Option unit for liquid discharge device

Abstract

To provide an option unit for a liquid discharge device that can reduce the risk that operation stability may deteriorate.SOLUTION: In an option unit for a liquid discharge device, in a first driving electric power output circuit that outputs a first driving electric power signal that is supplied to a first driving part, one end of a first capacitor, a cathode terminal of a first diode and one end of a first inductor are electrically connected to a first node, the other end of the first inductor and one end of a second capacitor are electrically connected to a second node, the other end of the second capacitor, an anode terminal of the first diode and one end of a first switching element are electrically connected to a third node, the other end of the first capacitor and the other end of the first switching element are electrically connected to a fourth node, a rectified voltage signal is supplied to the first node, one end of the first driving part is electrically connected to the second node, and the other end of the first driving part is electrically connected to the third node.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an option unit for a liquid ejection device. [Background technology]

[0002] In recent years, as liquid ejection devices have become larger, liquid ejection systems have become widespread in which some components of the liquid ejection device, such as a heater mechanism, medium winding mechanism, ink supply mechanism, etc., are separated from the main body of the liquid ejection device and combined according to the application of the liquid ejection device.

[0003] For example, Patent Document 1 discloses a configuration including an inkjet printer (liquid ejection device) and a print paper drying device as an accessory device that is provided independently of the inkjet printer and operates by being supplied with commercial power. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-284172 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the optional unit (accessory device) for a liquid ejection device described in Patent Document 1 is used in an area with a different power supply environment, such as the voltage value of the commercial power supply, changes in the voltage value of the commercial power supply directly affect the load, and there is a risk that the operational stability of the optional unit for the liquid ejection device will decrease. [Means for solving the problem]

[0006] One aspect of the optional unit for a liquid ejection device according to the present invention is to An optional unit for a liquid ejection device that is attached to the liquid ejection device and used, a rectifier circuit that receives a commercial power supply and outputs a rectified voltage signal; a first drive power output circuit that receives the rectified voltage signal and outputs a first drive power signal; a first drive unit that is driven by the first drive power signal; Equipped with The first driving power output circuit includes: a first capacitor, a second capacitor, a first inductor, a first diode, and a first switching element; one end of the first capacitor, a cathode terminal of the first diode, and one end of the first inductor are electrically connected to a first node; the other end of the first inductor and one end of the second capacitor are electrically connected to a second node; the other end of the second capacitor, the anode terminal of the first diode, and one end of the first switching element are electrically connected to a third node; the other end of the first capacitor and the other end of the first switching element are electrically connected to a fourth node; the rectified voltage signal is provided to the first node; The first driving unit has one end electrically connected to the second node and the other end electrically connected to the third node. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a liquid ejection system. [Diagram 2] FIG. 2 is a diagram illustrating an example of a functional configuration of a liquid ejection system. [Diagram 3] FIG. 2 is a diagram showing a configuration of a heater driving module. [Figure 4] FIG. 2 is a diagram illustrating an example of a configuration of a switch circuit. [Diagram 5] 4 is a diagram showing an example of a drive control signal Dr1 and a drive control signal Dr2. FIG. [Figure 6] 13 shows an example of the configuration of a heater driving module of a heater unit included in a liquid ejection system according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Preferred embodiments of the present invention will be described below with reference to the drawings. The drawings are used for the convenience of explanation. Note that the embodiments described below do not unduly limit the contents of the present invention described in the claims. Furthermore, not all of the configurations described below are necessarily essential components of the present invention.

[0009] 1. First embodiment 1.1 Liquid ejection system configuration FIG. 1 is a diagram showing a schematic configuration of a liquid ejection system PS. The liquid ejection system PS of this embodiment includes a liquid ejection device 1 that forms a desired image by ejecting ink onto a medium P, and a heater unit 2 that is an optional unit for the liquid ejection device attached to the liquid ejection device 1 and dries the ink ejected onto the medium by the liquid ejection device 1. Here, in FIG. 1, the description is given using three mutually orthogonal spatial axes, that is, the X-axis, the Y-axis, and the Z-axis. In addition, in the following description, when specifying the direction along each of the X-axis, the Y-axis, and the Z-axis, the tip side of the arrow indicating the direction along the illustrated X-axis may be referred to as the +X side, and the starting point side may be referred to as the -X side, the tip side of the arrow indicating the direction along the illustrated Y-axis may be referred to as the +Y side, and the starting point side may be referred to as the -Y side, and the tip side of the arrow indicating the direction along the illustrated Z-axis may be referred to as the +Z side, and the starting point side may be referred to as the -Z side.

[0010] The liquid ejection device 1 shown in this embodiment will be described as a so-called serial printing type inkjet printer in which a carriage 21 carrying a print head 22 moves back and forth along the X axis, and the print head 22 ejects ink onto a medium P transported along the Y axis, thereby forming a desired image on the medium P. The liquid ejection device 1 provided in the liquid ejection system PS is not limited to a serial printing type inkjet printer, and may be a line printing type inkjet printer. The liquid ejection device 1 is not limited to an inkjet printer, and may be a color material ejection device used in manufacturing color filters for liquid crystal displays and the like, an electrode material ejection device used in forming electrodes for organic electroluminescence displays, FEDs (surface emission displays), and the like, a bioorganic material ejection device used in biochip manufacturing, a three-dimensional modeling device for generating three-dimensional objects, a textile printing device for dyeing cloth, and the like.

[0011] The optional unit for the liquid ejection device of this embodiment, which will be described by taking the heater unit 2 as an example, is an optional unit that can be selectively added to the liquid ejection device 1 according to the needs of the user who uses the liquid ejection device 1. This optional unit for the liquid ejection device is not limited to a configuration that is added to the liquid ejection device 1 by the user, but also includes a configuration that is added by the manufacturer of the liquid ejection device 1 before shipping, such as during the manufacture of the liquid ejection device 1. In other words, the optional unit for the liquid ejection device attached to the liquid ejection device 1 is not limited to a configuration that is attached to the outside of the liquid ejection device 1, but also includes a configuration that is incorporated into the same housing as the liquid ejection device 1. The optional unit for the liquid ejection device is not limited to the heater unit 2, but may be, for example, a light source that irradiates ultraviolet light to cure the ink ejected onto the medium P.

[0012] The liquid ejection device 1 includes a control unit 10, a head unit 20, a moving unit 30, a transport unit 40, and an ink container 70.

[0013] The ink container 70 stores multiple types of ink to be ejected onto the medium P. As the ink container 70 for storing such ink, an ink cartridge, a bag-shaped ink pack formed of a flexible film, an ink tank that can be refilled with ink, or the like can be used.

[0014] The control unit 10 includes a processing circuit such as a CPU (Central Processing Unit) and an FPGA (Field Programmable Gate Array), and a storage circuit such as a semiconductor memory, and controls each element of the liquid ejection device 1 including the head unit 20.

[0015] The head unit 20 includes a carriage 21 and a print head 22. The carriage 21 is fixed to an endless belt 32 included in a moving unit 30, which will be described later. The print head 22 is mounted on the carriage 21. A control signal Ctrl-H and a head drive signal COM are input to the print head 22. Ink stored in an ink container 70 is supplied to the print head 22 via a tube (not shown) or the like. Based on the input control signal Ctrl-H and head drive signal COM, the print head 22 ejects ink supplied from the ink container 70 along the Z axis from the -Z side to the +Z side.

[0016] The moving unit 30 includes a carriage motor 31 and an endless belt 32. The carriage motor 31 operates to rotate forward and backward based on a control signal Ctrl-C input from the control unit 10. The endless belt 32 extends along the X-axis and rotates according to the operation of the carriage motor 31. Then, as the carriage motor 31 operates under the control of the control unit 10, the carriage 21 fixed to the endless belt 32 moves back and forth along the X-axis. In other words, the moving unit 30 moves the print head 22 mounted on the carriage 21 back and forth along the X-axis.

[0017] The transport unit 40 includes a transport motor 41, a transport roller 42, and a platen 43. The transport motor 41 operates based on a control signal Ctrl-T input from the control unit 10. The transport roller 42 holds the medium P and rotates according to the operation of the transport motor 41. The platen 43 supports the medium P. Then, by driving the transport motor 41 under the control of the control unit 10, the medium P held by the transport roller 42 is transported from the -Y side to the +Y side along the Y axis while being supported by the platen 43. That is, the transport unit 40 transports the medium P from the -Y side to the +Y side along the Y axis.

[0018] The heater unit 2 is located downstream of the print head 22 along the transport direction of the medium P transported along the transport unit 40. In other words, the heater unit 2 is located on the +Y side of the print head 22. The heater unit 2 generates heat to dry the ink that has landed on the medium P and fix the ink to the medium P.

[0019] The heater unit 2 includes a heater driving module 80 and a heater 90. The heater driving module 80 outputs a heater driving signal HC that drives the heater 90. The heater 90 is driven and generates heat based on the heater driving signal HC input from the heater driving module 80. The heat generated by the heater 90 heats the medium P. This dries the medium P and the ink that has landed on the medium P. As a result, the fixability of the ink that has landed on the medium P is improved.

[0020] In the liquid ejection system PS configured as above, the control unit of the liquid ejection device 1 Under the control of the liquid ejection system PS, the moving unit 30 controls the reciprocating movement of the carriage 21 in the scanning direction, the transport unit 40 controls transport in a direction along the transport direction of the medium P, and the print head 22 mounted on the carriage 21 included in the head unit 20 ejects ink onto the medium P. As a result, the ink ejected by the print head 22 lands on any surface of the medium P, forming a desired image on the medium P. Then, the heater unit 2 dries the medium P and the ink that has landed on the medium P, thereby improving the fixation of the ink that has landed on the medium P. This improves the quality of the image output by the liquid ejection system PS.

[0021] 1.2 Functional configuration of the liquid ejection system Next, the functional configuration of the liquid ejection system PS will be described. Fig. 2 is a diagram showing an example of the functional configuration of the liquid ejection system PS. As shown in Fig. 2, the liquid ejection system PS includes a liquid ejection device 1 and a heater unit 2.

[0022] The liquid ejection device 1 includes a control unit 10, a power supply voltage output circuit 12, a print head 22, a carriage motor 31, a linear encoder 33, and a transport motor 41.

[0023] The power supply voltage output circuit 12 generates a voltage signal VHV of a DC voltage used in the liquid ejection device 1 from a voltage signal Vac, which is a commercial power supply supplied to the liquid ejection system PS. The power supply voltage output circuit 12 then outputs the generated voltage signal VHV to various components of the liquid ejection device 1. Such a power supply voltage output circuit 12 includes, for example, an existing AC / DC converter such as a flyback converter. Here, the power supply voltage output circuit 12 may output a voltage signal VHV of a plurality of voltage values ​​corresponding to each of the components to which the voltage signal VHV is supplied. In this case, the power supply voltage output circuit 12 may include, in addition to an existing AC / DC converter such as a flyback converter, one or more DC / DC converters that convert the voltage value of the DC voltage output by the AC / DC converter according to the configuration to which it is supplied.

[0024] The control unit 10 has a head driving circuit 50, a reference voltage output circuit 52, and a control circuit 100. The control circuit 100 includes, for example, a processing circuit such as a CPU or FPGA, and a storage circuit such as a semiconductor memory. An image information signal including image data and the like is input to the control circuit 100 from an external device such as a host computer that is communicatively connected to the outside of the liquid ejection device 1. The control circuit 100 generates various signals for controlling the liquid ejection device 1 based on the input image information signal, and outputs the signals to corresponding components.

[0025] As a specific example, in addition to the image information signal described above, the control circuit 100 acquires a position information signal Pos based on the scanning position of the carriage 21 output by the linear encoder 33. In this way, the control circuit 100 grasps the scanning position of the carriage 21, which is the scanning position of the print head 22 mounted on the carriage 21. Then, the control circuit 100 generates various signals according to the image information signal input from an external device and the scanning position of the print head 22, and outputs them to the corresponding components.

[0026] In detail, the control circuit 100 generates a control signal Ctrl-C for controlling the reciprocating movement of the carriage 21 carrying the print head 22 along the scanning axis in accordance with the acquired scanning position of the print head 22, and outputs it to the carriage motor 31. This causes the carriage motor 31 to operate, controlling the scanning position of the print head 22 and its movement along the scanning axis. The control circuit 100 also generates a control signal Ctrl-T for controlling the transport of the medium P, and outputs it to the transport motor 41. This causes the transport motor 41 to operate, controlling the movement of the medium P along the transport direction. Note that the control signal Ctrl-C may be converted via a driver circuit (not shown) before being input to the carriage motor 31, and the control signal Ctrl-T may be converted via a driver circuit (not shown) before being input to the transport motor 31. The signal may be input to the computer 41.

[0027] In addition, the control circuit 100 generates a control signal Ctrl-H for controlling the ejection of ink from the print head 22 based on an image information signal input from an external device and the scanning position of the print head 22, and outputs it to the print head 22.

[0028] Furthermore, the control circuit 100 outputs a basic drive signal dA, which is a digital signal, to the head drive circuit 50. The head drive circuit 50 generates a head drive signal COM having a signal waveform defined by the basic drive signal dA, and outputs it to the print head 22. Specifically, the head drive circuit 50 performs digital / analog signal conversion on the basic drive signal dA, which is a digital signal input from the control circuit 100, and then generates the head drive signal COM by amplifying the converted analog signal by class D, and outputs it to the print head 22. Here, the basic drive signal dA may be an analog signal as long as it can define the signal waveform of the head drive signal COM. The head drive circuit 50 may also generate the head drive signal COM by amplifying the signal waveform defined by the basic drive signal dA by class A, class B, or class AB.

[0029] The reference voltage output circuit 52 generates a reference voltage signal VBS and outputs it to the print head 22. This reference voltage signal VBS is a constant potential signal that serves as a reference for driving a piezoelectric element 60 (described later) that the print head 22 has, and is a DC voltage signal with a constant potential such as ground potential, 5.5 V, or 6 V.

[0030] The print head 22 includes a drive signal selection circuit 200 and a plurality of piezoelectric elements 60. A control signal Ctrl-H and a head drive signal COM are input to the drive signal selection circuit 200. The drive signal selection circuit 200 generates a drive signal VOUT corresponding to each of the plurality of piezoelectric elements 60 by selecting or not selecting a signal waveform included in the head drive signal COM based on the input control signal Ctrl-H. The drive signal selection circuit 200 outputs the generated drive signal VOUT to one end of each of the corresponding piezoelectric elements 60. A reference voltage signal VBS output by the reference voltage output circuit 52 is commonly input to the other end of the plurality of piezoelectric elements 60. Each of the plurality of piezoelectric elements 60 is displaced by the potential difference between the drive signal VOUT input to one end and the reference voltage signal VBS input to the other end. The print head 22 ejects an amount of ink from the nozzle according to the amount of displacement generated in the piezoelectric element 60.

[0031] As described above, the liquid ejection device 1 operates using the voltage signal Vac, which is a commercial power source, as a drive source, and the print head 22 ejects ink to a desired position on the medium P in accordance with image data input from an external device. In this way, the liquid ejection device 1 forms a desired image on the medium P.

[0032] The heater unit 2 of the liquid ejection system PS includes a heater driving module 80 and a heater 90. The heater driving module 80 receives a voltage signal Vac, which is a commercial power supply, and outputs a heater driving signal HC, and the heater 90 generates heat in response to the heater driving signal HC.

[0033] The heater driving module 80 includes a rectifier circuit 81 , a heater driving circuit 82 , and a heater control circuit 83 .

[0034] A voltage signal Vac, which is a commercial power supply, is input to a rectifier circuit 81. The rectifier circuit 81 full-wave rectifies the input voltage signal Vac to generate a rectified voltage signal WR, which is output to a heater drive circuit 82. Note that the rectified voltage signal WR output by the rectifier circuit 81 is not limited to a signal obtained by full-wave rectifying the voltage signal Vac, and may be a signal obtained by half-wave rectifying the voltage signal Vac.

[0035] The heater control circuit 83 acquires a state detection signal Dt indicating the drive state of the heater drive circuit 82 from the heater drive circuit 82. Then, the heater control circuit 83 generates a drive control signal Dr according to the acquired state detection signal Dt, and outputs it to the heater drive circuit 82.

[0036] The heater drive circuit 82 generates a signal with a controlled voltage value of the rectified voltage signal WR by controlling the voltage value of the rectified voltage signal WR input from the rectifier circuit 81 based on the drive control signal Dr input from the heater control circuit 83. Then, the heater drive circuit 82 outputs the signal with the controlled voltage value of the generated rectified voltage signal WR as a heater drive signal HC to the heater 90.

[0037] The heater 90 generates heat in response to the input heater drive signal HC. For such a heater 90, a resistive load such as a nichrome wire can be used as a heating element. The heater 90 generates heat based on a current generated in response to the voltage value of the input heater drive signal HC. The heat generated by this heater 90 is transmitted to the medium P, causing the ink that has landed on the medium P to dry.

[0038] As described above, the heater unit 2 of the present embodiment is an optional unit for a liquid ejection device that is attached to and used with the liquid ejection device 1, and includes a rectifier circuit 81 that receives a voltage signal Vac from a commercial power source and outputs a rectified voltage signal WR, a heater drive circuit 82 that receives the rectified voltage signal WR and outputs a heater drive signal HC, and a heater 90 that is driven by the heater drive signal HC to generate heat. The heater unit 2 improves the quality of the image formed on the medium P by drying the ink ejected onto the medium P by the liquid ejection device 1.

[0039] 1.3 Configuration and operation of the heater drive module Next, a description will be given of the configuration and operation of the heater driving module 80 that drives the heater 90. Fig. 3 is a diagram showing the configuration of the heater driving module 80. As described above, the heater driving module 80 has a rectifier circuit 81, a heater driving circuit 82, and a heater control circuit 83.

[0040] The rectifier circuit 81 includes an inductor L1 and a diode bridge DB. One end of the inductor L1 is electrically connected to the wiring W1, and the other end is electrically connected to the wiring W2. One input end of the diode bridge DB is electrically connected to the wiring W2, the other input end is electrically connected to the wiring W3, the positive output end is electrically connected to the wiring W4, and the negative output end is electrically connected to the wiring W5. A voltage signal Vac supplied between the wiring W1 and the wiring W2 is input to the rectifier circuit 81.

[0041] In the rectifier circuit 81 configured as described above, the inductor L1 reduces normal mode noise superimposed on the voltage signal Vac supplied between the wiring W1 and the wiring W2, and the diode bridge DB full-wave rectifies the noise-reduced voltage signal Vac. The rectifier circuit 81 outputs the signal obtained by full-wave rectifying the voltage signal Vac by the diode bridge DB as a rectified voltage signal WR.

[0042] Here, the rectifier circuit 81 may have an inductor element such as a line filter that reduces common mode noise superimposed on the voltage signal Vac, instead of the inductor L1 or in addition to the inductor L1. The rectifier circuit 81 may have a diode element that half-wave rectifies the voltage signal Vac, instead of the diode bridge DB. In this case, the rectifier circuit 81 may output a signal obtained by half-wave rectifying the voltage signal Vac as the rectified voltage signal WR.

[0043] The heater driving circuit 82 includes capacitors C1 and C2, a diode D1, an inductor L2, and a switch circuit SW.

[0044] The capacitor C1 has one end electrically connected to the wiring W4 and the other end electrically connected to the wiring W6. The diode D1 has a cathode terminal electrically connected to the wiring W4 and an anode terminal electrically connected to the wiring W7. The inductor L2 has one end electrically connected to the wiring W4 and the other end electrically connected to the wiring W8. The capacitor C2 has one end electrically connected to the wiring W8 and the other end electrically connected to the wiring W7. The switch circuit SW has one end electrically connected to the wiring W7 and the other end electrically connected to the wiring W6. A drive control signal Dr output by the heater control circuit 83 is input to a control terminal of the switch circuit SW.

[0045] In other words, one end of the capacitor C1, the cathode terminal of the diode D1, and one end of the inductor L2 are electrically connected to the wiring W4, the other end of the capacitor C1 and the other end of the switch circuit SW are electrically connected to the wiring W6, the anode terminal of the diode D1, one end of the capacitor C2, and one end of the switch circuit SW are electrically connected to the wiring W7, and the other end of the inductor L2 and one end of the capacitor C2 are electrically connected to the wiring W8. The wiring W8 is electrically connected to one end of the heater 90, and the wiring W7 is electrically connected to the other end of the heater 90. That is, the heater drive circuit 82 outputs the voltage generated between the wiring W8 and the wiring W7 as the heater drive signal HC.

[0046] In the heater driving circuit 82 configured as above, the capacitor C1 functions as a filter circuit that reduces noise in the rectified voltage signal WR input to the wiring W4. The capacitance of the capacitor C1 is selected to have a small effect on the signal waveform of the full-wave rectification included in the rectified voltage signal WR and to reduce noise superimposed on the rectified voltage signal WR, and is 5 μF or less, preferably about 1 μF. This reduces the possibility that the power factor of the liquid ejection system PS will decrease due to the influence of the heater driving module 80, and also reduces the influence of noise superimposed on the rectified voltage signal WR. Furthermore, by setting the capacitance of the capacitor C1 to a capacitance of 5 μF or less and about 1 μF, it is possible to select a film capacitor or a chip capacitor, which has a smaller component size than an electrolytic capacitor, as the capacitor C1. This also makes it possible to miniaturize the heater driving circuit 82.

[0047] The switch circuit SW controls the conductive state between one end and the other end according to the logical level of the drive control signal Dr input to the control terminal. Specifically, when the logical level of the drive control signal Dr input to the control terminal is high, the switch circuit SW controls the one end and the other end to be conductive, and when the logical level of the drive control signal Dr input to the control terminal is low, the switch circuit SW controls the one end and the other end to be non-conductive. That is, the switch circuit SW performs a switching operation according to the drive control signal Dr.

[0048] In the following description, a state in which the switch circuit SW is controlled to be conductive between one end and the other end may be referred to as an ON state, and a state in which the switch circuit SW is controlled to be non-conductive between one end and the other end may be referred to as an OFF state. Note that the switch circuit SW may control the one end and the other end to be non-conductive when the logical level of the drive control signal Dr input to the control terminal is high, and may control the one end and the other end to be conductive when the logical level of the drive control signal Dr input to the control terminal is low.

[0049] By performing a switching operation of the switch circuit SW, the current accompanying the propagation of the heater drive signal HC, which is the current accompanying the propagation of the rectified voltage signal WR, is supplied to the heater 90. Specifically, when the switch circuit SW is in the ON state, the current associated with the propagation of the heater drive signal HC, which is the current associated with the propagation of the rectified voltage signal WR, is fed back to the rectifier circuit 81 via the switch circuit SW. As a result, the current associated with the propagation of the heater drive signal HC, which is the current associated with the propagation of the rectified voltage signal WR, is supplied to the heater 90. On the other hand, when the switch circuit SW is in the OFF state, the current associated with the propagation of the heater drive signal HC, which is the current associated with the propagation of the rectified voltage signal WR, is blocked by the switch circuit SW. As a result, the current associated with the propagation of the heater drive signal HC, which is the current associated with the propagation of the rectified voltage signal WR, is not supplied to the heater 90.

[0050] The inductor L2 and the capacitor C2 constitute a low-pass filter. The low-pass filter formed by the inductor L2 and the capacitor C2 smoothes the amplitude of the signal generated by the switching operation of the switch circuit SW. The cutoff frequency of the low-pass filter formed by the inductor L2 and the capacitor C2 is preferably greater than twice the frequency of the voltage signal Vac, which is the commercial power supply, and less than the switching frequency of the switch circuit SW, and is set to about several kHz to 10 kHz in this embodiment.

[0051] The diode D1 forms a feedback path for feeding back the charge stored in the inductor L2 to the wiring W4 when the switch circuit SW is controlled to the OFF state, thereby reducing the risk of distortion of the signal waveform of the heater drive signal HC due to the charge stored in the inductor L2 when the switch circuit SW is controlled to the OFF state.

[0052] The heater driving circuit 82 also includes a current detection circuit 821 and a voltage detection circuit 822 .

[0053] One end of the current detection circuit 821 is electrically connected to the wiring W6, and the other end is electrically connected to the wiring W5. The current detection circuit 821 detects the current value of the current accompanying the propagation of the heater drive signal HC, which is the current value of the current accompanying the propagation of the rectified voltage signal WR. The current detection circuit 821 generates a current detection signal Idt according to the detected current value, and outputs it to the heater control circuit 83 as a state detection signal Dt. As the current detection circuit 821, a resistive element having a resistance value sufficiently small compared to the resistance value of the heater 90 can be used. The current detection circuit 821 may be composed of one or more semiconductor elements instead of or in addition to the resistive element.

[0054] One end of the voltage detection circuit 822 is electrically connected to the wiring W8, and the other end is electrically connected to the wiring W7. The voltage detection circuit 822 detects the voltage value of the heater drive signal HC supplied to the heater 90. The voltage detection circuit 822 generates a voltage detection signal Vdt according to the detected voltage value, and outputs it to the heater control circuit 83 as a state detection signal Dt. Such a voltage detection circuit 822 can be configured using a plurality of resistive elements configured to have a resistance value sufficiently large compared to the resistance value of the heater 90. Note that the voltage detection circuit 822 may be configured to include one or a plurality of semiconductor elements instead of or in addition to the plurality of resistive elements.

[0055] The heater control circuit 83 generates a drive control signal Dr based on the current detection signal Idt input from the current detection circuit 821 and the voltage detection signal Vdt input from the voltage detection circuit 822, and outputs the drive control signal Dr to the switch circuit SW. The heater control circuit 83 includes, for example, a microcomputer, an FPGA, etc.

[0056] An example of the operation of the heater driving module 80 configured as above will be described. The heater driving module 80 of this embodiment is driven by the switching operation of the switch circuit SW. Thus, the heater drive module 80 controls the voltage value of the heater drive signal HC. This controls the amount of current supplied to the heater 90 as the heater drive signal HC is propagated. At that time, the switching operation of the switch circuit SW that controls the voltage value of the heater drive signal HC is controlled by a drive control signal Dr output by the heater control circuit 83. Therefore, in describing an example of the operation of the heater drive module 80, first, a specific example of the configuration of the switch circuit SW and an example of the signal waveform of the drive control signal Dr output by the heater control circuit 83 will be described.

[0057] 4 is a diagram showing an example of the configuration of the switch circuit SW. As shown in FIG. 4, the switch circuit SW has a transistor M1 and a transistor M2. The collector terminal of the transistor M1 is electrically connected to the wiring W7, and the emitter terminal is electrically connected to the wiring W6. The base terminal of the transistor M1 receives a drive control signal Dr1 among the drive control signals Dr output by the heater control circuit 83. The collector terminal of the transistor M2 is electrically connected to the wiring W7, and the emitter terminal is electrically connected to the wiring W6. The base terminal of the transistor M2 receives a drive control signal Dr2 among the drive control signals Dr output by the heater control circuit 83.

[0058] That is, the transistor M1 and the transistor M2 are connected in parallel in the switch circuit SW. When the drive control signal Dr1 input to the base terminal is at a high level, the transistor M1 controls the collector terminal and the emitter terminal to be conductive, and when the drive control signal Dr1 input to the base terminal is at a low level, the transistor M1 controls the collector terminal and the emitter terminal to be non-conductive. When the drive control signal Dr2 input to the base terminal is at a high level, the transistor M2 controls the collector terminal and the emitter terminal to be conductive, and when the drive control signal Dr2 input to the base terminal is at a low level, the transistor M2 controls the collector terminal and the emitter terminal to be non-conductive. That is, the transistor M1 performs a switching operation in response to the drive control signal Dr1, and the transistor M2 performs a switching operation in response to the drive control signal Dr2. The number of transistors included in the switch circuit SW is not limited to two.

[0059] In the following description, a state in which the collector terminal and emitter terminal of the transistor M1 are controlled to be conductive may be referred to as the ON state of the transistor M1, and a state in which the collector terminal and emitter terminal of the transistor M1 are controlled to be non-conductive may be referred to as the OFF state of the transistor M1. Similarly, a state in which the collector terminal and emitter terminal of the transistor M2 are controlled to be conductive may be referred to as the ON state of the transistor M2, and a state in which the collector terminal and emitter terminal of the transistor M2 are controlled to be non-conductive may be referred to as the OFF state of the transistor M2.

[0060] As described above, the switch circuit SW of the present embodiment includes transistors M1 and M2, and by the switching operation of the transistors M1 and M2, controls the supply of a current accompanying the propagation of the heater drive signal HC, which is a current accompanying the propagation of the rectified voltage signal WR, to the heater 90. Next, an example of a signal waveform of the drive control signal Dr output by the heater control circuit 83 will be described, including an example of the drive control signal Dr1 input to the transistor M1 and the drive control signal Dr2 input to the transistor M2.

[0061] Fig. 5 is a diagram showing an example of the drive control signal Dr1 and the drive control signal Dr2. As shown in Fig. 5, the heater control circuit 83 outputs, as the drive control signal Dr1, a pulse signal that is at a high level for a certain period every period td, and outputs, as the drive control signal Dr2, a pulse signal that is delayed by a period td / 2 with respect to the drive control signal Dr1 and is at a high level for a certain period every period td. That is, the heater control circuit 83 outputs the drive control signal Dr1 which is a pulse signal, and the drive control signal Dr2 which is a pulse signal whose phase is shifted by 180 degrees from the drive control signal Dr1.

[0062] Further, the heater control circuit 83 controls the ON-duty of the drive control signal Dr1 between 0% and 50% and controls the ON-duty of the drive control signal Dr2 between 0% and 50% based on at least one of the current detection signal Idt and the voltage detection signal Vdt. That is, the heater control circuit 83 outputs the drive control signals Dr1 and Dr2 that can be at a high level during the period td / 2 from the rising edge of the pulse signal. Here, as described above, the drive control signal Dr2 is a pulse signal whose phase is shifted by 180 degrees from the drive control signal Dr1. Therefore, as shown in FIG. 5, the heater control circuit 83 outputs the drive control signal Dr2 at a low level during the period when the drive control signal Dr1 at a high level can be output, and outputs the drive control signal Dr1 at a low level during the period when the drive control signal Dr2 at a high level can be output. That is, the heater control circuit 83 controls the transistor M2 to be in the OFF state during a period when the transistor M1 can be controlled to be in the ON state, and controls the transistor M1 to be in the OFF state during a period when the transistor M2 can be controlled to be in the ON state. In other words, the heater control circuit 83 controls the transistors M1 and M2 so that they are not in the ON state at the same time.

[0063] The switch circuit SW configured as above is controlled to be in the ON state when at least one of the transistors M1 and M2 is controlled to be in the ON state, and is controlled to be in the OFF state when the transistors M1 and M2 are controlled to be in the OFF state. Therefore, the switch circuit SW of this embodiment is controlled to be in the ON state or the OFF state according to the logic level of the drive control signal Dr1 during a period when the heater control circuit 83 can output a high-level drive control signal Dr1, and is controlled to be in the ON state or the OFF state according to the logic level of the drive control signal Dr2 during a period when the heater control circuit 83 can output a high-level drive control signal Dr2. As a result, the switch circuit SW of this embodiment operates at a frequency that is the sum of the frequency of the drive control signal Dr1 input to the transistor M1 and the frequency of the drive control signal Dr2 input to the transistor M2. At this time, the duty ratio at which the switch circuit SW is controlled to be in the ON state varies between 0% and 100%.

[0064] In the heater drive circuit 82 having the switch circuit SW configured as above, the switching frequency of each of the transistors M1 and M2 can be reduced. This allows the switching loss occurring in the transistors M1 and M2 to be reduced. In addition, in the heater drive circuit 82 having the switch circuit SW configured as above, even if the switching frequency of each of the transistors M1 and M2 is reduced, the operating frequency of the switch circuit SW can be increased in a pseudo manner. This improves the accuracy of the voltage value of the heater drive signal HC, and as a result, the accuracy of the current accompanying the propagation of the heater drive signal HC supplied to the heater 90 is improved. Therefore, the accuracy of the control of the temperature of the heater 90 is improved. Furthermore, in the heater drive circuit 82 of this embodiment, since the operating frequency of the switch circuit SW can be increased in a pseudo manner, the inductor L2 can be reduced in size, and as a result, the heater drive circuit 82 can also be reduced in size.

[0065] In the heater driving module 80 configured as above, when the switch circuit SW is controlled to the ON state, the current accompanying the propagation of the heater driving signal HC, which is the current accompanying the propagation of the rectified voltage signal WR, is fed back to the rectifier circuit 81 via the switch circuit SW. As a result, the voltage value of the heater driving signal HC rises toward the voltage value of the rectified voltage signal WR. On the other hand, when the switch circuit SW is controlled to the OFF state, the current accompanying the propagation of the heater driving signal HC, which is the current accompanying the propagation of the rectified voltage signal WR, is blocked by the switch circuit SW. As a result, the potential difference between the wiring W8 and the wiring W7 becomes smaller, and the voltage value of the heater driving signal HC decreases.

[0066] In the heater driving module 80 of this embodiment, the heater control circuit 83 compares the voltage value of the heater driving signal HC estimated based on the voltage detection signal Vdt input from the voltage detection circuit 822 with the voltage value of the heater driving signal HC that is the target output of the heater driving module 80. Then, depending on the comparison result between the voltage value of the heater driving signal HC estimated based on the voltage detection signal Vdt input from the voltage detection circuit 822 and the voltage value of the heater driving signal HC that is the target output of the heater driving module 80, the heater control circuit 83 controls the ON-duty of the drive control signal Dr that it outputs. As a result, the heater driving module 80 outputs the heater driving signal HC of a desired voltage value regardless of the voltage value of the input voltage signal Vac.

[0067] Specifically, when the voltage value of the heater drive signal HC estimated based on the voltage detection signal Vdt input to the heater control circuit 83 is smaller than the target voltage value of the heater drive signal HC, that is, when the voltage value of the heater drive signal HC input to the heater 90 is smaller than the target voltage value, the heater control circuit 83 increases the ON-Duty of the drive control signal Dr input to the switch circuit SW. This causes the voltage value of the heater drive signal HC output by the heater drive module 80 to rise toward the target voltage value.

[0068] On the other hand, when the voltage value of the heater drive signal HC estimated based on the voltage detection signal Vdt input to the heater control circuit 83 is greater than the target voltage value of the heater drive signal HC, that is, when the voltage value of the heater drive signal HC input to the heater 90 is greater than the target voltage value, the heater control circuit 83 reduces the ON-Duty of the drive control signal Dr input to the switch circuit SW. This causes the voltage value of the heater drive signal HC output by the heater drive module 80 to decrease toward the target voltage value.

[0069] As a result, the heater drive module 80 outputs the heater drive signal HC of a desired voltage value, regardless of the voltage value of the input voltage signal Vac. Therefore, even if the heater unit 2 is used in an area with a different power supply environment, such as a different commercial power supply voltage value, the risk of the change in the commercial power supply voltage value affecting the heater 90, which is a load, is reduced, and as a result, the risk of the stability of the operation of the heater 90, which is an optional unit for a liquid ejection device, is reduced.

[0070] In the liquid ejection system PS configured as above, the heater unit 2 is an example of an optional unit for a liquid ejection device that is attached to the liquid ejection device 1 for use, the voltage signal Vac is an example of a commercial power source, the heater drive signal HC is an example of a first drive power signal, the heater drive circuit 82 is an example of a first drive power output section, and the heater 90 is an example of a first drive section. The capacitor C1 of the heater drive circuit 82 is an example of a first capacitor, the capacitor C2 is an example of a second capacitor, the inductor L2 is an example of a first inductor, the diode D1 is an example of a first diode, at least one of the switch circuit SW and the transistor M1 included in the switch circuit SW is an example of a first switching element, and the transistor M2 included in the switch circuit SW is an example of a second switching element. The wiring W4 is an example of a first node, the wiring W8 is an example of a second node, the wiring W7 is an example of a third node, and the wiring W6 is an example of a fourth node.

[0071] 1.4 Effects As described above, the heater unit 2, which is an optional unit for a liquid ejection device used in the liquid ejection system PS of this embodiment, includes a rectifier circuit 81 that receives the voltage signal Vac and outputs the rectified voltage signal WR, and a heater drive signal HC that receives the rectified voltage signal WR and outputs the heater drive signal HC. The heater driving circuit 82 includes a capacitor C1, a capacitor C2, an inductor L2, a diode D1, and a transistor M1 included in a switch circuit SW, one end of the capacitor C1, a cathode terminal of the diode D1, and one end of the inductor L2 are electrically connected to a wiring W4, the other end of the inductor L2 and one end of the capacitor C2 are electrically connected to a wiring W8, the other end of the capacitor C2, the anode terminal of the diode D1, and one end of the switch circuit SW, which is a collector terminal of the transistor M1, are electrically connected to a wiring W7, and the other end of the capacitor C1 and the other end of the switch circuit SW, which is an emitter terminal of the transistor M1, are electrically connected to a wiring W6. The rectified voltage signal WR is supplied to the wiring W4, and the heater 90 has one end electrically connected to the wiring W8 and the other end electrically connected to the wiring W7.

[0072] In the heater drive circuit 82 having such a configuration, by controlling the conductive state between one end and the other end of the switch circuit SW and the conductive state between the collector terminal and the emitter terminal of the transistor M1, it is possible to output a heater drive signal HC of a constant voltage value to the heater 90 regardless of the voltage value of the input voltage signal Vac. This reduces the risk that changes in the voltage value of the commercial power supply will affect the heater 90 as a load, even if the heater unit 2 is used in an area with a different power supply environment, such as the voltage value of the commercial power supply, and as a result, reduces the risk that the stability of the operation of the heater 90, which is an optional unit for a liquid ejection device, will decrease.

[0073] In addition, in the heater unit 2, which is an optional unit for a liquid ejection device used in the liquid ejection system PS of this embodiment, the heater drive circuit 82 has a transistor M2, one end of the transistor M2, which is a collector terminal, is electrically connected to a wiring W7, and the other end of the transistor M2, which is an emitter terminal, is electrically connected to a wiring W6. That is, the transistors M1 and M2 are connected in parallel. This makes it possible to reduce the amount of current flowing through the transistors M1 and M2, and as a result, it is possible to reduce the power loss in the transistors M1 and M2.

[0074] In addition, in the heater unit 2, which is an optional unit for a liquid ejection device used in the liquid ejection system PS of this embodiment, during a period when the collector terminal, which is one end of the transistor M1, and the emitter terminal, which is the other end, of the transistor M2 are controlled to be conductive, the collector terminal, which is one end of the transistor M2, and the emitter terminal, which is the other end, of the transistor M2 are controlled to be non-conductive, and during a period when the collector terminal, which is one end of the transistor M2, and the emitter terminal, which is the other end, of the transistor M1 are controlled to be non-conductive. That is, the transistor M1 and the transistor M2 are not turned on at the same time. This makes it possible to increase the pseudo switching frequency of the switch circuit SW including the transistor M1 and the transistor M2, and as a result, it is possible to reduce the switching loss of the transistor M1 and the transistor M2.

[0075] 2. Second embodiment Next, a liquid ejection system PS of a second embodiment will be described. The liquid ejection system PS of the second embodiment differs from the liquid ejection system PS of the first embodiment in that the heater unit 2 has heaters 90a and 90b, a heater drive circuit 82a that outputs a heater drive signal HCa to the heater 90a, and a heater drive circuit 82b that outputs a heater drive signal HCb to the heater 90b. That is, in the liquid ejection system PS of the second embodiment, the heater unit 2 has a rectifier circuit 81 that receives a voltage signal Vac and outputs a rectified voltage signal WR, and a rectifier circuit 82a that receives the rectified voltage signal WR and outputs a heater drive signal HCa. a heater 90a driven by the heater drive circuit 82a, a heater drive circuit 82b receiving the rectified voltage signal WR and outputting a heater drive signal HCb, and a heater 90b driven by the heater drive circuit 82b. In describing the liquid ejection system PS of the second embodiment, the same reference numerals are used for the same components as those in the liquid ejection system PS of the first embodiment, and descriptions thereof will be simplified or omitted.

[0076] 6 shows an example of the configuration of a heater driving module 80 of a heater unit 2 included in a liquid ejection system PS of the second embodiment. The heater driving module 80 of the second embodiment has a rectifier circuit 81, heater driving circuits 82a and 82b, and a heater control circuit 83.

[0077] The rectifier circuit 81 has an inductor L1 and a diode bridge DB, as in the first embodiment, and receives a voltage signal Vac supplied between the wiring W1 and the wiring W2. The rectifier circuit 81 outputs a signal obtained by full-wave rectifying the voltage signal Vac by the diode bridge DB to the wiring W4 as a rectified voltage signal WR.

[0078] The heater driving circuit 82a includes capacitors C1a and C2a, a diode D1a, an inductor L2a, and a switch circuit SWa.

[0079] The capacitor C1a has one end electrically connected to the wiring W4 and the other end electrically connected to the wiring W6a. The diode D1a has a cathode terminal electrically connected to the wiring W4 and an anode terminal electrically connected to the wiring W7a. The inductor L2a has one end electrically connected to the wiring W4 and the other end electrically connected to the wiring W8a. The capacitor C2a has one end electrically connected to the wiring W8a and the other end electrically connected to the wiring W7a. The switch circuit SWa has one end electrically connected to the wiring W7a and the other end electrically connected to the wiring W6a. A drive control signal Dra output by the heater control circuit 83 is input to a control terminal of the switch circuit SWa.

[0080] In other words, one end of the capacitor C1a, the cathode terminal of the diode D1a, and one end of the inductor L2a are electrically connected to the wiring W4, the other end of the capacitor C1a and the other end of the switch circuit SWa are electrically connected to the wiring W6a, the anode terminal of the diode D1a, one end of the capacitor C2a, and one end of the switch circuit SWa are electrically connected to the wiring W7a, and the other end of the inductor L2a and one end of the capacitor C2a are electrically connected to the wiring W8a. The wiring W8a is electrically connected to one end of the heater 90a, and the wiring W7a is electrically connected to the other end of the heater 90a. That is, the heater driving circuit 82a outputs the voltage generated between the wiring W8a and the wiring W7a as the heater driving signal HCa.

[0081] The heater driving circuit 82a also includes a current detection circuit 821a and a voltage detection circuit 822a.

[0082] One end of the current detection circuit 821a is electrically connected to the wiring W6a, and the other end is electrically connected to the wiring W5. The current detection circuit 821a detects the current value of the current accompanying the propagation of the heater drive signal HCa, which is the current value of the current accompanying the propagation of the rectified voltage signal WR. The current detection circuit 821a generates a current detection signal Idta according to the detected current value, and outputs it to the heater control circuit 83 as a state detection signal Dta.

[0083] The voltage detection circuit 822a has one end electrically connected to the wiring W8a and the other end electrically connected to the wiring W7a. The voltage detection circuit 822a detects the voltage value of the operation signal HCa. Then, the voltage detection circuit 822a generates a voltage detection signal Vdta according to the detected voltage value, and outputs it to the heater control circuit 83 as a state detection signal Dta.

[0084] In the heater driving circuit 82a configured as described above, the capacitors C1a, C2a, diode D1a, inductor L2a, switch circuit SWa, current detection circuit 821a, and voltage detection circuit 822a correspond to the capacitors C1, C2, diode D1, inductor L2, switch circuit SW, current detection circuit 821, and voltage detection circuit 822 in the first embodiment, respectively, and perform similar operations.

[0085] The heater driving circuit 82b includes capacitors C1b and C2b, a diode D1b, an inductor L2b, and a switch circuit SWb.

[0086] The capacitor C1b has one end electrically connected to the wiring W4 and the other end electrically connected to the wiring W6b. The diode D1b has a cathode terminal electrically connected to the wiring W4 and an anode terminal electrically connected to the wiring W7b. The inductor L2b has one end electrically connected to the wiring W4 and the other end electrically connected to the wiring W8b. The capacitor C2b has one end electrically connected to the wiring W8b and the other end electrically connected to the wiring W7b. The switch circuit SWb has one end electrically connected to the wiring W7b and the other end electrically connected to the wiring W6b. A drive control signal Drb output by the heater control circuit 83 is input to a control terminal of the switch circuit SWb.

[0087] In other words, one end of the capacitor C1b, the cathode terminal of the diode D1b, and one end of the inductor L2b are electrically connected to the wiring W4, the other end of the capacitor C1b and the other end of the switch circuit SWb are electrically connected to the wiring W6b, the anode terminal of the diode D1b, one end of the capacitor C2b, and one end of the switch circuit SWb are electrically connected to the wiring W7b, and the other end of the inductor L2b and one end of the capacitor C2b are electrically connected to the wiring W8b. The wiring W8b is electrically connected to one end of the heater 90b, and the wiring W7b is electrically connected to the other end of the heater 90b. That is, the heater driving circuit 82b outputs the voltage generated between the wiring W8b and the wiring W7b as the heater driving signal HCb.

[0088] The heater driving circuit 82b includes a current detection circuit 821b and a voltage detection circuit 822b.

[0089] One end of the current detection circuit 821b is electrically connected to the wiring W6b, and the other end is electrically connected to the wiring W5. The current detection circuit 821b detects the current value of the current accompanying the propagation of the heater drive signal HCb, which is the current value of the current accompanying the propagation of the rectified voltage signal WR. The current detection circuit 821b then generates a current detection signal Idtb according to the detected current value, and outputs it to the heater control circuit 83 as a state detection signal Dtb.

[0090] The voltage detection circuit 822b has one end electrically connected to the wiring W8b and the other end electrically connected to the wiring W7b. The voltage detection circuit 822b detects the voltage value of the heater drive signal HCb supplied to the heater 90b. The voltage detection circuit 822b then generates a voltage detection signal Vdtb according to the detected voltage value and outputs it to the heater control circuit 83 as a state detection signal Dtb.

[0091] In the heater driving circuit 82b configured as above, the capacitors C1b, C2b, the diode D1b, the inductor L2b, the switch circuit SWb, the current detection circuit 821b, and the voltage detection circuit 822b are the same as those of the capacitors C1 and C2 in the first embodiment. , a diode D1, an inductor L2, a switch circuit SW, a current detection circuit 821, and a voltage detection circuit 822, and perform the same operations.

[0092] The heater control circuit 83 generates a drive control signal Dra based on the current detection signal Idta input from the current detection circuit 821a and the voltage detection signal Vdta input from the voltage detection circuit 822a, and outputs the drive control signal Drb to the switch circuit SWa. The heater control circuit 83 also generates a drive control signal Drb based on the current detection signal Idtb input from the current detection circuit 821b and the voltage detection signal Vdtb input from the voltage detection circuit 822b, and outputs the drive control signal Drb to the switch circuit SWb.

[0093] The heater unit 2 of the second embodiment configured as above achieves the same effects as the heater unit 2 of the first embodiment.

[0094] In addition, in the heater unit 2 of the second embodiment, the heater control circuit 83 outputs the drive control signal Dra and the drive control signal Drb at different frequencies. That is, in the heater unit 2 of the second embodiment, one end and the other end of the switch circuit SWa are repeatedly turned on and off in a switching period Fsw1 defined by the frequency of the drive control signal Dra, and one end and the other end of the switch circuit SWb are repeatedly turned on and off in a switching period Fsw2 defined by the frequency of the drive control signal Drb. At this time, the frequencies of the switching period Fsw1 and the switching period Fsw2 are different.

[0095] This reduces the possibility that the switching noise generated by the switching operation of the switch circuit SWa and the switching noise generated by the switching operation of the switch circuit SWb will interfere with each other, even if the heater unit 2 has, as the heater drive circuits 82, a heater drive circuit 82a that outputs a heater drive signal HCa to the heater 90a and a heater drive circuit 82b that outputs a heater drive signal HCb to the heater 90b as the multiple heater drive circuits 82, as in the heater unit 2 of the second embodiment. As a result, even if the heater unit 2 has, as the multiple heater drive circuits 82, a heater drive circuit 82a that outputs a heater drive signal HCa to the heater 90a and a heater drive circuit 82b that outputs a heater drive signal HCb to the heater 90b, the possibility that the stability of the operation of the heater unit 2 will decrease is reduced.

[0096] In the second embodiment of the liquid ejection system PS configured as described above, the heater unit 2 is an example of an optional unit for a liquid ejection device, the voltage signal Vac is an example of a commercial power source, the heater drive signal HCa is an example of a first drive power signal, the heater drive signal HCb is an example of a second drive power signal, the heater drive circuit 82a is an example of a first drive power output section, the heater drive circuit 82b is an example of a second drive power output section, the heater 90a is an example of a first drive section, and the heater 90b is an example of a second drive section. In addition, the capacitor C1a in the heater driving circuit 82a is an example of a first capacitor, the capacitor C2a is an example of a second capacitor, the inductor L2a is an example of a first inductor, the diode D1a is an example of a first diode, the switch circuit SWa and at least one of the transistor M1 included in the switch circuit SWa are an example of a first switching element, the capacitor C1b in the heater driving circuit 82b is an example of a third capacitor, the capacitor C2b is an example of a fourth capacitor, the inductor L2b is an example of a second inductor, the diode D1b is an example of a second diode, and the switch circuit SWb and at least one of the transistor M1 included in the switch circuit SWb are an example of a third switching element. In addition, the wiring W4 is an example of a first node and a fifth node, the wiring W8a is an example of a second node, the wiring W7a is an example of a third node, the wiring W6a is an example of a fourth node, the wiring W8b is an example of a sixth node, the wiring W7b is an example of a seventh node, and the wiring W6b is an example of an eighth node. The switching period Fsw1 is an example of a first switching period, and the switching period Fsw2 is an example of a second switching period.

[0097] Although the embodiments and modifications have been described above, the present invention is not limited to these embodiments, and can be embodied in various forms without departing from the spirit of the present invention. For example, the above embodiments can be appropriately combined.

[0098] The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations with the same functions, methods and results, or configurations with the same purpose and effect). The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that achieve the same effects as the configurations described in the embodiments or that can achieve the same purpose. The present invention also includes configurations in which publicly known technology is added to the configurations described in the embodiments.

[0099] The following can be derived from the above-described embodiment.

[0100] One aspect of the optional unit for a liquid ejection device is as follows: An optional unit for a liquid ejection device that is attached to the liquid ejection device and used, a rectifier circuit that receives a commercial power supply and outputs a rectified voltage signal; a first drive power output circuit that receives the rectified voltage signal and outputs a first drive power signal; a first drive unit that is driven by the first drive power signal; Equipped with The first driving power output circuit includes: a first capacitor, a second capacitor, a first inductor, a first diode, and a first switching element; one end of the first capacitor, a cathode terminal of the first diode, and one end of the first inductor are electrically connected to a first node; the other end of the first inductor and one end of the second capacitor are electrically connected to a second node; the other end of the second capacitor, the anode terminal of the first diode, and one end of the first switching element are electrically connected to a third node; the other end of the first capacitor and the other end of the first switching element are electrically connected to a fourth node; the rectified voltage signal is provided to the first node; The first driving unit has one end electrically connected to the second node and the other end electrically connected to the third node.

[0101] According to this optional unit for a liquid ejector, the voltage value of the first driving power signal can be controlled by the operation of the first switching element, regardless of the voltage value of the input commercial power source. Therefore, when this optional unit for a liquid ejector is used in an area with a different power supply environment, such as the voltage value of the commercial power source, even if the voltage value of the commercial power source changes, the risk of affecting the operation of the first driving unit, which is the load, is reduced. As a result, the risk of the stability of the operation of the optional unit for a liquid ejector being reduced is reduced.

[0102] In one embodiment of the optional unit for the liquid ejection device, the first driving power output circuit has a second switching element; one end of the second switching element is electrically connected to the third node; The other end of the second switching element may be electrically connected to the fourth node.

[0103] According to this optional unit for a liquid ejection device, the second switching element is provided in parallel with the first switching element, thereby making it possible to reduce losses in the first switching element and the second switching element that accompany the propagation of the first drive power signal.

[0104] In one embodiment of the optional unit for the liquid ejection device, During a period in which one end and the other end of the first switching element are controlled to be conductive, one end and the other end of the second switching element are controlled to be non-conductive, In a period in which one end and the other end of the second switching element are controlled to be conductive, one end and the other end of the first switching element may be controlled to be non-conductive.

[0105] According to this optional unit for a liquid ejection device, a second switching element is provided in parallel with the first switching element, and the first switching element and the second switching element alternately perform switching operations, thereby reducing switching losses in the first switching element and the second switching element.

[0106] In one embodiment of the optional unit for the liquid ejection device, a second driving power output circuit that receives the rectified voltage signal and outputs a second driving power signal; a second drive unit that is driven by the second drive power signal; Equipped with The second driving power output circuit includes: a third capacitor, a fourth capacitor, a second inductor, a second diode, and a third switching element; one end of the third capacitor, the cathode terminal of the second diode, and one end of the second inductor are electrically connected to a fifth node; the other end of the second inductor and one end of the fourth capacitor are electrically connected to a sixth node; the other end of the fourth capacitor, the anode terminal of the second diode, and one end of the third switching element are electrically connected to a seventh node; the other end of the third capacitor and the other end of the third switching element are electrically connected to an eighth node; the rectified voltage signal is provided to the fifth node; The second driving section may have one end electrically connected to the sixth node and the other end electrically connected to the seventh node.

[0107] According to this optional unit for a liquid ejector, even if a second driving power output circuit is provided in addition to the first driving power output circuit, the voltage values ​​of the first driving power signal and the second driving power signal can be controlled by the operation of the first switching element and the third switching element, regardless of the voltage value of the input commercial power source. Therefore, even if this optional unit for a liquid ejector is used in an area with a different power supply environment, such as the voltage value of the commercial power supply, and the voltage value of the commercial power supply changes, there is a reduced risk of affecting the operation of the first driving section and the second driving section, which are the loads. As a result, there is a reduced risk of the stability of the operation of the optional unit for a liquid ejector being reduced.

[0108] In one embodiment of the optional unit for the liquid ejection device, one end and the other end of the first switching element are repeatedly turned on and off in a first switching period; one end and the other end of the third switching element are repeatedly turned on and off in a second switching period; The first switching period and the second switching period may have a different frequency.

[0109] According to this optional unit for a liquid ejector, the switching frequency of the first switching element included in the first driving power output circuit is different from the switching frequency of the third switching element included in the second driving power output circuit, which reduces the possibility of mutual interference between the switching noise caused by the switching of the first switching element and the switching noise caused by the switching of the third switching element, thereby further reducing the possibility of a decrease in the stability of the operation of the optional unit for a liquid ejector.

[0110] In one embodiment of the optional unit for the liquid ejection device, The first driving unit may be a heater. [Explanation of symbols]

[0111] 1...liquid ejection device, 2...heater unit, 10...control unit, 12...power supply voltage output circuit, 20...head unit, 21...carriage, 22...print head, 30...movement unit, 31...carriage motor, 32...endless belt, 33...linear encoder, 40...transport unit, 41...transport motor, 42...transport roller, 43...platen, 50...head drive circuit, 52...reference voltage output circuit, 60...piezoelectric element, 70...ink container, 80...heater drive module, 81...rectifier circuit, 82, 82a, 82b...heater drive circuit, 83... heater control circuit, 90, 90a, 90b... heater, 100... control circuit, 200... drive signal selection circuit, 821, 821a, 821b... current detection circuit, 822, 822a, 822b... voltage detection circuit, C1, C1a, C1b, C2, C2a, C2b... capacitor, D1, D1a, D1b... diode, L1, L2, L2a, L2b... inductor, M1, M2... transistor, P... medium, PS... liquid ejection system, SW, SWa, SWb... switch circuit, W1 to W8, W6a, W6b, W7a, W7b, W8a, W8b... wiring

Claims

1. An optional unit for a liquid ejection device that is attached to the liquid ejection device and used, a rectifier circuit that receives a commercial power supply and outputs a rectified voltage signal; a first drive power output circuit that receives the rectified voltage signal and outputs a first drive power signal; a first drive unit that is driven by the first drive power signal; Equipped with The first driving power output circuit includes: a first capacitor, a second capacitor, a first inductor, a first diode, and a first switching element; one end of the first capacitor, a cathode terminal of the first diode, and one end of the first inductor are electrically connected to a first node; the other end of the first inductor and one end of the second capacitor are electrically connected to a second node; the other end of the second capacitor, the anode terminal of the first diode, and one end of the first switching element are electrically connected to a third node; the other end of the first capacitor and the other end of the first switching element are electrically connected to a fourth node; the rectified voltage signal is provided to the first node; the first driving unit has one end electrically connected to the second node and the other end electrically connected to the third node; 1 is a block diagram showing an optional unit for a liquid ejection device according to the present invention;

2. the first driving power output circuit has a second switching element; one end of the second switching element is electrically connected to the third node; The other end of the second switching element is electrically connected to the fourth node.

2. The option unit for a liquid ejection device according to claim 1.

3. During a period in which one end and the other end of the first switching element are controlled to be conductive, one end and the other end of the second switching element are controlled to be non-conductive, During a period in which one end and the other end of the second switching element are controlled to be conductive, one end and the other end of the first switching element are controlled to be non-conductive.

3. The option unit for a liquid ejection device according to claim 2.

4. a second drive power output circuit that receives the rectified voltage signal and outputs a second drive power signal; a second drive unit that is driven by the second drive power signal; Equipped with The second driving power output circuit includes: a third capacitor, a fourth capacitor, a second inductor, a second diode, and a third switching element; one end of the third capacitor, the cathode terminal of the second diode, and one end of the second inductor are electrically connected to a fifth node; the other end of the second inductor and one end of the fourth capacitor are electrically connected to a sixth node; the other end of the fourth capacitor, the anode terminal of the second diode, and one end of the third switching element are electrically connected to a seventh node; the other end of the third capacitor and the other end of the third switching element are electrically connected to an eighth node; the rectified voltage signal is provided to the fifth node; the second driving unit has one end electrically connected to the sixth node and the other end electrically connected to the seventh node; 2. The option unit for a liquid ejection device according to claim 1.

5. one end and the other end of the first switching element are repeatedly turned on and off in a first switching period; one end and the other end of the third switching element are repeatedly turned on and off in a second switching period; The frequency of the first switching period is different from the frequency of the second switching period.

5. The option unit for a liquid ejection device according to claim 4.

6. The first driving unit is a heater.

6. The option unit for a liquid ejection device according to claim 1,

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