JP4207617B2 - Inkjet recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus that records an image on a recording medium by ejecting ink from nozzles of a line head provided across the width direction of the recording medium.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an ink jet recording apparatus using a line type recording head (hereinafter referred to as a “line head”) provided in a long shape with a length in the width direction of a recording medium is known. (Patent Document 1). By using such a line head, it is possible to perform image recording by scanning the entire area of the recording medium only by relatively moving the recording medium and the line head in one direction crossing the nozzle arrangement direction. Image recording is possible.
[0003]
In the line head, nozzles are arranged over a range corresponding to the entire width of the recording medium. By ejecting ink droplets from the nozzles toward the recording surface of the recording medium, a desired area is formed in the recording area of the recording medium. An image is recorded and formed. In such a line head, nozzles that are hardly used for recording are generated depending on the image or the size (width) of the recording medium used.
[0004]
For example, the width (length) of the line head is set in accordance with the width of the largest recording medium that can be used in the ink jet recording apparatus. If recording is performed on a recording medium having a small width with this line head, the line head protrudes from the recording medium. Since the nozzles are not used for recording, ink droplets are not ejected for a long period of time, and there is a problem that clogging occurs due to the increase in viscosity caused by volatilization of water in the ink near the nozzle openings.
[0005]
In addition, as a recording mode, a mode for recording an “edgeless image” in which recording is performed on the entire surface of the recording medium, and a mode for recording an “image with margin” in which recording is performed leaving the peripheral edge of the recording medium. In the inkjet recording apparatus that can select any of these, the width (length) of the line head is set in accordance with the case of recording a borderless image so that an image with a border can be recorded. In this case, since the nozzles protruding from the recording area are not used for recording, there is a problem that clogging occurs as described above.
[0006]
When nozzle clogging occurs in this way, then when using all the nozzles of the line head to use a wide recording medium or to record borderless images, the clogged nozzles Ink is not ejected, or even if it is ejected, it is not ejected in a normal state, and there is a problem that image quality is degraded. Since the line head is fixed to the apparatus across the width direction of the recording medium, for example, when ink non-ejection from a certain nozzle occurs, image degradation is conspicuous at the same position along the conveyance direction of the recording medium. Therefore, the occurrence of such ink clogging is a serious problem particularly when a high-quality image is recorded using a line head.
[0007]
In general, a nozzle that has been clogged can be restored to a normal state by performing maintenance processing such as preliminary ejection for forcibly ejecting ink and ink suction for forcibly sucking ink from the nozzle. Since the line head continuously performs the recording operation on the recording medium, it is extremely difficult to perform such maintenance processing without interrupting the recording operation. Accordingly, there is a demand for an ink jet recording apparatus that can prevent nozzle clogging from the recording area of the recording medium without relying on maintenance processing.
[0008]
[Patent Document 1]
JP 2000-6389 A
[0009]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to prevent nozzle clogging out of the recording area of the recording medium without interrupting the recording operation of the line head, and when the nozzle is used for image recording. An object of the present invention is to provide an ink jet recording apparatus capable of ejecting ink constantly and stably.
[0010]
[Means for Solving the Problems]
The above problems are solved by the following inventions.
[0011]
The invention according to claim 1 is an ink jet recording apparatus that performs image recording by ejecting ink from nozzles corresponding to the recording area of the recording medium of the line head provided across the width direction of the recording medium, In the line head, each ink channel shares an adjacent side wall, and the side wall is made of a piezoelectric material having electrodes formed on both sides, and the side wall is deformed by applying a voltage to the electrode, and the ink Drive control means for causing the ink in the channel to fly from the nozzles, the drive control means, A portion of the line head that protrudes from the recording area of the recording medium Among the plurality of ink channels corresponding to the nozzles of the nozzles, rectangular waves having a width of 4AL (1/2 of the acoustic resonance period) are applied to the electrodes on the sidewalls of the even channels at 12AL intervals, and By applying a rectangular wave that is the same as the rectangular wave applied to the even-numbered channel to the electrode while being shifted by 4 AL, the ink channel The ink meniscus is vibrated as long as the ink does not fly. Ruko Inkjet recording apparatus characterized by the above.
[0012]
According to a second aspect of the present invention, there is provided an ink jet recording according to the first aspect, further comprising selection means for selecting a mode for recording a borderless image and a mode for recording a bordered image on the recording medium. Device.
[0013]
A third aspect of the present invention is the ink jet recording apparatus according to the first or second aspect, wherein the line head performs image recording on recording media having different widths.
[0014]
According to a fourth aspect of the present invention, the drive control means includes a nozzle corresponding to a recording area of the recording medium. Of which, non-discharge nozzles 4. The ink jet recording apparatus according to claim 1, wherein the ink meniscus is vibrated in a range where ink does not fly.
[0015]
According to a fifth aspect of the present invention, the drive control means determines the amplitude of the vibration of the ink meniscus of the nozzle that protrudes from the recording area of the recording medium. Our non-discharge nozzle 5. The ink jet recording apparatus according to claim 4, wherein the amplitude is larger than the amplitude of vibration of the ink meniscus.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0017]
FIG. 1 is a diagram illustrating a schematic configuration of an ink jet recording apparatus. In the inkjet recording apparatus 1, a recording medium P (indicated by a two-dot chain line in FIG. 1) is sandwiched between conveyance roller pairs 31 and 32 that are rotationally driven by a conveyance motor (not shown), and is conveyed in the direction A in the drawing. It has become.
[0018]
The line head 2 is provided between the conveyance roller pairs 31 and 32 so that the nozzle surface faces the recording surface PS of the recording medium P. The line head 2 is disposed across the width direction of the recording medium P, and the length thereof (the distance along the width direction of the recording medium P) is the maximum of the recording medium P used in the ink jet recording apparatus 1. It is provided with a length that can be significantly applied.
[0019]
An example of the line head 2 is shown in FIG. The line head 2 is composed of, for example, four heads 2 a to 2 d that discharge ink of each color of YMCK, for example, and a number of nozzles are arranged on the nozzle surface along the length direction of the line head 2. Nozzles 21a, 21b, 21c, and 21d are arranged. These nozzles 21a, 21b, 21c, and 21d are formed up to an area that protrudes outside the maximum width of the recording medium P to be used in order to record a borderless image described later. A direction A indicated by an arrow in FIG. 2 is a conveyance direction of the recording medium.
[0020]
The line head 2 includes a drive control unit (not shown) that controls generation of a drive signal for ejecting ink, which will be described later, and a fine vibration pulse that vibrates an ink meniscus in a range where the ink does not fly, via a flex cable (not shown). A desired inkjet image is recorded by ejecting ink droplets toward the recording surface PS of the recording medium P that is conveyed by the rotational drive of the conveying roller pair 31 and 32. ing.
[0021]
In FIG. 1, reference numeral 4 denotes a platen that is in contact with and supported by the back surface of the recording medium P on which an image is recorded by the line head 2. In the inkjet recording apparatus 1 shown in the present embodiment, it is possible to use a plurality of sizes (here, two sizes) of recording media P having different widths, and the platen 4 is used for the recording media P used in the inkjet recording device 1. It has a width equal to or greater than the maximum width.
[0022]
FIG. 3A is a plan view of the platen 4. A holding plate 41 that abuts against the back surface of the recording medium P is provided on the surface of the platen 4 formed in a box shape, and a plurality of suction ports 42 are opened in the holding plate 41. The inside of the platen 4 communicates with a suction means (not shown) such as a suction fan. By suctioning from the suction port 42 by the operation of this suction means, the recording medium P is sucked and adsorbed on the surface of the holding plate 41. The smoothness of the recording surface PS at the time of image recording by the line head 2 is maintained.
[0023]
In the holding plate 41, ink receiving openings 43 a to 43 c are provided at positions corresponding to both side edges of the recording medium P, respectively. In the ink jet recording apparatus 1 shown in the present embodiment, recording media having two types of widths, that is, a recording medium having a P1-P2 width and a recording medium having a P1-P3 width, can be used on the basis of the illustrated right end position P1. The openings 43a and 43b correspond to both side edges of the P1-P2 width recording medium P, and the openings 43a and 43c correspond to both side edges of the P1-P3 width recording medium P.
[0024]
Note that reference numerals 51 and 52 in FIG. 1 denote detection means for detecting the width size of the recording medium P, and the widths (P1-P2 width and P1-P3 width) of the recording medium P that can be used in the ink jet recording apparatus 1. ) At positions corresponding to the respective one end portions. As these detection means 51 and 52, well-known detection means, such as an optical sensor, can be used, for example.
[0025]
The ink jet recording apparatus 1 has a mode for recording an image without an edge to record an image on the entire surface of the recording medium P by the line head 2 and an edge for recording an image while leaving the peripheral edge of the recording medium P. Any one of the modes for recording an image can be selected by operating a mode selection switch (not shown) which is a selection unit, and the lengths of the openings 43a to 43c along the conveyance direction of the recording medium P are as follows: The length of the line head 2 is the same as or slightly longer than the length along the conveyance direction of the recording medium P. Accordingly, when the mode for recording the borderless image is selected by the selection means, the recording is performed when the ink droplets are ejected to a range larger than the width of the recording medium P in order to record the borderless image by the line head 2. Excess ink that protrudes from both side edges of the medium P is received.
[0026]
Next, the ink ejection mechanism of the line head 2 will be described. Since the plurality of line-shaped heads 2a to 2d constituting the line head 2 have the same structure, one of these heads (hereinafter denoted by reference numeral 20) will be described as an example.
[0027]
4A and 4B are diagrams showing a schematic configuration of the head 20, wherein FIG. 4A is an external perspective view, FIG. 4B is a cross-sectional view, and FIG. In the figure, 21 is a nozzle, 22 is a nozzle forming member, S is a side wall, 23 is a cover plate, 24 is an ink supply port, and 25 is a substrate. As shown in FIG. 4, the ink channel A is formed by the side wall S, the cover plate 23, and the substrate 25.
[0028]
FIG. 4B shows a cross-sectional view of one ink channel A having one nozzle 21. In the head operating in the actual shear mode, as shown in FIG. Between the plate 23 and the substrate 25, a plurality of side walls S, that is, ink channels A separated by S1, S2,... Sn + 1, that is, A1, A2,. One end of the ink channels A1, A2,... An (hereinafter sometimes referred to as nozzle end) is connected to the nozzle 21 formed on the nozzle forming member 22, and the other end (hereinafter sometimes referred to as manifold end). Is connected to an ink tank (not shown) from an ink supply port 25 constituting the ink supply unit, and an ink meniscus is formed in the nozzle 21 by ink.
[0029]
Each side wall S1, S2,... Is composed of side walls Sa and Sb made of two piezoelectric materials having different polarization directions as indicated by arrows in FIG. 3, that is, S1a, S2a,... And S1b, S2b,. The side walls S1 are provided with electrodes Q1 and Q2 formed in close contact, and the side walls S2 are provided with electrodes Q3 and Q4 formed in close contact. Similarly, electrodes are formed in close contact with each side wall, and each electrode Q1, Q2,... Is connected to a drive pulse generating circuit as drive control means.
[0030]
In such a head, when the electrodes Q1 and Q4 are connected to the ground and a drive pulse is applied to the electrodes Q2 and Q3 in the state shown in FIG. 5A, for example, the polarization direction of the piezoelectric material constituting the side walls S1 and S2 As shown in FIG. 5 (b), an electric field in a direction perpendicular to the side wall is generated, both the side walls S1a and S1b are deformed at the joint surfaces of the side walls, and the side walls S2a and S2b are also deformed in the opposite direction. The side walls S1a, S1b and the side walls S2a, S2b are deformed outward from each other, the volume of the ink channel A1 is enlarged, a negative pressure is generated in the ink channel A1, and ink flows. At the same time, the pressure starts to increase from the manifold end and the nozzle end, and the acoustic wave is transmitted toward the center of the ink channel. When 1AL has passed, the acoustic wave reaches the opposite end, and the pressure in the ink channel becomes positive.
[0031]
AL (Acoustic Length) is a time (unit: μs) represented by L / C, where L is the length of the ink channel (see FIG. 4B) and C is the speed of sound in the ink. Yes, half the acoustic resonance period of the ink channel. This AL measures the velocity of the ink droplet that is emitted by applying a rectangular wave to the side wall S, and when the rectangular wave voltage value is changed and the pulse width of the rectangular wave is changed, the flying velocity of the ink droplet is It is obtained as the maximum pulse width.
[0032]
The acoustic waves that have reached the nozzle end and the manifold end are reflected to become negative pressure waves whose phases are inverted by 180 ° and propagate toward the center of the ink channel. Further, when 1 AL has elapsed, negative pressure waves reach the other ends, and the inside of the ink channel becomes negative pressure. Thus, the pressure wave generated by moving the side wall repeats the reversal of pressure every AL time. Since the nozzle end is in contact with air with low acoustic impedance, it is almost 100% reflected, but the manifold end is partially reflected depending on the ratio of the cross-sectional area of the ink channel to the cross-sectional area of the manifold. Pressure decays.
[0033]
When the potential is returned to 0 after 1 AL has elapsed from the application of the first drive pulse, the side walls S1 and S2 return from the expanded position to the neutral position shown in FIG. 5A, and high pressure is applied to the ink. Next, as shown in FIG. 5C, when the drive pulse is applied so that the side walls S1a, S1b and S2a, S2b are deformed in opposite directions to reduce the volume of the ink channel A1, the ink channel A1 enters the ink channel A1. Positive pressure is generated. As a result, the ink meniscus in the nozzle 21 by a part of the ink filling the ink channel A <b> 1 changes in the direction pushed out from the nozzle 21. When the positive pressure becomes so large that the ink droplet is ejected from the nozzle 21, the ink droplet is ejected from the nozzle 21. After holding this state for 2AL, when the potential is returned to 0 and the side walls S1 and S2 are returned from the contracted position to the neutral position, the remaining pressure wave is canceled, so that the next ink droplet can be ejected. When small droplets of 0 to 7 droplets are continuously discharged and combined on the recording medium or in the flight to form 8 gradations, this is repeated 0 to 7 times according to the image data. Similarly, each ink channel operates in the same manner as described above by applying a drive pulse.
[0034]
As described above, when the side walls S1 and S2 of the ink channel A1 are deformed, the adjacent ink channel A2 is affected. Therefore, the ink channel is usually ejected in three groups every three channels. Is done. For example, A1, A4, A7... Are driven with pulses having the same period, and A2, A5, A8.
[0035]
In such a head 20, since one side wall S is shared by the ink channels A on both sides thereof, for example, when ejection is performed from the ink channel A1 shown in FIG. 5, the electrodes Q2 and Q3 of the ink channel A1 are shown in FIG. As shown in the figure, a 1AL width positive voltage drive pulse is applied, and then a 2AL width negative voltage is applied to the electrodes Q2 and Q3 of the ink channel A1, but a negative voltage is applied to the electrodes Q2 and Q3 of the ink channel A1. As shown in FIG. 7, instead of applying the voltage, a differential voltage applied to the side wall S is obtained by applying a driving pulse having a positive voltage of 2AL width to the electrodes Q1 and Q4 of the adjacent ink channels A0 and A2. It is also possible to perform the same drive as when the drive pulse of FIG. In particular, this embodiment is preferable because there is no trouble of using two positive and negative power supplies as in the case of applying the drive pulse shown in FIG.
[0036]
6 and 7, the ratio of the pulling voltage (1AL) for expanding the ink channel and the pressing voltage (2AL) for contracting the ink channel is 2: 1.
[0037]
Next, in the ink jet recording apparatus 1, a configuration in which the ink meniscus is vibrated with respect to the line head 2 in a range where ink does not fly will be described.
[0038]
In the present invention, the ink meniscus of the nozzle that protrudes from the recording area on the recording medium P in the line head 2 is vibrated within a range in which the ink does not fly (hereinafter, this may be referred to as slight vibration). It is said. Since the nozzles outside the recording area do not discharge ink, the ink meniscus of the nozzles outside the recording area is slightly vibrated during image recording. Even when the thickening is suppressed and the use of the nozzles in this portion is resumed, stable ink ejection can be immediately performed. Therefore, it is possible to always perform high-quality image recording without having to interrupt image recording for maintenance processing.
[0039]
As the nozzles of the portion of the line head 2 that protrudes from the recording area on the recording medium P, there are a mode for recording a borderless image and a mode for recording a bordered image as in the ink jet recording apparatus 1 shown in the present embodiment. When the image recording is performed on the nozzle corresponding to the “edge” area where the image is not recorded on the recording medium P when the bordered mode is selected or the recording medium P having a different width. For example, as shown in FIG. 3B, the width of P corresponds to a nozzle corresponding to a region of P2-P3 width when the size is changed from P1-P3 width to P1-P2 width.
[0040]
Since these nozzles that protrude from the recording area on the recording medium P are nozzles that do not contribute to image recording, ink droplets do not fly from the nozzle to the electrode on the side wall of the head. A fine vibration pulse for finely vibrating the ink meniscus is applied.
[0041]
An example of the fine vibration pulse at this time is shown in FIG. This fine vibration pulse repeats a 4AL width rectangular wave at 12AL intervals on the electrodes on the side walls (S2, S3, S4, S5, S6, S7...) Of even channels (for example, A2, A4, A6...). On the other hand, the minute vibration applied to the even-numbered channel is applied to the electrodes on the side walls (S1, S2, S3, S4, S5, S6...) Of the odd-numbered channels (for example, A1, A3, A5...). A rectangular wave having the same 4AL width and 12AL interval as the pulse is repeatedly applied to the even channel while being shifted by 4AL. The time for applying the fine vibration pulse may be 100 ms or more. Here, the ratio of the pulling voltage (4AL) for expanding the ink channel to the pressing voltage (4AL) for contracting the ink channel through the rest period of 4AL is 2: 1.
[0042]
Here, the rectangular wave means a waveform in which both the rise time and the fall time up to 0-90% of the voltage are within 1/4 of AL. However, even when AL is long, the time is within 1 μs.
[0043]
In the line head 2 shown in the present embodiment, each ink channel shares the side wall S with both adjacent ink channels, so that the influence of the driving of the side wall S of one ink channel extends to both the adjacent ink channels. . Therefore, when a fine vibration pulse is applied to the electrode Q on the side wall S of the even channel, not only the ink meniscus of the own channel but also the ink meniscus of the odd channel adjacent to both can be finely vibrated. The fine vibration pulse shown in FIG. 8 can have the same peak voltage as the drive pulse waveform shown in FIG. 6, and the ink is not ejected by increasing the pulse width.
[0044]
In addition, since the 4AL drive and 12AL pause are alternately repeated by shifting the timing by 4AL between the even channel and the odd channel, the side wall of each ink channel repeats 4AL drive and 4AL pause, and the ink of all ink channels is repeated. The meniscus can be finely vibrated.
[0045]
The fine vibration pulse applied to the nozzles outside the recording area of the recording medium P may not be continuous but may be intermittently applied at intervals that do not cause clogging.
[0046]
Note that the ink meniscus of the nozzle corresponding to the recording area of the recording medium P in the line head 2 is also preferably vibrated in a range where the ink does not fly under the control of the drive pulse generation circuit as the drive control means.
[0047]
Since the nozzles in the recording area of the recording medium P are nozzles that are driven for image formation, in order to slightly vibrate the ink meniscus of the nozzles, the non-ejection nozzles are detected from the driving signal, and ink is selectively used. It is preferable to perform a slight vibration of the meniscus. Since the recording data for one line is sent to the data buffer of the head, it is possible to detect an ink channel in which ink droplets are not ejected and does not contribute to image recording from this recording data.
[0048]
In this case, a fine vibration pulse composed of a rectangular wave for causing the ink meniscus in the ink channel A to vibrate without causing ink droplets to fly from the nozzle 21 to the electrode Q on the side wall S of the ink channel A that does not contribute to image recording. Apply. Therefore, even in the case of the nozzle corresponding to the recording area of the recording medium P, even if a very slight ejection interruption occurs during recording by giving a slight vibration to the ink meniscus in the ink channel A that does not contribute to the image recording. It is possible to suppress ink thickening.
[0049]
In the line head 2 shown in the present embodiment, since one side wall S is shared with both adjacent ink channels, when an ink droplet is ejected from one ink channel, it is automatically also in the non-ejection ink channel on both sides. A slight vibration is applied. Therefore, it is not necessary to give a fine vibration to all the non-ejection ink channels. In order to efficiently suppress the viscosity increase of the ink and the heat generation of the head, for example, all three adjacent ink channels A1, A2, and A3 shown in FIG. When not contributing, it is preferable to apply only to the electrodes on the side walls S2 and S3 of the central ink channel A2.
[0050]
An application example of the minute vibration pulse will be described with reference to FIGS. Here, the adjacent ink channels A1, A2, and A3 shown in FIG. 5A are taken as an example, and a case where two ink droplets are ejected in the ink channel A2 and then slightly vibrated will be described.
[0051]
In the case of a head that discharges three cycles, such as the line head 2 shown in this embodiment, as shown in FIG. 9, in the recording area, a drive pulse consisting of a rectangular wave of 2AL width is always applied to all ink channels at the same timing. PA is applied. At this time, no voltage difference is generated on the side wall S between the ink channels (A2-A1, A2-A3) as shown in the figure, so that shear deformation does not occur.
[0052]
When the ejection data comes, as shown in FIG. 10, if the 2AL width signal applied to the ink channel A2 is removed, and instead the 1AL width signal is applied with the timing advanced by 1AL, as described in FIG. Ink droplets can be ejected from the ink channel A2 by the potential difference between the side walls S2 and S3 between the adjacent ink channels A1 and A3. Further, in the case of slight vibration, it is only necessary to remove the 2AL width signal. The fine vibration pulse in the recording area shown in FIG. 10 has a smaller peak voltage than the waveform of the drive pulse shown in FIG. 6, and thus ink is not ejected.
[0053]
In this way, when the ink meniscus of the nozzle corresponding to the recording area of the recording medium P is also slightly vibrated, the amplitude of the vibration of the ink meniscus of the nozzle protruding from the recording area of the recording medium P is the nozzle corresponding to the recording area. It is preferable to make it larger than the amplitude of the vibration of the ink meniscus. This is because, in the nozzle corresponding to the image recording area, if the ink meniscus is vibrated greatly, it affects the ejection, so the vibration amplitude of the ink meniscus must be suppressed. Since the influence does not matter, the ink in the nozzles can be efficiently stirred by vibrating the ink meniscus to a greater extent, and a higher clogging prevention effect can be obtained. The amplitude of this vibration is the maximum amplitude in one pulse application.
[0054]
In order to make the amplitude of the vibration of the ink meniscus of the nozzle in the portion protruding from the recording area of the recording medium P larger than the amplitude of the vibration of the ink meniscus of the nozzle corresponding to the recording area, the voltage pulse constituting the fine vibration pulse The amplitude may be changed, or as shown in FIG. 10, a 2AL width rectangular wave applied to the recording area is used to apply a 2AL width rectangular wave larger than the voltage in the recording area. In short, it can be adjusted by changing the pulse width or the voltage.
[0055]
The inkjet recording apparatus 1 shown in the present embodiment has a mode for recording a borderless image and a mode for recording a bordered image, and is configured to perform image recording on recording media having different widths. Although described, it goes without saying that only one of the functions may be provided.
[0056]
【The invention's effect】
According to the present invention, it is possible to prevent clogging of the nozzles protruding from the recording area of the recording medium without interrupting the recording operation of the line head, and it is always stable when the nozzles are used for image recording. Thus, an ink jet recording apparatus capable of ejecting ink can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an ink jet recording apparatus.
FIG. 2 is a diagram showing an example of a line head
3A is a plan view of a platen, and FIG. 3B is a diagram illustrating a relationship between a recording area and a nozzle of a line head.
4A is an external perspective view showing a schematic configuration of a head, and FIG. 4B is a cross-sectional view thereof.
FIGS. 5A to 5C are diagrams showing the operation of the head.
FIG. 6 is a diagram showing an example of a drive pulse
FIG. 7 is a diagram showing another example of drive pulses
FIG. 8 is a diagram showing an example of a fine vibration pulse of a nozzle protruding from a recording area.
FIG. 9 is a diagram showing pulses applied to nozzles in a recording area.
FIG. 10 is a diagram showing a fine vibration pulse of a nozzle in a recording area.
[Explanation of symbols]
1: Inkjet recording apparatus
2: Line head
2a to 2d: head
21a-21d: Nozzle
31, 32: pair of conveyance rollers
4: Platen
41: Holding plate
42: Suction port
43a to 43c: ink receiving openings
51, 52: Detection means
P: Recording medium
PS: Recording surface

Claims (5)

An ink jet recording apparatus that performs image recording by ejecting ink from nozzles corresponding to the recording area of the recording medium of a line head provided across the width direction of the recording medium,
In the line head, each ink channel shares an adjacent side wall, and the side wall is made of a piezoelectric material having electrodes formed on both sides, and the side wall is deformed by applying a voltage to the electrode, and the ink Drive control means for causing ink in the channel to fly from the nozzles,
The drive control unit is configured to apply 4AL (1 / acoustic resonance period) to the electrode on the side wall of the even-numbered channel among the plurality of ink channels corresponding to the nozzles of the line head protruding from the recording area of the recording medium. 2) A rectangular wave having a width is applied at intervals of 12 AL, and the rectangular wave identical to the rectangular wave applied to the even channel is applied to the electrode on the side wall of the odd channel by shifting by 4 AL, whereby ink in the ink channel is applied. the meniscus, ink jet recording apparatus characterized and Turkey is vibrated to the extent that the ink does not fly.   2. The ink jet recording apparatus according to claim 1, further comprising selection means for selecting a mode for recording a borderless image and a mode for recording a bordered image on the recording medium.   The inkjet recording apparatus according to claim 1, wherein the line head performs image recording on recording media having different widths. 4. The ink jet according to claim 1, wherein the drive control means vibrates an ink meniscus of a non-ejection nozzle among nozzles corresponding to a recording area of the recording medium in a range where ink does not fly. Recording device. The drive control means makes the amplitude of the vibration of the ink meniscus of the nozzle in the portion protruding from the recording area of the recording medium larger than the amplitude of the vibration of the ink meniscus of the non-ejection nozzle among the nozzles corresponding to the recording area. The ink jet recording apparatus according to claim 4.

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