the occurrence of an abnormality is notified to the user, so that abnormal printing (recording failure) can be reduced and printing paper waste can be reduced.

[Other aspects]
In this embodiment, the communication test is performed while moving the head holding unit 142 from the image recording position to the moisturizing position, but from the moisturizing position to the image recording position, from the image recording position to the wiping position, from the wiping position to the image recording position, etc. A communication test can be performed while moving a necessary range as appropriate. The start position and the end position of the movement may be the same position.

Further, the present invention is not limited to the case where the inkjet heads 132M, 132K, 132C, and 132Y move in the X direction, and the paper transport unit 110 and the inkjet heads 132M, 132K, 132C, and 132Y (the signal generation board 122 and the control board 136M, If the physical state of the cables 140M, 140K, 140C, and 140Y changes as a result of relative movement between the positions before and after the relative movement, It is possible to perform a communication test at a position between. For example, the present invention can be applied to movement in the Y direction, movement in the Z direction, movement that rotates about the Z axis, and the like.

In this embodiment, test data is repeatedly transmitted and received without stopping the head holding unit 142 from the image recording position to the moisturizing position (during relative movement), but the head holding unit 142 is intermittently stopped. The test data may be transmitted and received at the stopped position (during the stop).

Also, the stationary cable test mode and the movable cable test mode may be combined. That is, the communication test may be performed before the start of movement, and then the communication test may be repeatedly performed during the movement, or the communication test may be repeatedly performed during the movement, and the communication test may be performed at the end of the movement. In addition, a mode in which a communication test is performed before the start of movement, during movement, and after completion of movement is also possible.

Furthermore, in this embodiment, the signal generator 28 is used as a test signal transmitter and the print signal receiver 30 is used as a test signal receiver. However, the present invention is not limited to this form. For example, the print signal receiver 30 may be used as the test signal transmitter, the signal generator 28 as the test signal receiver, the signal generator 28 as the test signal transmitter, and the print signal receiver 30 as the signal generator 28. The test signal retransmitting unit that retransmits the received test signal and the signal generating unit 28 may be used as a rereceiving unit for the retransmitted test signal.

The abnormality determination method described above can be grasped as a program for causing a computer to execute each process. In addition, changes, additions, and deletions can be made as appropriate without departing from the spirit of the present invention. In addition, the above-described configuration examples can be appropriately combined.

In this specification, an ink jet recording apparatus is exemplified as a configuration example of the image recording apparatus, but the present invention is widely applied to image recording apparatuses other than the ink jet recording apparatus (for example, an electrophotographic image recording apparatus). It is possible.

The technical scope of the present invention is not limited to the scope described in the above embodiment. The configurations and the like in the embodiments can be appropriately combined between the embodiments without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... High-order control part, 28 ... Signal generation part, 30 ... Print signal receiving part, 100 ... Inkjet recording device, 110 ... Paper conveyance part, 118 ... Rotary encoder, 120 ... Paper sensor, 122 ... Signal generation board, 124M, 124K , 124C, 124Y, 138M, 138K, 138C, 138Y ... connector, 130 ... image recording unit, 132M, 132K, 132C, 132Y ... inkjet head, 136M, 136K, 136C, 136Y ... control board, 140M, 140K, 140C, 140Y ... Cable, 150 ... Maintenance section, 154M, 154K, 154C, 154Y ... Moisturizing cap, 170 ... Moving mechanism

Claims (16)

1. A recording head having a recording element;
   A control unit for controlling the recording element based on a control signal;
   A support unit that integrally supports the recording head and the control unit;
   A signal generator for generating the control signal;
   Transmission means for transmitting the control signal from the signal generator to the controller;
   Moving means for moving the recording head relative to the signal generator;
   During the relative movement of the recording head from the first position where the transmission means is in a first physical situation to the second position where the transmission means is in a second physical situation, the first position and A communication test means for performing a communication test between the signal generation unit and the control unit at a position between the second position and the second position;
   An image recording apparatus comprising:
2. The image recording apparatus according to claim 1, wherein the communication test means performs a communication test while relatively moving the recording head.
3. 3. The image recording apparatus according to claim 1, wherein the communication test unit performs a communication test by stopping the recording head.
4. 4. The image recording apparatus according to claim 1, wherein the transmission unit includes a flexible cable.
5. The image recording apparatus according to claim 4, wherein the cable is connected to the control unit via a connector.
6. The image recording apparatus according to claim 4 or 5, wherein the cable is connected to the signal generation unit via a connector.
7. The image recording apparatus according to any one of claims 1 to 6, further comprising notification means for notifying a user when there is an abnormality in the result of the communication test.
8. 8. The communication test unit according to claim 1, wherein the communication test unit repeatedly performs a communication test between the signal generation unit and the control unit at a plurality of positions between the first position and the second position. The image recording apparatus described in 1.
9. 9. The image recording according to claim 1, wherein the communication test unit performs a communication test between the signal generation unit and the control unit at at least one of the first position and the second position. 10. apparatus.
10. The communication test means includes a test signal transmission section that transmits a test signal to the transmission means, a test signal reception section that receives the test signal via the transmission means, and the transmission means based on the received test signal An image recording apparatus according to claim 1, further comprising: a determination unit that determines success or failure of the image.
11. The image recording apparatus according to claim 10, wherein the test signal transmission unit is provided in the signal generation unit, and the test signal reception unit and the determination unit are provided in the control unit.
12. The moving means is means for moving the recording head;
    12. The image recording apparatus according to claim 1, wherein one of the first position and the second position is an image recording position for recording an image on a recording medium.
13. 13. The image recording apparatus according to claim 12, wherein a position other than the image recording position among the first position and the second position is a maintenance position for performing maintenance of the recording head.
14. The image recording apparatus according to claim 13, wherein the recording head is an inkjet head, and includes a moisturizing cap for moisturizing a nozzle surface of the inkjet head at the maintenance position.
15. Conveying means for conveying the recording medium;
    Synchronization signal output means for outputting a synchronization signal synchronized with the transport means;
    With
    The image recording apparatus according to claim 12, wherein the signal generation unit generates the control signal based on the synchronization signal.
16. A recording head having a recording element, a control unit that controls the recording element based on a control signal, a support unit that integrally supports the recording head and the control unit, and a signal generation unit that generates the control signal Transmission means for transmitting the control signal from the signal generation section to the control section; and movement means for moving the recording head relative to the signal generation section;
    An abnormality detection method for an image recording apparatus comprising:
    During the relative movement of the recording head from the first position where the transmission means is in a first physical situation to the second position where the transmission means is in a second physical situation, the first position and An abnormality detection method for performing a communication test between the signal generation unit and the control unit at a position between the second position and the second position.

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