JP5953053B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus that records an image using a recording head capable of ejecting ink.

  An ink jet recording apparatus is generally configured to record an image on a recording surface of a recording medium by ejecting ink from an ejection port of the recording head while relatively moving the recording head and the recording medium. In order to increase the recording speed, a recording head in which ink discharge ports are arranged at a high density or a long one that extends over the entire width of the recording area of the recording medium is used. .

  In such an ink jet recording apparatus, in order to record a high-quality image, the distance (inter-paper distance) between the discharge port forming surface of the recording head on which the discharge ports are formed and the recording surface of the recording medium. It is important to maintain a certain range. However, in the recording medium, the formation of the discharge port of the recording head is caused by the occurrence of curling (curling phenomenon) due to the difference in moisture content between the front and back surfaces, and the occurrence of wrinkles and wavy phenomenon (cockling phenomenon) due to ink adhesion. There is a risk of floating toward the surface.

  As a method for suppressing such lifting of the recording medium, as described in Patent Document 1, a suction-type conveyance belt that conveys the recording medium while adsorbing the recording medium to the surface by the suction force of air is used. There is a method to use.

JP 2007-302406 A

  However, when a suction-type transport belt is used, it is necessary to provide a source for generating air suction force, or to form a path for guiding the suction force to the ventilation hole of the transport belt. As a result, there is a risk of increasing the size and cost of the entire recording apparatus.

  An object of the present invention is to provide an ink jet recording apparatus capable of recording a high-quality image by suppressing the lifting of a recording medium due to a curling phenomenon or cockling phenomenon with a simple configuration.

Ink jet recording apparatus of the present invention includes a recording head for recording on a recording medium, said recording medium is said in conjunction with float regulating means for regulating the floating where floating predetermined amount, the float regulating means and the recording head And a moving means for moving in the thickness direction of the recording medium.

  According to the present invention, a high-quality image can be surely suppressed by the curling phenomenon or the cockling phenomenon by a simple configuration in which the regulating member for suppressing the floating of the recording medium is interlocked with the movement of the recording head. Can be recorded.

1 is a schematic configuration diagram of an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a curl regulating unit provided in the recording apparatus of FIG. 1 as viewed from the direction of arrow II in FIG. 1. It is explanatory drawing of the drive structure of the curl control part of FIG. It is a schematic block diagram of the curl control part of FIG. 2 at the time of recording operation. FIG. 2 is a block configuration diagram of a control system of the ink jet recording apparatus of FIG. 1. 2 is a flowchart for explaining a recording operation of the ink jet recording apparatus of FIG. 1. FIG. 4 is an explanatory diagram of a recording medium lifting control operation by the curl control unit of FIG. 2. FIG. 10 is a schematic perspective view of a sheet feeding unit 301 according to another embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described by way of example with reference to the accompanying drawings. However, the components described in the following embodiments are merely examples, and are not intended to limit the scope of the present invention only to them.

  In this specification, “recording” (also collectively referred to as image formation) is not only for forming significant information such as characters and graphics, but also for images, patterns, A case where a pattern or the like is formed or a medium is processed is also shown. The “recording medium” (also referred to as a sheet) is not only paper used in general recording apparatuses but also widely accepts ink such as cloth, plastic film, metal plate, glass, ceramics, wood, leather, etc. It shall also represent what is possible. Furthermore, “ink” is to be broadly interpreted in the same way as the definition of “recording”, and is applied to a recording medium to form an image, a pattern, a pattern, or the like, Or it shall represent the liquid used for the process of an ink. The ink treatment includes, for example, solidification or insolubilization of the colorant in the ink applied to the recording medium.

(First embodiment)
FIG. 1 is a front view schematically showing the ink jet recording apparatus of the present embodiment. A host PC (personal computer) 101 is connected to the inkjet recording apparatus 100 of this embodiment as a host apparatus for sending image information to the recording apparatus 100. The recording apparatus 100 includes a recording unit 201, a sheet feeding unit 301, a sheet conveying unit 401, a paper discharge unit 501, a curl regulating unit 601 (see FIG. 2), and a control unit 701 (see FIG. 5) as main parts. ing.

  The recording unit 201 includes a head holder 203 that can be moved up and down by a head drive motor 615 (see FIG. 5). The head holder 203 has a recording head 202 that can eject ink from an ejection port at the tip of the nozzle. Removably held. The head drive motor 615 constitutes a head moving mechanism (head moving means) for moving the recording head 202. In this example, recording heads 202K, 202C, 202M, and 202Y for discharging black, cyan, magenta, and yellow ink are held as the recording head 202. These recording heads 202 (202K, 202C, 202M, 202Y) are arranged so as to be aligned in the conveyance direction (arrow A direction) of the recording medium (cut paper in this example) P. The recording head 202 is a long line head that extends long in a direction that intersects (in the present example, orthogonal) with the conveyance direction of the recording medium P, and is the width direction of the recording area on the recording medium P (FIG. 1). It extends across the entire area (in the front and back direction of the middle page). In the case of this example, a plurality of nozzles are arranged in the recording head 202 over a range slightly longer than the maximum width of the recording medium P that can be recorded by the recording apparatus 100.

  The recording head 202 is provided with an ejection energy generating element for ejecting ink from the ejection port at the tip of the nozzle. As the ejection energy generating element, an electrothermal conversion element (heater), a piezoelectric element, or the like is used. it can. When the electrothermal conversion element is used, the ink is foamed by the heat generation, and the ink can be ejected from the ejection port at the tip of the nozzle using the foaming energy. The discharge ports are formed on the lower surface (discharge port forming surface) in FIG. 1 of the recording head 202 facing the recording medium P. The recording unit 201 incorporates a cleaning unit 204 so that the recording head 202 can stably eject ink. The cleaning unit 204 includes a known blade, an ink removing member, a blade holding member, a cap, and the like. At the time of image recording, the recording head 202 is lowered together with the head holder 203 so that a predetermined distance (inter-paper distance) is formed between the ejection port forming surface and the recording medium P as will be described later.

  A sheet feeding unit (supplying unit) 301 separates a plurality of stacked recording media P one by one and feeds them to the sheet conveying unit 401. The sheet conveying unit 401 moves the recording medium P fed from the sheet feeding unit 301 in the direction of arrow A through a recording position located immediately below the recording unit 201, that is, a position facing the ejection port forming surface of the recording head 202. Transport. The sheet conveying unit 401 of this example includes an endless conveying belt 402 on which the recording medium P is placed and conveyed. The conveying belt 402 is stretched between the driving roller 403, the driven roller 404, and the guide roller 406, and rotates around the driving roller 403 by the conveying motor 405, so that the conveying belt circulates in the conveying direction indicated by the arrow A. . A conveyance line of the recording medium P is formed by the conveyance belt 402, and an image is recorded on the recording medium P on the conveyance line.

  The paper discharge unit 501 accumulates recording media on which images are recorded, and the curl regulating unit 601 (see FIG. 2) regulates the floating of the recording medium P during image recording, as will be described later. As will be described later, the control unit 701 (see FIG. 5) includes a recording head 202, a conveyance motor 405 of the sheet feeding unit 301, a head driving motor 615 of the recording unit 201, a guide motor 607 of the curl regulating unit 601, and a guide position. The sensor 612 and the detection sensor 613 are controlled.

  The curl restricting portion 601 includes first and second curl restricting units 602a and 602b, which include curl guides (restricting members) 603a for restraining both side ends of the recording medium P in the width direction. 603b is arranged so as to extend in the conveying direction of arrow A. These curl guides 603a and 603b are arranged so that their leading ends are located between the conveyance belt 402 and the recording head 202. The curl guides 603a and 603b are rotatable about their rotation shafts 604a and 604b, and guide springs 605a and 605b are attached to the respective base ends. The curl guides 603a and 603b are urged by the guide springs 605a and 605b in the directions of arrows C1 and D1 that contact the guide stoppers 606a and 606b. When the recording head 202 is in the raised position together with the head holder 203, as shown in FIG. 2, the curl guides 603a and 603b are maintained in a rotating state (released state) in which they abut against the guide stoppers 606a and 606b. The curl guides 603a and 603b are provided with engagement portions 614a and 614b that come into contact with the head holder 203 when the recording head 202 is lowered together with the head holder 203 as shown in FIG.

  In this example, the first curl regulation unit 602a is fixed at a fixed position of the main body of the recording apparatus, and the second curl regulation unit 602b is in the width direction of the recording medium P (arrow B) with respect to the main body of the recording apparatus. Direction). As shown in FIG. 3, a moving belt 609 is stretched between the driving pulley 607 a driven by the guide motor 607 and the driven pulley 608 on the second curl regulating unit 602 b. Is connected to the curl regulating unit 602b. The curl regulating unit 602b is guided by the moving rail 610 so as to be movable in the direction of arrow B, and is moved by the guide motor 607 in the direction of arrow B via the moving belt 609. As described above, the second curl regulating unit 602b including the curl guide 603b is moved in the arrow B direction by the moving mechanism (regulating member moving unit) including the guide motor 607. A code wheel 611 that rotates in conjunction with the driven pulley 608 is attached to the driven pulley 608, and the rotation amount of the code wheel 611 is read by the detection sensor 613. The detection sensor 613 reads the rotation amount of the code wheel 611 with the movement position of the curl restriction unit 602b detected by the guide position sensor 612 as a reference (movement reference position), thereby detecting the movement position of the curl restriction unit 602b. Can do. By driving and controlling the guide motor 607 based on such a detection signal, the curl regulating unit 602b can be moved to a desired position.

  Next, the recording operation will be described based on the flowchart of FIG.

  After the recording data (image information) is input from the host PC (personal computer) 101 (step S1), the recording apparatus 100 first moves the second curl regulating unit 602b to a predetermined position. The image information from the host PC 101 also includes information (dimension information) relating to the dimension in the width direction of the recording medium P, and the second curl regulating unit 602b is moved to a target position corresponding to the dimension. That is, after the guide motor 607 is driven (step S2) and the guide position sensor 612 detects the movement reference position of the curl restriction unit 602b (step S3), the detection sensor 613 detects the movement amount of the curl restriction unit 602b. . Based on the detection signal of the detection sensor 613, it is determined whether or not the curl regulating unit 602b has moved to the target position corresponding to the width of the recording medium P (step S4). When the curl regulating unit 602b moves to the target position, the driving of the guide motor 607 is stopped (step S5).

  In the case of this example, the recording medium P is transported with reference to one end portion in the width direction located on the first curl regulating unit 602a side. Therefore, according to the width of the recording medium P, the position of the other end portion in the width direction changes in the arrow B direction. The target position for moving the second curl regulating unit 602b is the optimum position of the other end portion in the width direction of the recording medium P whose position changes in accordance with the width and the second curl regulating unit 602b. It is a position for establishing a relationship (see FIG. 7).

  Thereafter, as shown in FIG. 4, the head drive motor 615 is driven (step S6), and the recording head 202 is lowered together with the head holder 203 to the target lowered position (step S7). The image information from the host PC 101 includes information regarding the thickness of the recording medium P, and the target lowering position of the recording head 202 is set based on the information. The target lowering position (see FIG. 7) is a distance (paper) between the P surface (recording surface) of the recording medium whose position changes in the vertical direction according to the thickness and the ejection port forming surface of the recording head 202. It is a position for making the (distance between) the optimum distance. When the recording head 202 is lowered to the target lowering position, the driving of the head driving motor 615 is stopped (step S8). When the recording head 202 descends to the target lowered position, as shown in FIGS. 4 and 7, the head holder 203 comes into contact with the engaging portions 614a and 614b, and the curl guides 603a and 603b are moved against the guide springs 605a and 605b. Rotate to arrows C2 and D2. The curl guides 603a and 603b rotate the recording head 202 by an amount corresponding to the target lowered position. Further, the curl guides 603a and 603b are configured not to come into contact with the recording head 202 even when rotated in this way.

  Thereafter, the conveyance motor 405 of the sheet conveyance unit 401 is driven (step S9), and then the uppermost sheet is separated from the plurality of stacked recording media P by the sheet feeding unit 301 to the sheet conveyance unit 401. Feed (step S10). The recording medium P is conveyed in the direction of arrow A together with the conveying belt 402 while being placed on the conveying belt 402 of the sheet conveying unit 401. At that time, both ends of the recording medium P in the width direction pass below the curl guides 603a and 603b as shown in FIG. Therefore, when the recording medium P is curled as indicated by a two-dot chain line in FIG. 7, the rising of both end portions in the width direction of the recording medium P is the curl guides 603a and 603b located above the both end portions. Regulated by. The lifting of the recording medium P is a deformation in a direction away from the conveyance line formed by the conveyance belt 402. In this way, by preventing the recording medium P from rising due to the curl phenomenon or cockling phenomenon, contact between the recording medium P and the recording head 202 is avoided, and further, the recording surface of the recording medium P and the ejection openings of the recording head 202 are formed. The distance between the surfaces can be maintained within a certain range.

  In this way, when the recording medium P is conveyed by the sheet conveying unit 401 and the recording start position reaches a position facing the recording head 202K, the black ink from the plurality of nozzles in the recording head 202K is based on the recording data. Are selectively discharged. Similarly, color images are recorded on the recording medium P by ejecting cyan, magenta, and yellow inks in the order of the recording heads 202C, 202M, and 202Y in accordance with the transport position of the recording medium P (step S11). ). At that time, as described above, since the distance (inter-paper distance) between the recording surface of the recording medium P and the ejection port forming surface of the recording head 202 is maintained within a certain range, a high-quality image is recorded. can do.

  As described above, the recording head 202 is lowered to the target lowering position corresponding to the thickness of the recording medium P, and the curl guides 603a and 603b are rotated in conjunction with the lowering operation. For this reason, the curl guides 603a and 603b can be automatically moved to the optimum position in order to maintain a constant distance between the sheets in the thickness direction regardless of the thickness of the recording medium P. Further, since the curl guide 603 moves in accordance with the width of the recording medium P, the curl guides 603a and 603b maintain a constant distance between sheets in the width direction regardless of the width of the recording medium P. It is possible to move to the optimal position.

  Thereafter, the processes in steps S11 and S12 are repeated until all recording based on the recording data (image information) is completed (step S). The recording media P on which images are recorded are sequentially stacked on the paper discharge unit 501. When all the recording is completed, the driving of the conveying motor 405 of the sheet conveying unit 401 is stopped (step S13).

(Other embodiments)
In the embodiment described above, the size (width dimension) in the width direction of the recording medium is acquired from information included in the recording data from the host PC. As shown in FIG. 8, when the sheet feeding unit 301 is provided with a paper width guide 302 that can move in the direction of arrow B, a paper width guide sensor for detecting the width of the recording medium corresponding to the movement position of the paper width guide 302. From the detection signal 303, the width dimension of the recording medium can be acquired. The plurality of recording media P stacked in the sheet feeding unit 301 are guided at one end P1 in the width direction by a fixed guide at a fixed position and guided at the other end P2 by a paper width guide sensor 303. Since the paper width guide sensor 303 is moved according to the width of the recording medium P, the width dimension of the recording medium P can be acquired based on the detection signal of the paper width guide sensor 303 that detects the movement position. Similarly to the above-described embodiment, the target position of the second curl regulating unit 602b in the width direction of the recording medium can be set according to the acquired width dimension.

  Further, the facing distance between the curl regulating units 602a and 602b in the width direction of the recording medium P only needs to be changed according to the width of the recording medium P, and at least one of the curl regulating units 602a and 602b is in the width direction of the recording medium. If you can move to. The curl guides 603a and 603b only need to be able to move in conjunction with the recording head so as to maintain the inter-paper distance within a certain range without interfering with the recording head 202, in particular, without touching the discharge port forming surface. It is not specified only by the structure which rotates like the embodiment which did. For example, the curl guides 603a and 603b may be configured to interlock with the recording head with movement in the vertical direction or the horizontal direction in FIG.

  Further, the curl guides 603a and 603b may be attached to the head holder 203 side. In this case, the distance between the discharge port forming surface of the recording head 202 and the lower surfaces of the curl guides 603a and 603b located above both ends of the recording medium P is set constant. As a result, the curl guides 603a and 603b are automatically set to the optimum position in order to keep the distance between the sheets constant in the thickness direction regardless of the thickness of the recording medium P, as in the above-described embodiment. Can be moved to. In order to reduce the friction between the curl guides 603a and 603b and the recording medium P, at least one or a plurality of rollers are provided on the contact surface of the curl guides 603a and 603b with the recording medium P, or the sliding surface. May be formed.

  In the above-described embodiment, an example in which a so-called bubble jet recording type recording head using an electrothermal transducer as an ejection energy generating element for ejecting ink has been described. However, it is obvious that a recording head using a piezo element or the like as the ejection energy generating element can also be adopted.

  The above-described embodiment has been described as an application example to a so-called full-line recording apparatus that uses a long recording head and records an image while continuously transporting a recording medium. However, the present invention can be widely applied to various recording system ink jet recording apparatuses. For example, the present invention can also be applied to a so-called serial scan type recording apparatus that records an image by alternately repeating movement of a carriage on which a recording head is mounted and conveyance of a recording medium.

202 Recording Head 203 Head Holder 301 Sheet Feeding Unit (Supplying Unit)
402 Conveying belt 602 Curl regulation unit 603 Curl guide (regulation member)
701 Control means P Recording medium

Claims (9)

A recording head for recording on a recording medium;
A float regulating means for regulating the floating where the recording medium is floating predetermined amount,
Moving means for moving the recording head in the thickness direction of the recording medium in conjunction with the floating regulating means;
An ink jet recording apparatus comprising: The inkjet recording apparatus according to claim 1, wherein the floating restricting unit extends at least including a recording area of the recording head in a conveyance direction of the recording medium. It said moving means, an ink jet recording apparatus according to claim 1 or claim 2, characterized in that moving the lift-preventing means and said recording head according to the thickness of the recording medium. Said lift-preventing means is provided on both sides in the width direction perpendicular to the transport direction of the recording medium conveyed to the position where the recording head to record, at least one of said lift-preventing means is movable in the width direction The inkjet recording apparatus according to any one of claims 1 to 3, wherein An ink jet recording apparatus according to claim 4, characterized in that it comprises the action means for moving at least one of said lift-preventing means according to the size of the width direction of the recording medium in the width direction. It has a paper width detecting means for detecting the size of the width direction of the recording medium,
The inkjet recording apparatus according to claim 5 , wherein the action unit moves the floating restriction unit in the width direction according to a detection result of the sheet width detection unit. It said lift-preventing means, the distance between the discharge port forming surface and the surface of the recording medium of the recording head to a predetermined range, according to claim 1, characterized in that for regulating the floating of the recording medium the ink-jet recording apparatus according to any one of claims 6. Said moving means, to any one of claims 1 to 7, characterized in that mechanically interlocked with said lift-preventing means at a portion other than the discharge port forming surface of the recording head and said recording head The ink jet recording apparatus described. An ink jet recording apparatus according to any one of claims 1 to 8, characterized in that it comprises a conveyor belt for conveying the recording medium to the position where the recording head records.

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