JP2008012892A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the response characteristics of control calculation by estimating an initial load correcting means from paper width direction of the recording medium being an object to be conveyed to the friction correction within the control calculation, and by finding a final friction correcting quantity from the initial load correcting means, a load correcting means, and a roll paper residual quantity correcting means. <P>SOLUTION: In an inkjet recording device having various conveying route such as cassette paper supplying, roll paper supplying, manual paper supplying as paper supplying route, the recording device is provided which provides the stable conveying of the recording medium with high product quality by judging the change of the load condition changing from various conditions, and by stably driving a conveying roller drive system. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus that performs recording by ejecting ink from a recording head onto a recording material, and more particularly to an optimum operation method between the operation of the recording head and the conveying operation of the recording material.

  The ink jet recording apparatus is configured to form an image by ejecting ink droplets from a plurality of ink ejection ports provided in an ink ejection head and attaching them to a recording medium. The plurality of ink ejection openings are arranged in a direction parallel to the conveyance direction of the recording medium.

  As a scanning method of an ink jet recording apparatus, a serial scanning method is often employed. In this serial scanning method, an ink discharge head mounted on a carriage is mainly used in a direction crossing a recording medium conveyance direction (sub-scanning direction). By repeating the operation of scanning scanning, feeding a predetermined amount of paper after completing the recording for one main scanning, and then recording the image for the next main scanning on the recording medium stopped again, Recording is performed on the entire recording medium.

  FIG. 2 shows a general ink jet recording apparatus. In the figure, 101 is a recording head having an ink tank, and 102 is a carriage on which the recording head 101 is mounted. A guide shaft 103 is inserted into the bearing portion of the carriage 102 so as to be slidable in the main scanning direction, and both ends of the shaft are fixed to the chassis 114. The belt 104, which is a carriage drive transmission means engaged with the carriage 102, is disengaged, and the drive of a drive motor 105, which is a carriage drive means, is transmitted, so that the carriage 102 can move in the main scanning direction.

  During recording standby, the recording paper 115 is stacked on the paper supply base 106, and at the start of recording, the recording paper is supplied by a paper supply roller (not shown). In order to convey the fed recording sheet, the conveying roller is rotated via a gear train (motor gear 108, conveying roller gear 109) as a transmission means by a driving force of a sheet conveying motor (107) which is a DC motor, and a pinch is rotated. The recording paper 115 is conveyed by an appropriate feeding amount by the pinch roller 111 that is pressed against the conveying roller 110 by a roller spring (not shown) and rotates following the roller. Here, the carry amount is managed by detecting and counting the slits of the code wheel (rotary encoder film 116) press-fitted into the carry roller 109 with the encoder sensor 117, thereby enabling high-precision feeding.

  FIG. 3 is an example of a block diagram of control logic for driving the paper transport motor (107) and the transport roller (109). The command value generator 1 outputs the position, speed, acceleration, and the like as the target value 3, and the difference value from the position / speed information 5 output from the encoder sensor 117 that measures the state of the conveying roller 109 is supplied to the compensator 2. Entered. The compensator 2 is a control block composed of PID control and the like, and an operation amount 4 for moving the paper transport motor 107 is calculated. The power of the sheet conveyance motor 107 is transmitted to the conveyance roller, and the position and speed information is updated. By repeating the above-described series of flows every specific calculation cycle, the recording paper 115 can realize a desired operation.

  In recent ink jet recording apparatuses, not only the image quality and printing speed of printed output but also the driving sound during printing have become important factors as product quality. Also when the recording medium is transported, a rubbing sound, a sudden sound, or the like generated when the recording medium touches the casing of the recording apparatus is generated. In order to improve product quality, it is necessary to design in a direction that eliminates the sound source itself, and to create sound quality that does not make it uncomfortable. For this purpose, it is necessary to design a drive system that can reliably reproduce the intended operation.

  For example, Patent Document 1 and Patent Document 2 relate to increasing the product quality from the viewpoint of sound quality.

  In Patent Document 1, there is a feeding device that feeds a printing material, and a feeding roller that feeds the printing material, and at least a part of the printing material is placed and moved toward the feeding roller to feed the printing material. A hopper that contacts the substrate to be printed, a motor that drives the feed roller, a drive cam that drives the hopper as the motor rotates, and the rotation of the motor during the period when the hopper moves toward the feed roller A rotation control unit for reducing the speed. However, since the rotational speed of the motor can be reduced by a mechanical mechanism, it does not necessarily compensate that the non-printed material is kept stable even when the moving speed is the same.

Patent Document 2 discloses a recording apparatus that introduces a recording medium into a nip formed by a conveyance roller and a pressure member provided in contact with the conveyance roller, causes the recording medium to be nipped and conveyed, and executes predetermined printing on the recording medium. , An acceleration setting means for setting the acceleration during conveyance of the recording medium, and a control means for controlling the acceleration setting means so that the acceleration during conveyance of the recording medium is variable according to the properties of the recording medium. Prepare. Further, a pressing force setting unit that sets a pressing force for pressing the pressing member is provided, and the conveyance acceleration and the pressing force are controlled to be variable according to the properties of the recording medium. This pressing force is set corresponding to the maximum static friction coefficient of the recording medium. However, it does not compensate that control stability can always be maintained in consideration of load fluctuations.
JP2004-10311 JP2005-154113

  In the form of a general recording apparatus (FIG. 2), the recording medium to be conveyed is a standard paper, and the size is mainly up to about A3. On the other hand, FIG. 4 shows a cross-sectional view of the recording apparatus that is the subject of the proposal.

  A paper discharge roller 118 that supports paper discharge is provided downstream of the transport roller 109. A platen unit 119 exists between the transport roller 109 and the paper discharge roller 118, and printing is performed while the carriage moves on the platen unit 119. It will be.

  As a recording medium feeding path, there are a cassette unit 120 and a manual feed unit 122 for standard paper, and a roll unit 121 for roll paper.

  The recording medium to be transported by the apparatus is an apparatus in which the width of the recording medium is greatly different from A4 to A0, B0 and the types thereof are various.

  For this reason, it is necessary to design a driving condition for transporting the recording medium in consideration of various disturbance factors with respect to a general apparatus.

  Considering the disturbance factors when viewed from the conveyance roller drive system that conveys the recording medium, fluctuations in the force (load) applied to the recording medium can be considered.

  On the downstream side of the transport roller drive system, the purpose is to store the printed matter printed on the recording medium. Generally, there is little or almost constant force applied to the recording medium. There are many cases.

  On the other hand, on the upstream side, the conveyance path shape itself is different due to the difference in the paper feeding units. In the example of FIG. 3, since the curvatures are different from each other, the force applied to the recording medium also changes.

  Consider the change in the force applied to the recording medium from the characteristics of each paper feed unit.

  In the case of a cassette unit, it can be mentioned that the recording medium changes depending on the portion located in the transport path. When printing on the leading edge of the recording medium, most of the recording medium is bent along the curvature of the paper feed path. This is because when the part is passed, the state is close to a straight line.

  In the case of a roll unit, since the radius of the roll unit and the mass of the roll unit itself change according to the remaining amount of roll paper, the force applied to the recording medium changes depending on the amount of roll paper used. It is done.

  The above-described force fluctuation is transmitted as a load change to the transport roller drive system. FIG. 5 shows an example of a state when the conveyance roller drive system cannot cope with a change in load. FIG. 5 shows a change in the speed of the conveying roller on the time axis, and the solid line in the figure is an ideal speed change. The speed variation example 1 is when the load is lighter than the predicted value at the time of rising, and the speed variation example 2 is when the load is heavy. In either case, the result of the compensator operation is converged to the target value, but instantaneously changes from the target value. Considering the worst condition, vibration for converging the deviation is generated, and vibration amplified through the recording medium may be generated as flapping sound. When the load just before the stop is light, the example is the speed fluctuation 3, and since the load cannot be compensated for, it stops temporarily and spends some time until it starts moving again, and the behavior of the recording medium is unstable. It becomes a thing.

  Such speed fluctuations may cause the recording medium to resonate and amplify the rubbing noise, or it may not be possible to maintain the desired speed at the intended time, and sudden sound, tension, etc. may occur. It is done. In addition, instantaneous speed fluctuations cause fluctuations in the conveying force determined by the frictional force between the conveying roller and the recording medium, and a phenomenon in which the recording medium cannot follow the movement of the conveying roller occurs. It can be considered that it itself deteriorates.

  In this proposal, a change in the load state that changes from various states is judged, and the conveyance roller drive system is driven stably, thereby realizing a stable conveyance of the recording medium and a recording apparatus with high product quality. Will provide. Furthermore, as simple a logic as possible is constructed while satisfying the above conditions.

As means for solving the above-described problems, a carriage driving mechanism that scans a carriage mounted with a recording head having an ink ejection unit on a recording medium a plurality of times and ejects ink during acceleration during each scan; A recording medium conveying mechanism that moves the recording medium by a predetermined amount in a direction orthogonal to the scanning direction of the carriage between the scanning times, and a cassette unit paper feeding mechanism that moves the recording medium to the conveying roller; In a recording apparatus comprising a roll unit paper feed mechanism that moves the recording medium to the conveying roller, the recording medium width information of the recording medium, an initial load correcting means determined from the recording medium width information, and the conveying roller are driven. Load correction means determined from an operation amount to be performed, recording medium width information, and reference load information, and a paper feed path in the recording apparatus That has a feed path information, and a roll remaining amount correcting means to be determined from the roll remaining amount information and the paper feed path information and the recording medium width information in the roll unit feeding mechanism,
An initial load correction unit, a load correction unit, and a final load correction unit obtained from the remaining roll correction unit are added to the operation amount.

  Further, the load correction means described above is an operation obtained from an operation amount measured in the first conveyance after the paper feeding operation in which the recording medium is moved to the conveyance roller and an operation amount based on the reference load information. It is a quantity fluctuation ratio.

  Further, the roll remaining amount correcting means described above has a plurality of change curves determined from the recording medium width information described above, and is determined from the change curve and the remaining roll amount.

  Further, the roll remaining amount correcting means described above is set to 1 when the paper feed path information described above indicates other than the roll paper unit paper feed path.

  By executing the above means, it is possible to drive the conveying roller in a manner that corrects the load state changing from various states, and the recording medium resonates to amplify the rubbing noise, or at the intended time. Since the desired speed cannot be maintained, it is possible to reduce the state in which sudden sound, tension, etc. are generated.

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

  The target of the present proposal is an ink jet recording apparatus having a configuration as shown in FIG. There are three types of paper feed slots.

  When viewed from the conveyance roller 109 to be driven, all disturbances that the recording medium to be conveyed receives from the conveyance conditions can be received as a load change. FIG. 6 shows a change in load with respect to a change in the width direction of the recording medium. In general, the load value increases as the width increases. For this load change, a value obtained based on the change in the reference paper is used as the reference load information.

  FIG. 7 shows a load change transmitted from the roll unit to the transport roller, and changes from the remaining roll amount in the roll unit. The roll unit is considered to change the relationship between the remaining amount of the roll and the load change depending on the width direction of the recording medium to be handled. Therefore, from the maximum recording medium width supported by the recording apparatus itself, A value obtained by measuring the condition is used. In FIG. 7, two conditions A and B are assumed.

  The ratio of the operation amount in the above-described reference load information and the load value changing from the width condition of the recording medium, the remaining condition of the roll paper, and the above-described reference load information is set as the value of the roll paper remaining amount correcting means.

  FIG. 8 is an explanatory diagram for estimating a load to be finally corrected and obtaining a final load correcting means.

  The value of the initial load correction means is multiplied by the value of the load correction means as the first correction in order to correct the load condition change under the recording medium type condition (plain paper, glossy paper, glossy paper, etc.). Will be. The initial load correction means changes from the state of the conveying roller (static friction region, dynamic friction region, etc.).

  In the recording apparatus, it is conceivable to transport various types of recording media, and it can be said that the load applied to the transport roller changes depending on the conditions. To grasp all of them in advance requires a lot of examination, and it can be said that it is extremely difficult to grasp all phenomena in advance when changes due to aging are included. Therefore, by multiplying the aforementioned initial load correction means by the value of the load correction means, fluctuations in load conditions are absorbed.

  The load correction coefficient is obtained by using an operation amount of the carry motor that is carried at a constant speed and is measured in a stable state with little fluctuation in friction. The load correction means is required by comparing the operation amount measured in advance under the condition of the reference load information determined from the information in the width direction of the recording medium and the operation amount. Compared with the operation during printing, the operation amount is compared with the reproducibility without causing the movement of only the measurement by processing with the head-out operation that conveys the specified amount to just before the discharge head. It becomes possible.

  By multiplying the first load correction value multiplied by the value of the load correction means by the value of the remaining roll paper amount correction means, the final load correction means to be the final correction value is obtained. Become. In FIG. 8, since the recording medium width information indicates the area A, the value A of the roll paper remaining amount correcting means described in FIG. 7 is selected and multiplied. Unlike standard paper, when printing advertisements, etc., printing with a large printing area of 30 m may be considered, and the load change due to roll paper is expected to increase until one printed product is output. Is done. Therefore, it is necessary to update the roll paper remaining amount means every time the transport roller is driven.

  Excessive load correction causes vibration centered on the target position under the condition of operating in balance with the load near the target position. As the load correction, it is desirable to cope with a certain large change. When obtaining the friction correction coefficient, a slight relaxation coefficient is provided in the comparison value of the manipulated variable, and the correction generated from the path shape is not performed in the conveyance path (cassette unit, manual feed unit) that can be predicted that the load change is not so large The value of the final load correcting means is derived by combining the above methods. By adding the value to the operation amount as a load correction, it is possible to stably operate the transport roller driving system.

  FIG. 1 is a control block diagram in which the final load correcting means of FIG. 8 is added to the control logic of FIG. The width information of the recording medium to be conveyed becomes the recording medium width information 6. The initial load correction means 10 is a load correction value determined from the recording medium width information 6 as an initial value when performing load correction. The load correction means 11 is multiplied by the initial load correction means in order to absorb the load change caused by the type of the recording medium and the aging of the recording apparatus. The load correction means 11 is obtained from the ratio of the operation amount measured from the recording medium width information 6 and the reference load information 7 and the operation amount of the recording medium to be transported. When the remaining amount of roll paper 8 and the recording medium width information 6 are obtained, the remaining amount of roll paper correcting means 12 is obtained. Becomes 1. The multiplication value of the initial load correction unit 10, the load correction unit 11, and the roll paper calculation remaining amount correction unit 12 becomes the value of the final load correction unit 13, and is added to the operation amount 4 that is an output value from the compensator. The added value is output to the sheet conveying motor 104, and the conveying roller 106 is driven.

  FIG. 9 shows a sequence when printing is performed by the recording apparatus using the transport driving system having the control block of FIG.

  A paper feed operation 14 is performed in response to a print start command. The recording medium moves to the conveying roller, and a head picking operation 15 is performed. The operation amount is measured in the heading operation 15, compared with the operation amount measured by the reference load information 7 selected by the recording medium width information 6, and the load correction means 11 multiplied by the relaxation coefficient performs load correction. It is obtained by the coefficient value calculation 16. The load correction means 11 that is executed until the printing end operation uses the value that is obtained by the calculation 16 of the load correction means. In order to transport the recording medium to an area where the carriage can print the first print area, a transport motor drive command 17 is executed. For each control calculation for driving the transport motor, load correction means execution 19 is performed to multiply the initial load correction means 10 by the load correction means 11. The paper feed path is determined from the paper feed path information 9 in the paper feed path judgment 20, and in the case of roll paper feeding, the roll paper remaining amount correcting means 12 is executed in the roll paper remaining amount correcting means executing 21. The output value is the final load correction means execution 22. In the case of other than roll paper, the result of the load correction hand coefficient multiplication 19 is the final load correction means execution 22. The result of the final load correction means execution 22 is added to the operation amount 4, and the conveyance motor is driven by the operation amount output 23. The end of driving of the carry motor is determined at the carry motor drive end 24, and when finished, the process proceeds to the carriage drive start 25. . After the carriage drive is finished, the page print end 26 for determining the end of the entire page is reached. If the end is the end, the paper discharge operation 27 is returned. Transport. Printing ends when the paper discharge operation ends.

Control block diagram. FIG. FIG. 2 is a general control unit block diagram. FIG. 4 is a cross-sectional view of a recording medium conveyance system in the present proposal. Example of speed fluctuation. Recording medium width information and load fluctuation diagram. Roll paper remaining amount information and load fluctuation diagram. The derived image figure of a final load correction means. Control sequence diagram during printing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Command value generator 2 Compensator 3 Target value 4 Operation amount 5 Position / velocity information 6 Recording medium width information 7 Reference load information 8 Roll paper remaining amount information 9 Paper feed path information 10 Initial load correction means 11 Load correction means 12 Roll Paper remaining amount correction system value 13 Final load correction means 14 Paper feed operation execution block 15 Cue operation execution block 16 Load correction coefficient calculation execution block 17 Transport motor drive command execution block 18 Load correction value calculation execution block 19 Load correction coefficient multiplication execution Block 20 Paper feed path determination execution block 21 Roll paper remaining coefficient multiplication execution block 22 Final load correction means execution block 23 Operation amount update execution block 24 Transport motor drive end determination execution block 25 CR drive start execution block 26 Page printing end determination execution Block 27 Paper discharge operation execution block 101 IN A recording head having a tank 102 A carriage on which the recording head 101 is mounted 103 A guide shaft 104 A belt 105 A driving motor 106 A paper feeding base 107 A paper conveying motor 108 A motor gear 109 A conveying roller gear 110 A conveying roller 111 A pinch roller 114 A chassis 115 A recording sheet 116 A rotary encoder film 117 Encoder sensor 118 Paper discharge roller 119 Platen unit 120 Cassette unit 121 Roll unit 122 Manual feed unit

Claims (4)

A carriage drive mechanism that scans a recording medium having a recording head having an ink discharge portion on the recording medium a plurality of times and discharges ink during acceleration, and scanning of the carriage between the plurality of scans. A recording medium conveying mechanism that moves the recording medium by a predetermined amount in a direction orthogonal to the direction, a cassette unit paper feed mechanism that moves the recording medium to the conveying roller, and the recording medium that moves to the conveying roller. In a recording apparatus comprising a roll unit paper feed mechanism,
Recording medium width information of the recording medium; initial load correction means determined from the recording medium width information; load correction means determined from an operation amount for driving the conveying roller; recording medium width information; and reference load information; Paper feed path information for determining a paper feed path in the recording apparatus, and roll remaining amount correcting means determined from roll remaining amount information, paper feed path information, and recording medium width information in the roll unit paper feed mechanism. ,
An ink jet recording apparatus, comprising: an initial load correcting unit, a load correcting unit, and a final load correcting unit obtained from a roll remaining amount correcting unit.   The load correction means according to claim 1 is an operation obtained from an operation amount measured in a first conveyance after a paper feeding operation in which the recording medium is moved to a conveyance roller, and an operation amount based on reference load information. 2. The ink jet recording apparatus according to claim 1, wherein the ratio is a quantity variation ratio.   The roll remaining amount correcting means according to claim 1 has a plurality of change curves determined from the recording medium width information according to claim 1, and is determined from the change curve and the remaining roll amount. Inkjet recording device.   2. The ink jet recording apparatus according to claim 1, wherein the remaining roll correction means is 1 when the paper feed path information according to claim 1 indicates other than the roll paper unit paper feed path. .

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