JP4182602B2 - Inkjet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an ink jet printer that performs printing with magnetic ink.
[0002]
[Prior art]
  Conventionally, a laser printer is used to print on the surface of a print medium such as a security by using powdered toner in which magnetic particles made of a magnetic material are dispersed, so that it can be visually recognized, and security can be improved. A magnetic ink character recording apparatus using MICR (Magnetic Ink Character Recognition / magnetic ink character recognition) that can also be magnetically recognized has been proposed.
  However, a laser printer requires a warm-up time, so that the printer rises slowly, and an ink jet printer that rises faster than a laser printer is desired to print on a print medium with liquid magnetic ink in which magnetic particles are dispersed. . This magnetic ink is different from mixing magnetic particles in powdered toner, and disperses the magnetic particles in liquid ink so that the magnetic particles are small particles of about several tens of nanometers so as not to settle. There was a need. However, such fine magnetic particles have a small magnetic coercive force, and the necessary magnetization cannot be obtained. Therefore, in order to obtain a large magnetic coercive force, it has become necessary to use a magnetic ink containing magnetic particles having a large size of about several hundred to several thousand nm. However, when using magnetic ink containing magnetic particles of a large size of about several hundred to several thousand nm, the magnetic particles are not stably dispersed in the magnetic ink, and the magnetic particles settle in the magnetic ink flow path or the like, The smooth supply of magnetic ink may be hindered, and it has been necessary to prevent the magnetic particles from settling.
[0003]
  Therefore, for example, in the magnetic ink recording apparatus described in Japanese Patent Application Laid-Open No. 57-152964, as shown in FIG. 3 of the official gazette, a plurality of magnetic recording needles are provided and raised near the tip of the recording needle. Magnetic ink (magnetic ink) is attached to the print head that is in contact with the printing magnet to form a magnetic ink bulge at the tip of the recording needle, a voltage is applied to the recording electrode, and ink is ejected to perform recording. In the ink recording apparatus, a vibrator is disposed in contact with the ink in the vicinity of the raised magnet so that the magnetic ink adhering to the print head is agitated. It is possible to stir the adhering magnetic ink, and it is possible to prevent deterioration in print quality due to non-uniform magnetic ink concentration.
[0004]
[Problems to be solved by the invention]
  However, in the configuration of the magnetic ink recording apparatus described in Japanese Patent Application Laid-Open No. 57-152964, the stirable range is limited to a local range in the vicinity of the head portion, and the ink tank and the ink supply There is a problem that unevenness of the magnetic ink density in the path cannot be prevented, and the ink flow path is clogged due to sedimentation of the magnetic particles.
[0005]
  In addition, there are parts such as vibrators that perform mechanical operations, and there is a problem that they are worn out for a long time and the movable parts are broken.
[0006]
  Further, since the magnetic ink is mechanically vibrated by the vibrator, there is a problem of noise.
[0007]
  The present invention solves the above-mentioned problem, prevents clogging of the ink flow path due to sedimentation of magnetic particles, enables continuous printing with high print quality with magnetic ink having a uniform ink concentration, and has high durability. An object is to provide a printer.
[0008]
[Means for Solving the Problems]
  In order to achieve this object, in the ink jet printer according to the first aspect of the present invention, a magnetic ink in which magnetic particles are dispersed is used.An ink tank for storing, and communicating with the ink tank, the magnetic inkAn inkjet head for discharging onto a print medium;A platen that transports the print medium, the ink tank and the inkjet head, and a carriage that moves in a direction orthogonal to the transport direction of the print medium, and a direction that is orthogonal to the transport direction of the print medium by the platen A coil that is arranged on the end side of the platen and generates an alternating magnetic field by passing an electric current, and a carriage is moved to the end side where the coil is arranged to generate an alternating magnetic field in the coil. In the ink tankMagnetic stirring means for stirring the magnetic ink;Demagnetizing means for demagnetizing the magnetic ink by weakening the magnetic field to the ink tank by gradually separating the carriage from the coil or by gradually attenuating the current flowing through the coil.It is provided with.
[0009]
  In the ink jet printer according to this configuration, since the magnetic ink is agitated by applying a change in the magnetic field, the magnetic ink in the entire ink jet head can be agitated. Therefore, clogging of the ink flow path due to sedimentation of the magnetic particles in the entire ink jet head is prevented, and continuous printing with high print quality can be performed with magnetic ink having a uniform ink concentration.
  In the ink jet printer according to this configuration, since the magnetic stirring means generates an alternating magnetic field in the coil, the magnetic field generated by the coil can be changed only by electrical control. Therefore, the magnetic field can be changed even if the ink jet head and the magnetic stirring means are not relatively displaced. Furthermore, since there are no mechanical moving parts such as vibrators, failures due to wear and fatigue are less likely to occur even when used for a long time, and durability is increased, and no mechanical vibration or noise is generated.
  Further, in the ink jet printer according to this configuration, even when a residual magnetism is generated in the magnetic ink when a magnetic field for stirring is applied to the magnetic ink, the demagnetizing means relatively gradually moves from the ink jet head. The magnetic ink can be demagnetized by weakening the magnetic field with respect to the ink-jet head by separating or gradually attenuating the current. Therefore, it is possible to prevent the magnetic particles of the magnetic ink from coagulating or adhering due to residual magnetism.
[0010]
  In the ink jet printer of the invention according to claim 2,An ink tank that stores magnetic ink in which magnetic particles are dispersed, an ink jet head that communicates with the ink tank and discharges the magnetic ink onto a print medium, and the ink tank and the ink jet head are mounted on the print medium. A carriage that moves in a direction orthogonal to the conveyance direction of the carriage, an inclination fixed magnet in which a plurality of magnets having different polarities are alternately stacked with an inclination with respect to the movement direction of the carriage, and the carriage is attached to the inclination fixing magnet. A magnetic stirring means for moving the magnetic ink in the ink tank in the vicinity;It is provided with.
[0011]
  In the inkjet printer according to this configuration,It is not necessary to provide a complicated electric circuit for applying a magnetic field, and the magnetic field applied to the ink-jet head can be changed by tilted fixed magnets that are alternately stacked by using the displacement of the ink-jet head during scanning. Therefore, the structure of the magnetic stirring means can be simplified.
[0012]
  In the ink jet printer of the invention according to claim 3,An ink tank that stores magnetic ink in which magnetic particles are dispersed, an ink jet head that communicates with the ink tank and discharges the magnetic ink onto a print medium, and the ink tank and the ink jet head are mounted on the print medium. A carriage that moves in a direction perpendicular to the conveying direction, a rotating body in which a plurality of magnets having different polarities are alternately formed in the rotating direction, a driving means that rotates the rotating body, and the carriage that is a front rotating body A magnetic agitation means for agitating the magnetic ink in the ink tank by rotating the rotating body by the drive meansIt is provided with.
[0013]
  In the inkjet printer according to this configuration,Since the magnetic stirring means has a structure in which a rotating body in which a plurality of magnets are formed in an annular shape is rotated by a driving means, the magnetic field can be changed at the rotational speed of the rotating body regardless of the moving speed of the inkjet head. . For example, if the rotation of the platen is used as the driving means, it is not necessary to provide a separate driving device.
[0014]
[0015]
[0016]
[0017]
[0018]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, an inkjet printer according to a preferred embodiment of the inkjet printer according to the present invention will be described with reference to the accompanying drawings. First, an outline of the configuration of the inkjet printer 1 will be described with reference to the drawings.
[0019]
  FIG. 1 is a diagram showing an ink jet printer 1 according to an embodiment of the present invention. Here, the right side of FIG. 1 is the front surface and the left side is the back surface. The platen 10 is formed of a cylindrical drum, and is provided horizontally in a direction orthogonal to the conveyance direction (from the right side to the left side in FIG. 1) of the printing paper PP that is a printing medium. A shaft 12 of the platen 10 is rotatably supported by a frame 13 and is driven by a motor 14 via a drive gear train (not shown). An ink jet head 2 is provided at a position facing the platen 10.
[0020]
  The inkjet head 2 is disposed on the carriage 18 together with the ink tank 16. The ink-jet head 2 uses a piezoelectric element, which is a piezoelectric element. In the cavity storing ink, a voltage is applied to the piezoelectric element to reduce the volume of the cavity, and the increased internal pressure increases the magnetic ink MI from the orifice (not shown). Are ejected onto the printing paper PP to form characters and images with the magnetic ink MI on the printing paper PP.
[0021]
  The carriage 18 is slidably supported by a guide rod 20 disposed parallel to the axis of the shaft 12 of the platen 10 and is coupled to a timing belt 24 wound around a pair of driven pulleys 21 and a drive pulley 22. Has been. Then, the driving pulley 22 is driven by the motor 23, and the timing belt 24 is sent in a predetermined direction. Therefore, the carriage 18 is driven by the timing belt 24 while being guided by the guide rod 20, and is moved along the platen 10 with the inkjet head 2 facing the platen 10. A timing fence 19, which is a linear scale for recognizing the position of the carriage 18, is provided on the rear side of the upper end of the carriage 18. The timing fence 19 is projected by a laser projector (not shown), and the position is recognized by a photo sensor. Position information is sent to (see FIG. 2).
[0022]
  The control unit 9 includes a computer including a CPU, a ROM, and a RAM (not shown). The RAM includes an input buffer for storing external input data, a work area used for data processing, An output buffer is provided for storing bitmap data for printing. The ROM stores a control program and the like.
[0023]
  A wiping device 25 is disposed in the vicinity of the left end of the platen 10 in the sheet conveyance direction. The wiping device 25 is provided with a wiper 25a made of a rubber blade so as to be vertically movable. At the time of wiping, the wiper 25a is protruded upward. The carriage 18 passes above the protruded wiper 25a, contacts the wiper 25a with the surface of the inkjet head 2 passing therethrough, and the wiper from which the magnetic ink adhered to the surface of the inkjet head 2 is protruded. Wipe with 25a.
[0024]
  In addition, when the printing is started, the inkjet head 2 is moved to the upper side of the purge device 26 in a timely manner, and then the purge device 26 is moved to the upper portion, and the purge hole 26a provided on the upper portion of the purge device 26 is not shown Adhere to the orifice. A rubber member is provided around the purge hole 26a to maintain an airtight state. When a negative pressure is applied to the purge hole 26a by the pump 27 from this state, an ink having a viscosity increased from the orifice of the inkjet head 2 or the like. Then, ink solidified by the magnetic flow element MG is forcibly sucked out, and the ejection of ink from the orifice is normalized.
[0025]
  On the other hand, a magnetic stirrer 3 is disposed in the vicinity of the right end of the platen 10 in the sheet conveyance direction. The magnetic stirrer 3 includes a coil iron core 31 that is a U-shaped member having a rectangular iron plate bent and opened on the side (back side), and includes a guide rod 20, a drive pulley 22, and a timing fence 19. Is disposed so as to surround. The coil iron core 31 is configured such that the carriage 18 can freely enter and exit the coil iron core 31 without interfering with the coil iron core 31. On the front side of the coil core 31, a coil 32 is formed by winding a number of enameled wires, which are enamel-coated on the surface, to form a coil 32, and a drive circuit 35 (see FIG. 2) is provided at both ends of the coil 32. And is electrically connected to the control unit 9 (see FIG. 2). Since the magnetic stirring device 3 is configured as described above, the ink tank 16 and the inkjet head 2 are positioned close to the coil 32 when the carriage 18 is located inside the magnetic stirring device 3.
[0026]
  Here, FIG. 2 is a diagram showing an electrical configuration of the magnetic stirring device 3. The coil 32 of the magnetic stirrer 3 is connected to an AC power supply 34 and a drive circuit 35 by a conducting wire 33 to constitute a circuit. The drive circuit 35 is controlled by a control signal from the control unit 9 to indicate that the carriage 18 (see FIG. 1) has moved into the magnetic stirrer 3 and reflects the reflected light from the timing fence 19 (see FIG. 1). Recognized by a received signal from a photosensor (not shown) and when the carriage 18 enters the magnetic stirrer 3, an alternating voltage is applied to the coil 32 to generate an alternating magnetic field. Further, the controller 9 stops the drive signal to the drive circuit 35 when the carriage 18 moves from the inside of the magnetic stirrer 3 to the outside and the influence of the alternating magnetic field from the magnetic stirrer 3 becomes sufficiently small. Then, the application of the AC voltage to the coil 32 is stopped.
[0027]
  By controlling the magnetic stirrer 3 in this manner, a strong alternating magnetic field is applied to the carriage 18 and applied to the ink jet head 2 mounted on the carriage 18 and the magnetic ink MI in the ink tank 16 (see FIG. 1). The magnetic ink MI is agitated by changing the magnetic field. Further, the magnitude of the alternating magnetic field applied to the carriage 18 gradually decreases as the carriage 18 moves away. Therefore, a residual magnetic field biased in one direction is not generated unlike when a large magnetic field is applied in either direction and the magnetic field disappears. In other words, the magnetic stirrer 3 demagnetizes the magnetic ink MI in the ink jet head 2 and the ink tank 16 mounted on the carriage 18 while the carriage 18 moves away.
[0028]
  FIG. 9 is a schematic cross-sectional view of the carriage 18 as viewed from the XX portion of FIG. As shown in FIG. 9, the ink tank 16 includes an internal tank 16 b that stores ink in an external tank 16 a, and the external tank 16 a is supported by the carriage 18. An ink flow path 40 is provided at the bottom of the external tank 16a, and the magnetic ink MI is supplied to the ink jet head 2 in communication therewith. In addition, a filter 41 for preventing bubbles and foreign matter of the magnetic ink MI from entering the ink jet head 2 is disposed at the opening of the ink flow path 40 of the external tank 16a. The filter 41 is configured with a large number of fine holes. The magnetic particles MG of the magnetic ink MI of the present embodiment have a specific gravity larger than that of the liquid portion of the magnetic ink MI and have a particle diameter as large as several hundred to several thousand mn, so that the magnetic particles MG are likely to settle and the magnetic ink MI is not stirred. Magnetic particles MG settle on the surface of the filter 41. Then, the fluidity of the magnetic ink MI is lowered, and the deposit D of the magnetic ink MI is deposited on the surface of the filter 41, and the magnetic ink MI does not flow smoothly into the ink flow path 40.
[0029]
  Next, the operation of the ink jet printer 1 configured as described above will be described with reference to FIGS. 1 and 2. First, when the ink jet printer 1 is turned on, the control unit 9 rotates the motor 23 according to a predetermined check program, the carriage 18 is guided and moved by the guide rod 20, and there is no abnormality in the travel of the carriage 18. Is checked with reference to information from the timing fence 19. Similarly, the motor 14 is rotated to check whether there is any abnormality in the rotation of the platen 10. Next, the control unit 9 rotates the motor 23 to stir the magnetic ink MI, and moves the carriage 18 into the magnetic stirrer 3.
[0030]
  When the carriage 18 moves into the magnetic stirring device 3, the control unit 9 sends a drive signal to the drive circuit 35 and applies an AC voltage to the coil 32. The coil 32 to which the AC voltage is applied generates an alternating magnetic field. Then, a magnetic field that constantly changes in the vertical direction is applied to the ink tank 16 mounted on the carriage 18 and the inkjet head 2 shown in FIG. Then, the magnetic particles MG of the magnetic ink MI in the ink tank 16, the ink jet head 2, and the ink flow path 40 are vibrated by a constantly changing magnetic field, and the liquid that is a nonmagnetic material of the magnetic ink MI is caused by the vibration of the magnetic particles MG. The part is also vibrated and stirred. When the magnetic ink MI is stirred, the magnetic particles MG are uniformly dispersed in the magnetic ink MI, and the magnetic particles deposited on the filter 41 provided in the ink flow path 40 when the ink jet printer 1 is not used. MG can also be uniformly dispersed in the magnetic ink MI. Therefore, the density of the magnetic ink MI is made uniform and the ink flow in the ink flow path 40 is made smooth so that it is possible to perform uniform printing on the printing paper PP.
[0031]
  When the magnetic ink MI is stirred by the magnetic stirrer 3 in this way, the control unit 9 drives the motor 23 to move the carriage 18 from the inside of the magnetic stirrer 3 and from the magnetic stirrer 3. Separate. At this time, an AC voltage is applied to the magnetic stirring device 3, and a predetermined magnetic field is formed in the magnetic stirring device 3. Here, by separating the carriage 18 from the magnetic stirrer 3, the alternating magnetic field applied to the carriage 18 gradually weakens while changing the direction of the magnetic field. When the carriage 18 is sufficiently separated from the magnetic stirring device 3, the application of voltage to the magnetic stirring device 3 is stopped. Accordingly, residual magnetism biased in one direction does not remain, and as a result, the magnetic particles MG of the magnetic ink MI in the ink tank 16, the inkjet head 2, and the ink flow path 40 are demagnetized without being magnetized. Therefore, it is possible to prevent the magnetic particles MG from aggregating due to magnetization.
[0032]
  When the demagnetization of the magnetic ink MI is completed, the carriage 18 is then moved above the purge device 26 by the controller 9 and the above-described purge is performed. The magnetic ink MI whose viscosity has increased by drying near the orifice (not shown) of the inkjet head 2 due to the purge, or the magnetic ink MI in which the magnetic particles MG are aggregated is sucked and discharged from the orifice by the pump 27, and is discharged to the discharge tank 28. Discarded. This purge facilitates the ejection of the magnetic ink MI from the orifice.
[0033]
  When the purge is completed, the wiping device 25 performs wiping as described above in order to wipe off the magnetic ink MI adhering to the lower end portion of the inkjet head 2 having the orifice. This wiping wipes off the magnetic ink MI adhering to the periphery of the orifice by normal printing or purging.
[0034]
  In parallel with the above preparation, print data is read from an external computer (not shown) into an input buffer (not shown) of the control unit 9, and if necessary, the print data is expanded to an output buffer (not shown) in bit units. Remember. When the printing paper PP is conveyed by the motor 23 and reaches the printing start position, the carriage 23 is moved based on the position information from the timing fence 19 and a photo sensor (not shown) based on the data in the output buffer. The ink jet head 2 is driven at a predetermined position while performing main scanning in the direction orthogonal to the paper transport direction, and the magnetic ink MI is ejected onto the printing paper PP for printing. When the main scanning for one line is completed, the printing paper PP is sub-scanned relative to the inkjet head 2. Specifically, the printing paper PP is transported to the next printing position. In this way, when printing of characters and images to be printed on the printing paper PP is completed, the printing paper PP is conveyed and discharged.
[0035]
  When the above printing on the printing paper PP is completed, the inkjet head 2 moves above the purge device 26, and the purge device 26 moves up and adheres to the lower end of the inkjet head 2, so that the magnetic ink in the orifice while not in use is used. Prevent drying of MI.
[0036]
  The inkjet printer 1 has the following effects because it has the above-described configuration and operation. That is, the ink jet printer 1 has an effect that the magnetic ink MI can be agitated by changing the magnetic field. Therefore, the magnetic ink MI in the entire inkjet head 2 can be agitated, and in particular, since it is agitated in the vertical direction, the accumulation of the magnetic particles MG in the entire inkjet head 2 can be effectively prevented and the ink flow path 40 can be prevented. The magnetic ink MI in which the clogging is prevented and the ink density is made uniform has an effect that printing can be continuously performed with high printing quality.
[0037]
  In addition, since the magnetic stirring device 3 includes the coil 32, the magnetic field generated by the coil 32 can be changed only by electrical control. Therefore, even if the inkjet head 2 and the magnetic stirrer 3 are not displaced relatively, there is an effect that a magnetic field can be changed. Further, since there is no mechanical movable part such as a vibrator, there is an effect that durability due to wear and fatigue is less likely to occur even when used for a long time, and further, mechanical vibration and noise are not generated.
[0038]
  In addition, when a magnetic field for stirring is applied to the magnetic ink MI, the magnetic stirrer 3 acts as a demagnetizing unit even if residual magnetism may occur in the magnetic ink MI. By gradually separating them, there is an effect that the magnetic ink MI can be demagnetized by weakening the magnetic field to the ink-jet head 2. As a result, the magnetic particles MG of the magnetic ink MI can be prevented from solidifying or adhering due to residual magnetism.
[0039]
  Next, an inkjet printer 101 that is a modification of the inkjet printer 1 according to the first embodiment of the present invention will be described. Note that, in the embodiments described below and modifications thereof, the same or equivalent parts as those in the first embodiment of the present invention are denoted by the same reference numerals, and description thereof is omitted.
[0040]
  Here, FIG. 3 is a diagram showing the inkjet printer 101. The inkjet printer 1 has a shape in which the coil iron core 31 is open on the back side, and the coil 32 is wound only on the front surface side, whereas the ink jet printer 101 has a shape in which the coil iron core 131 is open on the lower side. The difference is that the coil 132a and the coil 132b are wound on both sides of the front side and the back side, respectively. Therefore, when the carriage 118 enters the magnetic stirring device 103, the carriage 118 on which the ink tank 116 and the inkjet head 102 are mounted is disposed between the two coils 132a and 132b. If a voltage is applied to the coils 132a and 132b by this arrangement, a magnetic field can be effectively applied to the deposit D of the magnetic ink MI as shown in FIG.
[0041]
  Here, FIG. 4 is a diagram showing an electrical configuration of the magnetic stirring device 103. In the magnetic stirring device 103, a coil 132a and a coil 132b are connected in parallel, and a conductive wire 133 on the AC power supply 134 side of the coil 132a includes a capacitor 136. The coils 132a and 132b are connected to an AC power source 134 and a drive circuit 135 to form a circuit. The drive circuit 135 is controlled by a control signal from the control unit 109, and reflects that the carriage 118 (see FIG. 3) has moved into the magnetic stirring device 103, and reflects the reflected light from the timing fence 19 (see FIG. 1). Recognized by a received signal from a photosensor (not shown) and when the carriage 118 enters the magnetic stirrer 103, an alternating voltage is applied to the coils 132a and 132b to generate an alternating magnetic field. In this case, since a predetermined phase difference is generated between the coil 132a and the coil 132b by the capacitor 136, the direction of the magnetic field alternately changes in accordance with the frequency of the power source. Therefore, a large magnetic field change can be given to the inkjet head 2 and the like, and the magnetic ink MI can be effectively stirred.
[0042]
  Further, the control unit 109 gradually reduces the voltage applied to the coils 132a and 132b by the variable resistance provided in the drive circuit 135, and attenuates the magnetic field applied to the carriage 118 inside the magnetic stirring device 103. Let
[0043]
  By controlling the magnetic stirrer 103 in this manner, a strong alternating magnetic field is applied to the carriage 118 and applied to the ink-jet head 102 mounted on the carriage 118 and the magnetic ink MI in the ink tank 116 (see FIG. 3). The magnetic ink MI is agitated by changing the magnetic field. Further, the applied electric field is gradually attenuated while changing the direction of the electric field applied to the carriage 118. Therefore, a residual magnetic field biased in one direction is not generated unlike when a large magnetic field is applied in either direction and the magnetic field disappears. That is, the magnetic stirrer 103 demagnetizes the magnetic ink MI in the ink jet head 102 and the ink tank 116 mounted on the carriage 118 by gradually attenuating the electric field applied to the carriage 118. .
[0044]
  The inkjet printer 101 has the following effects because it has the above-described configuration and operation. That is, since the coils 132a and 132b are disposed at positions sandwiching the carriage 118, a magnetic field for efficiently stirring the magnetic ink MI with respect to the carriage 118 on which the inkjet head 102 and the ink tank 116 are mounted. There is an effect that can be applied. Therefore, the magnetic ink MI is sufficiently stirred, and the deposit D of the magnetic ink MI shown in FIG. 9 is stirred and easily lost.
[0045]
  Furthermore, since the magnetic stirrer 103 of the ink jet printer 101 includes an electric circuit as shown in FIG. 4, there is an effect that alternating voltages having different phases can be applied to the two coils 132 a and 132 b. As a result, magnetic fields having different magnetic field directions can be generated between the two coils, and the magnetic ink MI can be more efficiently stirred.
[0046]
  In addition, the voltage applied to the coils 132a and 132b is gradually reduced by the variable resistance provided in the drive circuit 135 of the control unit 109, and the magnetic field applied to the carriage 118 inside the magnetic stirring device 103 is attenuated. As a result, the magnetic ink MI can be demagnetized. Therefore, it is possible to prevent the magnetic ink MI from being agglomerated and adhered due to magnetization.
[0047]
  Next, an ink jet printer 201 according to the second embodiment of the present invention will be described. FIG. 5 is a diagram illustrating the ink jet printer 201. The ink jet printer 1 according to the first embodiment shown in FIG. 1 is provided with a magnetic stirring device 3 in the vicinity of one end of the platen 10, and the carriage 18 moves here to stir the magnetic ink MI. As shown in FIG. 5, the ink jet printer 201 differs in that the magnetic stirring device 203 is mounted on the carriage 218 itself.
[0048]
  The carriage 218, the ink tank 216, and the inkjet head 202 have basically the same structure as the carriage 18, the ink tank 16, and the inkjet head 2 of the inkjet printer 1, and an enamel wire is wound around the coil 232a. , 232b are formed to face each other so as to sandwich the carriage. Here, FIG. 6 is a diagram showing an electrical configuration of the magnetic stirring device 203. As shown in FIG. 6, in the magnetic stirring device 203, a coil 232a and a coil 232b are connected in parallel, and a conductor 233 on the side of the AC power supply 234 of the coil 232a includes a capacitor 236. The coils 232a and 232b are connected to an AC power source 234 and a drive circuit 235 to form a circuit. That is, the coils 232a and 232b are connected to a circuit configured in the same manner as the electric circuit shown in FIG. Therefore, as with the magnetic stirrer 103 of the ink jet printer 101, when a voltage is applied from the drive circuit 235 to the coils 232a and 232b, the ink tank 216 and the ink jet head 202 mounted on the carriage 218 are alternated from the coils 232a and 232b. The magnetic ink MI is stirred by applying a magnetic field. Then, the AC voltage applied from the drive circuit 235 to the coils 232a and 232b is gradually lowered by the control unit 209, and the magnetic ink MI is demagnetized.
[0049]
  Since the inkjet printer 201 has the above-described configuration and operation, the coils 232a and 232b can be provided close to the inkjet head 202 and the like in addition to the same effects as the effects shown in the inkjet printer 101. There is an effect that the magnetic ink MI can be efficiently stirred. Further, as compared with the magnetic stirrer 103, when applying with the same magnetic field strength, the applied voltage can be lower. Further, by providing the coils 232a and 232b on the carriage 218, the magnetic stirrer 203 can be made compact, and the entire inkjet printer 201 can be made compact.
[0050]
  When the printer is not used, the magnetic stirrer 203 does not generate a magnetic field, so there is no aggregation or adhesion due to magnetization of the magnetic ink MI.
[0051]
  Next, an inkjet printer 301 according to a third embodiment of the present invention will be described. FIG. 7 is a diagram illustrating the inkjet printer 301. The ink jet printer 1 according to the first embodiment shown in FIG. 1 is configured such that a magnetic stirring device 3 is provided in the vicinity of one end portion of a platen 10 and a carriage 18 moves to apply an AC electric field. On the other hand, as shown in FIG. 7, the inkjet printer 301 has a carriage 318 in which a plurality of magnets having different polarities are striped at intervals of several mm above a purge device 326 provided near one end of the platen 310. Inclined fixed magnets 337a that are alternately stacked in an inclined manner with respect to the moving direction of the carriage 318 and arranged to face the back side of the carriage 318, and to face the front side of the carriage 318 near the other end of the platen 310. The magnetic stirrer 303 is different from the inclined fixed magnet 337b having the same configuration.
[0052]
  The magnetic stirrer 303 is composed of, for example, a plurality of magnets having different polarities, such as about 200 to 300 gauss, stacked in parallel at intervals of several mm. Specifically, a magnetic material mixed with rubber to form a sheet having a thickness of several millimeters and magnetized can be suitably used.
[0053]
  The inkjet printer 301 configured as described above has the following operation. That is, the magnetic stirrer 303 includes tilted fixed magnets 337a and 337b in which a plurality of magnets having different polarities are alternately stacked in a stripe shape with a few mm intervals tilted with respect to the moving direction of the carriage 318. Since the carriage 318 on which the moving inkjet head 302 and the ink tank 316 are mounted receives a different magnetic field depending on the position, the magnetic ink MI is agitated by the changing magnetic field.
[0054]
  For this reason, the inkjet printer 301 does not need to have a complicated electric circuit for applying a magnetic field, and the inkjet fixed heads 337a and 337b are alternately stacked by tilting using the displacement of the inkjet head 302 during scanning. Since the magnetic field applied to the head 302 can be changed, there is an effect that the structure of the magnetic stirring device 303 can be simplified.
[0055]
  The inclined fixed magnets 337a and 337b may be provided at both ends of the platen 310 as shown in FIG. 7, but may be provided only on one side. The home position of the carriage 318 is desirably a position away from the magnetic field of the inclined fixed magnets 337a and 337b so that the magnetic ink MI is not easily magnetized.
[0056]
  Next, an inkjet printer 401 according to a fourth embodiment of the present invention will be described. FIG. 8 is a diagram illustrating the inkjet printer 401. The ink jet printer 1 according to the first embodiment shown in FIG. 1 is configured such that a magnetic stirring device 3 is provided in the vicinity of one end of a platen 10 and a carriage 18 moves to apply an AC electric field. In contrast, as shown in FIG. 8, the inkjet printer 401 includes a rotating body 438 in which a plurality of magnets 438 a provided at one end of a platen 410 are formed in an annular shape on a cylindrical drum 438 b, and a rotating body 438. The magnetic stirrer 403 is configured to include a driving unit 439 for driving.
[0057]
  The rotating body 438 includes a cylindrical drum 438b. The rotating shaft 438c of the drum 438b is disposed so as to be parallel to the shaft 412 of the platen 410, and the rotating shaft 438c and the drum 438b can be rotated together. It is pivotally supported. The drum 438b is disposed at a position where it can face the carriage 418. Around the drum 438b, rod-shaped permanent magnets having a magnetic force of about 550 gauss are arranged in parallel and annularly in the height direction of the side surfaces so that the polarities are alternated. The rotation shaft 438c is a metal shaft, and protrudes toward the platen 410. An annular groove is provided at the tip, and the drive belt 439a is wound around the groove. The drive belt 439a is wound around a pulley (not shown) disposed at the end of the platen 410. Therefore, when the platen 410 rotates, the rotating body 438 is rotated by the drive belt 439a, and the rotational speed is several times the rotational speed of the platen 410.
[0058]
  In the ink jet printer 401 configured as described above, the magnetic stirrer 403 has a structure in which a rotating body 438 in which a plurality of magnets 438a are formed in an annular shape is rotated by a driving unit 439. Therefore, the ink tank 416 and the ink jet head 402 are used. Regardless of the moving speed of the carriage 418 mounted with the magnetic head, the rotating means 438 can be rotated by the driving unit 439 to change the magnetic field, and the magnetic ink MI in the ink tank 416 and the ink jet head 402 can be stirred. There is an effect. In particular, if the rotation of the platen 410 is used for the driving means 439, it is not necessary to provide a separate driving device, and a simple structure can be achieved.
[0059]
  As mentioned above, although demonstrated based on embodiment of this invention and its modification, this invention is not limited to embodiment mentioned above at all. For example, the magnetic stirrers 3, 103, 203, 303, and 403 can be used only when the magnetic ink MI can be stirred, only on the front side and the back side of the carriage 18, 118, 218, 318, and 418, or both sides thereof, and further up and down or It can be suitably provided in the left-right direction, and can be appropriately arranged on the left and right of the platens 10, 110, 310, 410.
[0060]
  In the above-described embodiment, the inkjet printers 1, 101, 201, 301, 401 perform main scanning with the inkjet heads 2, 102, 202, 302, 402, and print sheets with the platens 10, 110, 210, 310, 410. Although a serial printer that carries PP and performs sub-scanning has been described as an example, it can also be configured as a page printer that includes an inkjet head in the form of an array in the page width direction of printing paper PP, and uses a narrow print medium. Needless to say, it can be configured as a tape printer.
[0061]
  In addition, it can be easily inferred that various improvements can be made and modified without departing from the spirit of the present invention.
[0062]
【The invention's effect】
  As is apparent from the above description, the ink jet printer according to the first aspect of the present invention has an effect that the magnetic ink can be agitated by changing the magnetic field. Therefore, the magnetic ink in the entire inkjet head can be agitated, the clogging of the ink flow path due to the sedimentation of the magnetic particles in the entire inkjet head is prevented, and continuously with high print quality by the magnetic ink with uniform ink concentration. There is an effect that printing can be performed.
[0063]
  Claims1According to the inkjet printer of the invention, MagnetismAir stirring means is a coilTo generate an alternating magnetic fieldTherefore, there is an effect that the magnetic field generated by the coil can be changed only by electrical control. Therefore, there is an effect that the magnetic field can be changed even if the ink jet head and the magnetic stirring means are not displaced relatively. Further, since there is no mechanical movable part such as a vibrator, there is an effect that durability due to wear and fatigue is less likely to occur even when used for a long time, and further, mechanical vibration and noise are not generated.
[0064]
  Also,Claim1According to the inkjet printer of the invention, MagnetismWhen a magnetic field for stirring is applied to the gas ink, even if residual magnetism may be generated in the magnetic ink, the demagnetization means relatively gradually moves away from the inkjet head or gradually attenuates the current. This has the effect of demagnetizing the magnetic ink by weakening the magnetic field to the ink jet head. Therefore, the magnetic particles of the magnetic ink can be prevented from solidifying or adhering due to residual magnetism.
[0065]
  Claims2According to the inkjet printer of the invention, MagnetismIt is not necessary to provide a complicated electric circuit for applying a field, and the magnetic field for the ink-jet head can be changed by using tilted fixed magnets that are alternately inclined and stacked by using the displacement of the ink-jet head during scanning. Therefore, there is an effect that the structure of the magnetic stirring means can be simplified.
[0066]
  Claim3According to the inkjet printer of the invention, MagnetismThe air stirring means has a structure in which a rotating body in which a plurality of magnets are formed in an annular shape is rotated by a driving means, so that the magnetic field can be changed at the rotational speed of the rotating body regardless of the moving speed of the inkjet head. There is an effect that can be done. Further, for example, if the rotation of the platen is used for the driving means, there is an effect that it is not necessary to provide a separate driving device.
[Brief description of the drawings]
FIG. 1 is a diagram showing an inkjet printer 1 according to an embodiment of the present invention.
FIG. 2 is a diagram showing an electrical configuration of the magnetic stirring device 3;
FIG. 3 is a diagram illustrating an inkjet printer 101. FIG.
4 is a diagram showing an electrical configuration of a magnetic stirring device 103. FIG.
FIG. 5 is a diagram illustrating an inkjet printer 201. FIG.
6 is a diagram showing an electrical configuration of a magnetic stirring device 203. FIG.
FIG. 7 is a diagram illustrating an ink jet printer.
FIG. 8 is a diagram illustrating an inkjet printer 401.
9 is a schematic cross-sectional view of the carriage 18 as seen from the XX portion of FIG.
[Explanation of symbols]
1, 101, 201, 301, 401 Inkjet printer
2,102,202,302,402 Inkjet head
3,103,203,303,403 Magnetic stirrer
9, 109, 209 Control unit
10 Platen
12 axes
13 frames
14 Motor
16, 116, 216, 316, 416 Ink tank
16a External tank
16b Internal tank
18, 118, 218, 318, 418 Carriage
19 Timing Fence
20 Guide rod
21 Driven pulley
22 Drive pulley
23 Motor
24 Timing belt
25 Wiping device
25a Wiper
26 Purge device
26a Purge hole
27 Pump
28 Discharge tank
31,131 Coil core
32, 132a, 132b Coil
33, 133, 233 lead wire
34, 134, 234 AC power supply
35, 135, 235 drive circuit
136,236 capacitors
337a, 337b Tilt fixed magnet
438 Rotating body
438a Magnet
438b drum
438c Rotating shaft
439 Driving means
439a Drive belt
40 Ink flow path
41 Filter
D deposit
PP printing paper
MG magnetic particles
MI magnetic ink

Claims (3)

An ink tank for storing magnetic ink in which magnetic particles are dispersed ;
An inkjet head communicating with the ink tank and ejecting the magnetic ink onto a print medium;
A platen for conveying the print medium;
A carriage that mounts the ink tank and the inkjet head and moves in a direction perpendicular to the conveyance direction of the print medium;
A coil that is arranged on an end side of the platen in a direction orthogonal to the conveyance direction of the print medium by the platen and generates an alternating magnetic field by flowing an electric current;
Magnetic stirring means for moving the carriage to the end where the coil is disposed to generate an alternating magnetic field in the coil and stirring the magnetic ink in the ink tank ;
Demagnetizing means for demagnetizing the magnetic ink by weakening the magnetic field to the ink tank by gradually separating the carriage from the coil or by gradually attenuating the current flowing through the coil. Inkjet printer. An ink tank for storing magnetic ink in which magnetic particles are dispersed;
An inkjet head communicating with the ink tank and ejecting the magnetic ink onto a print medium;
A carriage that mounts the ink tank and the inkjet head and moves in a direction perpendicular to the conveyance direction of the print medium;
A plurality of magnets with different polarities are inclined and fixed magnets that are alternately stacked while being inclined with respect to the moving direction of the carriage,
By moving the carriage in the vicinity of the inclined stationary magnet, features and be Louis inkjet printers in that the magnetic ink of the ink tank with a <br/> with magnetic stirring means for stirring. An ink tank for storing magnetic ink in which magnetic particles are dispersed;
An inkjet head communicating with the ink tank and ejecting the magnetic ink onto a print medium;
A carriage that mounts the ink tank and the inkjet head and moves in a direction perpendicular to the conveyance direction of the print medium;
A rotating body in which a plurality of magnets having different polarities are alternately formed along the rotation direction;
Driving means for rotating the rotating body;
A magnetic stirring means for moving the carriage to a position close to the front rotating body and rotating the rotating body by the driving means to stir the magnetic ink in the ink tank. features and be Rui ink jet printer.

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