JP2020001361A - Ink jet recording device - Google Patents

Abstract

To provide an ink jet recording device that maintains high-quality image formation by performing an operation for removing paper powder from a nozzle forming surface in accordance with a recording medium to be conveyed.SOLUTION: A printer for forming an image by injecting ink onto card paper P conveyed while facing a nozzle formation surface 31a of a recording head 31, comprises: a cleaning mechanism that cleans the nozzle formation surface with a wiper blade; and a CPU that performs a cleaning control process that cleans a nozzle formation surface by operating the cleaning mechanism. A CPU acquires a positional relation between an image formation area Ar which faces the nozzle formation surface and to which ink is injected in a current image formation process and an end side Ps in a direction orthogonal to a conveying direction of the card paper used in the image formation process after the cleaning operation and till the previous image formation processes. On the basis of acquired information, the CPU performs a cleaning control process before the current image formation process.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an ink jet recording apparatus having a cleaning function for cleaning a nozzle forming surface of a recording head.

  2. Description of the Related Art In order to record and form a high-quality image on a recording medium, an inkjet recording apparatus is often provided with a cleaning function for cleaning a nozzle forming surface of a recording head on which nozzles for ejecting ink are arranged. Also, in an ink jet recording apparatus that forms an image on a recording medium (paper) where paper dust is generated, if the paper dust that accumulates on the platen comes into contact with the nozzle forming surface, the image quality deteriorates, and the recording head is evacuated. Patent Document 1 discloses moving paper to remove paper dust.

JP 2006-282296 A

  However, in the ink jet recording apparatus described in Patent Document 1, paper dust generated from a recording medium may adhere to the nozzle forming surface. In this case, the recording head is moved because it is not on the platen. However, it cannot remove the adhering paper dust.

  Further, in an ink jet recording apparatus having a cleaning function, it is possible to remove paper dust attached to the nozzle forming surface by the cleaning function. However, the paper dust does not adhere to the nozzle forming surface at a position corresponding to the nozzle that discharges the ink, but occurs and adheres to the recording medium being conveyed. This will affect the position where the powder accumulates and accumulates. For this reason, in the cleaning operation performed in accordance with the ink discharge conditions, paper dust cannot be removed from the nozzle forming surface at an optimal timing, and there is a possibility that deterioration of image quality cannot be avoided. is there.

  Accordingly, an object of the present invention is to provide an ink jet recording apparatus capable of maintaining high quality image formation by performing an operation of removing paper dust from a nozzle forming surface according to a recording medium being conveyed. And

  One aspect of the invention of an ink jet recording apparatus that solves the above-described problem is that ink ejecting nozzles are conveyed in a direction perpendicular to the parallel direction of the nozzles while facing nozzle forming surfaces arranged in one direction. An ink jet recording apparatus for forming an image by discharging the ink onto a recording medium, comprising: a cleaning mechanism for cleaning the nozzle forming surface; and a cleaning control process for operating the cleaning mechanism to clean the nozzle forming surface. Control means for performing the following, wherein the control means faces the nozzle forming surface, an image forming area where the ink is ejected in the current image forming process, and after the cleaning mechanism operates and The positional relationship between the recording medium and the edge in the direction perpendicular to the conveyance direction in the image forming process prior to this time is acquired, and based on the acquired information, Is characterized in performing said cleaning control treatment before the image forming process.

  As described above, according to one aspect of the present invention, the cleaning control process is performed based on the positional relationship between the edge of the recording medium and the image forming area in the previous and current image forming processes, and the nozzle forming surface is cleaned. To be.

  Therefore, for example, when the position of the edge of the previous recording medium has an effect on the image quality in the current image forming area, it is possible to execute the nozzle forming surface cleaning control process before the current image forming process. it can.

  As a result, it is possible to provide an ink jet recording apparatus capable of maintaining high quality image formation.

FIG. 1 is a schematic overall configuration diagram illustrating an example of a printer to which an inkjet recording apparatus according to a first embodiment of the present invention is applied. FIG. 2 is a block diagram illustrating a control system of the printer. FIG. 3 is a conceptual diagram illustrating a positional relationship between a nozzle forming surface of a recording head and a transport sheet. FIG. 4 is a flowchart illustrating an image forming process including cleaning of the nozzle forming surface. FIG. 5 is a conceptual diagram illustrating a positional relationship between a nozzle forming surface of a recording head and a transport sheet in an example of a printer to which the inkjet recording apparatus according to the second embodiment of the present invention is applied. FIG. 6 is a flowchart illustrating an image forming process including cleaning of the nozzle forming surface.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIGS. 1 to 4 are views showing an example of a printer to which an ink jet recording apparatus according to a first embodiment of the present invention is applied, and FIG. 1 is a conceptual schematic diagram illustrating an overall configuration of an image recording system including the printer. It is.

  In FIG. 1, a printer 10 is connected to a host device H that outputs image data so that various data can be exchanged, and forms an image recording system. The host device H is composed of, for example, a so-called personal computer (PC), and functions as an image recording system by exchanging various data with an external device including the printer 10. . For example, by executing a software program stored in a storage device (not shown), the host device H executes image processing of various types of information according to a user's operation instruction to generate image data of a processing result. Output to The printer 10 records image data received together with a print command from the host device H on a card sheet (recording medium) P of a recording medium that passes through an image forming area Ar described later by an inkjet recording method described later to form an image. Has become.

  Here, the card paper P set in the printer 10 is one in which images such as characters and illustrations are recorded and formed on one side or both sides, and are linearly conveyed one by one by a feeding unit 11 described later. An image is formed in the middle of the transport path. In the present embodiment, the card paper P is described as an example of a recording medium, but is not limited thereto. For example, as a recording medium, a recording sheet is rolled into a roll, a cut sheet that has been cut to a predetermined size, or fed out from a state of being folded in a bellows shape, and is folded and stacked again after image formation. It may be a recording medium. Further, the recording medium may be a label that is removably affixed to the backing paper, or may be a form of so-called fan-fold paper that is perforated for each page. Further, it goes without saying that the present invention may be applied to a printer that forms an image on a recording medium other than recording paper.

  The host device H includes, for example, a communication interface (I / F) for connecting a USB (Universal Serial Bus) cable W, and is connected to an external device such as the printer 10 so as to be able to perform information communication. The host device H is an information processing device that executes various control programs such as application software on a platform of an operating system and generates image data to be subjected to image forming processing by the printer 10 or the like. Then, the host device H creates (generates) image data to be recorded and formed on a recording medium such as card paper P by one or a plurality of connected printers 10 by, for example, executing various software by a user. I do. The host device H reads out the generated image data from a printer driver in the HDD, which will be described later, and transfers it to the printer 10 as image data that can be subjected to image formation processing. Note that the connection between the host device H and the printer 10 is not limited to the USB cable W, but may be, for example, a network cable, IEEE 1284, a wireless LAN, or the like.

  Although not shown, the host device H includes a CPU (Central Processing Unit), a HDD (Hard Disk Drive), a RAM (Random Access Memory), and a ROM (Read Only Memory) in addition to the I / F. It has mouse and keyboard operating devices and a monitor. The CPU integrally controls the entire host device H by appropriately executing various programs based on various information held in the storage device. The HDD is a large-capacity external storage device that stores various information in a nonvolatile manner. The RAM is a volatile internal memory used by the CPU as a work area. The ROM is a nonvolatile internal memory that stores various programs such as a CPU startup program and necessary fixed data such as parameters, and is configured by a read-only memory or a rewritable memory such as a flash ROM. The mouse is a pointing device operated by the user. The keyboard is an input device through which a user performs an input operation of an instruction or various data. The monitor is a display device that visually displays various information such as an LCD (Liquid Crystal Display) and an EL (electroluminescence).

  The printer 10 is configured to include a feeding unit 11, a recording unit 13, and a control unit 15.

  The feeding unit 11 includes a loading tray 21, a call roller 22, and a pair of sheet feeding rollers 23.

  After the stack of card papers P is placed at the descending position indicated by the dotted line in the drawing, the loading tray 21 rises in the Z direction in the drawing according to a printing command described later. The call roller 22 rotates in the feed direction while being pressed against the card paper P on the loading tray 21 to call from the upper card paper P and feed it in the direction of arrow A in the figure. The feed roller pair 23 sandwiches the sent card paper P and rotates forward and backward, respectively, so that the uppermost card paper P is placed one by one on the loading tray 21 while restricting the sending of the lower card paper P. And feed it out.

  As a result, in the feeding unit 11, the card paper P on the mounting tray 21 is sandwiched by the pair of paper feed rollers 23 and fed from the leading end to the image forming area Ar by the recording unit 13. The loading tray 21 of the feeding unit 11 is moved up and down in the Z direction in the figure by the driving force of an unillustrated elevating motor.

  The transport belt 24 is formed as an endless belt so as to be able to rotate around. Although not shown in the drawing, the transport belt 24 has suction holes arranged so that the upper side can be sucked by a suction fan provided below the image forming area Ar of the recording unit 13.

  As a result, in the feeding unit 11, the card paper P fed onto the transport belt 24 is transported so as to pass through the image forming area Ar of the recording unit 13 while being sucked by the suction fan through the suction holes. Is done.

  The transport roller pair 25 is disposed on the upstream side in the transport direction (the loading tray 21 side) of the recording unit 13 to the image forming area Ar, and is rotatable while sandwiching the transport belt 24 wound around the pulley 24p. Supported. The unloading roller pair 26 is arranged downstream of the image forming area Ar in the transport direction (toward a discharge tray 29 described below), is wound around the transport belt 24 and is rotatably supported. The transport motor 27 rotates the transport belt 24 wound around the rotating shaft 27a together with the pulley 24p and the carry-out roller pair 26 by the rotational power. The tension pulley 28 applies a constant tension to the transport belt 24 in a state of being wound. The paper discharge tray 29 holds the card paper P sent out from the conveyor belt 24.

  As a result, in the feeding unit 11, the image forming area Ar is located on the upper surface of the transport belt 24 stretched between the transport roller pair 25 and the discharge roller pair 26, and the transport belt 24 is moved by the transport motor 27. Is repeatedly rotated by the rotation of the rotation shaft 27a. For this reason, in the feeding unit 11, the card paper P fed from the loading tray 21 is sandwiched between the pair of transport rollers 25 and sent together with the transport belt 24 so as to pass through the image forming area Ar. It is transported in the transport direction A. Thereafter, in the feed unit 11, the card paper P passing through the image forming area Ar is delivered to the discharge roller pair 26 and is discharged from the conveyor belt 24 to the discharge tray 29.

  The feed unit 11 has an inlet sensor 51 and an outlet sensor 52 installed on the upstream side of the transport roller pair 25 and the carry-out roller pair 26, respectively, so that the card paper passes through the image forming area Ar on the upper surface of the transport belt 24. The leading and trailing ends of P are detected. An encoder (not shown) that detects the feed amount of the transport belt 24 is installed on the pulley 24p around which the transport belt 24 is wound (the detection of the rotation amount of the transport motor 27 may be used instead).

  Accordingly, the feeding unit 11 detects the transport position of the card paper P in the transport direction based on the detection information of the leading end and the rear end of the card paper P by the entrance sensor 51 and the exit sensor 52 and the detection information by the encoder of the pulley 24p. It has a possible configuration. In the feeding unit 11, after a predetermined amount of the conveyor belt 24 or the like is operated from the detection timing of the rear end of the final card paper P by the exit sensor 52, the card paper P is conveyed onto the discharge tray 29, By stopping the operation, the desired image forming process ends.

  In addition, the entrance sensor 51 and the exit sensor 52 have a function (structure) of detecting the end of the card paper P by either the reflection type or the transmission type. Possible structures may be provided. For example, when a detection mark is provided on a recording medium sheet that reflects (or may transmit) light, the presence or absence of the detection mark is detected based on the light reflectance, and the leading edge of the sheet on which an image is formed is formed. Can be detected. Further, when the mount on which the label is affixed transmits light, the light can be detected by the transmittance according to the presence or absence of the label, and the transport position of the leading end of the label to be image-formed can be detected. .

  The recording unit 13 is constructed by a plurality of recording heads 31 that eject ink, and the recording heads 31Bk and 31C for each color ink of black (Bk), cyan (C), magenta (M), and yellow (Y). , 31M, and 31Y. The recording units 13 are arranged in parallel so that the recording heads 31Bk, 31C, 31M, and 31Y are sequentially arranged in the transport direction A of the transport belt 24 of the feeding unit 11. The recording unit 13 forms a full-color image on one surface side of the card paper P by causing each of the recording heads 31 to sequentially eject ink of each color toward the upper surface of the image forming area Ar. The recording head 31 of the recording unit 13 includes a plurality of supply tanks 35 for storing ink to be ejected onto the card paper P. These supply tanks 35 have main tanks 35Bk, 35C, 35M, and 35Y for each color of black (Bk), cyan (C), magenta (M), and yellow (Y), and have recording heads 31Bk, 31C, 31M, and 35Y. Each color ink is supplied to 31Y. It is needless to say that the number and the color tone of the recording heads 31 described in the present embodiment are merely examples, and are not limited thereto.

  The recording head 31 of the recording unit 13 extends in the width direction of the transport belt 24 (a direction orthogonal to the transport direction A), and has nozzles 32 (see FIG. 3) for discharging (ejecting) ink arranged therein. It is manufactured in the form of a so-called full line head. The recording head 31 is manufactured so that the ink ejection range is longer (wider) than the width of the card paper P. Needless to say, the recording head 31 may be of a type using a heating element (heater) or a piezoelectric element (piezo element) as a method for generating the ink ejection pressure.

  Here, the recording head 31 of the recording unit 13 of the present embodiment is held by a mechanism (not shown) movable in the transport direction A and the vertical direction Z, and utilizes the driving force of the motor 39 shown in FIG. It is movably supported. This allows the recording head 31 to slide back and forth in the transport direction A of the card paper P, and to move up and down in the vertical direction Z with respect to the card paper P.

  In the recording head 31, a detachable cap 33 is installed at a position adjacent to each of the transport directions A on the formation surface 31 a side of the nozzle 32 that ejects ink. The recording head 31 is raised in the vertical direction Z to avoid collision with the cap 33, and is slid in the transport direction A and then lowered in the vertical direction Z so that the cap 33 is moved to the nozzle forming surface 31a. Attached to. By the way, for example, when the nozzle forming surface 31a is exposed to the atmosphere during storage of the printer 10 or at the time of printing standby, the solvent of the ink near the discharge port of the nozzle 32 volatilizes and increases. Viscosity and solidification occur. Further, in the recording head 31, dust adheres to the ink in the vicinity of the nozzle 32, so that the ink ejection quality is reduced and the image quality is deteriorated. With the recording head 31 attached with the cap 33, these inconveniences are prevented from occurring. The recording head 31 may be returned to an operable state by removing the cap 33 in the reverse order. That is, the recording head 31 is lifted in a direction away from the cap 33, slid in the horizontal direction opposite to the transport direction A, and then lowered and fitted into the positioning opening (not shown), so that the card paper P Is fixed at an image forming position where ink is ejected.

  Further, as described above, the recording head 31 according to the present embodiment has a function (mechanism) for recovering the quality of the ejected ink in addition to attaching and detaching the cap 33 in order to avoid inconvenience due to the exposure of the nozzle forming surface 31a. ) Is installed. For example, the recording unit 13 recovers the ink ejection performance during operation by causing the recording head 31 to perform a preliminary ink ejection operation in a state before the operation in which the cap 33 is attached to the recording head 31. Has functions. The ink discharged into the cap 33 is sucked and collected in a collection tank 36 below the supply tank 35. As the recovery function, in addition to the cap 33, a cleaning function of wiping and cleaning the nozzle forming surface 31a of the recording head 31 with a wiper blade 34 made of rubber or the like is also executed. This recovery mechanism applies, for example, a negative pressure to a space formed between the recording head 31 and the nozzle forming surface 31a in a state where the cap 33 is attached to the recording head 31 so that the vicinity of the discharge port of the nozzle 32 is reduced. The ink may be sucked to recover the ejection performance.

  As shown in FIG. 2, the control unit 15 is connected to the CPU 101 so that the ROM 102 and the RAM 103 can exchange various information. The CPU 101 is connected to the image memory 104 and the operation panel 105 via the control circuit 110 so that various kinds of information can be exchanged. The CPU 101 executes a control program stored in a ROM 102 and controls the entire printer 10 based on various sensor information temporarily stored in a work area of a RAM 103 and various setting instruction information input from an operation panel 105. Control. The ROM 102 stores a processing program for executing control processing for performing ink discharge of the recording head 31 and a cleaning operation of the nozzle forming surface 31a, and various tables for storing required fixed data. Accordingly, the CPU 101 performs an image forming process of recording the image data received from the host device H on the card paper P by the inkjet recording method. The control unit 15 executes control procedures such as an image forming process and an ink recovery process by exchanging various control signals with the host device H via the USB cable W.

  The control unit 15 is connected to the CPU 101 so that the host device H can exchange various information via the USB cable W. Further, a sensor group 50 installed in the feeding unit 11 and the recording unit 13 constituting the printer 10 is connected to the CPU 101 via a control circuit 110 so that various kinds of information can be obtained. The sensor group 50 includes, for example, an ink remaining amount sensor (not shown) that detects the remaining amount of ink in the recording head 31 in addition to the inlet sensor 51 and the outlet sensor 52 and an encoder (not shown). It is installed as appropriate and detects and acquires various information in order to perform required operations.

  The control unit 15 is connected to the CPU 101 so that the recording unit 13 can exchange various information via the head drive circuit 106. The head driving circuit 106 generates a driving signal for each color ink based on the image data sent from the CPU 101 and controls the recording heads 31Bk, 31C, 31M, and 31Y to discharge the color inks as appropriate. The CPU 101 receives various types of information on the recording head 31 via the head driving circuit 106, for example, sensor information for detecting the movement of the recording head 31 and the attachment of the cap 33, and drives the motor group 60 described later. The control is performed to execute various control processes.

  Then, the CPU 101 of the control unit 15 relays each color image data to be processed by the recording head 31 by rasterizing the image data received along with the print command from the host device H together with the print instruction by bitmap development and raster division while temporarily storing the image data in the image memory 104. I do. The CPU 101 controls the driving of the respective color recording heads 31Bk, 31C, 31M, and 31Y to which the respective color image data are assigned by the head driving circuit 106, thereby discharging the respective color inks toward the card paper P to form an image.

  At this time, the CPU 101 controls the ejection timing of each color ink of the recording head 31 based on the detection information of the entrance sensor 51 that detects the leading end of the card paper P carried into the image forming area Ar of the recording head 31. The CPU 101 sequentially relays the image data developed in the image memory 104 and discharges the respective color inks of the recording head 31 so as to synchronize with the card paper P carried into the image forming area Ar, thereby discharging the card ink. An image is formed on paper P. On the card paper P, black (Bk), cyan (C), magenta (M), and yellow (Y) color inks are sequentially selected from the recording head 31Bk to the recording heads 31C, 31M, and 31Y. And a full color image is formed.

  The CPU 101 is connected to the motor driver 107 via the control circuit 110 so as to be able to output various information. The motor driver 107 is connected to a group of various motors 60 such as the above-described transport motor 27 so as to be able to receive drive signals. Accordingly, the motor driver 107 generates a drive signal based on, for example, an instruction to form an image on the card paper P from the CPU 101 and drives the transport motor 27 of the feed unit 11 to move the card into the image formation area Ar. The sheet P is conveyed so as to pass therethrough. Further, the motor driver 107 generates an elevation signal and a slide signal of the recording head 31 based on an instruction to attach / detach the cap 33 in accordance with the ink recovery processing from the CPU 101 and drives various motors to form the nozzles of the recording head 31. The cap 33 is attached to and detached from the surface 31a.

  Then, the CPU 101 of the present embodiment executes a control program for operating a recovery function including a cleaning function stored in the ROM 102 in advance at a predetermined timing. Thus, the recording unit 13 refreshes the ink ejected from the recording head 31 and cleans the nozzle forming surface 31a to restore the ink ejection performance. That is, the CPU 101 constitutes control means for executing a cleaning control process for operating the cleaning mechanism to clean the nozzle forming surface 31a.

  For example, a first recovery operation condition and a second recovery operation condition are previously stored in the ROM 102 as operation timings of the recovery function, and when the CPU 101 confirms that these conditions are satisfied, the CPU 101 executes the above-described cleaning function. Activate the recovery function, including.

  In the ROM 102, an elapsed time, a total discharge amount, and the like are set as first recovery operation conditions that may cause deterioration in image forming accuracy. For example, the ink in the nozzles 32 ejected from the recording head 31 affects image forming accuracy after a certain period of time has elapsed since the previous ink ejection. This is set as a recovery operation condition. In addition, an integrated total amount having a margin up to a total discharge amount remaining by stacking on the nozzle forming surface 31a to the extent that the ink ejected from the recording head 31 contaminates the card paper P to be conveyed is also set as the first recovery operation condition. You.

  Accordingly, the recording unit 13 performs the recovery function including the above-described cleaning function to maintain high image quality before a problem occurs in the formation accuracy of an image to be recorded on the card paper P due to the ink. Can be.

  By the way, in order to prevent the image quality of the image recorded by the recording head 31 from deteriorating, the printer 10 constructs a transport path for the card paper P so as to avoid contact with peripheral members as much as possible. In this type of printer 10, various devices are particularly devised so that the non-contact state is maintained while the image forming surface Pa of the card paper P approaches the nozzle forming surface 31 a of the recording head 31.

  On the other hand, in the printer 10, it is necessary to feed (transport and carry out) the card paper P while positioning the card paper P with high precision with respect to the image forming area Ar by the recording head 31.

  Accordingly, as shown in FIG. 3, the printer 10 detects the leading edge Pf in the transport direction while also positioning the edge Ps in parallel with the transport direction A of the card paper P (and also detects the rear edge Pe). (May be performed). For this reason, in the printer 10, the length in the longitudinal direction of the nozzle forming surface 31a is set so that the largest image forming area Ar of the recording head 31 is wider than the largest image forming surface Pa of the card paper P. An image can be reliably formed by the ink discharged from the nozzle 32.

  At the time of image formation, the card paper P generates so-called paper dust because the edge Ps to be positioned and conveyed rubs against a peripheral member (not shown) forming the conveyance path. For this reason, in the printer 10, paper dust generated particularly at the edge Ps adheres and accumulates on the nozzle forming surface 31a facing the recording paper 31 in a state close to the card paper P (for example, about 1.5 mm). easy. In the recording head 31, when interference such as contact with paper powder on which the ink ejected from the nozzles 32 adheres and accumulates occurs, the ink ejection performance is deteriorated and the quality of the formed image is also deteriorated. That is, when there is a place where paper dust adheres or stays near the nozzle 32 for discharging ink in the image forming area Ar of the card paper P on which an image is formed, the recording head 31 cleans the nozzle forming surface 31a. Processing needs to be performed.

  Specifically, in the printer 10, one end side Ps1 on one side is made to extend along one end side (outer edge) Ars1 on one side in the width direction (direction orthogonal to the transport direction A) B of the image forming area Ar by the recording head 31. Then, the card paper P is passed below the nozzle forming surface 31a. In this card sheet P, the position of the other end (outer edge) Ps2 on the opposite side, which is separated from one end Ps1 on one side in the orthogonal direction B of the transport direction A, changes in the width direction B of the image forming area Ar by the recording head 31. .

  In short, the position of the other end side Ps2 of the card paper P changes according to the size of the image forming surface Pa on which image data is recorded in the width direction B. For example, an image is formed on a small-size image forming surface Pa-bef (shown by a two-dot chain line in FIG. 3) last time, and this time, a large-size image forming surface Pa-aft (solid line in FIG. 3) is formed. The position of the other end side Ps2 of the card paper P changes in the width direction B as in the case of forming an image as shown in FIG. In this case, the image is formed on the image forming surface Pa-aft of the current card paper P by ejecting ink from the nozzle 32 near the nozzle forming surface 31a facing the other end side Ps2 of the previous card paper P. Will be.

  For this reason, in the recording head 31, the paper dust generated at the time of the previous image formation adheres and accumulates on the nozzle formation surface 31 a to deteriorate the ink ejection performance. There is a case where it is located within Pa-aft and the quality of the formed image is reduced. FIG. 3 shows an example in which the nozzles 32 of the recording head 31 are formed in series in the longitudinal direction of the nozzle forming surface 31a that matches the width direction B of the image forming area Ar. A may have a plurality of rows arranged in parallel. The margin between the edge Ps of the card paper P and the image forming surface Pa is set to, for example, about 1.5 mm, but is not limited to this. It goes without saying that the form may be applied.

  Therefore, in the ROM 102 of the present embodiment, as the operation timing of the cleaning function for cleaning the nozzle forming surface 31a of the recording head 31 on which the paper dust of the card paper P adheres and accumulates, the CPU 101 executes the cleaning control process. The second recovery operation condition is stored in advance.

  Accordingly, the recording unit 13 performs the above-described cleaning function before a problem occurs in the formation accuracy of an image to be recorded on the card paper P due to paper dust generated due to the conveyance of the card paper P. The image quality can be maintained high by performing a recovery function including the above. That is, in addition to the first recovery timing of the total amount of ink ejected and the elapsed time (first condition), the ROM 102 stores the other end Ps2 of the card paper P and the corresponding other end Ars2 of the image forming area Ar. (Second condition) is stored as the second recovery timing. The CPU 101 has first and second recovery functions for executing a cleaning control process for operating the cleaning mechanism when the first and second recovery timings are satisfied.

  Specifically, the positional relationship between both ends Ars1 and Ars2 of the image forming area Ar by the recording head 31 and both ends Ps1 and Ps2 of the card paper P conveyed while facing the nozzle forming surface 31a of the recording head 31 is shown. It is stored in the ROM 102 as a second recovery operation condition. For example, the other end side Ps2 of the card paper P processed from the previous cleaning operation to the last time overlaps the vicinity of the other end side (outer edge) Ars2 of the current image forming area Ar, or is located inside the image forming area Ar. Is stored in advance as the second recovery operation condition. Also, when the card paper P on which an image has been formed from the previous cleaning operation to the previous time contains card paper P of a material that generates paper dust due to rubbing during conveyance, the card paper P is stored in advance as the second recovery operation condition. ing.

  More specifically, for example, the CPU 101 executes a control program in the ROM 102 to execute a job of an image forming control process including a cleaning control process of the nozzle forming surface 31a of the recording head 31 shown in the flowchart of FIG. It has become. Here, as one JOB to be processed by the printer 10, image data received from the host device H is image-recorded and formed on card paper P of the same size (transport direction length, orthogonal direction width) without switching control processing conditions. Will be described as an example.

  When the CPU 101 receives a print command of image data from the host device H, the CPU 101 starts an image formation control process (JOB) as shown in FIG. The CPU 101 first acquires various information such as the designated size of the card paper P together with the current image data, temporarily stores the acquired information in various memories, and then reads out the execution information of the cleaning function before storing the information in the memories. (Step S11).

  Next, the CPU 101 checks whether or not the cleaning function for cleaning the nozzle forming surface 31a of the recording head 31 after the previous image forming process is being operated based on the first and second recovery operation conditions (step S12). . Here, when the cleaning function is performed, the CPU 101 sets a flag indicating the execution of cleaning, and stores and holds the execution timing in a memory. When executing the image forming process after the cleaning, the CPU 101 sets the flag. Decrease flag.

  In step S12, the CPU 101 that has confirmed the execution of the cleaning (flag) after the previous image forming process performs the image forming process on the card paper P of the received image data as it is, and lowers the flag (step S13). Thereafter, each time the image forming process on one card sheet P is completed, the CPU 101 checks whether or not the image formation on the card sheets P of the number of prints received from the host device H has been completed ( Step S14).

  In step S14, the CPU 101 that cannot confirm that all image formation on the card paper P received from the host device H has been completed returns to step S13, and repeats the same image formation processing on the card paper P. In step S14, the CPU 101, which has confirmed the completion of the image formation on the card paper P, determines whether the material information of the card paper P on which the image has been formed this time is generated in a memory such as a resin film or other non-paper dust. It is confirmed whether or not the material is used (step S15).

  In step S15, the CPU 101, which has confirmed that the material information of the current card paper P is a resin film or the like set therein, erases the data without storing the other end side Ps2 described later stored in the memory. The image forming control process ends. Further, in step S15, the CPU 101, which has confirmed that the card paper P is thick paper, rewrites the other end Ps2 of the memory card P after the previous cleaning and the other end Ps2 of the current card paper P. Then, the current image forming control process is terminated (step S16). The other end side Ps2 to be rewritten this time in step S16 needs to be updated at a position closest to the one end side Ps1 when the cleaning operation is not performed in the control process described later. In step S16, if the other end Ps2 has not been written in the memory immediately after the cleaning has been performed, the CPU 101 writes the other end Ps2 of the card paper P on which the current image forming process is to be performed and performs the current image forming. The control processing ends.

  On the other hand, in step S12, after confirming that there is no flag indicating that the cleaning operation has not been performed after the previous image formation, the CPU 101 determines that the other end side Ps2 of the card paper P in the memory is the other end side (outer edge) Ars2 of the image forming area Ar. It is confirmed whether or not it is located within (step S21). That is, the CPU 101 determines from the position where the other end side Ps2 of the card paper P in the memory on which the image has been formed after the previous cleaning overlaps the other end side (outer edge) Ars2 of the current image forming area Ar to the one end side Ars1 side. Check if it is within the range.

  In short, in step S21, the CPU 101 satisfies the second recovery operation condition that the position of the other end Ps2 on one side, which positions the card paper P at a constant position, is within the image forming area Ar with reference to the other end Ps2. Or not. More specifically, a value obtained by subtracting a margin (safety value) “0.1 mm” from the separation width a to the other end Ps2 on the other side of the previous card paper P with reference to one end Ps1 on one side of the card paper P. Is smaller than or equal to the separation width b from the current image forming area Ar to the other end side Ars2. This margin “0.1 mm” is to take into account the spread range of the paper dust generated on the card paper P attached to the nozzle forming surface 31 a of the recording head 31. For example, in the image forming process, the setting value is a setting value that allows a margin to be determined when the other end side Ps2 of the previous card paper P and the other end side Ars2 of the current image forming area Ar overlap. This value is not limited to this, and the effect on the image quality can be reliably determined as described later according to the separation distance (about 1.5 mm in the present embodiment) between the nozzle forming surface 31a and the card paper P. What is necessary is just to set the value which can be avoided.

  In step S21, the CPU 101 confirms that the other end side Ps2 of the card paper P in the memory is located outside the current image forming area Ar, and thereafter, similarly proceeds to step S13 to perform image formation and the other end in the memory. The rewriting update of the side Ps2 is performed (steps S13 to S16).

  Also, in step S21, the CPU 101, which has confirmed that the other end side Ps2 of the card paper P in the memory is located within the current image forming area Ar, determines that the second recovery operation condition is satisfied, and proceeds to step S21. Proceed to S22.

  The CPU 101 that has proceeded to step S22 sets a flag by executing a cleaning function for wiping and cleaning the nozzle forming surface 31a of the recording head 31 with the wiper blade 34, and thereafter similarly proceeds to step S13 to perform image forming processing. And lower the flag. Thereafter, the CPU 101 similarly performs rewrite update processing of the other end side Ps2 of the card paper P held in the memory according to whether or not the current card paper P is a non-paper dust generating material (step S14). To S16). At the time of executing this cleaning function, processing for refreshing (recovering performance) of the ejected ink by attaching and detaching the cap 33 may also be executed.

  As a result, even when the other end side Ps2 of the card paper P on which the image has been formed after the cleaning of the nozzle forming surface 31a is located in the current image forming area Ar, the paper dust adheres in the previous image formation. The nozzle forming surface 31a is cleaned again before the image recording.

  As described above, in the printer 10 of the present embodiment, when the other end side Ps2 of the card paper P on which the image is formed after the cleaning of the nozzle forming surface 31a of the recording head 31 is located within the current image forming area Ar, the second operation is performed. It is determined that the recovery operation condition of the above is satisfied. For this reason, even in the printer 10, even before the first recovery operation condition is satisfied, the cleaning control processing of the nozzle forming surface 31a is executed, and the paper dust or the like adhering to the nozzle forming surface 31a is wiped and cleaned. Can be. Therefore, it is possible to provide the printer 10 that can maintain high-quality image formation even if images can be formed on card papers P of various sizes.

  Next, FIGS. 5 and 6 are views showing an example of a printer to which an ink jet recording apparatus according to a second embodiment of the present invention is applied. Here, since the present embodiment is configured substantially in the same manner as the above-described embodiment, the drawings will be diverted, and the same components will be denoted by the same reference numerals and the characteristic portions will be described.

  The printer 10 shown in FIG. 1 is constructed by including a feeding unit 11, a recording unit 13, and a control unit 15 similarly to the above-described embodiment, and prints image data received from the host device H onto a card paper P by ink jetting. Recording is performed by a recording method to form an image.

  In the printer 10 of the present embodiment, as shown in FIG. 5, the center C of the card paper P between the both side edges Ps1 and Ps2 is positioned with respect to the center C of the image forming area Ar of the recording head 31 in the width direction B. To pass under the nozzle forming surface 31a. In this card paper P, both positions of both ends Ps1 and Ps2 change uniformly in the left-right direction of the center C (the width direction B of the image forming area Ar).

  In short, the position of both ends Ps1 and Ps2 of the card paper P changes according to the size of the image forming surface Pa on which image data is recorded in the width direction B. For example, the image is formed on the small-sized image forming surface Pa-bef (two-dot chain line in FIG. 5) last time, and the image is formed on the large-sized image forming surface Pa-aft (solid line in FIG. 5) this time. In this case, the positions of both end sides Ps1 and Ps2 uniformly change from the center C in the width direction B to the left and right. In this case, ink is ejected onto the image forming surface Pa-aft of the current card paper P from the nozzles 32 near the nozzle forming surface 31a facing both ends Ps1 and Ps2 of the previous card paper P to form an image. Will be done.

  For this reason, in the recording head 31, the paper dust generated in the previous image forming process adheres and accumulates on the nozzle forming surface 31 a to deteriorate the ink ejection performance. There is a case where the quality of the formed image is deteriorated by being located in the surface Pa-aft.

  Therefore, the ROM 102 of the present embodiment stores the following positional relationship between the edge Ps of the card paper P and the outer edge of the image forming area Ar together with the material conditions of the card paper P as a second recovery operation condition. Is stored. For example, both end sides Ps1 and Ps2 of the card paper P processed from the previous cleaning operation to the last time overlap the vicinity of both end sides (outer edges) Ars1 and Ars2 of the current image forming area Ar, or more than that. Are stored in advance.

  More specifically, for example, the CPU 101 executes a control program in the ROM 102 to execute a job of an image forming control process including a cleaning control process of the nozzle forming surface 31a of the recording head 31 shown in the flowchart of FIG. It has become.

  When the CPU 101 first receives an image data print command from the host device H, the CPU 101 starts an image formation control process (JOB) as shown in FIG. The CPU 101 acquires the previous cleaning function execution information in the memory together with the current image data and various information of the card paper P, as in the above-described embodiment (step S11). Next, when the CPU 101 confirms the flag indicating the cleaning operation after the previous image forming process (step S12), the CPU 101 lowers the flag together with recording and forming the received image data on each card paper P (steps S13 and S14). . Next, when the card paper P is not a resin film or the like, the CPU 101 performs an updating process of rewriting the storage position data in the memory to both ends Ps1 and Ps2, and ends the current image forming control process (steps S15 and S16). ).

  On the other hand, in step S12, upon confirming that there is no flag indicating that the cleaning operation has not been performed since the previous image forming process, the CPU 101 locates both ends Ps1 and Ps2 of the card paper P in the memory within the current image forming area Ar. It is confirmed whether or not it is (step S21).

  In step S21, the CPU 101 confirms that the both ends Ps1 and Ps2 in the memory are located outside the current image forming area Ar, and thereafter similarly proceeds to step S13 to execute the image forming process and the two ends Ps1 and Ps2. A rewrite update is performed (steps S13 to S16).

  Here, in step S21 of the present embodiment, the CPU 101 determines that the positions of both ends Ps1 and Ps2 are within the image forming area Ar with respect to the card paper P and the center C of the image forming area Ar. The determination is made based on whether or not the operating condition is satisfied. In detail, based on the card paper P and the center C of the image forming area Ar, the value obtained by subtracting the margin “0.2 mm” from the separation width a between both end sides Ps1 and Ps2 of the previous card paper P is the current value. Judgment is made based on whether or not the distance is equal to or smaller than the separation width b between both ends Ars1 and Ars2 of the image forming area Ar. This margin “0.2 mm” doubles 0.1 mm for each side on both sides, and takes into account the spread range of paper dust generated on the card paper P attached to the nozzle forming surface 31 a of the recording head 31. To do that. For example, in the image forming process, the setting value is a setting value that allows a margin to be determined when both ends Ps1 and Ps2 of the previous card sheet P and both ends Ars1 and Ars2 of the current image forming area Ar overlap. This value is not limited to this, and the effect on the image quality can be reliably determined as described later according to the separation distance (about 1.5 mm in the present embodiment) between the nozzle forming surface 31a and the card paper P. What is necessary is just to set the value which can be avoided.

  Then, in step S21, the CPU 101, which has confirmed that both end sides Ps1, Ps2 of the card paper P in the memory are located within the current image forming area Ar, determines that the second recovery operation condition is satisfied, and Proceed to step S22.

  The CPU 101 that has proceeded to step S22 sets a flag by executing a cleaning function for wiping and cleaning the nozzle forming surface 31a of the recording head 31 with the wiper blade 34, and thereafter similarly proceeds to step S13 to perform image forming processing. And lower the flag. Thereafter, the CPU 101 similarly performs rewriting update processing of both ends Ps1 and Ps2 of the card paper P held in the memory according to whether or not the current card paper P is a non-paper dust generating material (step S101). S14 to S16).

  As a result, the printer 10 can perform the nozzle formation to which the paper dust adheres in the previous image formation even when the both ends Ps1 and Ps2 of the card paper P are located within the current image formation area Ar, as in the above-described embodiment. The surface 31a is cleaned again before the image recording.

  As described above, in the printer 10 according to the present embodiment, even when the paper is conveyed or the image is formed on the basis of the nozzle forming surface 31a of the recording head 31 or the center C of the card paper P in the width direction B, The same operation and effect as those of the above embodiment can be obtained.

  The scope of the invention is not limited to the exemplary embodiments shown and described, but also includes all embodiments that provide equivalent advantages to those intended. Furthermore, the scope of the present invention is not limited to the combination of features of the invention defined by each claim, but may be defined by any desired combination of specific features among all disclosed respective features. .

10 Printer 11 Feeding unit 13 Recording unit 15 Control unit 31, 31Bk, 31C, 31M, 31Y Recording head 31a Nozzle forming surface 32 Nozzle 33 Cap 34 Wiper blade 101 CPU
A: transport direction B: orthogonal direction (width direction)
Ar ... image forming areas Ars1, Ars2 ... edge H ... host device P ... card paper Ps, Ps1, Ps2 ... edge

Claims (4)

Recording means for discharging ink from nozzles arranged in a recording head to perform recording on a recording medium,
Recovery means for performing a recovery operation for recovering the ejection performance of the recording head,
Conveying means for conveying the recording medium in a direction orthogonal to a nozzle arrangement direction that is a direction in which the nozzles are arranged,
End position acquisition means for acquiring the position of the end of the recording medium used for recording in the nozzle array direction,
Control means for causing the recovery means to perform the recovery operation when the position of the end of the recording medium is changed;
An inkjet recording apparatus comprising:   The control means, when the position of the end of the recording medium before the change is included in the area for recording the recording medium after the change, before recording on the recording medium after the change, The ink jet recording apparatus according to claim 1, wherein a recovery operation is performed. Further comprising a medium type obtaining means for obtaining the type of the recording medium,
The ink jet recording apparatus according to claim 1, wherein the control unit sets whether or not to perform the recovery operation according to a type of the recording medium. An inkjet recording apparatus that forms an image by ejecting the ink onto a recording medium that is conveyed in a direction orthogonal to the parallel direction of the nozzles while facing a recording head in which nozzles that eject the ink are arranged,
Recovery means for performing a recovery operation for recovering the ejection performance of the recording head,
Control means for causing the recovery means to perform the recovery operation,
The control means includes: a first recovery function for executing the recovery operation at a first recovery timing that satisfies a first condition corresponding to a preset ink ejection amount; A second recovery function for performing the recovery operation at a second recovery timing that satisfies a second condition according to a positional relationship with an image forming region using ink.
The second recovery function includes: an edge facing the recording head in a direction perpendicular to a conveyance direction of the recording medium in a previous image forming process; and an image in which the ink is ejected in a current image forming process. An ink jet recording apparatus comprising: acquiring a positional relationship between a recording area and a formation area; and determining whether the acquired information satisfies the second condition.

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