Inkjet printer

Abstract

To save consumption power of an ink jet printer.SOLUTION: An ink jet printer (1) is equipped with a head (32) that has a nozzle (33) and a piezoelectric element (321) discharging ink from the nozzle (33), a driving voltage generating portion (80) that generates a driving voltage to be applied to the piezoelectric element (321), a carriage (31) that moves the head (32) and the driving voltage generating portion (80) in a moving direction, and a magnet group (72) that includes multiple magnets aligned in the moving direction. The driving voltage generating portion (80) has a coil (70) that generates electromotive force by interlinking magnetic fluxes of the magnet group (72) with the movement of the carriage (31), and generates the driving voltage by the electromotive force.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to inkjet printers. [Background technology]

[0002] Patent Document 1 discloses an inkjet printer having a power generating unit provided on the carriage. The power generating unit includes a gear and a power generating motor. When the carriage moves out of the printing area, the gear meshes with a rack gear provided on a carriage shaft that supports the carriage so that it can reciprocate, and rotates with braking energy that stops the carriage. The power generating motor rotates with the rotation of the gear to generate electricity. The generated electricity is used to drive the head unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-103723 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the inkjet printer of Patent Document 1, the carriage motor that drives the carriage needs to generate not only braking energy for stopping the carriage, but also load torque for rotating the gears and the generator motor, which poses the problem that the carriage motor needs extra power to generate the load torque.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to reduce the power consumption of an inkjet printer. [Means for solving the problem]

[0006] In order to solve the above problems, an inkjet printer according to a first aspect of the present disclosure comprises a head having a nozzle and an ejection element for ejecting ink from the nozzle, a drive voltage generation unit for generating a drive voltage to be applied to the ejection element, a carriage for moving the head and the drive voltage generation unit in a movement direction, and a magnet group including a plurality of magnets arranged in the movement direction, the drive voltage generation unit having a coil that generates an electromotive force by linking with the magnetic flux of the magnet group as the carriage moves, and generates the drive voltage from the electromotive force.

[0007] According to the inkjet printer of the first aspect, the drive voltage is generated from the electromotive force generated in the coil as the carriage moves, so that the ejection elements can be driven by applying the drive voltage. This eliminates the need to generate extra load torque in the motor that moves the carriage in order to generate the drive voltage to be applied to the ejection elements. This makes it possible to reduce the power consumption of the inkjet printer.

[0008] A second aspect is the inkjet printer of the first aspect, wherein the drive voltage generating unit further includes a rectifier circuit that rectifies the AC voltage generated by the electromotive force of the coil, a smoothing circuit that smoothes the rectified voltage of the rectifier circuit, and a conversion circuit that converts the smoothed voltage of the smoothing circuit into the drive voltage.

[0009] According to the ink jet printer of the second aspect, a drive voltage suitable for driving the ejection elements can be obtained from the electromotive force of the coil by the rectifier circuit, smoothing circuit, and conversion circuit.

[0010] A third aspect is the inkjet printer according to the second aspect, wherein the conversion circuit has a storage circuit that stores power by the driving voltage.

[0011] In the inkjet printer of the third aspect, the electromotive force of the coil generated when the carriage movement amount is small may not be sufficient to drive the ejection elements. In response to this, the storage circuit mainly stores electricity when the carriage movement amount is large, so that a sufficient drive voltage for driving the ejection elements can be obtained even when the carriage movement amount is small.

[0012] In a fourth aspect, the inkjet printer according to the third aspect further comprises a carriage control unit that, when a drive command to drive the ejection elements is generated, moves the carriage before driving the ejection elements.

[0013] According to the inkjet printer of the fourth aspect, the carriage is moved in response to the generation of the drive command, and the storage circuit is charged with the drive voltage obtained from the electromotive force of the coil. As a result, even if the storage circuit does not have enough stored power to drive the ejection elements when the drive command is generated, the movement of the carriage allows the storage circuit to store enough power to drive the ejection elements.

[0014] A fifth aspect is the inkjet printer of the fourth aspect, wherein, when the drive command is generated, the carriage control unit does not move the carriage if a predetermined value or more of power is stored in the storage circuit, and moves the carriage if the predetermined value or more of power is not stored in the storage circuit.

[0015] According to the inkjet printer of the fifth aspect, when a predetermined amount of power or more is stored in the power storage circuit, the carriage does not move. This prevents the carriage from moving unnecessarily when a drive command is issued, and allows the drive operation of the ejection elements to start promptly.

[0016] A sixth aspect is the inkjet printer of the fifth aspect, wherein the carriage control unit determines that power equal to or greater than the predetermined value has been stored in the storage circuit when the time elapsed from the end of the drive operation of the previous ejection element to the generation of the drive command is within a predetermined time.

[0017] According to the inkjet printer of the sixth aspect, if the time until the maximum power stored in the storage circuit falls below a predetermined value due to self-discharge of the storage circuit is defined as the predetermined time, if the time elapsed from the end of the drive operation of the ejection elements to the generation of a drive command is within the predetermined time, it can be considered that the storage circuit has stored power of the predetermined value or more. On the other hand, if the time elapsed from the end of the drive operation of the ejection elements to the generation of a drive command is not within the predetermined time, it means that the storage circuit does not store enough power for the head to respond, and it can be considered that the storage circuit does not store power of the predetermined value or more.

[0018] This makes it possible to estimate whether or not a predetermined value or more of power is stored in the power storage circuit without measuring the power stored in the power storage circuit.

[0019] A seventh aspect is the inkjet printer according to any one of the fourth to sixth aspects, wherein the carriage control unit moves the carriage at least within a range in which the group of magnets is arranged.

[0020] According to the seventh aspect of the inkjet printer, by moving the carriage at least in the range where the magnet group is arranged, more power can be stored in the storage circuit than when the carriage is moved in a part of the range where the magnet group is arranged, thereby improving the power generation efficiency.

[0021] An eighth aspect is the inkjet printer according to any one of the fourth to seventh aspects, wherein the drive command is a print command for executing printing.

[0022] According to the inkjet printer of the eighth aspect, at least during printing, the power for driving the ejection elements can be stored in the storage circuit.

[0023] A ninth aspect is the inkjet printer according to any one of the first to eighth aspects, wherein the magnet group is disposed within a range that includes a moving range of the carriage.

[0024] According to the inkjet printer of the ninth aspect, power can be generated by the coils over the entire range of movement of the carriage, and therefore power generation efficiency can be improved compared to a configuration in which the magnet group is disposed in only a portion of the range of movement of the carriage.

[0025] A tenth aspect is the inkjet printer according to any one of the first to ninth aspects, wherein the length of the magnet in the moving direction is longer than the length of the coil in the moving direction.

[0026] According to the ink jet printer of the tenth aspect, the amount of magnetic flux that cancels out the magnetic flux that links the coil is reduced, thereby improving the power generation efficiency.

[0027] Aspect 11 is an inkjet printer of any one of aspects 1 to 10, wherein the carriage has a head placement surface on which the head is placed, and a coil placement surface, different from the head placement surface, on which the coil is placed.

[0028] According to the inkjet printer of the eleventh aspect, since the head mounting surface and the coil mounting surface are different surfaces, the coil can be mounted on the carriage without being restricted by the position of the head. This allows the coil to be formed with the maximum size determined by the size of the coil mounting surface on the carriage. This can therefore increase the power generation efficiency.

[0029] A twelfth aspect is the inkjet printer according to any one of the first to tenth aspects, wherein the coil is disposed on a horizontal surface of the carriage, and the magnet group is disposed above or below the coil.

[0030] According to the inkjet printer of the twelfth aspect, in a configuration in which the coil is disposed on the side of the carriage, the carriage needs to be formed at a height according to the size of the coil in order to form the coil to a predetermined size. In contrast, in a configuration in which the coil is disposed on the horizontal surface of the carriage, the carriage height is not determined by the size of the coil as described above, so the carriage can be formed low. This allows the carriage to be made smaller. In addition, by disposing the magnet group above or below the coil, it becomes easier to link the strong magnetic flux of the magnet group to the coil from above or below, thereby improving power generation efficiency.

[0031] A thirteenth aspect is the inkjet printer of the twelfth aspect, in which the coil is disposed on an upper surface of the carriage, and the magnet group is disposed above the coil.

[0032] According to the inkjet printer of the thirteenth aspect, there are usually no obstacles above the carriage, unlike below where the printing paper passes. By arranging the coil on the upper surface of the carriage, it is possible to bring the coil close to the group of magnets arranged above the coil. This allows the coil to generate a large electromotive force by passing through a portion of the magnet group where the magnetic flux generated by each magnet is strong. This can therefore increase the power generation efficiency.

[0033] A 14th aspect is an inkjet printer according to any one of the 1st to 13th aspects, wherein the area of ​​a coil arrangement region in which the coil is arranged in the carriage is larger than the area of ​​a nozzle arrangement region in which the multiple nozzles are arranged in the head.

[0034] According to the inkjet printer of the fourteenth aspect, the area occupied by the nozzle arrangement region in the head is large. Therefore, the size of the head is determined by the area of ​​the nozzle arrangement region. The size of the carriage is determined according to the size of the head, and the area of ​​the coil arrangement region is also determined. Therefore, the area of ​​the coil arrangement region is larger than the area of ​​the nozzle arrangement region, which occupies a large area on the head arrangement surface of the carriage, so that the coil can be formed large. This makes it possible to improve the power generation efficiency.

[0035] The inkjet printer according to each aspect of the present invention may be realized by a computer. In this case, the inkjet printer print control program that causes the computer to operate as each part (software element) of the inkjet printer to realize the inkjet printer, and the computer-readable recording medium on which it is recorded, also fall within the scope of the present invention. Effect of the Invention

[0036] According to one aspect of the present invention, it is possible to reduce the power consumption of an inkjet printer. [Brief description of the drawings]

[0037] [Figure 1] 1 is a partial cross-sectional view showing an internal configuration of an inkjet printer according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a block diagram showing a system configuration of the inkjet printer. [Diagram 3] FIG. 2 is a diagram showing the arrangement of coils and magnets used in the inkjet printer. [Figure 4] FIG. 2 is a diagram showing the magnetic flux of the magnet interlinking with the coil. [Diagram 5] FIG. 2 is a diagram showing the magnetic flux of the magnet interlinking with the coil. [Figure 6] 4 is a plan view showing the positional relationship between a carriage and a group of magnets in the inkjet printer. FIG. [Figure 7]4 is a front view showing the positional relationship between the carriage and the magnet. FIG. [Figure 8] 3A and 3B are block diagrams showing a detailed configuration of a head provided on the carriage. [Figure 9] 4 is a flowchart showing a procedure of a printing process of the inkjet printer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] [Embodiment] An inkjet printer 1 according to one embodiment of the present invention will be described below with reference to Figures 1 to 9. For ease of description, the upper side of Figure 1 will be referred to as the upper side of the inkjet printer 1, the lower side of Figure 1 will be referred to as the lower side of the inkjet printer 1, the left side of Figure 1 will be referred to as the rear side of the inkjet printer 1, and the right side of Figure 1 will be referred to as the front side of the inkjet printer 1.

[0039] <Overall configuration of inkjet printer 1> The inkjet printer 1 is a multifunction machine having a printer section and a scanner section composed of a flatbed scanner 42, and has multiple functions such as a scan function, a print function, a copy function, and a fax function. The inkjet printer 1 has a print function of an inkjet recording method that records an image on paper P, which is an example of a recording medium, based on print data by ejecting ink. The printer section is mainly connected to an external information device such as a computer, and records images and characters on the recording medium based on print data including image data and document data transmitted from the external information device. The scanner section is a flatbed scanner 42. In the present invention, the scanner section is an optional configuration, so a description of the configuration related to the operation of the scanner section is omitted in this specification. The inkjet printer 1 may be a printer having only a print function.

[0040] As shown in Fig. 1, the inkjet printer 1 includes a feed tray 20, a feed section 2, a transport roller 60, an image recording section 3, a discharge roller 62, and a discharge tray 30. An opening is formed in the front of the inkjet printer 1. A box-shaped feed tray 20 with an open top is disposed in the opening so as to be movable in the front-rear direction. A plurality of stacked sheets of paper P are stored in the feed tray 20. Note that the sheets of paper P are not limited to paper media, and may also be other resin media such as overhead projector sheets.

[0041] The feeding section 2 has a feeding roller 21, a feeding arm 22, and a shaft 23. The feeding section 2 feeds the paper P stored in the feeding tray 20 to the transport path R by forward rotation of the feeding roller 21. The feeding roller 21 is rotatably supported at the tip of the feeding arm 22. The feeding arm 22 is rotatably supported by a shaft 23 supported by the frame of the inkjet printer 1. The feeding arm 22 is urged to rotate toward the feeding tray 20 by its own weight or an elastic force of a spring or the like. A driving force due to reverse rotation of the motor 102 shown in FIG. 2 is transmitted to the feeding roller 21, causing the feeding roller 21 to rotate forward.

[0042] The transport path R refers to a space formed by guide member 51, guide member 52, image recording unit 3, guide member 53, guide member 54, etc. The transport path R extends upward from the rear end of the feed tray 20, curves in the area defined by guide members 51 and 52, passes through the position of the image recording unit 3, extends linearly in the area defined by guide members 53 and 54, and reaches the discharge tray 30.

[0043] A transport roller 60 is disposed upstream of the image recording unit 3 in the transport path R in the transport direction. A pinch roller 61 is disposed at a position facing the lower part of the transport roller 60. The transport roller 60 is driven by a motor 102. The pinch roller 61 rotates with the rotation of the transport roller 60. As the transport roller 60 and the pinch roller 61 rotate forward, the paper P is pinched between the transport roller 60 and the pinch roller 61 and transported to an image recording position X on the transport path R. The image recording position X is a position where the head 32 records an image on the paper P. A driving force generated by the forward rotation of the motor 102 is transmitted to the transport roller 60 by a transmission mechanism (not shown), and the transport roller 60 rotates forward. Also, a driving force generated by the reverse rotation of the motor 102 is transmitted to the transport roller 60, and the transport roller 60 rotates backward.

[0044] The image recording unit 3 is disposed between the transport roller 60 and the discharge roller 62 on the transport path R. The image recording unit 3 has a carriage 31, a head 32, a plurality of nozzles 33, a coil 70, a metal guide 71, a magnet group 72, and a platen 34.

[0045] The carriage 31 receives the driving force of a carriage motor 103 shown in FIG. 2 and reciprocates on a metal guide 71 in a direction perpendicular to the conveying direction, that is, in the width direction of the paper P.

[0046] As shown in FIG. 1, the carriage 31 is equipped with a head 32 and a coil 70. A plurality of nozzles 33 are provided on the bottom surface of the head 32. The head 32 ejects ink droplets from the nozzles 33 by vibrating a piezoelectric element 321, which is an example of an ejection element. The coil 70 generates an electromotive force by linking with a magnetic flux generated by a magnet group 72 arranged above the carriage 31. The electromotive force generated here is used to generate a drive voltage for driving the piezoelectric element 321 inside the head 32. The platen 34 is a rectangular plate-shaped member on which the paper P is placed. During the process in which the carriage 31 moves toward the paper P supported by the platen 34, the head 32 selectively ejects ink droplets, thereby recording an image on the paper P.

[0047] The carriage 31 is also provided with a carriage encoder 123. The carriage encoder 123 is a linear encoder that outputs an encoder signal corresponding to the displacement of the carriage 31 in the width direction of the paper P. The carriage encoder 123 includes an encoder scale and an optical sensor (not shown). The encoder scale is disposed along the width direction of the paper P on a frame that supports the carriage 31. The optical sensor is mounted on the carriage 31. The carriage encoder 123 inputs an encoder signal corresponding to a change in the relative position between the encoder scale and the optical sensor to the control unit 10.

[0048] Discharge rollers 62 serving as a conveying unit are disposed downstream of the image recording unit 3 in the conveying direction on the conveying path R. Spurs 63 are disposed in a position facing the upper part of the discharge rollers 62. The discharge rollers 62 are driven by a motor 102. The spurs 63 rotate in conjunction with the rotation of the discharge rollers 62. As the discharge rollers 62 and the spurs 63 rotate forward, the paper P is sandwiched between the discharge rollers 62 and the spurs 63 and is discharged to the discharge tray 30.

[0049] The discharge tray 30 is disposed above the feed tray 20. The discharge tray 30 supports the paper P discharged by the discharge rollers 62.

[0050] A registration sensor 120 is provided between the conveying roller 60 and the image recording unit 3 on the conveying path R. The registration sensor 120 is a sensor that detects that the paper P passes through the contact position between the paper P and the conveying roller 60. As the registration sensor 120, a sensor having an actuator that oscillates when the paper P comes into contact with it, an optical sensor, etc. can be used. The registration sensor 120 outputs an ON signal when the paper P passes through the contact position between the paper P and the conveying roller 60, and outputs an OFF signal when the paper P does not pass through the contact position between the paper P and the conveying roller 60. The detection signal by the registration sensor 120 is output to the control unit 10.

[0051] The conveying roller 60 is provided with an encoder 121 that detects the rotation of the conveying roller 60. The encoder 121 outputs a pulse signal to the control unit 10 in response to the rotation of the conveying roller 60. Specifically, the encoder 121 has an encoder disk (not shown) and an optical sensor (not shown). The encoder disk rotates together with the rotation of the conveying roller 60. The optical sensor reads the rotating encoder disk to generate a pulse signal, and outputs the generated pulse signal to the control unit 10.

[0052] Further, the feed roller 21 is provided with an encoder 122 that detects the rotation of the feed roller 21. The encoder 122 has a similar configuration to the encoder 121, and outputs a pulse signal to the control unit 10 in response to the rotation of the feed roller 21.

[0053] <Inkjet Printer 1 System Configuration> FIG. 2 is a block diagram showing the system configuration of the inkjet printer 1 according to the first embodiment.

[0054] As shown in FIG. 2, the control unit 10 is mainly composed of a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, an EEPROM (Electrically Erasable Programmable Read-Only Memory) 14 (registered trademark), and an ASIC (Application Specific Integrated Circuit) 15. These are connected to a printer unit, a scanner unit, an operation panel 41, etc. via a bus 16 so as to be able to transmit and receive data. The ROM 12 stores programs and the like for the CPU 11 to control various operations. The RAM 13 is used as a storage area for temporarily recording data, signals, etc. used when the CPU 11 executes the programs, or as a working area for data processing. The EEPROM 14 (registered trademark) stores setting information to be retained even after the power is turned off.

[0055] The motor 102 and the carriage motor 103 are connected to the ASIC 15. The ASIC 15 supplies a drive current to the motor 102 and the carriage motor 103 via a drive circuit (not shown). The motor 102 and the carriage motor 103 are DC motors that rotate faster as the drive current supplied thereto increases and rotate slower as the drive current supplied thereto decreases. The control unit 10 controls the rotation of the motor 102 and the carriage motor 103, for example, by PWM (Pulse Width Modulation) control.

[0056] The control unit 10 also applies a drive voltage to the piezoelectric element 321 of the head 32 to eject ink droplets from the nozzle 33. The ASIC 15 is also connected to a registration sensor 120, an encoder 121, an encoder 122, and a carriage encoder 123. The control unit 10 detects the state of the inkjet printer 1 based on signals output from the registration sensor 120, the encoder 121, the encoder 122, and the carriage encoder 123.

[0057] Specifically, the control unit 10 detects that the paper P has passed the contact position with the conveyance roller 60 based on a detection signal output from the registration sensor 120. The control unit 10 detects the amount of rotation of the conveyance roller 60 based on a pulse signal output from an encoder 121, and detects the amount of rotation of the feed roller 21 based on a pulse signal output from an encoder 122. The control unit 10 also estimates the position of the paper P on the conveyance path R based on the pulse signal output from the encoder 121 after an on signal is output from the registration sensor 120.

[0058] The control unit 10 detects the position of the carriage 31 in the width direction of the paper P based on the encoder signal input from the carriage encoder 123. The control unit 10 acquires print data and has a function as a discharge detection unit that detects the end of ink discharge from the head 32 during the recording process based on the acquired print data and the detected position of the carriage 31.

[0059] In recording an image on paper P, the control unit 10 ejects ink from the nozzles 33 of the head 32 while moving the carriage 31 in the width direction of the paper P while the transport of the paper P is stopped. The control unit 10 controls the carriage 31 and the head 32 to repeat a recording process in which an image for one line is recorded on the paper P while ejecting ink, and a line feed process in which the transport rollers 60 and the discharge rollers 62 are driven to transport the paper P by a predetermined line feed amount.

[0060] An operation panel 41 is connected to the ASIC 15. Operation instructions for the printer unit, the size of the paper P, and the resolution of the recorded image inputted through the operation panel 41 are stored in the RAM 13 as size information and resolution information via the ASIC 15 and the bus 16.

[0061] An interface (I / F) 40 is connected to the ASIC 15. The control unit 10 can transmit and receive data to and from an external information device via the interface 40. The external information device is, for example, a computer on which a printer driver is installed. In other words, the size and resolution input when operating the printer unit may be input from the operation panel 41 or from the printer driver of the external information device.

[0062] <Principle of electromotive force generation by coil 70> In the first embodiment, the electromotive force generated in the coil 70 linked with the magnetic flux generated by the magnet 721 is used as the drive voltage for the head 32 .

[0063] FIG. 3 shows the principle by which an electromotive force is generated in the coil 70. As shown in FIG.

[0064] Coil 70 is moved in the direction of the arrow above magnet 721. Magnet 721 generates a magnetic flux in space from the north pole to the south pole, so coil 70 interlinks with the magnetic flux in space by moving. According to Faraday's law, an electromotive force is generated between the terminals of coil 70.

[0065] The electromotive force thus generated by the coil 70 is used to drive the piezoelectric element 321 disposed within the head 32 , causing ink to be ejected from the nozzle 33 .

[0066] 4 and 5 show an example of the arrangement of the coil 70 and the magnet 721. Fig. 4 shows a case where the length of the coil 70 in the movement direction of the carriage 31 is shorter than the length of the magnet 721 in said movement direction. Fig. 5 shows a case where the above-mentioned length of the coil 70 is longer than the above-mentioned length of the magnet 721. In the following description, the "length" of the coil 70 and the magnet 721 refers to the length in the movement direction of the carriage 31.

[0067] As shown in Fig. 4, when the length of magnet 721 is longer than the length of coil 70, the amount of change in magnetic flux caused by the movement of coil 70 is large, and therefore a large electromotive force can be obtained. In contrast, as shown in Fig. 5, when the length of magnet 721 is shorter than the length of coil 70, the magnetic fluxes cancel each other out due to the movement of coil 70, and therefore only a small electromotive force can be obtained. Therefore, a larger electromotive force can be obtained when magnet 721 is longer than coil 70.

[0068] <Arrangement of Carriage 31 and Magnet Group 72> Fig. 6 is a plan view showing the positional relationship between the carriage 31 and the magnet group 72, and Fig. 7 is a front view showing the positional relationship between the carriage 31 and the magnet group 72. The inkjet printer 1 further includes a metal guide 71 and a magnet group 72 in addition to the configuration shown in Fig. 1.

[0069] Two metal guides 71 are arranged in parallel at equal intervals along the movement direction of the carriage 31. Although not shown, the carriage 31 engages with the metal guide 71 so as to be slidable relative to the metal guide 71, and is driven by the carriage motor 103 to move on the metal guide 71.

[0070] A head 32 and a coil 70 are attached to the carriage 31. The carriage 31 moves in the movement direction, thereby moving the head 32 and the coil 70 in the movement direction.

[0071] The carriage 31 has a head arrangement surface 31a which is a horizontal plane, and a coil arrangement surface 31b which is a horizontal plane and an upper surface. The head arrangement surface 31a and the coil arrangement surface 31b are different surfaces. The head 32 is arranged on the head arrangement surface 31a, and the coil 70 is arranged on the coil arrangement surface. Note that the coil 70 may be arranged in a position close to the coil arrangement surface 31b inside the carriage 31.

[0072] Since the head mounting surface 31a and the coil mounting surface 31b are different surfaces, the coil 70 can be mounted on the carriage 31 without being restricted by the position of the head 32. This allows the coil 70 to be formed in the carriage 31 with a maximum size determined by the size of the coil mounting surface 31b. This can improve the power generation efficiency.

[0073] The coil 70 moves in the movement direction due to the movement of the carriage 31. As the coil 70 moves, it interlinks with the magnetic flux generated from the magnet group 72 to generate an electromotive force. As described later, the generated electromotive force generates a drive voltage that drives the piezoelectric element 321 of the head 32.

[0074] The magnet group 72 includes a plurality of magnets 721. The plurality of magnets 721 are connected in a row and arranged above the carriage 31, i.e., above the coil 70, and parallel to the moving direction of the carriage 31. The magnet group 72 may be disposed below the carriage 31.

[0075] In a configuration in which the coil 70 is disposed on the side of the carriage 31, the carriage 31 must be formed to a height according to the size of the coil 70 in order to form the coil 70 to a predetermined size. In contrast, in a configuration in which the coil 70 is disposed on the horizontal surface of the carriage 31, the height of the carriage 31 is not determined by the size of the coil 70 as described above, so the carriage 31 can be formed low. This allows the carriage 31 to be made more compact. In addition, by disposing the magnet group 72 above or below the coil 70, it becomes easier to link the strong magnetic flux of the magnet group 72 to the coil 70 from above or below, thereby improving power generation efficiency.

[0076] Normally, there are no obstacles above the carriage 31, unlike below where the paper P passes. By arranging the coil 70 on the upper surface of the carriage 31, the coil 70 can be brought close to the magnet group 72 arranged above the coil 70. This allows the coil 70 to generate a large electromotive force by passing through a portion of the magnet group 72 where the magnetic flux is strong, generated by each magnet 721. This can increase the power generation efficiency.

[0077] Moreover, the magnet group 72 is disposed in a range that includes the movement range of the carriage 31. This allows power generation by the coil 70 throughout the entire movement range of the carriage 31. This allows for greater power generation efficiency than a configuration in which the magnet group 72 is disposed in only a portion of the movement range of the carriage 31.

[0078] Here, as described above, the length of the magnet 721 is longer than the length of the coil 70 .

[0079] Of the magnetic fluxes linking the coil 70, the amount of magnetic fluxes that cancel each other out is reduced, improving power generation efficiency.

[0080] A plurality of nozzles 33 are arranged at intervals in a matrix on the underside of the head 32. The area of ​​a coil arrangement region on the coil arrangement surface 31b, where the coil 70 is arranged, is larger than the area of ​​a nozzle arrangement region on the head arrangement surface 31a, where the plurality of nozzles 33 are arranged.

[0081] The nozzle arrangement region occupies a large area in the head 32. Therefore, the size of the head 32 is determined by the area of ​​the nozzle arrangement region. The size of the carriage 31 is determined according to the size of the head 32, and the area of ​​the coil arrangement region is also determined. Therefore, since the area of ​​the coil arrangement region is larger than the area of ​​the nozzle arrangement region, which occupies a large area on the head arrangement surface 31a of the carriage 31, the coil 70 can be formed to be large. This makes it possible to improve the power generation efficiency.

[0082] <Detailed configuration of head 32 and control configuration of carriage 31 and head 32> 8 is a block diagram showing a detailed configuration of the head 32. The head 32 includes a rectifier circuit 324, a smoothing circuit 325, a conversion circuit 326, a piezoelectric element 321, a drive circuit 322, a head control circuit 323, and a nozzle 33. The conversion circuit 326 includes a drive voltage conversion circuit 3261, a drive voltage storage circuit 3262, a power supply voltage conversion circuit 3263, and a power supply voltage storage circuit 3264. The control unit 10 includes a carriage control unit 17 and a head control unit 18.

[0083] The drive voltage generating unit 80 also includes a coil 70 , a rectifier circuit 324 , a smoothing circuit 325 , and a conversion circuit 326 .

[0084] The rectifier circuit 324 is configured with a bridge rectifier circuit, and rectifies the AC voltage generated by the AC electromotive force generated by the movement of the carriage 31, thereby converting it into a positive rectified voltage.

[0085] The smoothing circuit 325 smoothes the rectified voltage and converts it into a smoothed voltage. The smoothing circuit 325 is formed of a smoothing capacitor.

[0086] The conversion circuit 326 converts the smoothed voltage into a drive voltage that drives the piezoelectric element 321. The conversion circuit 326 then converts the smoothed voltage into a power supply voltage for the drive circuit 322 and a power supply voltage for the head control circuit 323. In the first embodiment, the drive voltage is, for example, 30 to 33 V. The power supply voltage is, for example, 3.3 V.

[0087] Furthermore, the conversion circuit 326 includes a drive voltage storage circuit 3262 that stores power from the drive voltage, and a power supply voltage storage circuit 3264 that stores power from the power supply voltage. When a drive voltage capable of driving the piezoelectric element 321 cannot be obtained from the electromotive force of the coil 70, the drive voltage storage circuit 3262 applies a drive voltage to the piezoelectric element 321 in place of the coil 70. When a power supply voltage cannot be obtained from the electromotive force of the coil 70, the power supply voltage storage circuit 3264 applies a power supply voltage to the drive circuit 322 and the head control circuit 323 in place of the coil 70.

[0088] It is preferable that the conversion circuit 326 includes a drive voltage storage circuit 3262 and a power supply voltage storage circuit, but this is not essential.

[0089] The head control circuit 323 controls the drive circuit 322 by providing a drive control signal to the drive circuit 322 .

[0090] The drive circuit 322 generates a drive signal based on a drive control signal from the head control circuit 323. The drive circuit 322 provides the drive signal to the piezoelectric element 321 to drive the piezoelectric element 321.

[0091] The piezoelectric element 321 deforms the piezoelectric body in response to a drive signal from a drive circuit 322 to press out ink, thereby causing the ink to be ejected from the nozzle 33 .

[0092] The head control unit 18 provides a head control signal to the head control circuit 323. The head control signal includes data such as a print pattern, a drive command signal, and the like. The drive command signal is a signal that provides a command to drive the head 32, i.e., a drive command to drive the piezoelectric element 321. The drive command includes a print command to eject ink from the nozzle 33 and print on the paper P, and a maintenance command to remove ink clogging in the nozzle 33. In addition, the head control unit 18 receives a response signal from the head control circuit 323 in response to the drive command signal, and recognizes that the head 32 is capable of printing.

[0093] The carriage control unit 17 provides a carriage control signal to the carriage motor 103 to control the carriage motor 103. The carriage control unit 17 moves the carriage 31 at least in the range in which the magnet group 72 is arranged. The carriage motor 103 moves the carriage 31 based on the carriage control signal.

[0094] According to the drive voltage generating unit 80 configured as described above, the drive voltage is generated from the electromotive force generated in the coil 70 as the carriage 31 moves, and the piezoelectric element 321 can be driven by applying the drive voltage. This eliminates the need to generate extra load torque in the carriage motor 103 in order to generate the drive voltage to be applied to the piezoelectric element 321. This allows the inkjet printer 1 to consume less power.

[0095] Rectifier circuit 324, smoothing circuit 325 and conversion circuit 326 make it possible to obtain a drive voltage suitable for driving piezoelectric element 321 from the electromotive force of the coil.

[0096] The electromotive force of the coil 70 generated when the amount of movement of the carriage 31 is small may not be sufficient to drive the piezoelectric element 321. In contrast, the drive voltage storage circuit 3262 and the power supply voltage storage circuit 3264 store electricity mainly when the amount of movement of the carriage 31 is large, so that a drive voltage sufficient to drive the piezoelectric element 321 can be obtained even when the amount of movement of the carriage 31 is small.

[0097] The carriage control unit 17 moves the carriage 31 at least in the range in which the magnet group 72 is arranged. This allows more power to be stored in the drive voltage storage circuit 3262 and the power supply voltage storage circuit 3264 than if the carriage 31 were moved in a part of the range in which the magnet group 72 is arranged. This allows the power generation efficiency to be improved.

[0098] <Printing process of inkjet printer 1> The following describes the printing process of the inkjet printer 1. Fig. 9 is a flow chart showing the procedure of the printing process of the inkjet printer 1.

[0099] START: The user issues the above-mentioned drive command to the inkjet printer 1.

[0100] Step S101: The carriage control unit 17 determines whether or not a predetermined time has passed since the previous, i.e., immediately preceding, drive operation of the piezoelectric element 321 ended (step S101). If the predetermined time has passed since the previous drive operation of the piezoelectric element 321 ended (YES in step S101), proceed to step S104. Otherwise (NO in step S101), proceed to step S102.

[0101] If step S101 is NO, the carriage control unit 17 determines that a predetermined amount of power or more is stored in the drive voltage storage circuit 3262 and the power supply voltage storage circuit 3264 (hereinafter referred to as storage circuits). In that case, there is no need to move the carriage 31. On the other hand, if step S101 is YES, it is considered that the storage circuit has not stored a predetermined amount of power or more due to discharging. In that case, it is necessary to move the carriage 31 and store power in the storage circuit.

[0102] Step S 102 : The head control unit 18 outputs a drive command signal to the head control circuit 323 .

[0103] Step S103: The head control unit 18 determines whether or not there is a response signal from the head control circuit 323. If there is a response signal from the head control circuit 323 (YES in step S103), proceed to step S106. Otherwise (NO in S103), proceed to step S104.

[0104] Step S105: If the predetermined amount of stored power is reached (YES in step S105), the carriage control unit 17 proceeds to step S106, otherwise (NO in step S105), the process returns to step S104.

[0105] Step S106: The piezoelectric element 321 starts its driving operation.

[0106] END: The driving operation of the piezoelectric element 321 ends.

[0107] As described above, in step S103, if there is a response signal from the head control circuit 323 (YES), the carriage control unit 17 assumes that a predetermined amount of power or more has been stored in the power storage circuit, and does not move the carriage 31. On the other hand, if there is no response signal from the head control circuit 323 (NO), the carriage control unit 17 moves the carriage 31 because no power has been stored in the power storage circuit.

[0108] In this way, when a predetermined amount of power or more is stored in the power storage circuit, the carriage 31 does not move. This makes it possible to prevent the carriage 31 from moving unnecessarily when a drive command is issued, and to promptly start the drive operation of the piezoelectric element 321.

[0109] The carriage control unit 17 moves the carriage 31 when there is a response signal from the head control circuit 323, but the carriage 31 may be moved when a drive command signal is issued from the head control unit 18.

[0110] In this way, by moving the carriage 31 in response to issuance of a drive command before driving the piezoelectric element 321, the storage circuit is charged with the drive voltage obtained from the electromotive force of the coil 70. As a result, even if the storage circuit does not have enough stored power to drive the piezoelectric element 321 when the drive command is generated, the movement of the carriage 31 allows the storage circuit to store enough power to drive the piezoelectric element 321.

[0111] If the time until the maximum power stored in the storage circuit falls below a predetermined value due to self-discharge of the storage circuit by the process of step S101 is set as the predetermined time, then if the time that has elapsed from the end of the drive operation of the piezoelectric element 321 to the generation of a drive command is within the predetermined time, it can be considered that power equal to or greater than the predetermined value has been stored in the storage circuit. On the other hand, if the time that has elapsed from the end of the drive operation of the piezoelectric element 321 to the generation of a drive command is not the predetermined time, this means that the power stored in the storage circuit is not sufficient for the head 32 to respond, and it can be considered that power equal to or greater than the predetermined value has not been stored in the storage circuit.

[0112] This makes it possible to estimate whether or not a predetermined value or more of power is stored in the power storage circuit without measuring the power stored in the power storage circuit.

[0113] Here, the drive command may be a print command for executing printing. This allows power for driving the piezoelectric element 321 to be stored in the power storage circuit at least during printing.

[0114] [Software implementation example] The functions of the inkjet printer 1 (hereinafter referred to as the "device") can be realized by a program for causing a computer to function as the device, and a program for causing a computer to function as the control unit 10 of the device.

[0115] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program to realize each function described in each of the above embodiments.

[0116] The program may be non-transitory and may be recorded in one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be provided to the device via any wired or wireless transmission medium.

[0117] In addition, some or all of the functions of each of the control blocks can be realized by a logic circuit. For example, an integrated circuit in which a logic circuit that functions as each of the control blocks is formed is also included in the scope of the present invention. In addition, the functions of each of the control blocks can be realized by, for example, a quantum computer.

[0118] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of symbols]

[0119] 1. Inkjet printer 17 Carriage control unit 31 Carriage 31a Head placement surface 31b Coil placement surface (horizontal surface, top surface) 32 Head 33 Nozzle 321 Piezo element (ejection element) 70 Coil 71 Metal Guide 72 Magnets 80 Drive voltage generating unit 103 Carriage motor 324 Rectifier circuit 325 Smoothing circuit 326 Conversion Circuit 3261 Drive voltage conversion circuit (conversion circuit) 3262 Drive voltage storage circuit (storage circuit) 3263 Power supply voltage conversion circuit (conversion circuit) 3264 Power supply voltage storage circuit (storage circuit)

Claims

1. a head having nozzles and ejection elements for ejecting ink from the nozzles; a drive voltage generating unit that generates a drive voltage to be applied to the ejection elements; a carriage that moves the head and the driving voltage generating unit in a movement direction; A magnet group including a plurality of magnets arranged in the moving direction; Equipped with an inkjet printer characterized in that the drive voltage generating unit includes a coil that generates an electromotive force by interlinking with the magnetic flux of the group of magnets as the carriage moves, and an electric circuit that is connected to the coil on the carriage and generates the drive voltage from the electromotive force.

2. A head having a nozzle and an ejection element for ejecting ink from the nozzle; a drive voltage generating unit that generates a drive voltage to be applied to the ejection elements; a carriage that moves the head and the driving voltage generating unit in a movement direction; A magnet group including a plurality of magnets arranged in the moving direction; a carriage control unit that moves the carriage before driving the ejection elements when a drive command for driving the ejection elements is generated; Equipped with The drive voltage generating unit a coil that generates an electromotive force by interlinking with the magnetic flux of the magnet group as the carriage moves; a rectifier circuit that rectifies an AC voltage generated by the electromotive force of the coil; a smoothing circuit that smoothes the rectified voltage of the rectifier circuit; a conversion circuit for converting a smoothed voltage of the smoothing circuit into the driving voltage; having The conversion circuit includes: a storage circuit that stores power by the driving voltage; The inkjet printer is characterized in that, when the drive command is generated, the carriage control unit does not move the carriage if a predetermined value or more of power is stored in the storage circuit, and moves the carriage if the predetermined value or more of power is not stored in the storage circuit.

3. 3. The inkjet printer according to claim 2, wherein the carriage control unit determines that the power stored in the storage circuit is equal to or greater than the predetermined value when a time elapsed from the end of the drive operation of the previous ejection element to the generation of the drive command is within a predetermined time.

4. 4. The inkjet printer according to claim 2, wherein the carriage control unit moves the carriage at least within a range in which the group of magnets is arranged.

5. 5. The inkjet printer according to claim 2, wherein the drive command is a print command for executing printing.

6. 6. The inkjet printer according to claim 1, wherein the magnet group is disposed within a range that includes a range in which the carriage moves.

7. 7. The inkjet printer according to claim 1, wherein the length of the magnet in the moving direction is longer than the length of the coil in the moving direction.

8. 8. The inkjet printer according to claim 1, wherein the carriage has a head arrangement surface on which the head is arranged, and a coil arrangement surface, which is a surface different from the head arrangement surface and on which the coil is arranged.

9. A head having a nozzle and an ejection element for ejecting ink from the nozzle; a drive voltage generating unit that generates a drive voltage to be applied to the ejection elements; a carriage that moves the head and the driving voltage generating unit in a movement direction; A magnet group including a plurality of magnets arranged in the moving direction; Equipped with the drive voltage generating unit has a coil that generates an electromotive force by interlinking with the magnetic flux of the magnet group as the carriage moves, and generates the drive voltage from the electromotive force; The coil is disposed on a horizontal surface of the carriage; The inkjet printer according to claim 1, wherein the magnet group is disposed above or below the coil.

10. the coil is disposed on an upper surface of the carriage; 10. The inkjet printer according to claim 9, wherein the magnet group is disposed above the coil.

11. A head having a nozzle and an ejection element for ejecting ink from the nozzle; a drive voltage generating unit that generates a drive voltage to be applied to the ejection elements; a carriage that moves the head and the driving voltage generating unit in a movement direction; A magnet group including a plurality of magnets arranged in the moving direction; Equipped with the drive voltage generating unit has a coil that generates an electromotive force by interlinking with the magnetic flux of the magnet group as the carriage moves, and generates the drive voltage from the electromotive force; an area of ​​a coil arrangement region in which the coil is arranged in the carriage is larger than an area of ​​a nozzle arrangement region in which the plurality of nozzles are arranged in the head;

Images