JP2009285998A - Recorder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To record a high-quality image and to attain cost reduction. <P>SOLUTION: Six power supply circuits 71 generate mutually different voltages. The six power supply circuits 71 and eight inkjet heads 1 are connected each other so that four of the six power supply circuits 71 each supply the voltages to only one inkjet head 1 and so that two of the power supply circuits 71 supply the voltages to respective two inkjet heads 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a recording apparatus having a plurality of recording heads for recording an image on a recording medium.

  An ink jet printer having a plurality of ink jet heads has a power supply device that supplies a voltage for driving each ink jet head. As an inkjet head, for example, there is a head having a flow path unit in which a nozzle for ejecting ink and a pressure chamber communicating with the nozzle are formed, and a plurality of actuators for applying ejection energy to the ink in the plurality of pressure chambers. . The actuator applies pressure to the ink in each pressure chamber by changing the volume of the pressure chamber when a voltage is applied, and thereby the ink is ejected from the nozzle. In such an ink jet head, there is a difference in ink ejection speed due to the influence of manufacturing errors of the actuator and the ink flow path. If there is a difference in ink ejection speed among a plurality of inkjet heads, it is difficult to print a high-quality image. Therefore, a technique for selecting a voltage supplied to the inkjet head so that ink is ejected at a uniform speed between the inkjet heads is known (see, for example, Patent Document 1). Thereby, the discharge speed of the ink is made uniform between the plurality of inkjet heads, and a high-quality image can be printed.

JP-A-10-272766 (FIG. 4)

  In the ink jet printer described in Patent Document 1, since it is necessary to supply an appropriate voltage to each ink jet head, the same number of power supply circuits as the number of ink jet heads are required, which increases the cost of the ink jet printer.

  SUMMARY An advantage of some aspects of the invention is that it provides a recording apparatus capable of recording a high-quality image and reducing the cost.

  The recording apparatus of the present invention includes m (natural number: m ≧ 3) recording heads that record an image on a recording medium, and n (natural number: m> n ≧ 2) power supply circuits that can output different voltages. The voltage output from at least one of the power supply circuits is supplied to the plurality of recording heads.

  According to the present invention, since the voltage input to the recording head can be selected according to the recording characteristics depending on the voltage of the recording head, a high-quality image can be recorded. Further, since the number of power supply circuits is smaller than the number of recording heads, the cost of the recording apparatus can be reduced. Here, the recording characteristics relate to dots formed on the recording medium, and include, for example, ink ejection speed and dye transfer amount.

  In the present invention, the width of the distribution range of m recording characteristic values related to the m recording heads is such that the voltage output from any one of the n power circuits is the m. Voltages output by two or more of the power supply circuits are supplied to the m recording heads so as to be equal to or less than the width of the distribution range of the recording characteristic values when supplied to the recording heads. It is preferable. According to this, a higher quality image can be recorded.

  In the present invention, the recording head has a recording unit in which a voltage rank indicating a voltage range to be supplied to the recording head is recorded, and the voltage rank recorded in the recording unit is acquired. Based on the content stored in the storage means, the storage means for storing the voltage ranks related to the m recording heads acquired by the acquisition means, and the voltage output by each power supply circuit, Voltages output by one of the power supply circuits so as to fall within the voltage range indicated by the voltage rank recorded in the recording unit of the recording head to which the voltage is supplied are the same voltage rank or mutually. A voltage supply circuit for supplying a voltage output from each power supply circuit to the m recording heads so as to be supplied to the plurality of recording heads belonging to two adjacent voltage ranks. It is preferably provided to al. According to this, the recording characteristics of the recording heads are discriminated and the optimum voltage is automatically supplied to each recording head, so that the connection and replacement work of the recording heads is facilitated.

  At this time, the voltage supply circuit controls a plurality of connection circuits that electrically connect a power supply terminal of the power supply circuit and a voltage input terminal of the recording head, and an electrical connection state of the plurality of connection circuits. It is preferable to have a control means. According to this, the voltage supply circuit can be realized with a simple configuration.

  In the present invention, the recording head has a head-side connection portion that is electrically connected to the voltage input terminal of the recording head, and the power supply circuit is electrically connected to the power supply terminal of the power supply circuit. And a plurality of power supply side connection portions that are detachably connected to the head side connection portion, and the head side connection portion is connected to at least one of the plurality of power supply side connection portions. It is preferable. According to this, the connection relationship between the recording head and the power supply circuit can be easily changed.

  At this time, it is more preferable that the recording head has a recording unit in which a voltage rank indicating a voltage range to be supplied to the recording head is recorded. According to this, the user can easily determine to which power source side connection portion the head side connection portion of the recording head should be connected.

  In the present invention, it is preferable to further include a signal output circuit that outputs an electric signal indicating to which of the power supply circuits the recording head is connected. According to this, the connection relationship between the power supply circuit and the recording head can be grasped based on the electric signal.

  Furthermore, in the present invention, the recording head records an image on the recording medium by ejecting any of a plurality of types of ink, and the voltage output by one of the power supply circuits is the ink with the highest brightness. A plurality of the recording heads including the recording head to be ejected may be supplied. According to this, the highest brightness ink has a smaller visual effect than other types of ink. Therefore, in the power supply circuit that outputs voltage to the recording head that discharges the ink with the highest brightness and the recording head that discharges other types of ink droplets, the voltage is optimal for the recording head that discharges other types of ink droplets. Therefore, it is possible to efficiently prevent the image quality from deteriorating.

  In addition, according to the present invention, the recording head records an image on the recording medium by ejecting any one of a plurality of types of ink, and the voltage output from one power supply circuit is the ink with the lowest brightness. May be supplied only to the recording head that discharges ink. According to this, the ink with the lowest brightness has a larger visual effect than the other types of ink and is frequently used. Therefore, a single power supply circuit is occupied by the recording head that discharges the ink with the lowest brightness, so that a high-quality image can be recorded and the maximum load of the power supply circuit can be reduced.

  Furthermore, in the present invention, it is preferable that at least one of the n power supply circuits can adjust a voltage to be output. According to this, since the voltage adjusted to the optimum voltage is supplied to the recording head, it is possible to record an even higher quality image.

  According to the present invention, since the voltage input to the recording head can be selected according to the recording characteristics of the recording head, a high-quality image can be recorded. Further, since the number of power supply circuits is smaller than the number of recording heads, the cost of the recording apparatus can be reduced.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a schematic side view showing the overall configuration of the ink jet printer according to the first embodiment of the present invention. As shown in FIG. 1, the inkjet printer 101 is a color inkjet printer having eight inkjet heads 1. The inkjet printer 101 includes a control device 16 that controls the operation of the inkjet printer 101 and a power supply unit 17 that supplies voltages to the eight inkjet heads 1. The ink jet printer 101 includes a paper feeding unit 11 on the left side in the drawing and a paper discharge unit 12 on the right side in the drawing.

  Inside the ink jet printer 101, a paper transport path is formed through which the paper P is transported from the paper feed unit 11 toward the paper discharge unit 12. A pair of feed rollers 5a and 5b for nipping and conveying the paper are arranged immediately downstream of the paper supply unit 11. The pair of feed rollers 5a and 5b are for feeding the paper P from the paper feeding unit 11 to the right in the drawing. A transport mechanism 13 is provided at an intermediate portion of the paper transport path. The transport mechanism 13 is disposed in an area surrounded by the two belt rollers 6 and 7, an endless transport belt 8 wound around the rollers 6 and 7, and the transport belt 8. Platen 15. The platen 15 supports the conveyance belt 8 so that the conveyance belt 8 does not bend downward at a position facing the inkjet head 1. A nip roller 4 is disposed at a position facing the belt roller 7. The nip roller 4 presses the sheet P fed from the sheet feeding unit 11 by the feed rollers 5 a and 5 b against the outer peripheral surface 8 a of the transport belt 8.

  The conveyance belt 8 travels when the conveyance motor (not shown) rotates the belt roller 6. Thereby, the conveyance belt 8 conveys the paper P pressed against the outer peripheral surface 8 a by the nip roller 4 toward the paper discharge unit 12 while being adhesively held. A weak adhesive silicon resin layer is formed on the surface of the conveyor belt 8.

  A peeling plate 14 is provided immediately downstream of the conveying belt 8. The peeling plate 14 is configured to peel the paper P adhered to the outer peripheral surface 8a of the conveyor belt 8 from the outer peripheral surface 8a and guide it toward the paper discharge unit 12 on the right side in the drawing.

  The eight ink-jet heads 1 have an elongated rectangular parallelepiped shape that is long in a direction orthogonal to the paper transport direction (main scanning direction: a direction perpendicular to the paper surface in FIG. 1), and are arranged in a staggered manner in the paper transport direction. . At this time, each inkjet head 1 is disposed so as to be reversed in order along the paper transport direction. Each of the two inkjet heads 1 that appear in order from the upstream side in the sheet conveyance direction forms an inkjet head set. These four inkjet head sets correspond to four different colors of ink (cyan (C), magenta (M), yellow (Y), black (K)), and each inkjet head 1 corresponds to a corresponding color. Ink droplets are ejected.

  The two inkjet heads 1 of each inkjet head set are adjacent to each other in the sheet conveyance direction when viewed from the main scanning direction orthogonal to the sheet conveyance direction so that a part thereof overlaps along the sheet conveyance direction. So that it is fixed. In the ink jet head set, the length of the ink discharge range in the main scanning direction is longer than the width of the paper P. That is, the ink jet printer 101 is a line printer.

  Each inkjet head 1 has a head body 2 at its lower end. The head main body 2 has an elongated rectangular parallelepiped shape that is long in the main scanning direction. Further, the bottom surface of the head body 2 is an ink ejection surface 2 a that faces the outer peripheral surface 8 a of the transport belt 8. When the paper P transported by the transport belt 8 sequentially passes immediately below the eight head bodies 2, ink of each color is ejected from the ink ejection surface 2a toward the upper surface of the paper P, that is, the printing surface. Thus, a desired color image can be formed on the printing surface of the paper P.

  Next, the head main body 2 will be described with reference to FIGS. FIG. 2 is a plan view of the head body 2. FIG. 3 is an enlarged view of a region surrounded by a one-dot chain line in FIG. In FIG. 3, for convenience of explanation, the pressure chamber 110, the aperture 112, and the nozzle 108 that are to be drawn with broken lines below the actuator unit 21 are drawn with solid lines. FIG. 4 is a partial cross-sectional view taken along the line IV-IV shown in FIG. FIG. 5 is a partial cross-sectional view of the actuator unit 21.

  The head main body 2 is assembled with a reservoir unit (not shown) that stores ink from an ink tank (not shown) and supplies it to the flow path unit 9 and a driver IC (not shown) that generates a drive signal for driving the actuator unit 21. Thus, the inkjet head 1 is configured.

  As shown in FIG. 2, the head body 2 has four actuator units 21 fixed to the upper surface 9 a of the flow path unit 9. As shown in FIG. 3, the flow path unit 9 has an ink flow path including a pressure chamber 110 and the like formed therein. The actuator unit 21 includes a plurality of actuators corresponding to the pressure chambers 110, and has a function of selectively applying ejection energy to ink in the pressure chambers 110 when driven by a driver IC.

  As shown in FIG. 2, the flow path unit 9 has a rectangular parallelepiped shape. A total of ten ink supply ports 105b are opened on the upper surface 9a of the flow path unit 9 corresponding to the ink outflow flow path (not shown) of the reservoir unit. As shown in FIGS. 2 and 3, each of the flow path units 9 has a flow path unit 9 in the vicinity of the end in the short direction (sub-scanning direction or paper transport direction) of the flow path unit 9. Two manifold channels 105 communicating with the five ink supply ports 105b arranged in the longitudinal direction (main scanning direction) are formed. Each manifold channel 105 has a plurality of sub-manifold channels 105a that are branched in parallel to each other and extend in the main scanning direction. On the lower surface of the flow path unit 9, there is formed an ink ejection surface 2a in which a large number of nozzles 108 are arranged in a matrix. A large number of pressure chambers 110 are also arranged in a matrix like the nozzles 108 on the fixed surface of the actuator unit 21 in the flow path unit 9.

  As shown in FIG. 4, the flow path unit 9 is composed of nine plates 122 to 130 made of a metal material such as stainless steel. These plates 122 to 130 have a rectangular plane elongated in the main scanning direction.

  By laminating these plates 122 to 130 while aligning them with each other, the through holes formed in the plates 122 to 130 are connected, and the two manifold channels 105 and each manifold channel 105 are connected to the channel unit 9. A large number of individual ink channels 132 from the outlet of the sub-manifold channel 105a to the nozzle 108 through the pressure chamber 110 are formed.

  Next, the ink flow in the flow path unit 9 will be described. The ink supplied from the reservoir unit into the flow path unit 9 via the ink supply port 105 b is distributed to the sub manifold flow path 105 a in each manifold flow path 105. The ink in the sub-manifold channel 105a flows into each individual ink channel 132 and reaches the nozzle 108 through the aperture 112 and the pressure chamber 110 functioning as a throttle.

  The actuator unit 21 will be described. As shown in FIG. 2, each actuator unit 21 has a trapezoidal planar shape. The actuator unit 21 is made of a lead zirconate titanate (PZT) ceramic material having ferroelectricity, and is composed of three piezoelectric sheets (piezoelectric layers) 141 to 143 as shown in FIG. ing. An individual electrode 135 is formed at a position on the piezoelectric sheet 141 facing the pressure chamber 110. The individual electrode 135 has an electrode portion arranged to face the pressure chamber 110 and an extending portion drawn out to a region facing the pressure chamber 110, and a land 136 is formed on the extending portion. Is formed. A common electrode 134 formed on the entire surface of the sheet is interposed between the uppermost piezoelectric sheet 141 and the lower piezoelectric sheet 142.

  The common electrode 134 is equally grounded in the region corresponding to all the pressure chambers 110. On the other hand, the individual electrode 135 is electrically connected to the driver IC via the land 136, and a drive signal from the driver IC is selectively inputted. That is, in the actuator unit 21, a plurality of actuators corresponding to the number of the pressure chambers 110 are formed with a portion sandwiched between the individual electrodes 135 and the pressure chambers 110 as individual actuators.

  Here, a driving method of the actuator unit 21 will be described. The piezoelectric sheet 141 is polarized in the thickness direction, and a portion corresponding to the individual electrode 135 (electrode portion) functions as an active portion that is bent by the piezoelectric effect. When the individual electrode 135 has a potential different from that of the common electrode 134, an electric field is applied to the active portion in the polarization direction. The active portion expands in the thickness direction and contracts in the plane direction when the electric field and the polarization direction are the same. In addition, the amount of displacement at this time is larger in the surface direction than in the thickness direction. Thus, the actuator unit 21 uses the upper one piezoelectric sheet 141 farthest from the pressure chamber 110 as an active layer including an active portion, and the lower two piezoelectric sheets 142 and 143 close to the pressure chamber 110. Is a so-called unimorph type actuator using a non-active layer. The piezoelectric sheets 141 to 143 are fixed to the upper surface of the cavity plate 122 that partitions the pressure chamber 110. Here, when there is a difference in distortion in the plane direction between the electric field application portion of the piezoelectric sheet 141 and the piezoelectric sheets 142 and 143 below the electric field applying portion, the entire piezoelectric sheets 141 to 143 become convex toward the inside of the pressure chamber 110. (Unimorph deformation). As a result, pressure (discharge energy) is applied to the ink in the pressure chamber 110, and a pressure wave is generated in the pressure chamber 110. Then, the generated pressure wave propagates from the pressure chamber 110 to the nozzle 108, whereby ink is ejected from the nozzle 108.

  In this embodiment, a predetermined potential is applied to the individual electrode 135 in advance, and a ground potential is once applied to the individual electrode 135 every time there is a discharge request, and then the predetermined potential is applied again at a predetermined timing. A drive signal to be applied to the individual electrode 135 is output from the driver IC (see FIG. 9). At this timing, the negative pressure wave generated when the ground potential is applied reverses the phase and returns to the pressure chamber 110 again. In this case, at the timing when the individual electrode 135 becomes the ground potential, the pressure of the ink in the pressure chamber 110 drops and the ink is sucked from the sub manifold channel 105 a into the individual ink channel 132. Thereafter, the ink pressure in the pressure chamber 110 rises at the timing when the individual electrode 135 is set to a predetermined potential again, and the ink is ejected from the nozzle 108.

  In any of the driving methods described above, the ink ejection speed from the nozzle 108 is applied between the operating characteristics of the actuator unit 21, the flow path shape of the flow path unit 9, and the individual electrode 135 and the common electrode 134. It is determined by the voltage etc. Here, the operating characteristics of the actuator unit 21 and the flow path shape of the flow path unit 9 vary depending on manufacturing errors, and are unique to each inkjet head 1. Therefore, in order to make the ink ejection speed uniform in each inkjet head, it is preferable to adjust the voltage applied between the individual electrode 135 and the common electrode 134 to an appropriate voltage for each inkjet head 1. Each ink-jet head 1 is supplied with a voltage rank (supplied to the ink-jet head 1) based on Table 1 from an appropriate voltage measured in advance (for example, a voltage at which a test liquid obtained by removing a pigment component from ink is ejected at 9 m / s). Any one of the voltage ranges A to E is assigned. The inkjet head 1 is attached with a barcode label 1b on which barcodes of assigned voltage ranks A to E and characters indicating the voltage ranks are recorded (see FIG. 6).

  Table 2 shows examples of appropriate voltages and assigned voltage ranks A to E according to the eight inkjet heads 1 of the present embodiment. It should be noted that the two inkjet heads 1 that eject black (K) ink are ejected from K1, K2, and the two inkjet heads 1 that eject magenta (M) ink are ejected from M1, M2, and cyan (C). Two ink-jet heads 1 that discharge C1, C2, and yellow (Y) ink are denoted as Y1 and Y2.

  As will be described later, the power supply unit 17 has six power supply circuits 71 and can output a maximum of six types of voltages (see FIG. 6). The power supply unit 17 supplies the ink jet heads 1 with voltages corresponding to the voltage ranks A to E assigned to the ink jet heads 1, thereby uniformizing the ink droplet ejection speed among the eight ink jet heads 1. Let

  Next, the control device 16 and the power supply unit 17 will be described in detail with reference to FIG. FIG. 6 is a functional block diagram of the control device 16 and the power supply unit 17. As illustrated in FIG. 6, the control device 16 includes a storage unit 67, a voltage adjustment unit 68, and a head control unit 69. A bar code reader 65 is connected to the control device 16. The power supply unit 17 supplies voltage to the eight inkjet heads 1 and includes six power supply circuits 71, twelve sockets 72, and a selection SW 73.

  The storage unit 67 is connected to the six power supply circuits 71 of the power supply unit 17 and the eight inkjet heads 1 (K1, K2, M1, M2, C1, C2, Y1, Y2), and the voltage of each inkjet head 1 The ranks A to E are stored. When manufacturing the inkjet printer 101, when the operator assembles each inkjet head 1 to the inkjet printer 101, the barcode label 1 b attached to the inkjet head 1 is read by the barcode reader 65. The reading results are stored in the storage unit 67 as the voltage ranks A to E of the inkjet heads 1. Further, the operator connects the plug 1c of each inkjet head 1 to a socket 72 corresponding to a power supply circuit 71 (described later in detail) of the power supply unit 17, so that the voltage input terminal of the inkjet head and the power supply of the power supply circuit 71 are connected. In addition to being electrically connected to the terminals, which power supply circuit 71 each inkjet head 1 is connected to is set in a selection switch (hereinafter referred to as selection SW) 73 of the power supply unit 17 (see FIG. 8). Later). As a result, an electrical signal including information related to the connection relationship between the six power supply circuits 71 and the eight inkjet heads 1 is output from the selection SW 73 to the control device 16, and the contents are stored in the storage unit 67.

  Based on the storage contents of the storage unit 67, the voltage adjustment unit 68 generates a voltage generated by each power supply circuit 71 so that each inkjet head 1 is supplied with voltages corresponding to the voltage ranks A to E related to the inkjet head. Is to adjust. The voltage adjustment unit 68 controls the power supply circuit 71 by outputting an ON / OFF signal and a voltage variable signal to the power supply circuit 71. The ON / OFF signal controls the start and stop of voltage generation related to the power supply circuit 71, and the voltage variable signal adjusts the voltage generated by the power supply circuit 71. The head controller 69 controls the driving of the inkjet head 1.

  The power supply circuit 71 will be described with further reference to FIG. FIG. 7 is a schematic circuit diagram of the power supply circuit 71. The power supply circuit 71 generates a voltage to be supplied to the inkjet head 1. As shown in FIG. 7, in the power supply circuit 71, the voltage control IC 71a opens and closes the transistor FET1, thereby changing the period of the voltage waveform input to the choke coil L1, and the pulse input to the choke coil L1. Voltage is rectified by a rectifier circuit including the choke coil L1 and output to the outside (power supply terminal: not shown). As shown in FIG. 7, the rectifier circuit includes a diode D1 and a capacitor C1 in addition to the choke coil L1. At this time, the output voltage varies depending on the period of the voltage input to the rectifier circuit. Further, the voltage control IC 71a adjusts the opening / closing timing of the transistor FET1 so that the voltage generated by the power supply circuit 71 becomes a predetermined value while monitoring the feedback voltage from the choke coil L1. The voltage control IC 71a starts and stops the generation of voltage according to the ON / OFF signal from the voltage adjustment unit 68 of the control device 16, and adjusts the voltage to be generated based on the voltage variable signal.

  Returning to FIG. 6, the socket 72 is detachable from the plug 1 c of the inkjet head 1. When the socket 72 and the plug 1c are connected, the power supply terminal of the power supply circuit 71 corresponding to the socket 72 and the voltage input terminal of the inkjet head 1 corresponding to the plug 1c are electrically connected. Two sockets 72 are arranged for one power supply circuit 71. That is, one power supply circuit 71 can supply a voltage to a maximum of two inkjet heads 1.

  As described above, the worker performs the connection work of the inkjet head 1 to the power supply unit 17 (power supply circuit 71). Here, the connection work will be described. Among magenta (M), cyan (C), yellow (Y), and black (K), black (K) ink having the lowest brightness has a large visual influence and is frequently used. Therefore, the operator supplies the voltage to only the inkjet head 1 (K1, K2) from the power supply circuits 71 different from each other for the inkjet head 1 (K1, K2) that discharges black (K) ink. The inkjet head 1 (K1, K2) and the power supply circuit 71 are connected to each other. Thus, since each inkjet head 1 (K1, K2) occupies one power supply circuit 71, the voltage of the power supply circuit 71 is adjusted within the voltage ranks A to E related to the inkjet head 1 (K1, K2). By doing so, the ink-jet head 1 (K1, K2) can be driven at an appropriate voltage. Further, the maximum load of the power supply circuit 71 can be reduced.

  In this embodiment, only the ink jet head 1 (K1) of voltage rank D is connected to the power supply circuit 71 (No1), and only the ink jet head 1 (K2) of voltage rank B is connected to the power supply circuit 71 (No2). Has been. The voltage generated by the power supply circuit 71 (No1) is adjusted in the voltage rank D, and the voltage generated by the power supply circuit 71 (No2) is adjusted in the voltage rank B.

  In the present embodiment, the two inkjet heads 1 (K1, K2) are connected to different power supply circuits 71, but the voltage ranks A to E of the two inkjet heads 1 (K1, K2). Are the same and the capacity of the power supply circuit 71 is sufficiently large, the two inkjet heads 1 (K1, K2) may be connected to one power supply circuit 71.

  Then, the operator confirms the voltage ranks A to E assigned to the inkjet head 1 for the other inkjet heads 1, and the inkjet heads 1 to which the same voltage ranks A to E are assigned have voltages from the same power supply circuit 71. The inkjet head 1 and the power supply circuit 71 are connected to each other so as to be supplied. In the present embodiment, two inkjet heads 1 (M1, M2) having a voltage rank C are connected to the power supply circuit 71 (No3). The voltage generated by the power supply circuit 71 (No 3) is adjusted within the voltage rank C.

  Furthermore, when it is necessary to connect the inkjet heads 1 to which the different voltage ranks A to E are assigned to the same power supply circuit 71, the operator is the same as the inkjet head 1 to which the adjacent voltage ranks A to E are assigned. The inkjet head 1 and the power supply circuit 71 are connected to each other so that a voltage is supplied from the power supply circuit 71.

  In this case, among cyan (C), magenta (M), yellow (Y), and black (K), yellow (Y) ink having the highest lightness has a small visual influence. The inkjet head 1 and the power supply circuit 71 are prioritized so that voltages are supplied from the same power supply circuit 71 to the inkjet head 1 (Y1, Y2) that discharges the ink of (Y) and the other inkjet heads 1. Connect. Accordingly, by adjusting the voltage of the power supply circuit 71 within the voltage ranks A to E related to the other ink jet heads 1, the other ink that ejects ink having a greater visual influence than yellow (Y) ink is discharged. The inkjet head 1 can be driven with an appropriate voltage. In the present embodiment, the ink jet head 1 (C1) having the voltage rank C and the ink jet head 1 (Y1) having the voltage rank B are connected to the power supply circuit 71 (No4). The voltage generated by the power supply circuit 71 (No. 4) is adjusted within the voltage rank C.

  The inkjet head 1 that does not correspond to any of the above connects the inkjet head 1 and the power supply circuit 71 such that a voltage is supplied only from the different power supply circuit 71 to the inkjet head 1. In the present embodiment, the inkjet head 1 (C2) with the voltage rank A is connected to the power supply circuit 71 (No5), and the inkjet head 1 (Y2) with the voltage rank D is connected to the power supply circuit 71 (No6). The voltage generated by the power supply circuit 71 (No5) is adjusted in the voltage rank A, and the voltage generated by the power supply circuit 71 (No6) is adjusted in the voltage rank D. The connection operation described above is the same in the replacement operation of the inkjet head 1.

  At this time, the operator causes the barcode reader 65 to read the barcode label 1 b attached to the inkjet head 1. The reading results are stored in the storage unit 67 as the voltage ranks A to E of the inkjet heads 1.

  The selection SW 73 will be described with reference to FIG. FIG. 8 is an external view of the selection SW 73. The selection SW 73 is set by an operator to indicate which of the six power supply circuits 71 each inkjet head 1 is connected to, that is, which of the six power supply circuits 71 is supplied with the voltage. Each of the inkjet heads 1 (K1, K2, M1, M2, C1, C2, Y1, Y2) has six dip switches 73a corresponding to one power supply circuit 71 (No1 to No6). ing. The operator turns on only the dip switch 73a corresponding to the power supply circuit 71 to which the inkjet head 1 is connected among the six dip switches 73a related to each inkjet head 1. The contents of the dip switch 73 a are output as an electrical signal to the control device 16, and information related to the connection relationship between the six power supply circuits 71 and the eight inkjet heads 1 is stored in the storage unit 67.

  As described above, the voltage adjustment unit 68 of the control device 16 adjusts the voltage generated by each power supply circuit 71 based on the stored contents of the storage unit 67. For this reason, the width of the distribution range of the ejection speeds of the eight inks related to the eight inkjet heads 1 is such that a specific voltage (voltage output from one power supply circuit 71) is supplied to the eight inkjet heads 1. It becomes below the width of the distribution range of the ink ejection speed. Thereby, the discharge speed of the ink between the inkjet heads 1 is made uniform, and a high-quality image can be recorded on the paper P.

  As described above, according to the present embodiment described above, the voltage input to the inkjet head can be selected according to the ink ejection characteristics of the inkjet head 1, so that a high-quality image can be recorded on the paper P. Further, since the number of power supply circuits 71 is smaller than the number of ink jet heads 1, the cost of the ink jet printer 101 can be reduced.

  Moreover, since the plug 1c of the inkjet head 1 and the socket 72 of the power supply circuit 71 are detachable, the inkjet head 1 can be easily attached and detached.

  Further, since the barcode label 1b on which the voltage ranks A to E of the inkjet head 1 are written is attached to the inkjet head 1, to which power supply circuit 71 the operator should connect the inkjet head 1 Can be easily determined. Further, by causing the barcode reader 65 to read the barcode label 1b, the contents of the voltage ranks A to E of each inkjet head 1 can be easily stored in the storage unit 67.

  In addition, since the operator sets the selection SW 73, information related to the connection relationship between the six power supply circuits 71 and the eight inkjet heads 1 is stored in the storage unit 67. Can be grasped.

  Since each power supply circuit 71 can adjust a voltage to be generated, an appropriate voltage can be supplied to the connected inkjet head 1. As a result, the ink ejection speed can be made more uniform between the inkjet heads 1.

  Further, since the voltage adjustment unit 68 adjusts the voltage generated by each power supply circuit 71 based on the stored contents of the storage unit 67, the ink is automatically transferred between the inkjet heads 1 without the operator performing adjustment work. The discharge speed can be made uniform.

Second Embodiment
A second embodiment according to the present invention will be described with reference to FIGS. 9 and 10. FIG. 9 is a functional block diagram of the control device 116 and the power supply unit 17 according to the second embodiment. FIG. 10 is a functional block diagram of the voltage supply circuit 170. Note that the second embodiment is different from the first embodiment in that the control device 116 does not have the selection SW 73 but has the voltage supply circuit 170. Therefore, the voltage supply circuit 170 will be mainly described below, and the other members and functional units are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted.

  As shown in FIG. 9, the control device 116 has a voltage supply circuit 170 that connects the power supply circuit 71 and the inkjet head 1. As shown in FIG. 10, the voltage supply circuit 170 includes 48 relays 81 and a switching control unit 82 that controls the 48 relays 81. The 48 relays 81 turn ON / OFF the connection between the power supply circuit 71 and the inkjet head 1, and the matrix so that each of the 8 inkjet heads 1 can be connected to any of the 6 power supply circuits 71. Connected.

  The switching control unit 82 controls the 48 relays 81 to connect the inkjet head 1 and the power supply circuit 71. Further, the switching control unit 82 uses the voltage ranks A to E of the respective inkjet heads 1 stored in the storage unit 67 to switch between the six power supply circuits 71 and the eight inkjet heads 1 under the same conditions as in the first embodiment. The connection relationship is determined, and 48 relays 81 are controlled so that the inkjet head 1 and the power supply circuit 71 are connected in accordance with the determination. At this time, the determination content is stored in the storage unit 67.

  Then, the voltage adjustment unit 68 of the control device 116 adjusts the voltage generated by each power supply circuit 71 based on the stored contents of the storage unit 67. For this reason, the width of the distribution range of the ejection speeds of the eight inks related to the eight inkjet heads 1 is such that a specific voltage (voltage output from one power supply circuit 71) is supplied to the eight inkjet heads 1. It becomes below the width of the distribution range of the ink ejection speed. Thereby, the discharge speed of the ink between the inkjet heads 1 is made uniform, and a high-quality image can be recorded on the paper P.

  As described above, according to the present embodiment described above, the voltage input to the inkjet head can be selected according to the ink ejection characteristics of the inkjet head 1, so that a high-quality image can be recorded on the paper P. In addition, since the number of power supply circuits 71 is smaller than the number of inkjet heads 1, the cost of the inkjet printer can be reduced.

  Further, the switching control unit 82 determines the voltage ranks A to E of the inkjet head 1, connects the six power supply circuits 71 and the eight inkjet heads 1, and the voltage adjustment unit 68 sets the optimum voltage for the inkjet head 1. Since the ink is automatically supplied, connection and replacement work of the inkjet head 1 is facilitated.

  Furthermore, since the switching control unit 82 controls the 48 relays 81 to be turned on and off, the power supply circuit 71 and the inkjet head 1 are connected, so that the switching control unit 82 can be realized with a simple configuration.

<Modification>
In the present embodiment, the voltage supply circuit 170 has 48 relays 81 connected in a matrix so that each of the eight inkjet heads 1 can be connected to one of the six power supply circuits 71. However, the relay 81 may be configured such that each inkjet head 1 can be connected to only one of the six power supply circuits 71. For example, as shown in FIG. 11, the inkjet head 1 (K1, K2, M1, M2) can be connected to any one of the power supply circuits 71 (No1 to No3), and the inkjet head 1 (C1, C2, Y1). , Y2) can be connected to any of the power supply circuits 71 (No4 to No6). According to this configuration, since the number of relays 81 can be reduced as compared with the configuration of FIG. 10, the cost can be reduced.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the first embodiment described above, an operator causes the barcode reader 65 to read the voltage ranks A to E of each inkjet head 1 and sets the selection SW 73, and the voltage adjustment unit 68 is based on the reading result. In this configuration, the voltage of the power supply circuit 71 is adjusted, but the operator does not read the voltage ranks A to E of the inkjet heads 1 with the barcode reader 65 or set the selection SW 73, so that each power supply circuit 71 is set. The voltage may be adjusted directly.

  In the first and second embodiments, the voltage generated by all the power supply circuits 71 can be adjusted. However, at least a part of the power supply circuits may generate a fixed voltage. Good. In this case, the operator in the first embodiment, the voltage supply circuit in the second embodiment, the voltage value generated by each power supply circuit and the voltage ranks A to E of the inkjet head 1 are matched. It is preferable to determine the connection relationship between the inkjet head 1 and the power supply circuit.

  Furthermore, in the first and second embodiments, the inkjet printer 101 has eight inkjet heads 1 and six power supply circuits 71. However, if the number of power supply circuits is less than the number of inkjet heads, the inkjet printer 101 May have an arbitrary number of inkjet heads and power supply circuits. For example, the inkjet printer may be configured to include four inkjet heads and three power supply circuits.

  In the first and second embodiments, the voltage ranks A to E are assigned to each inkjet head 1, and the connection relationship between the inkjet head 1 and the power supply circuit is determined using the voltage ranks A to E. However, the connection relationship between the inkjet head 1 and the power supply circuit may be determined based on the appropriate voltage of each inkjet head 1 without using the voltage rank.

  Furthermore, in the first and second embodiments, the inkjet head 1 is connected to all the power supply circuits 71, but the power supply circuit 71 to which the inkjet head 1 is not connected may be present.

  Moreover, in 1st and 2nd embodiment, it is the structure which acquires the voltage ranks AE of the said inkjet head 1 by reading the barcode label 1b affixed on the inkjet head 1 with the barcode reader 65. FIG. However, the method for obtaining the voltage ranks A to E may be arbitrary. For example, the voltage ranks A to E may be stored in a memory installed in the inkjet head 1, and the control device 16 may acquire the voltage ranks A to E stored in the memory by communicating with the inkjet head 1. . Alternatively, RFID (Radio Frequency IDentification) in which the voltage ranks A to E are stored may be attached to the inkjet head 1, and the control device 16 may acquire the voltage ranks A to E directly from the RFID.

  In the first embodiment, the control device 16 acquires the connection relationship between the power supply circuit 71 and the inkjet head 1 by the operator setting the selection SW 73. However, any one of the first and second embodiments may be used. In addition, the inkjet head 1 has a signal line for transmitting identification information for identifying the inkjet head 1 in addition to the power supply wiring, and the control device 16 receives the identification information from the signal line of the inkjet head 1. Therefore, the connection relationship between the power supply circuit 71 and the inkjet head 1 may be acquired. Note that the inkjet head 1 may be configured to transmit identification information using a power supply wiring without using such a signal line.

  In addition, in the first and second embodiments, the example in which the present invention is applied to the inkjet printer 101 having the inkjet head 1 that ejects ink by driving the actuator unit 21 has been described. The present invention is also applicable to printers having other driving methods and other recording methods. In this case, it is preferable to determine the connection relationship between each head and the power supply circuit so that the recording characteristics of each head are optimized.

1 is an external side view of an inkjet printer according to a first embodiment of the present invention. FIG. 3 is a plan view of the head main body shown in FIG. 2. It is an enlarged view of the area | region enclosed with the dashed-dotted line shown in FIG. It is the IV-IV sectional view taken on the line shown in FIG. It is sectional drawing of the actuator unit shown in FIG. It is a functional block diagram of the control apparatus and power supply unit shown in FIG. FIG. 7 is a schematic circuit diagram of the power supply circuit shown in FIG. 6. It is an external view of selection SW shown in FIG. It is a functional block diagram of the control apparatus and power supply unit which concern on 2nd Embodiment. FIG. 10 is a functional block diagram of the voltage supply circuit shown in FIG. 9. It is a figure which shows the modification concerning 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet head 1b Barcode label 1c Plug 9 Flow path unit 13 Conveyance mechanism 16, 116 Control apparatus 17 Power supply unit 21 Actuator unit 65 Barcode reader 67 Memory | storage part 68 Voltage adjustment part 69 Head control part 71 Power supply circuit 72 Socket 73 Selection SW
73a DIP switch 81 Relay 82 Switching control unit 101 Inkjet printer 108 Nozzle 110 Pressure chamber 134 Common electrode 135 Individual electrodes 141 and 142 Piezoelectric sheet 170 Voltage supply circuit 71a Voltage control IC

Claims (10)

M (natural number: m ≧ 3) recording heads for recording an image on a recording medium;
N (natural number: m> n ≧ 2) power supply circuits capable of outputting different voltages from each other,
A recording apparatus, wherein a voltage output from at least one of the power supply circuits is supplied to the plurality of recording heads.   The width of the distribution range of m recording characteristic values related to the m recording heads is such that the voltage output from any one of the n power supply circuits is the voltage output to the m recording heads. Voltages output by two or more of the power supply circuits are supplied to the m recording heads so as to be equal to or less than the width of the distribution range of the recording characteristic values when being supplied. The recording apparatus according to claim 1. The recording head has a recording unit in which a voltage rank indicating a voltage range to be supplied to the recording head is recorded;
Obtaining means for obtaining the voltage rank recorded in the recording unit;
Storage means for storing each voltage rank relating to the m recording heads acquired by the acquisition means;
Based on the contents stored in the storage means, the voltage output from each power supply circuit falls within the voltage range indicated by the voltage rank recorded in the recording unit of the recording head to which the voltage is supplied. In addition, the voltage output from each power supply circuit is supplied so that the voltage output from one power supply circuit is supplied to the plurality of recording heads belonging to the same voltage rank or two voltage ranks adjacent to each other. The recording apparatus according to claim 1, further comprising a voltage supply circuit that supplies the m recording heads. The voltage supply circuit is
A plurality of connection circuits for electrically connecting a power supply terminal of the power supply circuit and a voltage input terminal of the recording head;
The recording apparatus according to claim 3, further comprising a control unit that controls an electrical connection state of the plurality of connection circuits. The recording head has a head-side connection portion electrically connected to the voltage input terminal of the recording head;
The power supply circuit has a plurality of power supply side connection portions that are electrically connected to power supply terminals of the power supply circuit and are detachable from the head side connection portion,
The recording apparatus according to claim 1, wherein the head side connection portion is connected to at least one of the plurality of power supply side connection portions.   The recording apparatus according to claim 5, wherein the recording head includes a recording unit in which a voltage rank indicating a voltage range to be supplied to the recording head is recorded.   7. The recording apparatus according to claim 5, further comprising a signal output circuit that outputs an electrical signal indicating to which of the power supply circuits the recording head is connected. The recording head records an image on the recording medium by discharging any one of a plurality of types of ink;
8. The voltage output from one of the power supply circuits is supplied to a plurality of the recording heads including the recording head that discharges ink having the highest brightness. The recording device described. The recording head records an image on the recording medium by discharging any one of a plurality of types of ink;
9. The recording apparatus according to claim 1, wherein a voltage output from one of the power supply circuits is supplied only to the recording head that discharges ink having the lowest brightness.   The recording apparatus according to claim 1, wherein at least one of the n power supply circuits can adjust an output voltage.

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