JP2005081591A - Recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image formation apparatus which can carry out image formation by a high image quality at a high speed. <P>SOLUTION: Hole parts 26 are formed on an endless belt 24 in accordance with an arrangement of unit recording heads 32. Ink droplets are discharged (dummy jetted) by the unit recording heads 32 by a timing when the hole parts 26 are detected by a hole part detection sensor 42. In other words, the timing when the unit recording head 32 and the hole part 26 are opposed to each other can be precisely detected in spite of sliding of the endless belt 24 to a driving roll 20. Therefore, the ink droplets which pass the hole parts 26 by a timing when no paper is present even in the middle of continuous image formation are surely held in an ink receiving member 40, so that the good ink droplet discharging performance can be maintained. At the same time, high-speed printing can be achieved without moving the unit recording heads 32. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus that performs recording by ejecting ink droplets onto a recording medium, and a recording apparatus that is used as an output device such as a facsimile, a copier, a printer multifunction peripheral, or a workstation having these functions.

  2. Description of the Related Art Conventionally, ink jet recording apparatuses that perform printing by ejecting ink droplets are known as image forming apparatuses used in printers, facsimiles, copying machines, and the like. This recording apparatus forms an image on a recording medium (such as paper) by ejecting ink droplets from nozzles (ejection ports) of a recording head.

In recent years, in order to increase the image forming speed (printing output speed) of the ink jet system, a system in which a recording head is arranged over the entire width of the paper has been studied. A paper transport belt is provided at a position facing the recording head, and continuously. Researches have been made to transport paper and form images at high speed.
Such a recording apparatus can stably convey the sheet to the image forming position at a high speed, and therefore can prevent image quality defects (abnormality of the sheet and uneven feeding) that occur in the sheet conveyance.
On the other hand, in order to maintain the ink droplet ejection performance, the recording head needs to eject ink droplets (dummy printing) during non-image formation. Also, in order to prevent clogging of the nozzles of the recording head due to ink drying, nozzle cleaning (wiping) to remove unnecessary ink adhering to the nozzle surface of the recording head, and the tip of the nozzle when the recording apparatus is not in use It is necessary to perform maintenance such as capping to prevent the ink of the ink from drying and sticking.

In order to perform the above-described maintenance, in the conventional example, an ink recovery mechanism, a nozzle cleaning mechanism, and a nozzle capping mechanism are arranged around the paper transport mechanism, and the recording head is used as a transport belt when performing the cleaning operation and the capping operation. It is configured to move from an opposing position (image forming position) to a position of the mechanism (maintenance position) to perform each operation (for example, Patent Documents 1 and 2; hereinafter referred to as Conventional Examples 1 and 2). .
In such a configuration, since a nozzle cleaning mechanism, a capping mechanism, and the like are provided around the paper transport belt, there is a disadvantage that the apparatus becomes large. Further, since the recording head is moved between the image forming position and the maintenance position with each maintenance operation, the time until the image forming return is increased. Therefore, even if the image forming speed itself can be increased by using the paper conveying belt, there arises a problem that the print output speed is lowered as a result.
Furthermore, since the recording head is moved greatly in accordance with the maintenance operation, the recording head position at the image forming position is likely to vary, and the movement is likely to cause image misregistration and color misregistration. There is an inconvenience that requires more time.
Therefore, in order to solve such a problem, a configuration has been proposed in which dummy printing is performed on the sheet conveying belt from the recording head, and ink attached to the belt is removed by belt cleaning means provided on the downstream side of the recording head. (For example, Patent Document 3; hereinafter referred to as Conventional Example 3). On the other hand, a nozzle cleaning mechanism for cleaning the nozzle and a capping mechanism for protecting the nozzle are arranged at the lateral position of each recording head, and when performing wiping or capping, the recording head is separated from the paper transport belt and the recording head and the paper A space is provided between the conveyor belts to perform each maintenance operation. Accordingly, since the ink recovery necessary for post-processing of dummy printing can be achieved by a part of the paper transport belt mechanism (belt cleaning means), the apparatus can be prevented from being enlarged, and the nozzle cleaning mechanism and the capping mechanism can be used as the paper transport belt. Since it is arranged in the vicinity, the time required for each operation can be shortened.
JP 2000-198210 A JP 2002-59559 A JP 2000-127362 A

  However, in the method of performing dummy printing on the paper transport belt of Conventional Example 3, it is necessary to bring a cleaning means (for example, a blade) into contact with the belt in order to remove ink on the paper transport belt. When the cleaning unit comes into contact with the paper transport belt during recording (image formation), a load fluctuation occurs in the paper transport belt, and the belt speed changes. As a result, the positional relationship between the image formation (ink droplet ejection) timing and the paper is shifted, resulting in image quality defects such as image positional shift and color shift. In order to remove the influence of the load fluctuation, it is necessary to interrupt the image forming operation during the cleaning operation, and the print output speed is reduced.

  In Conventional Example 3, since the recording head is moved toward and away from the paper transport belt during the wiping operation and the capping operation, it is difficult to perfectly align the recording head disposed at the time of image formation. Since the amount of movement of the recording head is small, the image position shift and color shift are not completely eliminated although the degree is small.

  In order to solve the above problems, the present invention provides a recording apparatus that performs high-quality image recording with a high print output speed.

  2. The recording apparatus according to claim 1, wherein the recording apparatus forms an image with droplets on the recording medium, and a plurality of unit recording heads that eject droplets to the recording medium are combined to discharge droplets over the entire width of the recording medium. A non-scanning type recording head configured to be capable of conveying, and a belt conveying unit including a conveying belt that conveys a recording medium under the recording head and has a plurality of holes corresponding to the arrangement of the unit recording heads; An ink collecting operation for collecting droplets ejected from the recording head during non-image formation, which is disposed opposite to the unit recording head with the conveying belt interposed therebetween, and maintains the ink droplet ejection performance of the unit recording head; A capping operation that passes through a portion and abuts against a droplet discharge surface of the unit recording head to hold the droplet discharge surface in an airtight manner, and passes through the recording hole portion to form the unit recording head. Maintenance means for performing at least one maintenance operation of a cleaning operation for contacting the liquid droplet ejection surface to remove dirt on the liquid droplet ejection surface, hole position detecting means for detecting the hole position of the transport belt, Control means for controlling the maintenance operation based on the hole position detected by the hole position detecting means.

  The operation of the recording apparatus according to claim 1 will be described.

  In the recording apparatus of the present invention, liquid droplets are ejected from the non-scanning recording head (a plurality of unit recording heads) to the recording medium transported by the transport belt, so that high-speed printing is possible. In addition, maintenance means for maintaining the droplet discharge performance of the recording head is disposed to face each unit recording head with the conveying belt interposed therebetween, and a hole corresponding to the arrangement of the unit recording head is provided in the conveying belt. Therefore, it is possible to perform maintenance for maintaining the droplet discharge performance of the recording head through the hole of the conveying belt without moving the recording head (unit recording head). For example, when the maintenance operation is an ink recovery operation (dummy printing), there is no sheet under the unit recording head, and the droplets from the unit recording head pass when the hole of the transport belt passes under the unit recording head. Is performed by discharging. As a result, the droplets by the dummy printing are reliably collected by the ink collecting means without passing through the hole of the conveying belt and adhering to the conveying belt. Therefore, dummy printing can be performed without moving the recording head, and the droplet discharge performance of the unit recording head can be maintained well. When the maintenance operation is a capping operation or a cleaning operation, the driving of the conveying belt is stopped at a position where the unit recording head and the hole face each other, and the maintenance unit passes through the hole of the conveying belt and passes the unit recording head. The droplet discharge surface is brought into contact with the liquid droplet discharge surface, and the droplet discharge surface is kept airtight or the droplet discharge surface is cleaned. As a result, the droplet discharge performance of the unit recording head can be maintained satisfactorily.

  As described above, since the recording head does not move in any maintenance operation, it is not necessary to correct misalignment accompanying the movement of the recording head, and the time from the maintenance state to the start of image formation is suppressed, resulting in high speed. Printing is achieved.

  Further, the hole position detecting means detects the hole position of the conveying belt, and based on the hole position, the control means controls the maintenance means etc. with the hole facing the unit recording head to perform the maintenance operation. Therefore, the maintenance operation can be performed with high accuracy even if the conveyor belt slips.

  According to a second aspect of the present invention, in the recording apparatus according to the first aspect, a hole is formed in the conveying belt by repeating an arrangement pattern corresponding to the arrangement of the unit recording heads a plurality of times along the conveying direction. It is characterized by being.

  The operation of the recording apparatus according to claim 2 will be described.

  Since a plurality of holes formed in an arrangement pattern corresponding to the arrangement of the unit recording heads are formed at a plurality of locations in the conveyance direction of the conveyance belt, a maintenance operation can be performed at a plurality of positions on the conveyance belt. Accordingly, it is possible to shorten the time required for the maintenance operation. Here, the arrangement pattern is an arrangement of the minimum unit hole portions in which the arrangement of the hole portions is the same at different positions in the transport direction. For example, if four color recording heads are arranged at different positions in the transport direction, the unit recording heads constituting each recording head correspond to the arrangement of the unit recording heads as long as the unit recording heads constituting each color recording head have the same arrangement. The arrangement of the holes to be performed corresponds to the arrangement pattern.

  According to a third aspect of the present invention, in the recording apparatus of the first or second aspect, the hole position detecting means detects that the hole passes through a predetermined position as the transport belt moves. Features.

  The operation of the recording apparatus according to claim 3 will be described.

  The hole position detection means can accurately detect the timing at which the hole of the conveyor belt passes a predetermined position. Therefore, even if the transport belt moves relative to the drive roll (slides), the hole position on the transport belt can be detected with high accuracy, and the maintenance operation can be performed reliably.

  The recording apparatus according to claim 4, wherein the belt conveyance unit is configured to move the conveyance belt relative to a driving roll on which the conveyance belt is stretched. The anti-slip means for preventing the anti-slip is provided, and the hole position detecting means detects the hole position based on the rotation amount of the drive roll.

  The operation of the recording apparatus according to claim 4 will be described.

  Since the belt conveyance means is provided with a slip prevention means for preventing the conveyance belt from moving relative to the drive roll, the rotation amount of the drive roll and the hole position have a certain relationship. Therefore, the hole position detection means can detect the hole position with high accuracy only by detecting the rotation amount of the drive roll.

  A recording apparatus according to a fifth aspect is the recording apparatus according to the fourth aspect, wherein the slip prevention means includes an engaging portion provided on one of the transport belt and the driving roll, and the engagement provided on the other. It is comprised from the to-be-engaged part which a joint part engages.

  The operation of the recording apparatus according to claim 5 will be described.

  By adopting a configuration in which the engaging portion provided on one of the conveying belt and the driving roll and the engaged portion provided on the other are engaged, the conveying belt becomes the driving roll along with the rotation of the driving roll. It moves without moving (sliding) relatively. Therefore, the hole position detection means can accurately detect the hole position based on the rotation amount of the drive roll, and based on this, the maintenance is good when the hole of the conveying belt comes to the position facing the unit recording head. Can be done.

  The recording apparatus according to claim 6 is the recording apparatus according to claim 4 or 5, wherein among the plurality of holes formed over the entire length of the conveyance belt, the conveyance direction interval between the holes at the same position in the width direction is It is 1 / integer multiple of the circumference of the drive roll.

  The operation of the recording apparatus according to the sixth aspect will be described.

  Since the conveyance belt does not move relative to the drive roll, the conveyance direction interval of the plurality of holes formed at the same position in the width direction of the conveyance belt is set to 1 / integer multiple of the circumference of the drive roll. The positional relationship between the rotational position (0 ≦ θ <2π) of the drive roll and the hole 26 is constant. Therefore, the hole position detection means can detect the hole position by detecting the timing at which the rotational position of the drive roll becomes a predetermined value, for example, the mark formed on the side surface of the drive roll by the sensor.

  The recording apparatus according to claim 7 is the recording apparatus according to any one of claims 1 to 6, wherein the belt conveying mechanism includes a negative pressure generating means for adsorbing the sheet onto the conveying belt. It is provided on the side opposite to the sheet holding side.

  The operation of the recording apparatus according to claim 7 will be described.

  By providing the negative pressure generating means on the side opposite to the paper holding side of the transport belt, the paper placed on the transport belt is sucked and held on the transport belt by the negative pressure acting through the hole of the transport belt. The Therefore, it is stably conveyed under the recording head, and an image is formed with high image quality. In particular, when a metal belt is used as the conveyance belt, it is possible to hold the sheet with a simple configuration, which is preferable.

  In the recording apparatus according to the present invention, it is possible to suppress the image formation interruption time associated with the maintenance operation and enable high-speed printing, and realize high-quality image formation.

[First Embodiment]
An ink jet recording apparatus according to a first embodiment of the present invention will be described.

  As shown in FIG. 1, the inkjet recording apparatus 10 includes a belt conveyance mechanism 12 that conveys a sheet to a printing position, and magenta (M) and cyan (C) arranged to face the endless belt 24 of the belt conveyance mechanism 12. ), Yellow (Y), black (K) recording heads 14M, 14C, 14Y, 14K (hereinafter referred to as 14M to 14K; the same applies to other numbers) and recording heads 14M to 14K. The maintenance devices 16M to 16K are arranged to face each other across the endless belt 24.

  The belt transport mechanism 12 includes a drive roll 20, a driven roll 22, and an endless belt 24 stretched between both rolls. As shown in FIG. 2, holes 26 are formed in the endless belt 24 in a staggered manner corresponding to the arrangement of unit recording heads 32 (described later) constituting the recording head 14.

  As shown in FIG. 2, each of the recording heads 14 </ b> M to 14 </ b> K is configured by a combination of a plurality of unit recording heads 32 disposed on the top of the endless belt 24. For example, the recording head 14M is disposed on the head support plate 30M1 with a plurality of unit recording heads 32 (recording head array 34M1) disposed at a predetermined interval and on the head support plate 30M2 at a predetermined interval. The unit recording head 32 (recording head array 34M2) is configured to be able to discharge ink droplets without interruption across the entire width in the width direction by shifting the unit recording heads 32 of the recording head arrays 34M1 and 34M2 in the width direction. It is said that. The same applies to the recording heads 14C, 14Y, and 14K.

  Further, the interval between the unit recording heads 32 constituting the recording head array 34M1 of the recording head 14M and the unit recording heads 32 constituting the recording head array 34M2 in the paper transport direction (arrow X1 direction), and the units constituting the recording head array 34M2. The intervals in the paper transport direction between the recording heads 14C disposed adjacent to the recording heads 32 and the unit recording heads 32 constituting the recording head array 34C1 in the paper transport direction are equally arranged with a length L1. That is, the conveyance direction intervals between the unit recording heads constituting the adjacent recording head array 34 are all set equal to the length L1. Further, the interval between unit recording heads having the same width direction position is L2 (= 2 × L1) (see FIG. 2).

  The ink droplet ejection method of the unit recording head 32 may be any known method such as a piezo method or a thermal method.

  On the other hand, the hole 26 formed in the endless belt 24 is formed corresponding to the arrangement of the unit recording heads 32. In other words, the hole 26 is a rectangular hole that is slightly wider than the unit recording head 32, and is formed in a staggered manner like the unit recording head 32. The distance between adjacent holes in the transport direction is L1. The interval between the holes having the same position in the width direction is L2 (= 2 × L1) and is formed over the entire circumference (see FIG. 2). That is, when one hole 26 faces the unit recording head 32, the hole 26 of the endless belt 24 is positioned at a position where all the unit recording heads 32 face each other.

  As shown in FIG. 1, the maintenance devices 16M to 16K are disposed inside the belt conveyance mechanism 12 so as to face the recording heads 14M to 14K with the endless belt 24 interposed therebetween.

  The maintenance devices 16M to 16K are constituted by ink receiving members 40 arranged to face the unit recording heads 32 constituting the recording head 14M, and each of the dummy printing ink droplets ejected from the unit recording heads 32. It is the structure which accommodates.

  In the belt transport mechanism 12, a hole detection sensor 42 installed in the support plate 30 supported between the support plates 28A and 28B is disposed upstream of the recording head 14 in the paper transport direction (see FIG. 2). The hole detection sensor 42 is the same in the width direction as the unit recording heads 32 constituting the recording head array 34M2, and is disposed upstream in the transport direction by a distance L2. Therefore, the entire unit recording head 32 and the hole 26 face each other at the timing when the hole 26 is detected by the hole detection sensor 42. The hole detection sensor 42 is configured to detect passage of the hole 26 and output a hole detection signal to the control unit 44.

  On the other hand, the control unit 44 generates a dummy print (ink droplet discharge) signal for each unit so as to discharge ink droplets from the unit recording head 32 based on the hole detection signal (hole detection timing) from the hole detection sensor 42. In this configuration, a stop signal is output to the drive motor 46 that outputs to the recording head 32 or drives the drive roll 20. The endless belt 24 is always stopped at a position where the unit recording head 32 and the hole 26 face each other.

  The operation of the ink jet recording apparatus configured as described above will be described.

  First, when normal printing is performed, a sheet supplied from a sheet supply unit (not shown) is conveyed onto the belt 24 of the belt conveying mechanism 12, and the sheet placed on the belt 24 passes under the recording heads 14M to 14K. By passing, ink droplets are ejected from each unit recording head 32 constituting the recording heads 14M to 14K, and an image is formed on the paper.

  On the other hand, dummy printing is performed during non-image formation. Here, both of the case where the image forming operation is not performed during non-image formation and the case where there is no sheet under the unit recording head 32 during continuous printing on a plurality of sheets are included.

  When performing dummy printing when image formation is not being performed, the endless belt 24 is stopped at a position where the hole 26 faces the unit recording head 32, so that the control unit 44 immediately applies to each unit recording head 32. An ink droplet ejection signal is output. As a result, the ink droplets (dummy printing) discharged from each unit recording head 32 pass through the hole 26 and are reliably accommodated in the ink receiving member 40 (see FIG. 3).

  On the other hand, when performing dummy printing during continuous printing, the control unit 44, as shown in FIG. 4A, precedes the sheet preceding the unit recording head 32 constituting the recording head array 34 that performs dummy printing. Timing (hereinafter referred to as “inter-sheet timing”) (T1) until the trailing edge of P1 passes and the leading edge of the succeeding paper P2 arrives, and timing when a hole detection signal is input from the hole detection sensor 42 ( By outputting an ink droplet ejection signal to the unit recording head 32 at the timing when T2) overlaps, the ink droplet (dummy printing) ejected from the unit recording head 32 passes through the hole 26 and the ink receiving member 40. Is housed in.

  As described above, since the dummy printing is performed based on the timing at which the hole detection sensor 42 detects the hole 26, even if the endless belt 24 slips (relative movement) with respect to the drive roll 20, it faces the unit recording head 32. Dummy printing can be performed in a state where the hole portion 26 is always located at the position where the endless belt 24 is stained. Further, since the blade or the like is brought into contact with the endless belt 24 to remove the ink attached thereto, and no load fluctuation occurs in the endless belt 24, the sheet can be stably conveyed.

  Further, since it is not necessary to move the recording head 14 (unit recording head 32) in order to perform dummy printing, the speed of image formation is achieved, and the misalignment of the image forming position due to the movement of the recording head 14 occurs. In other words, since the correction for the misalignment is performed, the high speed is prevented from being hindered. Therefore, high-speed and high-quality image formation can be performed (see FIG. 3).

  The endless belt 24 of the present embodiment is preferably formed of a metal belt from the viewpoint of strength because the hole 26 is formed over the entire circumference.

In addition, although the other hole 26 is configured to face the unit recording head 32 at the timing when the hole detection sensor 42 detects the hole 26, the present invention is not limited to this, and the control unit 44 receives from the hole detection sensor 42. A configuration in which the hole position is detected based on the hole detection signal and the timing at which the hole 26 faces the unit recording head 32 may be used.
[Second Embodiment]
An ink jet recording apparatus according to a second embodiment of the present invention will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, as shown in FIG. 5B, the hole 26 of the endless belt 24 is not formed (the sheet is not placed), and circular at a predetermined interval along the rotation direction at both ends in the width direction. The engagement holes 50 are formed at regular intervals. Further, as shown in FIG. 5A, engagement protrusions 52 that engage with the engagement holes 50 at predetermined intervals in the circumferential direction are also formed at both ends in the width direction on the circumferential surface of the drive roll 20. It is. Further, instead of the hole detection sensor of the first embodiment, a detection sensor 56 for detecting a reference position mark 54 provided on the side surface of the drive roll 20 is provided. The control unit 44 is configured to detect the timing at which the hole 26 of the endless belt 24 faces the unit recording head 32 (hereinafter referred to as dummy printing timing) based on the detection signal of the detection sensor 56. is there. The control unit 44 is configured to control the drive motor 46 of the drive roll 20 based on the detection signal of the reference position mark 54 of the detection sensor 56.

  With this configuration, the following effects are obtained.

  That is, since the engagement protrusion 52 of the drive roll 20 is driven with the engagement hole 50 of the endless belt 24 engaged (inserted), the endless belt 24 is displaced relative to the drive roll 20 (sliding). It turns without producing.

  Therefore, the control unit 44 performs dummy printing by ejecting ink droplets from the unit recording head 32 at the dummy printing timing detected based on the detection signal of the reference position mark 54 input from the detection sensor 56. As a result, ink droplets for dummy printing ejected from the unit recording head 32 pass through the hole 26 of the endless belt 24 and are accommodated in the ink receiving member 40. That is, an image can be formed without ink droplets for dummy printing adhering to the endless belt 24 and without interrupting continuous printing. Further, since the endless belt 24 is driven in a state in which the engagement protrusion 52 of the drive roll 20 is engaged with the engagement hole 50 of the endless belt 24, the endless belt 24 is prevented from meandering and more stable paper conveyance is achieved. As a result, high-quality image formation is achieved.

In this case, the interval (pitch) L2 between the holes 26 formed at the same position in the width direction is preferably set to 1 / integer times the circumferential length Q of the drive roll 20 (see FIG. 6). With this configuration, the positional relationship between the rotational position (0 ≦ θ <2π) of the drive roll and the hole 26 is constant. Therefore, dummy printing can be performed at a fixed timing after the detection sensor 56 detects the reference position mark 54. Note that the circumferential length L of the endless belt 24 is also preferably an integral multiple of the circumferential length Q of the drive roll 20 and the interval L2 between the holes 26. This is because the relationship between the hole detection timing of the detection sensor 56 and the timing of passing under the unit recording head 32 is kept constant even when the belt rotates.
[Third Embodiment]
An ink jet recording apparatus according to a third embodiment of the present invention will be described. The same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present invention, as shown in FIG. 7, a configuration in which the maintenance device 16 includes not only the ink receiving member 40 but also the wiping device 60 and the capping device 62 will be described.

  As shown in FIG. 7, the ink receiving member 40 is normally disposed at a position facing the unit recording head, and is moved along the guide bar 64 by a first drive mechanism (not shown) in the paper transport direction (X1 direction) or vice versa. It is configured to be movable integrally in a direction (X2 direction) (the X direction is a combination of both).

  Further, below the ink receiving member 40, a wiping device 60 and a capping device 62 are arranged adjacent to each other in the X direction by a second drive mechanism (not shown), and along the guide bar 66 by the second drive mechanism, the X direction. It is comprised so that movement is possible integrally. A piston rod 68 is provided below the wiping device 60 and the capping device 62 at a position facing the unit recording head 32. The wiping device 60 or the capping device 62 is raised at the time of capping or wiping described later, The unit recording head 32 is in contact with the unit recording head 32.

  The ink jet recording apparatus configured as described above will be described.

  In the ink jet recording apparatus, at the time of normal printing, as shown in FIG. 7, the ink receiving member 40 is disposed at a position facing the unit recording head 32, and the timing when the hole 26 is detected by the hole detection sensor 42 ( By performing dummy printing (ink droplet ejection) at the timing when the unit recording head 32 and the hole 26 face each other) T2 and the inter-paper timing T1 overlap, the ink droplets ejected from the unit recording head 32 are endless belts. The ink receiving member 40 is accommodated through the 24 holes 26.

  On the other hand, at the time of wiping, as shown in FIG. 8, the control unit 44 outputs a stop signal to the drive motor 46 based on the input of the detection signal from the hole detection sensor 42, whereby the drive roll 20 stops rotating. As a result, the hole 26 of the endless belt 24 is positioned so as to face the nozzle surface of the unit recording head 32.

  On the other hand, a drive signal is output from the control unit 44 to the first drive mechanism, and the ink receiving member 40 moves in the X2 direction along the guide bar 64 to retreat from the bottom of the unit recording head 32. The wiping device 60 located below is raised by driving the piston rod 68, and the wiping device 60 passes through the hole 26 of the endless belt 24 and comes into contact with the nozzle surface of the unit recording head 32. In this state, the nozzle surface is cleaned by the wiping device 60 slidingly contacting the nozzle surface of the unit recording head. After the wiping is completed, the wiping device 60 is lowered by the deactivation of the piston rod 68, and the ink receiving member 40 is moved in the X1 direction by driving the first drive mechanism to return to the original position facing the unit recording head 32. As a result, the maintenance operation ends.

  Further, at the time of capping, as shown in FIG. 9, the rotation of the drive roll 20 is stopped at the position where the hole 26 of the endless belt 24 faces the unit recording head 32, and the driving of the first drive mechanism is performed as in the case of wiping. As a result, the ink receiving member 40 moves in the X2 direction and retracts from the position where the unit recording head 32 faces. In addition, the wiping device 60 and the capping device 62 are integrally moved in the X1 direction by driving the second drive mechanism, and the capping device 62 is positioned on the piston rod 68. In this state, the piston rod 68 is urged, and the capping device 62 moves up through the hole 26 of the endless belt 24 and presses against the nozzle surface of the unit recording head 32. As a result, the nozzle surface of the unit recording head 32 is kept airtight.

  When releasing the capping, the capping device 62 is lowered by de-energizing the piston rod 68, and the ink receiving member 40 is moved in the X1 direction by driving the first drive mechanism, so as to face the unit recording head 32. The maintenance operation is completed by returning to the original position.

By configuring the ink jet recording apparatus in this manner, not only dummy printing but also wiping and capping can be performed without moving the recording head 14 (unit recording head 32). Therefore, even if these maintenance operations are performed, the time generated with the movement of the recording head 14 and the correction time for dealing with the positional deviation of the unit recording head 32 become unnecessary, and the image formation can be quickly returned to. As a result, high-speed printing is achieved. Further, since the wiping device 60 and the capping device 62 are also arranged inside the belt conveying mechanism 12, the ink jet recording device 10 can be reduced in size. In the present embodiment, the configuration of the drive mechanism is not limited to the present embodiment as long as the maintenance operation can be performed through the hole without moving the recording head. Moreover, it cannot be overemphasized that there exists an effect similar to 1st, 2nd embodiment.
[Fourth Embodiment]
An ink jet recording apparatus according to a fourth embodiment of the present invention will be described. The same components as those in the first to third embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, in order to hold the sheet on the belt, negative pressure generators 70A and 70B and a suppression roll are provided on the upstream side and the downstream side in the transport direction across the image forming position (recording head 14) in the transport belt unit 12. It is characterized in that 72A and 72B are provided. That is, the negative pressure generators 70A and 70B are provided below (inside) the belt 24, and the control rolls 72A and 72B are disposed on the opposite side across the belt 24 with the negative pressure generators 70A and 70B.

  With this configuration, the paper P supplied to the belt transport mechanism 12 is pressed onto the endless belt 24 by the restraining roll 72A, and endless by the negative pressure acting through the hole 26 from the negative pressure generating device 70A. Adsorbed on the belt 24. In this state, the leading edge of the paper that has passed under the recording heads 14M to 14K is pressed onto the endless belt by the restraining roll 72B, and the negative pressure of the negative pressure generating device 70B acts through the hole portion 26 so as to be on the endless belt 24. To be adsorbed. Therefore, the paper P can pass under the unit recording head 32 without floating on the belt, and high-quality printing can be performed.

  Further, in the ink jet recording apparatus 10 that achieves high-speed printing by performing the maintenance operation through the hole portion 26 as in the present embodiment, the negative pressure suction is performed by using the hole portion 26 of the endless belt 24. Paper holding can be achieved with a limited configuration. In particular, even when a metal plate is used to ensure the strength of the belt, it is possible to ensure a sheet holding configuration with a simple configuration.

  In the present embodiment, the example in which the negative pressure suction unit is provided has been described for the purpose described above. However, the present invention is not limited to this as long as the unit can reliably hold the paper on the belt. Other means may be used.

  The maintenance devices 16M to 16K are applicable to the present invention as long as they perform at least one of ink recovery (dummy printing) operation, capping operation, and cleaning operation, and are not limited to the embodiments.

1 is a schematic side view illustrating a recording apparatus according to a first embodiment of the invention. 1 is a schematic plan view of a recording apparatus according to a first embodiment of the present invention. It is principal part explanatory drawing which shows the dummy printing state in the recording device which concerns on 1st Embodiment of this invention. 6 is a timing chart for explaining a dummy printing control state of the recording apparatus according to the first embodiment of the invention. (A) is a schematic side view which shows the recording device based on 2nd Embodiment of this invention, (B) is a top view of the belt which concerns on 2nd Embodiment of this invention. It is relationship explanatory drawing of the positional relationship of the hole of the variation which concerns on 2nd Embodiment of this invention, and the circumference of a drive roll. It is a schematic side view of the inkjet recording device which concerns on 3rd Embodiment of this invention. FIG. 6 is an explanatory diagram of a wiping state of an ink jet recording apparatus according to a third embodiment of the present invention. It is a capping state explanatory drawing of the inkjet recording device which concerns on 3rd Embodiment of this invention. It is a schematic side view of the recording apparatus which concerns on 4th Embodiment of this invention.

Explanation of symbols

10 Inkjet recording device (recording device)
12 Conveying belt mechanism 14 Recording head 16 Maintenance device 20 Driving roll 24 Endless belt 26 Hole 32 Unit recording head 34 Recording head array 40 Ink receiving member 42 Hole detection sensor 44 Control unit 60 Wiping device 62 Capping device

Claims (7)

In a recording apparatus for forming an image with droplets on a recording medium,
A non-scanning type recording head configured such that a plurality of unit recording heads that discharge droplets to the recording medium can be combined to discharge droplets over the entire width of the recording medium;
Belt conveying means including a conveying belt that conveys the recording medium under the recording head and in which a plurality of holes corresponding to the arrangement of the unit recording heads are formed;
An ink collecting operation for collecting droplets ejected from the recording head during non-image formation, which is disposed opposite to the unit recording head with the conveying belt interposed therebetween, and maintains the ink droplet ejection performance of the unit recording head; A capping operation that passes through the portion and contacts the droplet discharge surface of the unit recording head to keep the droplet discharge surface airtight, and contacts the droplet discharge surface of the unit recording head through the recording hole. Maintenance means for performing at least one maintenance operation of a cleaning operation for removing dirt on the droplet discharge surface;
Hole position detecting means for detecting the hole position of the conveyor belt;
Control means for controlling the maintenance operation based on the hole position detected by the hole position detecting means;
A recording apparatus comprising:   2. The recording apparatus according to claim 1, wherein a hole is formed in the conveying belt by repeating an arrangement pattern corresponding to the arrangement of the unit recording heads a plurality of times along the conveying direction.   The recording apparatus according to claim 1, wherein the hole position detection unit detects that the hole of the transport belt passes a predetermined position.   The belt conveying means is provided with anti-slip means for preventing relative movement of the conveying belt with respect to the driving roll on which the conveying belt is stretched, and the hole position detecting means is based on the rotation amount of the driving roll. The recording apparatus according to claim 1, wherein the hole position is detected.   The slip prevention means includes an engaging portion provided on one of the transport belt and the drive roll, and an engaged portion provided on the other and engaged with the engaging portion. The recording apparatus according to claim 4.   The conveyance direction interval of the holes at the same position in the width direction among the plurality of holes formed over the entire length of the conveyance belt is 1 / integer multiple of the circumferential length of the drive roll. 4. The recording device according to 4 or 5.   7. The belt conveying unit according to claim 1, wherein a negative pressure generating unit for adsorbing paper onto the conveying belt is provided on the side opposite to the recording medium holding side of the conveying belt. The recording device described.

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