JP2017030337A - Recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording apparatus capable of suppressing not only a discharge defect caused by paper powder, but also a discharge defect caused by starch.SOLUTION: When it is determined that the amount of starch nearby a head is small based upon a result of comparison between a value (acquired value Z) associated with the amount of starch nearby the head and a threshold Tz, YES at S3, normal maintenance processing S4 is performed, and when it is determined that the amount of starch nearby the head is large, NO at S3, special maintenance processing S5 is performed. In the special maintenance processing, large-amount purging (purging larger in ink discharge amount than purging included in the normal maintenance processing) and large-frequency (an integer equal to or larger than 0) idling wiping (idling wiping larger in frequency than idling wiping included in the normal maintenance) are performed.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a recording apparatus, and more particularly to a recording apparatus that performs recording by discharging a liquid onto a recording medium.

  In Patent Document 1, the degree of adhesion of paper dust to the nozzle surface (ejection surface) of a recording head (liquid ejection unit) is counted, and when the degree of paper dust adhesion exceeds a threshold value, liquid is sucked and discharged from the nozzle. It is disclosed that a cleaning operation including a head suction operation is performed (see paragraphs 0060 and 0069).

JP 2014-46649 A

  If paper dust enters the discharge port opened on the discharge surface, a discharge failure may occur. Therefore, if the cleaning operation is performed when the adhesion degree of the paper dust is equal to or greater than the threshold value as in Patent Document 1, the paper dust that has entered the discharge port is discharged together with the liquid, and the ejection failure caused by the paper dust is suppressed. be able to. However, starch other than paper powder is a substance that can enter the discharge port and cause discharge failure. Patent Document 1 does not consider starch at all. Starch may be applied to the surface of recording media (especially postcards) and has properties such as smaller particle size than paper powder, higher solubility in liquid than paper powder, and increased liquid viscosity. Inferred to have. Due to the difference in properties, the maintenance operation (usually maintenance processing) performed on paper dust cannot sufficiently remove the starch that has entered the discharge port, and it is difficult to suppress discharge failures caused by starch. .

  An object of the present invention is to provide a recording apparatus capable of suppressing not only ejection failure caused by paper powder but also ejection failure caused by starch.

  The recording apparatus according to the present invention includes a discharge surface having a plurality of discharge ports for discharging a liquid, a liquid discharge section having a plurality of individual flow paths reaching each of the plurality of discharge ports, and the plurality of individual flows. A pump for performing a purge for applying a pressure to the liquid in the passage and discharging the liquid from the plurality of discharge ports, a wiper for wiping the discharge surface, and the wiper in contact with the discharge surface The movement mechanism for moving at least one of the wiper and the liquid discharge unit so that the wipe is performed by moving relative to the liquid discharge unit in the movement direction along the discharge surface. A storage unit that stores a predetermined threshold for the amount of starch produced from the recording medium in the vicinity of the liquid ejection unit, and a control unit, and the control unit satisfies a predetermined condition. In this case, a value related to the amount of starch in the vicinity of the liquid discharge unit is acquired, and a comparison process for comparing the acquired value with a threshold value stored in the storage unit, and the acquired value increases as the amount of starch increases. If the acquired value is less than the threshold value in the comparison process, and if the acquired value is a value that decreases as the amount of starch increases, When the acquired value is determined to be equal to or greater than the threshold, at least of the purge, the wipe, and an empty wipe that is a wipe that is performed after the wipe is performed after the wipe is performed. In the normal maintenance process that controls the pump so that the purge is performed, and when the acquired value is a value that increases as the amount of starch increases, in the comparison process When the acquired value is determined to be greater than or equal to the threshold value, and when the acquired value is a value that decreases as the amount of starch increases, the acquired value is determined to be less than the threshold value in the comparison process. Sometimes, in the purge included in the normal maintenance process, a large amount purge, which is the purge that discharges a larger amount of liquid than the amount of liquid discharged from the plurality of discharge ports, and the normal maintenance process It is possible to execute a special maintenance process for controlling the pump and the moving mechanism so that the number of times of empty wipes (an integer greater than or equal to 0) is greater than the number of times of empty wipes. Features.

  According to the present invention, normal maintenance processing is performed when it is determined that the amount of starch in the vicinity of the liquid discharge portion is small according to the comparison result between the value (acquired value) regarding the amount of starch in the vicinity of the liquid discharge portion and the threshold value. On the other hand, when it is determined that the amount of starch in the vicinity of the liquid discharge portion is large, a special maintenance process is performed. Thereby, not only the discharge failure resulting from paper dust but the discharge failure resulting from starch can be suppressed. In the special maintenance process, a large amount of liquid is discharged and empty wipes are performed many times, so that starch that has entered the discharge port is efficiently removed.

  The special maintenance process may repeat a set of the large-volume purge and the multi-time empty wipe performed after the large-volume purge twice or more.

  According to the said structure, the starch which penetrate | invaded in the discharge outlet is removed more reliably.

  In the group that is repeated two or more times, among the two groups that are performed consecutively, the multiple-time empty wipe that is performed first is one of the forward direction and the reverse direction of the moving direction, and is performed later. The multi-time empty wipe may be the other of the forward direction and the reverse direction.

  According to the said structure, the starch which penetrate | invaded in the discharge outlet is removed more reliably.

  The special maintenance process may include the empty wipes in the forward direction and the reverse direction of the moving direction.

  According to the said structure, the starch which penetrate | invaded in the discharge outlet is removed more reliably.

  The recording apparatus according to the present invention is a transport mechanism for transporting a recording medium along a transport path toward a position facing the discharge surface, and is disposed upstream of the transport path from the liquid discharge section. A transport mechanism including a path forming member that forms the transport path may be provided.

  According to the above configuration, when starch adhering to the recording medium or starch floating in the apparatus adheres to the path forming member, the starch moves from the path forming member to the recording medium as the conveyance mechanism is driven, and further recording is performed. There is a possibility of moving from the medium to the discharge surface and entering the discharge port. However, in the present invention, even in such a case, by performing the special maintenance process, the starch can be efficiently removed, and the discharge failure caused by the starch can be suppressed.

  The recording apparatus according to the present invention may further include a paper dust removing mechanism for removing paper dust attached to the recording medium upstream of the path forming member and upstream of the transport path.

  Even if the paper dust attached to the recording medium can be removed by the paper dust removing mechanism, it is difficult to remove the starch attached to the recording medium due to the difference in properties between the paper powder and the starch. Starch that remains on the recording medium without being removed by the paper dust removal mechanism moves to the downstream of the conveyance path together with the recording medium as the conveyance mechanism is driven, and moves to the path forming member and the ejection surface. May invade. However, in the present invention, even in such a case, by performing the special maintenance process, the starch can be efficiently removed, and the discharge failure caused by the starch can be suppressed.

  The recording apparatus according to the present invention further includes a sensor for detecting a value related to the amount of the starch adhering to a portion of the path forming member forming the transport path, and the acquired value is detected by the sensor. It may be based on a value.

  The starch adhering to the path forming member moves to the recording medium, and further moves from the recording medium to the ejection surface and can enter the ejection opening. In view of this, in the above-described configuration, a sensor for detecting a value related to the amount of starch attached to a portion of the path forming member that forms the conveyance path is provided, and normal maintenance processing is performed based on the value detected by the sensor. And whether to perform special maintenance processing. If special maintenance processing is frequently performed, processing may take time and high-speed recording may be hindered. However, according to the above configuration, excessive execution of special maintenance processing is suppressed, and ejection failure due to starch is suppressed. And high-speed recording can be realized together.

  The storage unit further stores a recorded number that is the number of recording media recorded by ejecting liquid from the liquid ejecting unit, and the control unit obtains the acquired value in the comparison process. The acquired value may be calculated based on a value detected by the sensor and a recorded number stored in the storage unit.

  As the number of records on the recording medium increases, the starch generated from the recording medium is more likely to float in the apparatus or adhere to each part of the apparatus (particularly the components of the transport mechanism), and the starch may enter the discharge port. Becomes higher. In view of this, in the above-described configuration, it is determined which of the normal maintenance process and the special maintenance process is performed using the acquired value calculated based on the value detected by the sensor and the recorded number. As a result, it is possible to more reliably suppress the execution of the special maintenance process excessively, and it is possible to realize both the suppression of ejection failure caused by starch and the high-speed recording.

  The storage unit further stores a postcard recorded number, which is the number of postcards of a recording medium, recorded by discharging liquid from the liquid discharge unit, and the acquired value is stored in the storage unit It may be based on the number of postcards recorded.

  Discharge failure due to starch is particularly likely to occur when a postcard is used as a recording medium. In view of this, in the above configuration, it is determined whether to perform normal maintenance processing or special maintenance processing using the acquired value based on the number of recorded postcards. If special maintenance processing is frequently performed, processing may take time and high-speed recording may be hindered. However, according to the above configuration, excessive execution of special maintenance processing is suppressed, and ejection failure due to starch is suppressed. And high-speed recording can be realized together.

  According to the present invention, normal maintenance processing is performed when it is determined that the amount of starch in the vicinity of the liquid discharge portion is small according to the comparison result between the value (acquired value) regarding the amount of starch in the vicinity of the liquid discharge portion and the threshold value. On the other hand, when it is determined that the amount of starch in the vicinity of the liquid discharge portion is large, a special maintenance process is performed. Thereby, not only the discharge failure resulting from paper dust but the discharge failure resulting from starch can be suppressed. In the special maintenance process, a large amount of liquid is discharged and empty wipes are performed many times, so that starch that has entered the discharge port is efficiently removed.

FIG. 2A is a side view showing the inside of the ink jet printer according to the first embodiment of the present invention. FIG. 2B is a partial cross-sectional view of a head included in the printer. 4A and 4B are side views showing a wiper and a wiper moving mechanism included in the printer, where FIG. 5A shows a state where the wiper is at a standby position, and FIG. 5B shows a state where the ejection surface is wiped. 1 is a block diagram illustrating an electrical configuration of an inkjet printer according to a first embodiment of the present invention. It is a flowchart which shows the control content which CPU performs in 1st Embodiment of this invention. (A) is a flowchart which shows a normal maintenance process. (B) is a flowchart which shows a special maintenance process. It is a flowchart which shows the control content which CPU performs in 2nd Embodiment of this invention.

  An ink jet printer (hereinafter simply referred to as “printer”) 1 according to a first embodiment of the present invention includes a rectangular parallelepiped housing 1a as shown in FIG. An inkjet head (hereinafter simply referred to as “head”) 10, a support unit 40, a storage unit 3, a transport mechanism 20, and a control unit 100 are disposed in the housing 1 a. A receiving portion 4 is provided on the top plate of the housing 1a.

  The head 10 is a line head that is long in the main scanning direction. The head 10 corresponds to a “liquid ejection unit” according to the present invention, and as shown in FIG. 1B, the ejection surface 10a having a plurality of ejection ports 14a for ejecting ink and a plurality of ejection ports. 14a, and a plurality of individual flow paths 14 reaching each of 14a. The head 10 includes a flow path unit 12 and an actuator unit 17. The flow path unit 12 is formed by laminating plates 12a to 12d. The lower surface of the flow path unit 12 is the discharge surface 10 a, and a plurality of individual flow paths 14 are formed inside the flow path unit 12. Further, a manifold channel 13 common to the plurality of individual channels 14 is formed inside the channel unit 12. Each individual flow path 14 extends from the outlet of the manifold flow path 13 to the discharge port 14 a via the pressure chamber 16. The actuator unit 17 is formed by laminating a diaphragm 17a, a piezoelectric layer 17b, and an individual electrode 17c provided for each pressure chamber 16. The vibration plate 17 a is fixed to the upper surface of the flow path unit 12 and closes the plurality of pressure chambers 16. The piezoelectric layer 17 b is fixed to the upper surface of the vibration plate 17 a and faces the plurality of pressure chambers 16. Each individual electrode 17 c is fixed to the upper surface of the piezoelectric layer 17 b and faces each pressure chamber 16. A portion corresponding to each individual electrode 17c in the actuator unit 17 constitutes a drive unit 17x for applying ejection energy to the ink, and can be independently deformed in accordance with application of a voltage to each individual electrode 17c. By deforming the drive unit 17x so as to protrude toward the pressure chamber 16, the volume of the pressure chamber 16 is reduced, pressure is applied to the ink in the pressure chamber 16, and ink is ejected from the ejection port 14a. .

  A cartridge containing ink is disposed in the housing 1a, and the cartridge and the flow path unit 12 communicate with each other via a tube (not shown). The ink stored in the cartridge is supplied to the flow path unit 12 through the tube by driving the pump 10P (see FIG. 3) under the control of the control unit 100. The pump 10P is driven when purging (operation for applying pressure to the ink in the plurality of individual flow paths 14 and discharging the ink from the plurality of discharge ports 14a) is performed.

  As shown in FIG. 1A, the support portion 40 is a flat plate and is disposed below the head 10. The upper surface of the support portion 40 is opposed to the ejection surface 10a of the head 10 while being spaced apart, and constitutes a support surface 40a for supporting the paper P.

  The storage unit 3 is a tray that can store the paper P and is detachable from the housing 1a.

  The transport mechanism 20 includes guides 29a to 29f, a paper feed roller 21 and roller pairs 22 to 28, and is configured to transport the paper P stored in the storage unit 3 along the transport path. Each guide 29a-29f includes a pair of guide plates spaced from each other in the thickness direction. The paper feed roller 21 is disposed so as to be in contact with the uppermost surface of the paper P in the storage unit 3. Each roller pair 22-28 includes two rollers in contact with each other. The conveyance path is formed by the space between the pair of guide plates of the guides 29a to 29f, the contact point between the rollers of the roller pairs 22 to 28, and the gap between the discharge surface 10a and the support surface 40a. It extends from the portion 3 to the receiving portion 4 via a position facing the discharge surface 10a. The roller pairs 22 to 28 are disposed between guides 29a to 29f that are spaced apart along the transport path. The feed roller 21 and one of the roller pairs 22 to 28 are drive rollers that are rotated by the drive of the transport motor 20M (see FIG. 3) under the control of the control unit 100. The other roller of each of the roller pairs 22 to 28 is a driven roller that rotates as the one roller rotates. In each of the roller pairs 22 to 28, one roller and the other roller rotate in opposite directions while sandwiching the paper P.

  The roller pair 24 corresponds to a “path forming member” according to the present invention, and is disposed upstream of the transport path from the head 51 and forms the transport path. A sensor 24S is provided at a position facing the outer peripheral surface (portion forming the transport path) of one roller of the roller pair 24. The sensor 24S corresponds to the “sensor for detecting a value related to the amount of starch adhering to a portion of the path forming member forming the conveyance path” according to the present invention, and in this embodiment, one roller of the roller pair 24. It is comprised with the optical sensor which detects the color of the outer peripheral surface. Starch is generated from the recording medium (paper P in the present embodiment), and as the amount of starch adhering to the outer peripheral surface of the roller increases, the outer peripheral surface becomes white and the value detected by the sensor 24S (detection value Y). Becomes smaller.

  Further, a paper dust removing mechanism 30 is provided for the roller pair 23 located upstream of the roller pair 24 in the transport path. The paper dust removing mechanism 30 is for removing paper dust attached to the paper P, and includes a sponge 31 and a paper dust container 32. The sponge 31 is disposed so as to contact the outer peripheral surface of one roller of the roller pair 23. When the roller pair 23 rotates, the roller is charged by sliding contact with the sponge 31, and the paper dust adhering to the paper P is adsorbed by the roller. The paper powder adsorbed by the roller is dropped into the paper powder container 32 by the sponge 31.

  A wiper 50 and a wiper moving mechanism 55 are further provided in the housing 1a (see FIGS. 2A and 2B).

  The wiper 50 is for wiping the discharge surface 10a (hereinafter simply referred to as “wipe”), and is made of an elastic body such as rubber.

  The wiper moving mechanism 55 corresponds to a “moving mechanism” according to the present invention, and includes a holder 55a that supports the wiper 50, a slide bar 55b that supports the holder 55a so as to be slidable along the main scanning direction, and a wiper moving motor. 55M (see FIG. 3). The wiper 50 is normally disposed at a standby position (a position shown in FIG. 2A) that does not face the ejection surface 10a in the vertical direction. Under the control of the control unit 100, the wiper moving motor 55M is driven to move the holder 55a in the main scanning direction (moving direction along the ejection surface 10a) while being supported by the slide bar 55b. At this time, the wiper 50 is wiped by moving in the main scanning direction while the wiper 50 is in contact with the ejection surface 10a. The wiper 50 is movable in both the forward direction and the reverse direction along the main scanning direction (see FIG. 2B).

  As shown in FIG. 3, the control unit 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, an ASIC (Application Specific Integrated Circuit) 104, An I / F (Interface) 105 and an I / O (Input / Output Port) 106 are included. The ROM 102 stores fixed data such as a program executed by the CPU 101. The RAM 103 temporarily stores data necessary for the CPU 101 to execute the program. The ASIC 104 performs rewriting and rearrangement of image data (for example, signal processing and image processing). The I / F 105 transmits / receives data to / from an external device (for example, a PC connected to the printer 1). The I / O 106 transmits and receives signals to and from various sensors. The CPU 101 is electrically connected to each unit other than the CPU 101 included in the control unit 100, and performs control based on data received from each unit.

  The CPU 101 corresponds to a “control unit” according to the present invention. The ROM 102 and the RAM 103 correspond to a “storage unit” according to the present invention. The RAM 103 stores the recorded number X (the number of sheets P recorded by ejecting ink from the head 51). The recorded number X is a value related to all types of paper P regardless of the type (size or thickness) of the paper P. The ROM 102 stores a threshold value Tx for the recorded number X, a threshold value Ty for the detection value Y, and a threshold value Tz that is predetermined for the amount of starch in the vicinity of the head 51.

  Next, the control contents executed by the CPU 101 will be described with reference to FIG.

  First, the CPU 101 determines whether or not a recording command is received from an external device (S1). When determining that the recording command has not been received (S1: NO), the CPU 100 repeats the process of S1. If it is determined that the recording command has been received (S1: YES), the CPU 100 reads the recorded number X from the RAM 103, reads the threshold values Tx and Ty from the ROM 102, acquires the detection value Y from the sensor 24S, It is determined whether or not at least one of the condition that the completed number X exceeds the threshold value Tx and the condition that the detected value Y is less than the threshold value Ty is satisfied (S2).

  When it is determined that at least one of the above conditions is satisfied (S2: YES), the CPU 101 obtains a value obtained by dividing the recorded number X by the detection value Y as an acquired value Z (a value related to the amount of starch near the head 51). ) And the threshold value Tz is read from the ROM 102, and it is determined whether or not the condition “the acquired value Z is less than the threshold value Tz” is satisfied (S3). S3 corresponds to the “comparison process” according to the present invention. S2: YES corresponds to “when a predetermined condition is satisfied” according to the present invention.

  If it is determined that the condition that “the acquired value Z is less than the threshold value Tz” is satisfied (S3: YES), the CPU 101 executes normal maintenance processing (S4). On the other hand, if it is determined that the condition that “the acquired value Z is less than the threshold value Tz” is not satisfied (S3: NO), the CPU 101 executes a special maintenance process (S5). The normal maintenance process (S4) and the special maintenance process (S5) will be described in detail later.

  After the normal maintenance process (S4) or the special maintenance process (S5), the CPU 101 sets a roller cleaner 24C (FIG. 1 (FIG. 1)) on the outer peripheral surface of one roller of the roller pair 24 to be detected by the sensor 24S. The cleaning is performed in step a), and a foreign matter (paper powder, starch, etc.) adhering to the outer peripheral surface of the roller is removed (S6). After S6, the CPU 101 resets the recorded number X stored in the RAM 103 to 0 (S7).

  After S7 or when it is determined in S2 that none of the above conditions are satisfied (S2: NO), the CPU 101 performs the recording operation on one sheet of paper P and the transport motor 20M and the head 51. Is controlled (S8). After S8, the CPU 101 adds 1 to the recorded number X stored in the RAM 103 (S9). After S9, the CPU 101 determines whether or not the recording based on the recording command received in S1 is completed (S10). If it is determined that the recording has not been completed (S10: NO), the CPU 101 returns the process to S2. When it is determined that the recording is completed (S10: YES), the CPU 101 ends the routine.

  In the normal maintenance process (S4), as shown in FIG. 5A, the CPU 101 first controls the pump 10P so that the purge is performed (S21). After S21, the CPU 101 controls the wiper movement motor 55M so that the wipe is performed (S22). After S22, the CPU 101 ends the routine.

  In the special maintenance process (S5), as shown in FIG. 5B, the CPU 101 firstly performs a large amount purge (a purge that ejects a larger amount of ink than the amount ejected from the ejection port 14a in the purge of S21). ) Is controlled (S31). For example, in the large amount purge, the CPU 101 increases the drive speed of the pump 10P (in addition to or instead of this, lengthens the drive time of the pump 10P) as compared with the purge (S21), thereby increasing the ink discharge amount. To increase.

  After S31, the CPU 101 controls the wiper movement motor 55M so that the wipe is performed (S32). After S32, the CPU 101 controls the wiper movement motor 55M so that the positive direction wipe is performed five times (that is, the “multiple times wipe” according to the present invention is performed) (S33). “Empty wipe” refers to a wipe that is performed without a purge after the purge is performed after the purge. “Positive wipe in the positive direction” refers to an empty wipe performed by moving the wiper 50 in the positive direction in contact with the ejection surface 10a as shown in FIG. 2B.

  Note that the CPU 101 may perform a process of cleaning the wiper 50 with a wiper cleaner (not shown) and removing foreign matter attached to the wiper 50 after S32 and before S33.

  After S33, the CPU 101 controls the pump 10P so that a large purge is performed (S34). After S34, the CPU 101 controls the wiper movement motor 55M so that the wipe is performed (S35). After S35, the CPU 101 controls the wiper movement motor 55M so that the reverse direction wipe is performed five times (that is, the “multiple times wipe” according to the present invention is performed) (S36). The “reverse empty wipe” refers to an empty wipe performed by moving the wiper 50 in the reverse direction (see FIG. 2B) in a state where the wiper 50 is in contact with the ejection surface 10a.

  After S36, the CPU 101 controls the pump 10P so that a large purge is performed (S37). After S37, the CPU 101 controls the wiper movement motor 55M so that the wipe is performed (S38). After S38, the CPU 101 controls the pump 10P so that a large purge is performed (S39). After S39, the CPU 101 controls the wiper movement motor 55M so that the wipe is performed (S40). After S40, the CPU 101 ends the routine.

  As described above, according to the present embodiment, it is determined that the amount of starch in the vicinity of the head 51 is small according to the comparison result between the value (acquired value Z) regarding the amount of starch in the vicinity of the head 51 and the threshold value Tz. If it is determined (S3: YES), normal maintenance processing (S4) is performed, while if it is determined that the amount of starch in the vicinity of the head 51 is large (S3: NO), special maintenance processing (S5) is performed. Is called. Thereby, not only the discharge failure resulting from paper dust but the discharge failure resulting from starch can be suppressed. In the special maintenance process, a large amount of ink is ejected and empty wipes are performed many times, so that starch that has entered the ejection port 14a is efficiently removed.

  In the special maintenance process (see FIG. 5 (b)), a combination of a large quantity purge and a multi-time empty wipe performed after the large quantity purge is performed twice or more (in this embodiment, the group of S31 and S33, and the group of S34 and S36). Repeat twice). According to the said structure, the starch which penetrate | invaded in the discharge outlet 14a is removed more reliably.

  Of the two sets (S31, S33 set and S34, S36 set) performed in succession, the first multi-time empty wipe (S33) is in the positive direction, and the second multi-time empty wipe ( S36) is the reverse direction. According to the said structure, the starch which penetrate | invaded in the discharge outlet 14a is removed more reliably.

  The special maintenance process (see FIG. 5B) includes forward and reverse empty wipes (see S33 and S36). According to the said structure, the starch which penetrate | invaded in the discharge outlet 14a is removed more reliably.

  The printer 1 includes a transport mechanism 20 that includes a roller pair 24 that is disposed upstream of the transport path and forms the transport path (see FIG. 1A). According to the above configuration, when starch adhering to the paper P or starch floating in the housing 1 a adheres to the roller pair 24, the starch moves from the roller pair 24 to the paper P as the transport mechanism 20 is driven. Further, there is a possibility that the sheet P moves to the discharge surface 10a and enters the discharge port 14a. However, in this embodiment, even in such a case, the special maintenance process is performed, whereby the starch can be efficiently removed and the discharge failure caused by the starch can be suppressed.

  The printer 1 further includes a paper dust removing mechanism 30 for removing paper dust adhering to the paper P upstream of the pair of rollers 24 in the conveyance path (see FIG. 1A). Even if the paper dust attached to the paper P can be removed by the paper dust removing mechanism 30, it is difficult to remove the starch attached to the paper P due to the difference in properties between the paper powder and the starch. The starch that is not removed by the paper dust removing mechanism 30 and remains attached to the paper P moves along with the paper P to the downstream of the transport path as the transport mechanism 20 is driven, and moves to the roller pair 24 and further to the discharge surface 10a. There is a possibility of entering the discharge port 14a. However, in this embodiment, even in such a case, the special maintenance process is performed, whereby the starch can be efficiently removed and the discharge failure caused by the starch can be suppressed.

  The starch adhering to the roller pair 24 moves to the paper P, and further moves from the paper P to the discharge surface 10a and can enter the discharge port 14a. In view of this, in the present embodiment, a sensor 24S for detecting a value related to the amount of starch adhering to the outer peripheral surface of one roller of the roller pair 24 is provided, and a value (detection value Y) detected by the sensor 24S is provided. ) To determine whether to perform normal maintenance processing or special maintenance processing (see S3 in FIG. 4). If special maintenance processing is frequently performed, processing may take time and high-speed recording may be hindered. However, according to the above configuration, excessive execution of special maintenance processing is suppressed, and ejection failure due to starch is suppressed. And high-speed recording can be realized together.

  As the number of recordings on the sheet P increases, the starch generated from the sheet P is more likely to float in the casing 1a or adhere to each part (particularly, a component of the transport mechanism 20) in the casing 1a. The possibility that starch will enter 14a increases. In view of this, in the present embodiment, the recorded number X is stored in the RAM 103, and the acquired value is based on the value detected by the sensor 24S (detected value Y) and the recorded number X stored in the RAM 103. And whether to perform normal maintenance processing or special maintenance processing is determined according to a comparison result between the acquired value and the threshold value Tz. As a result, it is possible to more reliably suppress the execution of the special maintenance process excessively, and it is possible to realize both the suppression of ejection failure caused by starch and the high-speed recording.

  Next, a printer according to a second embodiment of the invention will be described with reference to FIG. The second embodiment differs from the first embodiment in the information stored in the RAM 103 and the control content executed by the CPU 101, and is otherwise the same as the first embodiment.

  In the present embodiment, the RAM 103 stores not only the recorded number X for all types of paper P but also the postcard recorded number (the number of postcards of the paper P recorded by ink ejection from the head 51). To do.

  The processing of S51 to S60 performed by the CPU 101 in the present embodiment is the same as the processing of S1 to S10 performed by the CPU 101 in the first embodiment, except that S3 and S53 are the same.

  S53 corresponds to the “comparison process” according to the present invention. In S <b> 53, the CPU 101 reads “the number of postcards recorded” from the RAM 103, and uses this as an acquired value Z to determine whether or not the condition “the acquired value Z is less than the threshold Tz” is satisfied. That is, in the present embodiment, the acquired value Z is based on the “number of postcards recorded” stored in the RAM 103.

  Discharge failure due to starch is particularly likely to occur when a postcard is used as a recording medium. In view of this, in the present embodiment, it is determined which of the normal maintenance process (S4) and the special maintenance process (S5) is performed using the acquired value Z based on the number of postcards recorded. If special maintenance processing is frequently performed, processing may take time and high-speed recording may be hindered. However, according to the above configuration, excessive execution of special maintenance processing is suppressed, and ejection failure due to starch is suppressed. And high-speed recording can be realized together.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims.

The acquired value may be based on only the value detected by the sensor (not based on the recorded number). For example, in the first embodiment, the detection value Y may be the acquired value. In this case, the storage unit does not have to store the recorded number. In this case, since the acquired value becomes smaller as the amount of starch is larger, the control unit performs normal maintenance processing when the acquired value is determined to be greater than or equal to the threshold value in the comparison process, and the acquired value is less than the threshold value. Special maintenance processing is performed when it is determined.
The path forming member to be detected by the sensor is not limited to the roller pair, and may be a conveyance belt, a guide plate, or the like.
In the first embodiment, the value obtained by dividing the “recorded number X for all types of paper P” by the detected value Y is used as the acquired value Z. However, the value obtained by dividing the “postcard recorded number” by the detected value Y is used. The acquired value Z may be used.
-When not using the detection value by a sensor like 2nd Embodiment, you may abbreviate | omit a sensor.
The purge may be either a pressure purge or a suction purge (an operation in which the inside of the cap is set to a negative pressure and the liquid is sucked from the discharge port while the discharge surface is sealed with the cap).
-A movement mechanism is not limited to moving a wiper, A liquid discharge part may be moved, and both a wiper and a liquid discharge part may be moved.
The normal maintenance process includes a wipe in the above-described embodiment, but may not include a wipe. In addition, as long as the condition that the number of empty wipes (multiple empty wipes) included in the normal maintenance process is performed in the special maintenance process is satisfied, the purge, wipe, and The number of empty wipes is not particularly limited, and the normal wipe may be performed one or more times.
In the special maintenance process, the timing of performing the forward direction empty wipe and the reverse direction empty wipe is arbitrary. For example, in each step of S33 and S36, one or a plurality of forward direction empty wipes and reverse direction empty wipes are performed. It may be done once. Further, the empty wipe performed in the special maintenance process may be only in the forward direction or only in the reverse direction.
-The paper dust removal mechanism may be omitted.
The transport mechanism is not limited to a configuration including a pair of rollers that rotate while sandwiching the recording medium, and may include a belt that travels while supporting the recording medium on the surface.
-A liquid discharge part is not limited to a line type, A serial type may be sufficient.
The number of liquid ejection units included in the recording apparatus is arbitrary, not limited to one, and may be plural.
The recording medium is not limited to paper, and may be cloth.
The recording apparatus is not limited to a printer, and may be a facsimile, a copier, a multifunction machine, or the like.

1 Inkjet printer (recording device)
10 Inkjet head (liquid ejection part)
10a discharge surface 10P pump 14 individual flow path 14a discharge port 20 transport mechanism 24 roller pair (path forming member)
24S sensor 30 Paper dust removing mechanism 50 Wiper 55 Wiper moving mechanism (moving mechanism)
101 CPU (control unit)
102 ROM (storage unit)
103 RAM (storage unit)
P paper (recording medium)

Claims (9)

A liquid ejection section having a plurality of individual flow paths reaching each of the plurality of ejection openings and an ejection surface having a plurality of ejection openings for ejecting liquid;
A pump for applying a pressure to the liquid in the plurality of individual flow paths to discharge the liquid from the plurality of discharge ports;
A wiper for wiping the discharge surface;
The wiper and the liquid discharge unit are configured such that the wipe is performed by moving relative to the liquid discharge unit in a moving direction along the discharge surface while the wiper is in contact with the discharge surface. A moving mechanism for moving at least one of
A storage unit that stores a predetermined threshold for the amount of starch produced from the recording medium in the vicinity of the liquid ejection unit;
And a control unit,
The controller is
When a predetermined condition is satisfied, a value related to the amount of starch in the vicinity of the liquid ejection unit is acquired, and a comparison process for comparing the acquired value with a threshold value stored in the storage unit,
When the acquired value is a value that increases as the amount of starch increases, when the acquired value is determined to be less than the threshold in the comparison process, and the acquired value increases as the amount of starch increases. If the acquired value is smaller than the threshold value in the comparison process, the purge, the wipe, and the wipe after the purge are performed are not sandwiched after the purge is performed. A normal maintenance process for controlling the pump so that at least the purge is performed among the empty wipes that are performed
When the acquired value is a value that increases as the amount of starch increases, when the acquired value is determined to be greater than or equal to the threshold value in the comparison process, and the acquired value increases as the amount of starch increases. When the value is smaller than the amount of liquid discharged from the plurality of discharge ports in the purge included in the normal maintenance process when the acquired value is determined to be less than the threshold value in the comparison process. A large-scale purge, which is the purge that discharges a large amount of liquid, and a multi-times empty wipe, which is the number of empty wipes that is greater than the number of empty wipes (an integer greater than or equal to 0) included in the normal maintenance process, are performed. And a special maintenance process for controlling the pump and the moving mechanism.   The recording apparatus according to claim 1, wherein the special maintenance process repeats a set of the large-volume purge and the multi-time empty wipe performed after the large-volume purge twice or more.   In the group that is repeated two or more times, among the two groups that are performed consecutively, the multiple-time empty wipe that is performed first is one of the forward direction and the reverse direction of the moving direction, and is performed later. The recording apparatus according to claim 2, wherein the multi-time empty wipe is the other of the forward direction and the reverse direction.   The recording apparatus according to claim 1, wherein the special maintenance process includes the empty wipes in a forward direction and a reverse direction in the moving direction.   A transport mechanism for transporting a recording medium along a transport path toward a position facing the discharge surface, the path forming being disposed upstream of the transport path and forming the transport path with respect to the liquid discharge unit The recording apparatus according to claim 1, further comprising a transport mechanism including a member.   The recording apparatus according to claim 5, further comprising a paper dust removing mechanism for removing paper dust attached to the recording medium upstream of the path forming member from the conveyance path. A sensor for detecting a value related to the amount of the starch adhering to a portion forming the transport path in the path forming member;
The recording apparatus according to claim 5, wherein the acquired value is based on a value detected by the sensor. The storage unit further stores a recorded number that is the number of recording media recorded by discharging liquid from the liquid discharging unit;
The control unit calculates the acquired value based on a value detected by the sensor and a recorded number stored in the storage unit when acquiring the acquired value in the comparison process. The recording apparatus according to claim 7. The storage unit further stores a postcard recorded number, which is the number of postcards of the recording medium, recorded by discharging the liquid from the liquid discharge unit,
The recording apparatus according to claim 1, wherein the acquired value is based on a recorded number of postcards stored in the storage unit.

Images