JP2000272110A - Ink jet recorder and ejection recovery method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recorder and an ejection recovery method therefor capable of achieving high speed recording without spending the time for preliminary ejection by a constitution wherein a position for the preliminary ejection on a conveying body such as a conveyer belt can be changed. SOLUTION: Preliminary ejection regions 11, 12, 13, 14 on a conveyer belt 31 can be changed corresponding to a loaded position of a recording paper P on the conveyer belt 31. Ink is preliminarily ejected from recording heads 7K, 7C, 7M, 7Y on the preliminary ejection regions 11, 12, 13, 14. The ink preliminarily ejected on the conveyer belt 31 is removed by a pair of cleaning rollers 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for performing recording by discharging ink onto a recording medium such as recording paper, and a method for recovering the discharge.

[0002]

2. Description of the Related Art In general, an ink jet recording apparatus performs recording by discharging ink from a recording head to a recording medium, and it is easy to make the recording head compact.
High-definition images can be recorded at high speed, running costs are low, non-impact method reduces noise, and it is easy to record color images using multi-color inks. Has advantages. Above all, for example, a full-line type recording apparatus using a line type recording head in which a large number of ejection ports are arranged along the width direction of paper as a recording medium can further increase the recording speed. .

However, in such a full-line type recording apparatus, the distance from the recording head at the most upstream position to the recording head at the most downstream position in the recording paper transport direction is considerably long. In the recording area,
There is a possibility that the recording paper as a recording medium is lifted up, and the recorded image is disturbed or a jam occurs. Therefore, it is necessary to urge the recording paper downward so as not to float. As such means, a method of providing a conductive electrode, giving an electric charge to generate an electrostatic force, and adsorbing a recording sheet is generally used in many cases.

[0004] Preliminary ejection is a process performed in an ink jet apparatus to maintain good ink ejection performance of a recording head. In other words, the ink that is not involved in printing is ejected from the recording head to a predetermined location other than the recording paper, for example, thereby removing the thickened ink, fine bubbles, and the like in the recording head as the ink is ejected. is there. The thickened ink and the fine bubbles may cause an ejection failure such as a decrease in the ejection ink amount, deflection of the ejection direction, and non-ejection of the ink, and are likely to occur when the ink ejection is not performed for a long time.

[0005] The preliminary ejection performed for the purpose of eliminating the thickened ink or the like is generally performed at regular time intervals when the apparatus power is turned on or while the power is turned on. For example, immediately after the power is turned on, preliminary ejection of 500 ejections is performed, and immediately before recording, preliminary ejection of 20 ejections is performed.
When a plurality of print heads are provided for color printing, the timing of the preliminary ejection may be different for each print head corresponding to the ink color.

In such an ink jet recording apparatus, a recording sheet fed as a recording medium by a sheet feeding device is attracted and held on the upper surface of a transport belt by an electrostatic attraction plate provided on a platen in a recording area. Then, the sheet is conveyed by a conveying belt while being recorded by the recording head.

In such an ink jet recording apparatus, in order to perform the preliminary ejection, in the case of a configuration in which the recording head is moved to a position of a preliminary ejection receiver formed of an adsorbent provided outside the transport belt, the recording head is used. As the size of the recording head increases, it takes a longer time to move the recording head. In the printing apparatus having such a configuration, when the preliminary ejection is performed, the start-up time at the time of turning on the power becomes long, or the printing operation is interrupted every time the preliminary ejection between the printing pages during the printing operation is performed. In other words, the recording time becomes longer.

As a countermeasure against such a problem, a preliminary discharge is performed at a predetermined position on the transport belt, and a cleaning mechanism provided on the transport belt is used to clean the surface of the transport belt contaminated by the preliminary discharge. There is a known method.

[0009]

However, in the case of the above-mentioned conventional ink jet recording apparatus, since the position on the conveyor belt for performing the preliminary ejection is fixedly determined in advance, the preliminary ejection is performed when the preliminary ejection is performed. (Hereinafter, referred to as a “preliminary ejection area”) must be conveyed to a position directly below the head and facing the recording head.

For this reason, if the preliminary ejection area is not located immediately below the head when the preliminary ejection is to be performed, it is necessary to first advance the transport belt so that the preliminary ejection area is located immediately below the head, and then perform the preliminary ejection. There is. In the case of an ink jet recording apparatus having a plurality of recording heads corresponding to the recording of a color image, since it is necessary to perform preliminary ejection for each recording head, the preliminary ejection area is moved immediately below each recording head. However, a predetermined amount of preliminary ejection must be performed, and the time required for preliminary ejection increases in proportion to the number of print heads.

When the number of preliminary ejection areas provided on the conveyor belt is small, it takes time to move the preliminary ejection area to just below the head. It can take a considerable amount of time to go close to one lap.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and an object of the present invention is to variably set a preliminary discharge position on a conveyance body such as a conveyance belt, thereby wasting waste for preliminary discharge. An object of the present invention is to provide an ink jet recording apparatus capable of performing high-speed recording without spending a great amount of time, and an ejection recovery method of the ink jet recording apparatus.

[0013]

According to the present invention, there is provided an ink jet recording apparatus for recording an image on a recording medium conveyed while being mounted on a conveying body by using a recording head capable of discharging ink, and In an ink jet recording apparatus capable of restoring the ejection performance of the recording head by preliminary ejecting ink not contributing to image recording from the recording head, the ink jet recording apparatus according to the mounting position of the recording medium on the carrier, Setting means for variably setting a pre-ejection position avoiding the recording medium, control means for pre-ejection of ink from the recording head to the pre-ejection position, and ejection to the pre-ejection position Cleaning means for removing ink.

According to a second aspect of the present invention, there is provided a method for recovering an ink jet recording apparatus, wherein an image is recorded on a recording medium conveyed while being placed on a conveying body by using a recording head capable of discharging ink, and In a discharge recovery method of an ink jet recording apparatus capable of recovering the discharge performance of the recording head by preliminary discharging ink not contributing to the recording of an image from the above, according to the mounting position of the recording medium on the conveyance body On the carrier, variably set a preliminary ejection position avoiding the recording medium, and at the preliminary ejection position, preliminary ejection of ink from the recording head,
The ink ejected to the preliminary ejection position is removed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIGS. 1 and 2 are structural views of the inside of an ink jet recording apparatus according to the present invention.
A recording apparatus 1 having an automatic paper feeder includes a paper feed unit 2, a paper feed unit 3, a paper discharge unit 4, and a print head unit 7. FIG. 1 is a cross-sectional view showing the overall configuration of the recording apparatus 1, and FIG. Hereinafter, using FIGS. 1 and 2, each unit 2, 3, 7, and 4 will be described as items (I) paper feed unit, (1I) paper feed unit, (III) recording head unit, and (IV) paper discharge unit. Will be described separately.

(I) Paper Feeding Unit The paper feeding unit 2 has a base 20 on which a pressure plate 21 on which recording paper P as a recording medium is loaded and a feed rotator 22 for feeding the recording paper P are mounted. It has become. The pressure plate 21 is rotatable about a rotation axis a coupled to the base 20, and is urged by a pressure plate spring 24 in the direction of the feeding rotating body 22. A separation pad 25 made of a material having a large friction coefficient, such as artificial skin, is provided on a portion of the pressure plate 21 facing the feed rotating body 22 to prevent double feeding of the recording paper P. Further, the separation claw 2 covering the corner on one side of the recording paper P is provided on the base 20 to separate the recording paper P one by one.
6, and a release cam (not shown) for releasing the contact between the pressure plate 21 and the rotary feeder 22 are provided.

In the above configuration, in the standby state, the release cam pushes the pressure plate 21 down to a predetermined position. Thereby, the contact between the pressure plate 21 and the feeding rotating body 22 is released. Then, in this state, the transport roller 3 described later
2 is transmitted to the feed rotator 22 and the release cam by a gear or the like, so that the release cam
1, the pressure plate 21 rises, and the recording paper P comes into contact with the feeding rotating body 22. Then, the recording paper P is picked up and fed by the rotation of the feed rotating body 22, and the recording paper P is separated one by one by the separation claw 26 and sent to the paper feeding unit 3. The feed rotator 22 feeds the recording paper P to the paper feeding unit 3.
After that, the recording paper P is again brought into a standby state in which the contact between the recording paper P and the feed rotator 22 is released, and the driving force from the transport roller 32 is cut off.

Reference numeral 90 denotes a feeding rotating body for manual paper feeding. The recording paper P set on the manual feed tray 91 is fed by the feeding rotating body 90 in accordance with a recording command signal from a control unit such as a computer, and is conveyed to the conveying rollers 32.

(II) Paper Feeding Unit The paper feeding unit 3 is a transport belt 3 that sucks and transports the recording paper P.
1 and a PE sensor (not shown). The transport belt 31 is mounted on a transport roller 32 and a pressure roller 35 which are driven rollers so as to be driven by a drive roller 34. The support arm 51A having the pressure roller 35 attached to the distal end is rotatably supported at the base end thereof,
The pressure roller 35 is urged by the spring 51B in the direction of pressing the pressure roller 35 against the transport belt 31.

A pinch roller 33 driven by the conveyor belt 31 is provided in contact with the conveyor belt at a position facing the conveyor roller 32. The pinch roller 33 guides the recording paper P to a recording unit by being pressed against the transport belt 31 by a spring (not shown). Further, an upper guide 27 and a lower guide 28 for guiding the recording paper P are provided at an entrance of the paper feeding unit 3 to which the recording paper P is conveyed.
Further, the upper guide 27 is provided with a PE sensor lever 29 of a PE sensor (not shown) for detecting the leading edge and the trailing edge of the recording paper P. Further, the transport roller 3
A recording head 7 for forming an image on the recording paper P based on the image information is provided on the downstream side in the recording paper conveyance direction of No. 2.

In the above configuration, the recording paper P sent to the paper feeding section 3 is guided by the upper guide 27 and the lower guide 28, and is sent by a pair of rollers including a transport roller 32 and a pinch roller 33. At this time, by detecting the leading end of the recording paper P conveyed by the PE sensor lever 29, the recording position of the recording paper P, for example, is determined. The recording paper P is transported by rotating the transport belt 31 via transport rollers 32 by an ultrasonic motor described later.

(III) Recording Head Section The recording head 7 of the present embodiment has a line in which a plurality of nozzles are arranged in a direction perpendicular to the direction in which the recording paper P is conveyed (the direction of the front and back of the paper in FIGS. 1 and 2). Ink jet recording heads of the type are used, and a recording head 7K for discharging black ink, a recording head 7C for discharging cyan ink, and a recording head 7 for discharging magenta ink are arranged from the upstream side in the transport direction of the recording paper P.
The recording heads 7Y for ejecting M and yellow inks are arranged in this order at predetermined intervals. The recording head 7 is attached to a head holder. The recording head 7 can apply heat to the ink by a heater or the like.
Then, the ink causes film boiling due to the heat, and the pressure change caused by the growth or shrinkage of bubbles due to the film boiling causes the ink to be ejected from the nozzles of the recording head 7 and the ink droplets to form an image on the recording paper P. You.

The recording head 7 is rotatably supported at one end by a shaft 71, and a projection 7A formed at the other end is engaged with a rail 72, whereby the nozzle surface and the recording paper P are engaged.
The distance (between papers) is defined.

(IV) Paper Discharge Unit The paper discharge unit 4 includes a paper discharge roller 41 and a spur 42. The recording paper P on which an image has been formed by the recording unit is conveyed by being sandwiched between a paper ejection roller 41 and a spur 42, and is discharged onto a paper ejection tray 43.

(Recording Unit) Next, the structure and operation of suction conveyance in the recording unit will be described with reference to FIGS.

Reference numeral 31 denotes a transport belt which moves while adsorbing and holding the recording paper P, and is made of a synthetic resin such as polyethylene or polycarbonate having a thickness of about 0.1 mm to 0.2 mm, and has an endless belt shape. Has formed. Reference numeral 36 denotes a suction force generating means, which is fixedly provided at a position facing the recording head 7. The attraction force generating means 36 generates an attraction force on the transport belt 31 facing the recording portion of the recording head 7 by applying a voltage of about 0.5 V to 10 kV. It is connected to a high-voltage power supply (not shown) that generates.

As described above, the rollers 32, 34, and 35 are rollers that support the transport belt 31 and apply an appropriate tension. The rollers 34 are connected to the paper feed motor 50.
As pressing means for pressing the recording paper P against the transport belt 31, a paper pressing member 39 is rotatably mounted around the rotation axis of the pinch roller 33, and the paper pressing member 39 is provided with a not-shown attachment. It is urged toward the conveyor belt 31 by urging means. The paper pressing member 39 is made of a conductive metal plate.

Numeral 38 denotes a cleaning roller pair, which is provided so as to clamp the belt 31. The roller pair 38 is capable of absorbing ink to remove dirt such as ink attached to the belt 31 and has a small pore diameter (10 μm) in order to prevent deterioration in durability.
(preferably from m to 30 μm).

Next, the operation will be described.

The recording paper P is nipped between the pinch roller 33 and the transport belt 31 and guided to the recording section. The recording paper P is pressed against the transport belt 31 by the paper pressing member 39 and is sent to the suction force generating section. enter in. Then, the recording paper P is attracted to the flat portion of the transport belt 31 by the attraction force given by the attraction force generating means 36, and the recording head 7
The paper is fed in the direction of the arrow a by the paper feed motor 50 and the rollers 34 while the printing or the like is recorded. At this time, the recording paper P
Since there is no part traveling to the recording head 7 when recording the leading and trailing ends of the recording paper P, recording can be performed while the ejection nozzle at the end of the recording head and the end of the recording paper P are close to each other. A good recorded image can be obtained.

When a large amount of ink is ejected on the recording paper P, the recording paper P swells, and a wavy (cockling) occurs. Also in this case, the recording paper P is generated by the suction force of the suction force generating means 36 and the pressing force of the paper pressing member 39.
Is attracted to the conveyor belt 31 side, so that the recording paper P does not float to the head 7 side, and stable recording without contact between the recording head 7 and the recording paper P can be performed. Further, even when the end of the recording paper P is wavy or curled due to changes in the environment such as temperature and humidity, the recording paper P is pressed against the transport belt 31 by the paper pressing member 39 to cause the paper to be wavy or curled. Since the recording paper P can be conveyed to the suction force generating section in a state where is removed, stable suction can be performed in the recording section.

(Control Unit) FIG. 3 is a block diagram showing the configuration of the control unit of the ink jet recording apparatus according to the present invention and the devices controlled by the control unit.

As described above, 7K is a recording head for black, 7C is a recording head for cyan, 7M is a recording head for magenta, and 7Y is a recording head for yellow. 100
Is a solenoid for controlling the cleaning roller 38. 50 is a motor for driving the driving roller 34 for driving the transport belt 31. Reference numeral 102 denotes a sensor for detecting the reference position of the transport belt 31.
Reference numeral 103 denotes a sensor for detecting the end of the recording paper P, which is connected to the PE sensor lever 29. In addition,
Although not shown in FIGS. 1 and 2, the transport belt position detecting sensor 102 is provided on the back side of the transport belt 31 between the transport roller 32 and the pressure roller 35.

Reference numeral 80 denotes a control unit. 80a is a CPU, 8
0b is a ROM for storing a program, 80c is a work memory required for control, 80d is a gate array,
Each is connected via a system bus. The gate array 80 d includes control signals for the drive roller motor 50 and the feed rotator motor 101, a control signal for the cleaning roller solenoid 100, an image signal for the recording head 7, a control signal for the recording head 7, and a control signal for the transport belt 31. The reading of information from the dirt detection sensor and the PE sensor 103 is performed.

FIGS. 4A, 4B, and 4C show the positional relationship between the recording sheet P and the preliminary ejection area on the conveyor belt 31, and the setting of the preliminary ejection area, and the state transition of the preliminary ejection and cleaning. FIG. P is recording paper, I1, I
2, I3 is a preliminary ejection area on the conveyor belt 31, L1 is a sheet distance, L2 is a distance between the leading end of the recording paper P and the preliminary ejection area I3, L3 is a distance between the PE sensor lever 29 and the recording head 7K. Is the distance. Preliminary ejection areas I1, I2, I
3 is not a fixed position on the transport belt 31 but a recording paper P
Is set as a position ahead of the front end by a predetermined distance. The number of preliminary ejection areas is not fixed, but varies according to the total length of the conveyor belt 31, the distance between the recording head 7 and the cleaning mechanism, the size of the recording paper P being conveyed, and the like. FIG.
In the examples of (a), (b) and (c), there are three preliminary ejection regions I1, I2 and I3. FIG.
3A, the preliminary ejection area I1 is located at a position where the ink adhered to the transport belt 31 by the preliminary ejection is cleaned by the cleaning roller. The preliminary ejection area 13 in FIG. 4A is located immediately below the magenta recording head 7M, and following the preliminary ejection of the black and cyan recording heads 7K and 7C, the preliminary ejection of the magenta recording head 7M. Is in the position where is performed. FIG. 4B shows the preliminary ejection area 1 on the conveyor belt 31.
Reference numeral 3 indicates a state in which the recording head has advanced to immediately below the yellow recording head 7Y.

FIGS. 5, 6, and 7 are flow charts for explaining control of the ink jet recording apparatus according to the present invention.

First, the preliminary ejection process shown in the flowchart of FIG. 5 is called by an interrupt event each time the recording paper P is fed during the recording operation. Step S
According to 101, the apparatus waits until the leading end of the recording paper P is fed to the position of the PE sensor lever 29 disposed on the upstream side of the transport belt 31. PE sensor lever 29
The status of the recording paper P is detected by monitoring the status change of the PE sensor 103 connected to the recording paper P.

The leading edge of the recording paper P is the PE sensor lever 29
Is reached, the leading end position of the paper P on the conveyor belt 31 is acquired (step S102). Conveyor belt 31
Is detected by a step count counted by a belt position management process of FIG. 7 described later, that is, a step count (hereinafter, simply referred to as “step count”) representing a relative position of the conveyor belt 31 from a reference position. In this case, it is performed by acquiring as needed. Therefore, by correcting the step count obtained at the time of step S102 by the number of steps corresponding to the distance from the transport belt reference position detection sensor 102 to the PE sensor lever 29, the leading end position of the paper P can be obtained. .

Next, a predetermined distance L3 between the PE sensor lever 29 and the recording head 7K is stored in the ROM 80.
b (step S103). Also, the predetermined inter-sheet distance L1 is obtained from the ROM 80b, and the appropriate inter-sheet distance L1 and the distance L3 are determined to determine an appropriate position of the preliminary ejection area I4 (step S10).
4). In this embodiment, the preliminary ejection area I4 is set forward by a distance L2 from the leading end of the recording paper P. Distance L
2 is 1/2 of the sheet distance L1.

Next, the conveyor belt 31 determined in this way is
It waits until the upper preliminary ejection area I4 reaches just below the recording head 7K (step S105). That is, when the transport belt 31 advances by the number of steps corresponding to the distance L3 from the step count when the leading end of the recording paper P is detected, the set preliminary ejection area I4 is changed to the recording head 7K.
Has just arrived. And the recording head 7K
When the preliminary ejection area I4 reaches just below the recording head 7K
Only perform a predetermined preliminary ejection operation (step S10).
6).

Next, the position of the preliminary discharge area I4 on the conveyor belt 31 that has performed such preliminary discharge is obtained (step S107), and the position is stored in the RAM of the format shown in FIG.
80c is additionally stored in the table (step S10).
8). In this table (hereinafter referred to as a “preliminary ejection list”), records of all the preliminary ejection regions existing on the transport belt 31 are created, and information for one preliminary ejection region is recorded for each record. ing. The record includes a record number, a position of a preliminary ejection area represented by a step count, and the like. Since the record related to the preliminary ejection area cleaned by the belt cleaning processing is deleted by the belt cleaning processing in the flowchart shown in FIG. 6, only the information of the valid preliminary ejection area is always held in the preliminary ejection list. You.

Subsequently, the recording head 7K and the recording head 7C
Is obtained (step S109). Then, as in step S105, after waiting until the preliminary ejection area I4 on the transport belt 31 to which the recording head 7K has previously ejected first reaches just below the recording head 7C (step S110), recording is performed on the preliminary ejection area I4. Only the head 7C performs a predetermined preliminary ejection (step S111).

Subsequently, the recording head 7C and the recording head 7M
Is obtained (step S112). After waiting until the preliminary ejection area I4 on the conveyor belt 31 from which the recording head 7C has preliminarily ejected reaches just below the recording head 7M (step S113), the preliminary ejection area I
In step 4, only the recording head 7M performs predetermined preliminary ejection (step S114).

Subsequently, the recording head 7M and the recording head 7Y
Is obtained (step S115). After waiting until the preliminary ejection area I4 on the transport belt 31 from which the recording head 7M has preliminarily ejected reaches just below the recording head 7Y (step S116), the preliminary ejection area I
In step 4, only the recording head 7Y performs a predetermined preliminary ejection (step S117).

As described above, when the recording paper P is fed, the recording heads provided in the ink jet recording apparatus are dynamically placed in the preliminary ejection area I4 which is not fixed but variably set according to conditions. Are sequentially performed in accordance with the movement of the conveyor belt. 4 (a), (b),
I1, I2, and I3 in (c) are preliminary ejection areas that are dynamically set when the recording paper P is fed, like the preliminary ejection area I4.

The belt cleaning process shown in the flowchart of FIG. 6 is called when the transport belt 31 starts to move for the recording operation.

First, a position PA on the conveyor belt 31 immediately below the cleaning roller 38 is obtained (step S201). The position of the cleaning roller 38 is determined by counting the step count from the reference position of the conveyor belt 31 between the conveyor belt reference position detection sensor 102 on the conveyor belt 31 and the cleaning roller 38, as in the case of the preliminary ejection process of FIG. Is obtained by correcting with the number of steps corresponding to the distance.

Next, a preliminary ejection area closest to the cleaning roller 38, that is, a preliminary ejection area that moves to a position facing the cleaning roller 38 earliest, is obtained from the preliminary ejection list illustrated in FIG. 8 (step). S
202).

Then, the position of the conveyor belt 31 immediately below the cleaning roller acquired in step S201 and the position of the conveyor belt 3 in the preliminary ejection area acquired in step S202.
(Step S2).
03). For example, in the case of FIG.
The distance acquired at 03 corresponds to the distance L8.

Based on the distance obtained in step S203, the apparatus waits until the preliminary ejection area reaches a position immediately below the cleaning roller 38 (also referred to as a "cleaning position") (step S204). By performing a predetermined cleaning process (step S205), the ink preliminarily ejected to the preliminary ejection area of the transport belt 31 is removed.

Next, the record of the pre-ejection area for which cleaning has been completed is deleted from the pre-ejection list illustrated in FIG. 8 (step S206).

Finally, by checking the preliminary ejection list, it is determined whether or not there is a preliminary ejection area record that has not been cleaned (step S207). In the preliminary ejection list, unnecessary records that have been cleaned are stored in step S2.
Since the records are sequentially deleted at 06, the determination in step S207 only needs to confirm the presence or absence of a record. If it is determined that there is still a preliminary ejection area to be cleaned, the processing from step S201 is repeated to perform the cleaning processing continuously. Then, when all the records have disappeared from the preliminary ejection list, the cleaning process ends.

The belt position management processing shown in the flowchart of FIG. 7 is called every time the drive roller motor 50 is driven by one step.

First, in step S301, a belt reference position is detected. At this time, a conveyor belt dirt detection sensor provided for detecting belt dirt is used to detect a belt reference position detection mark pattern previously marked at one location of the conveyor belt 31. . In the present embodiment, a solid line of a specific color formed so as to be drawn across the width direction of the transport belt 31 is used so that even if the belt reference position is detected by the optical sensor, it is easy to determine that the belt is contaminated by ink or the like. It is a mark for detecting the belt reference position. Then, based on the detection information of such a sensor, it is determined whether or not the current detection position of the conveyor belt 31 by the sensor is the belt reference position (step S302). This determination is made simply by comparing a belt reference position pattern prepared in advance with information detected by the sensor, that is, a read pattern.

If it is determined that the current detection position is the belt reference position, the step counter indicating the driving amount of the motor 50 from the belt reference position is reset (step S303). If the determination result is not the belt reference position, the step counter is incremented and the driving amount is counted.

As described above, the means for determining the specific position of the conveyor belt 31 is provided, and the shift amount of the conveyor belt 31 from the sensor position is constantly managed and held, whereby the preliminary ejection process shown in FIG. In the belt cleaning process, the position of the transport belt 31 can be specified at an arbitrary timing.

(Second Embodiment) The present invention is not limited to the above embodiment.

In the above embodiment, the transport belt 31
The position of the upper preliminary ejection area is dynamically set for each recording sheet P when the recording sheet P is fed. However, if the paper size of the recording paper P handled in one recording process is constant, after the first preliminary ejection position is set, based on the transport direction size of the recording paper P and the paper distance, Since the second and subsequent preliminary ejection areas can be determined, a plurality of preliminary ejection areas may be set when the first page is fed at the start of printing.

With this configuration, the recording paper P
It is not necessary to newly set the preliminary ejection area every time the sheet is fed, and the processing during the printing operation can be reduced, which is effective.

(Third Embodiment) In the above embodiment, the cleaning process of the transport belt 31 is sequentially performed during the recording operation.

However, when the transport belt 31 is driven by one rotation from the start of recording and a preliminary discharge area for one rotation is set on the transport belt 31, a new preliminary discharge area is set. May be stopped. In this case, the cleaning process is not performed during the printing operation, and the setting of the preliminary ejection area is maintained. Then, one of the conveyor belts 31
By controlling the paper feeding timing of the recording paper P with reference to the preliminary ejection list after the first cycle, the recording paper P is controlled between the two preliminary ejection areas on the conveyor belt 31 so that the recording paper P does not fall on the preliminary ejection area. Is supplied with the recording paper P. Then, after the recording is completed, all the preliminary ejection areas on the conveyor belt 31 may be cleaned while referring to the preliminary ejection list.

With this configuration, the number of times of the cleaning process can be reduced, and the deterioration and consumption of the transport belt 31 and the cleaning roller 38 due to the cleaning process can be suppressed. Further, it is effective because it is possible to avoid the adverse effect of performing the cleaning process during the recording operation, that is, the adverse effect on the recorded image due to the vibration of the transport belt 31 or the like.

(Fourth Embodiment) In the above embodiment, the inter-paper distance is fixed, and the preliminary ejection area is set in front of the leading end of the recording paper based on the distance.

However, prior to recording, the size of the recording paper P to be fed may be acquired, and the preliminary ejection area may be appropriately set on the entire circumference of the conveyor belt 31 based on the size of the recording paper. At this time, it is set so that the largest number of preliminary ejection areas can be arranged while keeping the minimum sheet distance. Then, the recording paper P is set such that the preset preliminary ejection area at the start of recording is positioned between the papers, that is, between the preceding and succeeding recording papers P on the conveyor belt 31.
The paper feed timing and the paper interval may be controlled.

(Fifth Embodiment) In the above embodiment, the preliminary ejection position between the sheets is determined based on only the predetermined sheet distance.

However, the position of the preliminary ejection area between the sheets may be corrected in accordance with the content of the preliminary ejection (the number of preliminary ejections, the preliminary ejection pattern, etc.) to be processed immediately thereafter. That is, even when the preliminary ejection is performed, since the transport belt 31 is continuously transported at a predetermined paper transport speed without stopping, the preliminary ejection area has a certain width according to the transport speed and the number of times of preliminary ejection. In the transport direction. That is, if the width of the preliminary ejection area in the transport direction is increased, the distance between the preliminary ejection area and the recording paper P is reduced, which may adversely affect the subsequent recording on the recording paper P. The right column in the table of FIG. 8 shows an example of the ink ejection amount corresponding to the number of preliminary ejections, that is, an example of the number of ink dots formed by the preliminary ejection.

Therefore, for example, when the number of preliminary ejections is larger than usual, the position of the preliminary ejection area is corrected forward in the transport direction, and the start timing of the preliminary ejection is advanced so that the number of preliminary ejections can be increased. The recording head recovery process can be performed without any adverse effect on recording, which is extremely effective.

(Sixth Embodiment) In addition, the form of the ink jet recording apparatus according to the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also a copying apparatus combined with a reader and the like. May be in the form of a facsimile machine having a transmission / reception function, or may be a device capable of printing on cloth or the like.

(Others) It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for discharging ink, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As this pulse-shaped drive signal, those described in U.S. Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angle liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, the recording head fixed to the apparatus main body or the electric connection with the apparatus main body or the ink from the apparatus main body is attached to the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

It is preferable to add a recording head ejection recovery unit, a preliminary auxiliary unit, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The type and number of the recording heads to be mounted are not limited to those provided only for one color ink, and for a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink may be in a liquid state. In addition, in order to positively prevent the temperature rise due to thermal energy by using the energy of the state change from the solid state of the ink to the liquid state, or to prevent the ink from evaporating, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not limited to those used as image output terminals of information processing equipment such as computers, copying apparatuses combined with readers and the like, and facsimile apparatuses having a transmission / reception function. It may take a form.

[0079]

As described in detail above, according to the present invention,
A pre-ejection position on a conveyance body such as a conveyance belt is variably set, ink is pre-ejected from the recording head to the variably set pre-ejection position, and the pre-ejection ink is removed to remove the pre-ejection ink. Images can be recorded without interrupting the recording process and without decreasing the recording speed.

Further, since the preliminary ejection position can be variably set to an arbitrary position, a recording medium such as a recording paper can be supplied at the same time as the conveyance by the conveyance body such as the conveyance belt is started. Therefore, for example, redundant positioning processing of a transport body such as a transport belt becomes unnecessary, and the output time (first print) of the first recording medium such as recording paper can be shortened.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an overall configuration of an inkjet recording apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a paper feeding unit in the ink jet recording apparatus of FIG.

FIG. 3 is a block diagram of a control unit in the inkjet recording apparatus of FIG.

FIGS. 4A, 4B, and 4C are explanatory diagrams of transition of a preliminary ejection area in the inkjet recording apparatus of FIG.

FIG. 5 is a flowchart illustrating a preliminary ejection process in the inkjet recording apparatus of FIG. 1;

FIG. 6 is a flowchart illustrating a belt cleaning process in the inkjet recording apparatus of FIG. 1;

FIG. 7 is a flowchart illustrating a belt position management process in the inkjet recording apparatus of FIG. 1;

FIG. 8 is a configuration diagram of a preliminary ejection area management table in the inkjet recording apparatus of FIG. 1;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 recording device 2 paper feeding unit 3 paper feeding unit 4 paper discharging unit 7 recording head unit 21 pressure plate 22 feeding rotating body 24 spring 25 separation pad 26 separation claw 27 upper guide 28 lower guide 29 PE sensor lever 30 platen 31 transport belt 32 Conveying roller 33 Pinch roller 34 Drive roller 35 Pressure roller 36 Attraction force generating means 38 Cleaning roller pair 39 Paper pressing member 41 Paper discharge roller 42 Spur 43 Paper discharge tray 52 Power supply brush 53 Holding member

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65H 5/00

Claims (32)

[Claims] An image is recorded on a recording medium conveyed while being placed on a conveyance body by using a recording head capable of discharging ink, and ink not contributing to recording of the image from the recording head is reserved. In the inkjet recording apparatus capable of restoring the ejection performance of the recording head by ejecting, the recording medium is avoided on the carrier according to a mounting position of the recording medium on the carrier. Setting means for variably setting a preliminary ejection position; control means for preliminarily ejecting ink from the recording head at the preliminary ejection position; and cleaning means for removing ink ejected to the preliminary ejection position. Characteristic inkjet recording device. 2. A management unit for managing the preliminary ejection position set by the setting unit, wherein the cleaning unit removes ink ejected to the preliminary ejection position based on management information of the management unit. The inkjet recording apparatus according to claim 1, wherein the recording is performed. 3. The apparatus according to claim 1, wherein the setting unit sets the preliminary ejection position between the recording media positioned before and after in the transport direction on the transport body. Ink jet recording device. 4. The ink-jet apparatus according to claim 1, wherein the setting unit sets the preliminary ejection position every time the recording medium is supplied onto the conveyance body. Recording device. 5. The apparatus according to claim 1, wherein the setting unit sets the preliminary ejection position in accordance with a size of the recording medium before the recording medium is supplied onto the conveyance body. 4. The ink jet recording apparatus according to any one of 1 to 3. 6. The ink-jet recording apparatus according to claim 1, wherein the setting unit can fix and set the preliminary ejection position once set so as not to change. 7. The ink jet recording apparatus according to claim 1, wherein the setting unit corrects the preliminary ejection position according to a form of the preliminary ejection. 8. The pre-discharge position according to claim 7, wherein the setting unit corrects the pre-discharge position according to at least one of the number of ink ejections and the ink ejection pattern in the pre-ejection. Ink jet recording device. 9. A supply device for supplying the recording medium to a position on the conveyance body avoiding the preliminary ejection position based on the preliminary ejection position set by the setting device. The ink jet recording apparatus according to any one of claims 1 to 8, wherein: 10. The ink jet recording apparatus according to claim 1, wherein the setting unit can set a plurality of the preliminary ejection positions on the conveyance body. 11. The ink jet printer according to claim 1, wherein the cleaning unit is capable of removing the ink at the preliminary ejection position during an image recording operation by the recording head. Recording device. 12. The cleaning device according to claim 1, wherein the cleaning unit is capable of removing the ink at the preliminary ejection position after the recording operation of the image by the recording head is completed.
11. The inkjet recording device according to any one of items 1 to 10. 13. The recording medium according to claim 1, further comprising: means for adsorbing the recording medium on the carrier.
The inkjet recording device according to any one of the above. 14. The ink jet recording apparatus according to claim 1, wherein the transport member is a transport belt that moves in a circulating manner. 15. The recording head is a plurality of recording heads which are shifted in a conveying direction of the recording medium and are capable of ejecting different inks, and wherein the control means responds to a conveying position of the recording medium. hand,
2. A method according to claim 1, wherein said plurality of recording heads sequentially discharge ink to said preliminary discharge position.
5. The ink jet recording apparatus according to any one of 4. 16. The ink jet recording apparatus according to claim 1, wherein the recording head has an electrothermal converter that generates thermal energy as energy for discharging ink. 17. An image recording method using a recording head capable of discharging ink on a recording medium conveyed while being mounted on a conveying body, and ink not contributing to image recording from the recording head is reserved. In the ejection recovery method for an ink jet recording apparatus capable of restoring the ejection performance of the recording head by ejecting, the recording medium is formed on the carrier according to a mounting position of the recording medium on the carrier. An ink jet recording apparatus that variably sets a preliminary ejection position avoiding a medium, preliminarily ejects ink from the recording head to the preliminary ejection position, and then removes the ink ejected to the preliminary ejection position. Ejection recovery method. 18. The method according to claim 17, wherein the management unit managing the set preliminary ejection position is used, and the ink ejected to the preliminary ejection position is removed based on management information of the management unit. 3. The ejection recovery method for an ink jet recording apparatus according to item 1. 19. The ejection of the ink jet recording apparatus according to claim 17, wherein the preliminary ejection position is set between the recording media positioned before and after in the transport direction on the transport body. Recovery method. 20. The ejection recovery of an ink jet recording apparatus according to claim 17, wherein the preliminary ejection position is set every time the recording medium is supplied onto the conveyance body. Method. 21. The method according to claim 17, wherein the preliminary ejection position is set according to a size of the recording medium before the recording medium is supplied onto the transport body. An ejection recovery method for an ink jet recording apparatus according to any one of the above. 22. The ejection recovery method for an ink jet recording apparatus according to claim 17, wherein the preliminary ejection position can be fixedly set so as not to be changed after being set once. 23. The ejection recovery method for an ink jet recording apparatus according to claim 17, wherein the preliminary ejection position is corrected according to a form of the preliminary ejection. 24. The ejection of the ink jet recording apparatus according to claim 23, wherein the preliminary ejection position is corrected according to at least one of the number of ink ejections and the ink ejection pattern in the preliminary ejection. Recovery method. 25. The recording medium according to claim 17, wherein the recording medium is supplied to a position on the conveyance body that avoids the preliminary discharge position based on the set preliminary discharge position. 3. The ejection recovery method for an ink jet recording apparatus according to item 1. 26. The ejection recovery method for an ink jet recording apparatus according to claim 17, wherein a plurality of the preliminary ejection positions are set on the carrier. 27. The ejection recovery method for an ink jet recording apparatus according to claim 17, wherein the ink at the preliminary ejection position is removed during an image recording operation by the recording head. 28. The ejection recovery method for an ink jet recording apparatus according to claim 17, wherein the ink at the preliminary ejection position is removed after the image recording operation of the recording head is completed. 29. The method according to claim 17, wherein the recording medium is adsorbed on the transport body. 30. The ejection recovery method for an ink jet recording apparatus according to claim 17, wherein the transport body is a transport belt that moves in a circulating manner. 31. The recording head, comprising: a plurality of recording heads which are displaced in a conveying direction of the recording medium and are capable of discharging different inks; 31. The ejection recovery method for an ink jet recording apparatus according to claim 17, wherein preliminary ejection of ink from the recording head to the preliminary ejection position is performed. 32. The recording head according to claim 17, wherein the recording head includes an electrothermal converter that generates thermal energy as energy for discharging ink.
The ejection recovery method for an inkjet recording apparatus according to any one of the above.