JP7102892B2 - Device that discharges liquid - Google Patents

Description

The present invention relates to a device that discharges a liquid.

In an inkjet type image forming apparatus, for example, as in Patent Document 1, a technique for providing a damping function in a sub-tank to reduce pressure fluctuation is disclosed.

However, in the configuration of Patent Document 1, since the pressure fluctuation of a plurality of heads is damped in one tank, the effect of reducing the pressure fluctuation is not sufficient.

An object of the present invention is to provide a device for discharging a liquid that more efficiently reduces pressure fluctuations.

In order to achieve such an object, the device for discharging the liquid according to the present invention is via a plurality of liquid discharge heads for discharging the liquid, a plurality of head tanks through which the liquid passes through the liquid discharge head, and the liquid discharge head. The head tank includes a liquid chamber for storing the liquid and a gas chamber adjacent to the liquid chamber via a wall member, and the head tank includes a plurality of the liquid discharges . For each of the heads, a first head tank provided in a liquid path leading to the liquid supply port to the liquid discharge head and a second head leading to the liquid discharge port provided in the liquid discharge head. The tank is provided, and the gas chamber of the first head tank communicates with the gas chamber of the other first head tank .

According to the present invention, pressure fluctuation can be reduced more efficiently.

It is a schematic explanatory drawing of the printing apparatus which is an example of the apparatus which discharges a liquid which concerns on this invention. It is a plane explanatory view which shows an example of a head unit. It is an external perspective explanatory view which shows an example of a liquid discharge head. It is sectional drawing in the direction orthogonal to the nozzle arrangement direction of a liquid discharge head (the longitudinal direction of a liquid chamber). It is a piping explanatory drawing of the liquid circulation mechanism in the apparatus which discharges a liquid. It is a functional block diagram of the control part of the apparatus which discharges a liquid. It is explanatory drawing which shows an example of the structure of the head tank, is (a) front view, (b) AA sectional view. It is explanatory drawing of the connection form of the head tank shown in FIG. It is explanatory drawing which shows the other example of the structure of the head tank, (a) front view, (b) AA sectional view. (A) An explanatory diagram of the behavior of the diaphragm and the detection area of the photosensor, and (b) an explanatory diagram of the drive of the air pump. It is explanatory drawing of the connection form of the head tank shown in FIG. It is explanatory drawing which shows the other example of the structure of the head tank, (a) front view, (b) AA sectional view. It is explanatory drawing of the connection form of the head tank shown in FIG. It is explanatory drawing in another example of the connection form of a head tank. It is explanatory drawing in another example of the connection form of a head tank. It is explanatory drawing in another example of the connection form of a head tank.

Hereinafter, the configuration according to the present invention will be described in detail based on the embodiments shown in FIGS. 1 to 16.

[First Embodiment]
The device for discharging the liquid according to the present embodiment includes a plurality of liquid discharge heads (liquid discharge head 100) for discharging the liquid, and a plurality of head tanks (head tank 300) for passing the liquid to the liquid discharge heads, respectively. The head tank includes a liquid chamber (liquid chamber 304) for storing liquid and a gas chamber (air chamber 305) adjacent to the liquid chamber via a wall member (diaphragm 302), and the gas chamber of the head tank is provided. , It communicates with the gas chamber of other head tanks.

Further, in the present embodiment, the liquid path through which the liquid circulates through the liquid discharge head (liquid discharge head 100) and the liquid supply port (supply port) to the liquid discharge head for each of the plurality of liquid discharge heads. A first head tank (first head tanks 300a, 300c, 300e) provided in the liquid path leading to 171) and a second head tank leading to a liquid discharge port (discharge port 181) provided in the liquid discharge head. (Second head tanks 300b, 300d, 300f), and the gas chamber of the first head tank communicates with the gas chamber of another first head tank.
Further, in the present embodiment, the gas chamber of the second head tank communicates with the gas chamber of another second head tank.
In addition, the code in parentheses and the application example are shown.

(Printing equipment)
First, a printing device, which is an embodiment of a device for discharging a liquid according to the present invention, will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic explanatory view of a printing apparatus, and FIG. 2 is a plan explanatory view of an example of a head unit of the printing apparatus.

The printing device 1000, which is a device for discharging this liquid, includes a carry-in means 1 for carrying in the continuum 10, a guide transport means 3 for guiding and transporting the continuum 10 carried in from the carry-in means 1 to the printing means 5, and a continuous body. It is provided with a printing means 5 for printing to form an image by ejecting a liquid with respect to 10, a drying means 7 for drying the continuum 10, a discharging means 9 for discharging the continuum 10, and the like.

The continuum 10 is sent out from the original winding roller 11 of the carrying-in means 1, guided and conveyed by the rollers of the carrying-in means 1, the guiding and transporting means 3, the drying means 7, and the discharging means 9, and is guided and conveyed by the winding roller 91 of the discharging means 9. It is wound up at.

The continuum 10 is conveyed on the transfer guide member 59 in the printing means 5 facing the head unit 50 and the head unit 55, an image is formed by the liquid discharged from the head unit 50, and the continuous body 10 is discharged from the head unit 55. Post-treatment is performed with the treatment liquid to be treated.

Here, the head unit 50 is, for example, a full-line head array 51K, 51C, 51M, 51Y for four colors from the upstream side in the medium transport direction (hereinafter, referred to as "head array 51" when the colors are not distinguished). Is placed.

Each head array 51 is a liquid discharging means, and discharges black K, cyan C, magenta M, and yellow Y liquids to the conveyed continuum 10. The types and numbers of colors are not limited to this.

The head array 51 is, for example, as shown in FIG. 2, in which liquid discharge heads (hereinafter, also simply referred to as heads) 100 are arranged in a staggered pattern on the base member 52, but the head array 51 is not limited to this.

(Liquid discharge head)
Next, an example of the liquid discharge head will be described with reference to FIGS. 3 and 4. FIG. 3 is an external perspective explanatory view of the liquid discharge head, and FIG. 4 is a cross-sectional explanatory view of the head in a direction orthogonal to the nozzle arrangement direction (liquid chamber longitudinal direction).

In this liquid discharge head, a nozzle plate 101, a flow path plate 102, and a diaphragm member 103 as a wall surface member are laminated and joined. A piezoelectric actuator 111 that displaces the vibration region (diaphragm) 130 of the diaphragm member 103, a common liquid chamber member 120 that also serves as a frame member of the head, and a cover 129 are provided. The portion composed of the flow path plate 102 and the diaphragm member 103 is referred to as a flow path member 140.

The nozzle plate 101 has a plurality of nozzles 104 for discharging a liquid.

The flow path plate 102 penetrates the nozzle 104 as an individual liquid chamber 106 that communicates with the nozzle communication passage 105 via a nozzle communication passage 105, a supply-side fluid resistance portion 107 that communicates with the individual liquid chamber 106, and a liquid introduction portion 108 that communicates with the supply-side fluid resistance portion 107. It forms holes and grooves. The nozzle communication passage 105 is a flow path that connects to the nozzle 104 and the individual liquid chamber 106, respectively. Further, the liquid introduction portion 108 communicates with the common liquid chamber 110 on the supply side through the opening 109 of the diaphragm member 103.

The diaphragm member 103 has a deformable vibration region 130 that forms the wall surface of the individual liquid chamber 106 of the flow path plate 102. Here, the diaphragm member 103 has a two-layer structure (not limited), and is formed of a first layer for forming a thin-walled portion from the flow path plate 102 side and a second layer for forming a thick-walled portion. A deformable vibration region 130 is formed in a portion corresponding to the individual liquid chamber 106.

A piezoelectric actuator 111 including an electromechanical conversion element as a driving means (actuator means, pressure generating means) for deforming the vibrating region 130 of the vibrating plate member 103 on the side opposite to the individual liquid chamber 106 of the vibrating plate member 103. Is placed.

In the piezoelectric actuator 111, the piezoelectric member joined on the base member 113 is grooved by half-cut dicing to form a required number of columnar piezoelectric elements 112 in a comb-teeth shape at predetermined intervals.

Then, the piezoelectric element 112 is joined to the convex portion 130a, which is an island-shaped thick portion formed in the vibration region 130 of the diaphragm member 103. Further, a flexible wiring member 115 is connected to the piezoelectric element 112.

The common liquid chamber member 120 forms a supply side common liquid chamber 110 and a discharge side common liquid chamber 150. The supply-side common liquid chamber 110 is connected to the supply port 171 and the discharge-side common liquid chamber 150 is connected to the discharge port 181.

Here, the common liquid chamber member 120 is composed of a first common liquid chamber member 121 and a second common liquid chamber member 122, and the first common liquid chamber member 121 is placed on the diaphragm member 103 side of the flow path member 140. The second common liquid chamber member 122 is laminated and joined to the first common liquid chamber member 121.

The first common liquid chamber member 121 forms a downstream common liquid chamber 110A, which is a part of the supply side common liquid chamber 110 leading to the liquid introduction portion 108, and a discharge side common liquid chamber 150 leading to the discharge flow path 151. ing. Further, the second common liquid chamber member 122 forms the upstream side common liquid chamber 110B which is the rest of the supply side common liquid chamber 110.

Further, the flow path plate 102 is formed with a discharge flow path 151 along the surface direction of the flow path plate 102 that communicates with each individual liquid chamber 106 via the nozzle communication passage 105. The discharge flow path 151 leads to the common liquid chamber 150 on the discharge side.

In this liquid discharge head, for example, by lowering the voltage applied to the piezoelectric element 112 from the reference potential (intermediate potential), the piezoelectric element 112 contracts, and the vibration region 130 of the vibrating plate member 103 is pulled to obtain the volume of the individual liquid chamber 106. As the liquid expands, the liquid flows into the individual liquid chamber 106.

After that, the voltage applied to the piezoelectric element 112 is increased to extend the piezoelectric element 112 in the stacking direction, and the vibration region 130 of the vibrating plate member 103 is deformed in the direction toward the nozzle 104 to contract the volume of the individual liquid chamber 106. As a result, the liquid in the individual liquid chamber 106 is pressurized, and the liquid is discharged from the nozzle 104.

Further, the liquid that is not discharged from the nozzle 104 passes through the nozzle 104 and is discharged from the discharge flow path 151 to the discharge side common liquid chamber 150, and is again discharged from the discharge side common liquid chamber 150 to the supply side common liquid chamber 110 through an external circulation path. Be supplied.

The method of driving the head is not limited to the above example (pull-pushing), and pulling or pushing may be performed depending on the driving waveform.

(Liquid circulation mechanism)
Next, the liquid circulation mechanism in the device for discharging the liquid according to the present embodiment will be described with reference to FIG. FIG. 5 is an explanatory view of piping of the liquid supply mechanism. A plurality of circulatory heads 100 are arranged in a line in the width direction of the continuum 10 to circulate the liquid.

The liquid circulation mechanism 200 includes a main tank 201 (liquid tank), a first sub tank 220 (pressurized sub tank), a second sub tank 210 (decompression sub tank), which is a liquid storage means for storing the liquid discharged from the head 100. It includes a third sub-tank 290, a first liquid feeding pump 202, a second liquid feeding pump 203, and a third liquid feeding pump 209.

Further, the first manifold 230 and the second manifold 240 through which the plurality of heads 100 communicate, the first head tank 300a and the second head tank 300b for each head 100, and the degassing means for removing the dissolved gas in the liquid. The degassing device 260 is provided. Details of the first head tank 300a and the second head tank 300b (hereinafter, referred to as a head tank 300 (buffer tank) when not distinguished) will be described later.

Here, the third sub-tank 290 is arranged between the first sub-tank 220 and the second sub-tank 210, and the third sub-tank 290 is connected to the third sub-tank 290 by the third liquid feed pump 209 from the main tank 201 via the liquid path 289 including the filter 205. Liquid is sent (supplied).

The third sub-tank 290 includes a liquid level detecting means 291 and a solenoid valve 292 that constitutes an atmospheric opening mechanism that opens the inside to the atmosphere.

The third sub-tank 290 and the second sub-tank 210 are connected to each other through a liquid path 283, and a second liquid feeding pump 203 is provided in the liquid path 283. Further, the third sub tank 290 and the second sub tank 210 are connected through a backflow liquid path 285, and a solenoid valve 287 is provided in the backflow liquid path 285.

The second sub-tank 210 has a gas chamber 210a, and has a configuration in which a liquid and a gas coexist. The second sub-tank 210 is provided with a liquid level detecting means 211 for detecting the liquid level and a solenoid valve 212 as an atmospheric opening mechanism for opening the inside to the atmosphere.

The third sub-tank 290 and the first sub-tank 220 are connected to each other through a liquid path 284, and a first liquid feeding pump 202 is provided in the liquid path 284. Further, the third sub tank 290 and the first sub tank 220 are connected through a backflow liquid path 286, and a solenoid valve 288 is provided in the backflow liquid path 286.

The first sub-tank 220 has a gas chamber 220a, and has a configuration in which a liquid and a gas coexist. The first sub-tank 220 is provided with a liquid level detecting means 221 for detecting the liquid level and a solenoid valve 222 as an air opening mechanism for opening the inside to the atmosphere.

The first sub-tank 220 is connected to the first manifold 230 through a liquid path 281 including a degassing device 260 and a filter 261.

The first manifold 230 communicates with the supply port 171 (supply port) side of the head 100 via the supply path 231. The supply path 231 is connected to the supply port 171 of the head 100 via the first head tank 300a. The supply path 231 is provided with a solenoid valve 232 that opens and closes the path upstream of the first head tank 300a. The solenoid valve 232 is provided according to the number of heads 100, and can be individually opened and closed. Further, the pressure sensor 233 is provided on the first manifold 230.

The second sub tank 210 is connected to the second manifold 240 via the liquid path 282.

The second manifold 240 is connected to the discharge port 181 (discharge port) side of the head 100 via the discharge path 241. The discharge path 241 is connected to the discharge port 181 of the head 100 via the second head tank 300b. The discharge path 241 is provided with a solenoid valve 242 that opens and closes the path downstream of the second head tank 300b. The solenoid valve 242 is provided according to the number of heads 100, and can be individually opened and closed. A pressure sensor 243 is provided on the second manifold 240.

Further, a bypass path 270 is provided through the first manifold 230 and the second manifold 240. The bypass path 270 is provided with a solenoid valve 271 on the first manifold 230 side and a solenoid valve 272 on the second manifold 240 side.

Here, from the third sub tank 290, the third sub tank 290 passes through the liquid path 284, the first sub tank 220, the liquid path 281, the deaerator 260, the first manifold 230, the head 100, the second manifold 240, and the second sub tank 210. A circulation route is constructed by the route returning to.

Further, the solenoid valve 232,242,271,272 blocks the space between the head 100 and the circulation path, and the bypass path 270 forms a part of the circulation path, and the bypass path 270 and the circulation path are separated from each other. The space is cut off, and the head 100 constitutes a means for switching to a second path forming a part of the circulation path.

That is, by closing the solenoid valves 232 and 242 and opening the solenoid valves 271,272, the bypass path 270 becomes a part of the circulation path, and the head 100 forms a first path that does not become a part of the circulation path.

Further, by opening the solenoid valves 232 and 242 and closing the solenoid valves 271,272, a second path is configured in which the head 100 becomes a part of the circulation path and the bypass path 270 does not become a part of the circulation path.

Further, the first sub-tank 220, the second sub-tank 210, the first liquid feeding pump 202, and the second liquid feeding pump 203 constitute a means for generating a pressure for the liquid to circulate in the circulation path.

Next, the supply and circulation of the liquid will be described.
(1) Liquid transfer from the main tank 201 to the third sub tank 290 When the liquid level detecting means 291 detects a lack of liquid, the third liquid pump 209 is used to transfer the liquid from the main tank 201 to the third sub tank 289 via the liquid path 289. The liquid level detecting means 291 supplies the liquid to the third sub tank 290 until the liquid level is full.

(2) Liquid transfer from the third sub tank 290 to the first sub tank 220 The liquid is supplied from the third sub tank 290 to the first sub tank 220 via the liquid path 284 by using the first liquid supply pump 202.

(3) Liquid transfer from the second sub tank 210 to the third sub tank 290 The liquid is supplied from the second sub tank 210 to the third sub tank 290 via the liquid path 283 by using the second liquid supply pump 203.

(4) Liquid feeding from the first sub tank 220 to the head 100 and from the head 100 to the second sub tank 210 The first liquid feeding pump 202 is used until the pressure sensor 233 reaches the target pressure (for example, the pressure to be pressurized). The first sub tank 220 is supplied with ink, and the second liquid feeding pump 203 is used to supply liquid to the third sub tank 290 until the pressure sensor 243 reaches a target pressure (for example, a pressure that becomes a negative pressure). A differential pressure is generated between the sub tank 220 and the second sub tank 210. Depending on this differential pressure, the filter 261 and the deaerator 260, the first manifold 230, the plurality of supply paths 231 and the plurality of first head tanks 300a and the plurality of heads are sent from the first sub tank 220 via the liquid path 281. Liquid can be circulated to the second sub tank 210 via 100, a plurality of discharge paths 241, a plurality of second head tanks 300b, a second manifold 240, and a liquid path 282. At this time, the solenoid valves 232 and 242 are open, and the solenoid valves 271,272 are closed.

On the other hand, when the solenoid valves 232 and 242 are closed and the solenoid valves 271,272 are open, the first liquid feed pump 202 and the second liquid feed pump 203 are driven to generate a differential pressure. The liquid from the first sub tank 220 to the second sub tank 210 via the filter 261 and the deaerator 260, the first manifold 230, the bypass path 270, the second manifold 240, and the liquid path 282 via the liquid path 281. Circulation is possible.

The liquid level detecting means 221, 211, 291 provided in each sub tank is not particularly limited, and for example, the presence or absence of liquid is detected by a float type, or the voltage detected by using at least two or more electrode pins. A method of detecting the presence or absence of a liquid, a liquid level detection method using a laser, or the like can be used according to the output of.

Further, each sub-tank is provided with solenoid valves 212, 222, 292 as an atmosphere opening mechanism, and by controlling these, it is possible to communicate each sub-tank with the atmosphere.

Next, the roles of the gas chamber 220a of the first sub-tank 220 and the gas chamber 210a of the second sub-tank 210 will be described. In the gas chamber 220a and the gas chamber 210a, the liquid level of the liquid is in contact with, for example, air.

Here, when the pressurized state of air is generated in the first sub tank 220 and the depressurized state of air is generated in the second sub tank 210, the gas is compressible, so that pressure can be stored. The air in this case is considered to be the same as the capacitor component when expressed by an equivalent electric circuit, and can also be expressed as compliance (elastic component).

When the first sub-tank 220 and the third sub-tank 290, the first liquid-feeding pump 202 and the second liquid-feeding pump 203 communicating with the second sub-tank 210 and the third sub-tank 290 are driven, a pressure change (pulsation) occurs. .. This pressure change is transmitted through the liquid path, and when it is transmitted to the nozzle meniscus, it leads to the overflow of liquid and the entrainment of air bubbles.

Therefore, compliance (elastic component) is required to suppress this. In general, air has a compressible property and is therefore a compliance component. By having the gas chambers 220a and 210a, the pressure change (pulsation) can be suppressed.

(Control unit)
Next, the outline of the control unit of the device for discharging the liquid will be described with reference to FIG. FIG. 6 is a functional block diagram of the control unit.

The control unit 500 includes a CPU 501 that controls the entire device, a ROM 502 that stores fixed data such as various programs including programs executed by the CPU 501, and a main control unit 500A that includes a RAM 503 that temporarily stores image data and the like. ing.

The control unit 500 includes a rewritable non-volatile memory 504 (NVRAM) for holding data even while the power of the device is cut off. The control unit 500 includes an ASIC 505 that processes various signal processes for image data, image processing that performs sorting, and other input / output signals for control, and also communicates with the printer driver 590 via the host I / F 506. Send and receive data with.

The control unit 500 includes a print control unit 508 including a data transfer means for driving and controlling each head 100 of the head unit 50, a drive signal generating means, and a bias voltage output means, and a drive IC for driving each head 100 ( Here, it is referred to as a "head driver".) 509 is provided.

The control unit 500 includes a solenoid valve control unit 510 that drives and controls the solenoid valves 232,242,271,272 and the solenoid valves 212,222,292,287,288 of the solenoid valve group 550.

The control unit 500 includes a supply system control unit 511 that drives and controls the third liquid feed pump 209.

The control unit 500 includes a pressure system control unit 512 that drives and controls the first liquid feed pump 202 and the second liquid feed pump 203.

The control unit 500 has an I / O unit 513. The I / O unit 513 can process various sensor information, and acquires the detection results of the pressure sensors 233 and 243 and the information from the various sensor groups 515. Then, the information necessary for controlling the device is extracted and used for control by the print control unit 508, the solenoid valve control unit 510, the supply system control unit 511, the pressure system control unit 512, and the like.

An operation panel 514 for inputting and displaying information necessary for this device is connected to the control unit 500.

(Head tank)
Next, the first head tanks 300a, 300c, 300e and the second head tanks 300b, 300d, 300f connected in the vicinity of the head 100 will be described. In the following embodiment, the case where the liquid circulation mechanism 200 includes both the first head tank and the second head tank will be described as an example, but the liquid circulation mechanism 200 includes only one of the head tanks. May be good.

7A and 7B are explanatory views of the configuration of the head tank 300 in the liquid circulation mechanism 200, where FIG. 7A is a front view and FIG. 7B is a sectional view taken along the line AA of FIG. 7A. As shown in FIG. 7, the head tank 300 is a manifold (first manifold 230 in the case of the first head tanks 300a, 300c, 300e, second manifold 240 in the case of the second head tanks 300b, 300d, 300f). A liquid chamber is provided with a liquid port 306a to which a tube connected to is connected and a liquid port 306b to which a tube connected to a head 100 is connected, and one surface is formed of a diaphragm 302 (flexible member) made of a flexible material. It is equipped with 304.

The space outside the diaphragm 302 is covered with a casing 303, and an air chamber 305 is formed. The casing 303 is provided with two air ports 307a and 307b (referred to as air ports 307 when not distinguished) communicating with the air chamber 305. In FIG. 7B, the diaphragm 302 shown by the solid line shows a state in which the liquid chamber 304 expands and becomes convex toward the air chamber 305, and the diaphragm 302 shown by the dotted line shows the liquid chamber 304 having the liquid chamber 304. It shows a state in which it has shrunk and becomes concave toward the liquid chamber 304 side.

FIG. 8 shows a connection mode of the head tank 300 in the liquid circulation mechanism 200 according to the present embodiment. FIG. 8 is an explanatory view obtained by cutting out a part of the piping explanatory view shown in FIG. 5, and is an explanatory view of a liquid circulation path from the first manifold 230 to the head 100 and from the head 100 to the second manifold 240. Although the head 100 shows three examples in FIG. 8, it goes without saying that the number of heads is not limited to this.
Further, in FIG. 8, the first head tanks 300a, 300c, 300e are shown as the first head tank, and the second head tanks 300b, 300d, 300f are shown as the second head tank. However, it is not limited to this.

The head 100 is a liquid circulation type head 100 shown in FIG. 4, and the first head tank 300a is connected to the supply side common liquid chamber 110, and the second head tank 300b is connected to the discharge side common liquid chamber 150. Be connected. Further, the first head tank 300a is connected to the first manifold 230, and the second head tank 300b is connected to the second manifold 240.

In the liquid circulation path shown in FIG. 8, the flow of the liquid when the droplets are ejected from the head 100 to form a pattern is the first manifold 230, the first head tank 300a (or the first head tank 300c, 300e). ), The head 100, the second head tank 300b (or the second head tanks 300d, 300f), and the second manifold 240.

In the present embodiment, since the number of heads is 3, the number of head tanks 300 is as follows: three first head tanks connected to the first manifold 230 and a second head tank connected to the second manifold 240. There are three, and a total of six are arranged.

The air ports 307 of the three first head tanks 300a, 300c, and 300e are connected by a connecting path 602 (for example, a tube) as shown by an alternate long and short dash line in FIG. In the example shown in FIG. 8, the air port 307a of the first head tank 300a and the air port 307b of the first head tank 300c, the air port 307a of the first head tank 300c and the air port 307b of the first head tank 300e Are connected respectively. Further, the air port 307b of the first head tank 300a is connected to the first atmosphere release valve 320. Further, the air port 307a of the first head tank 300e is sealed by a cap 321.

As a result, all three first head tanks 300a, 300c, 300e communicate with each other, and when the first air release valve 320 is closed, the three first head tanks 300a, 300c, 300e form a common closed space. Will have.

Similarly, the air ports 307 of the three second head tanks 300b, 300d, and 300f are connected by a connecting path 602 as shown by an alternate long and short dash line in FIG. In the example shown in FIG. 8, the air port 307a of the second head tank 300b and the air port 307b of the second head tank 300d, the air port 307a of the second head tank 300d and the air port 307b of the second head tank 300f Are connected respectively. Further, the air port 307b of the second head tank 300b is connected to the second atmosphere release valve 330. Further, the air port 307a of the second head tank 300f is sealed by a cap 331.

As a result, the three second head tanks 300b, 300d, and 300f all communicate with each other, and when the second atmospheric release valve 330 is closed, the three second head tanks 300b, 300d, and 300f form a common closed space. Will have.

Next, the discharge operation by the liquid circulation mechanism 200 and the operation of the head tank 300 will be described with reference to FIGS. 5 and 8.

First, in the liquid circulation mechanism 200, when the first liquid feed pump 202 and the second liquid feed pump 203 are stopped (hereinafter referred to as a stopped state), the first air release valve 320 and the second air release valve 330 are opened. Once opened, the air chambers of all the head tanks 300 are opened to the atmosphere.

Next, after closing the first air release valve 320 and the second air release valve 330 to make the air chambers of the first head tanks 300a, 300c, 300e and the second head tanks 300b, 300d, 300f a closed space, the first The 1st liquid feeding pump 202 and the 2nd liquid feeding pump 203 are driven to circulate the liquid.

As described above, the liquid feed flow rates of the first liquid feed pump 202 and the second liquid feed pump 203 are controlled based on the detection results of the pressure sensors 233 and 243. Further, the liquid is supplied from the third sub tank 290 to the first sub tank 220, the deaerator 260, the first manifold 230, the first head tank 300a, the head 100, the second head tank 300b, the second manifold 240, and the second. It circulates in the route of the sub tank 210 and the third sub tank 290.

In this liquid circulation, the liquid is degassed by the degassing device 260 and does not come into contact with air before being supplied to the head 100, so that the air does not melt into the head 100 and the degassing degree does not decrease. It is possible to supply the degassed liquid.

By the way, the pressure of the liquid in the liquid discharge head is set to a negative pressure of, for example, about −0.5 kPa in the vicinity of the nozzle, but the negative pressure momentarily increases by discharging the liquid, and the liquid in the head The liquid is refilled in the room to return to the original pressure. At this time, if the refill resistance is large due to a long flow path of the liquid to be refilled or the like, the refill time is long, so that the refill of the liquid cannot be made in time for the discharge.

Therefore, if the negative pressure rises and normal ejection cannot be performed, or if the pressure fluctuation in the head due to ejection and refilling becomes large even if non-ejection does not occur, the volume and speed of the droplets to be ejected become large. May fluctuate, resulting in a problem that a good image cannot be obtained.

On the other hand, in the technique described in Patent Document 1, the two tanks that produce the circulating flow rate are provided with a diaphragm and have a pressure buffering function, but the connection distance with the head is long and the pressure of a plurality of heads fluctuates. Is configured to be damped in one tank, so that pressure fluctuations caused by discharge cannot be satisfactorily damped.

On the other hand, in the liquid circulation mechanism 200 according to the present embodiment, a head tank 300 whose volume can be changed by a diaphragm 302 is provided in the immediate vicinity of the head 100.

As a result, the pressure fluctuation caused by discharging the liquid from the head 100 can be instantly damped, and the liquid is appropriately refilled in the head 100 even when the liquid is discharged in a large amount such as high frequency discharge. Therefore, it is possible to stably maintain the pressure of the liquid chamber in the head 100.

Further, when the liquid is circulated including the head 100, the fluid resistance of the flow path in the head 100 is large, so that it is necessary to increase the pressure difference between the first sub tank 220 and the second sub tank 210. As a result, the first sub-tank 220 is pressurized, so that the liquid chamber 304 of the first head tank is in an expanded state (the state of the diaphragm 302 shown by the solid line in FIG. 7B). On the other hand, since the pressure in the second sub tank 210 is reduced, the liquid chamber 304 of the second head tank is in a contracted state (the state of the diaphragm 302 shown by the dotted line in FIG. 7B).

At this time, the larger the pressure of the liquid, the larger the deformation of the diaphragm 302. However, in the head tank 300 of the present embodiment, since the air chamber 305, which is the space outside the diaphragm 302, is sealed, the pressure of the liquid causes the diaphragm 302. When is pushed, the air in the air chamber 305 is pushed back, so that excessive deformation of the diaphragm 302 can be prevented even when the pressure of the liquid is large and a large pressure is applied to the diaphragm 302, and the durability of the diaphragm 302 is improved. be able to.

Further, in the head tank 300 of the present embodiment, since the air chambers 305 of the plurality of head tanks 300 communicate with each other, the air layer of the head tank 300 of the other head 100 with low load discharge can be used, and the pressure can be used. Damping performance can be improved.

Further, since the first head tank and the second head tank of the present embodiment are provided with air release valves 320 and 330, respectively, and the air chamber 305 of the head tank 300 can communicate with the air, the head tank 300 The amount of air in the air chamber 305 can be reset, and the air chamber 305 can be opened to the atmosphere when the liquid circulation mechanism 200 is stopped. It is possible to prevent problems such as the air chamber 305 expanding due to the temperature rise and the pressure of the liquid in the liquid chamber 304 rising and the liquid leaking from the head 100.

As described above, by using the head tank 300 of the present embodiment, it is possible to reduce the pressure fluctuation caused by the droplet discharge of the head 100 and to stably maintain the pressure damping performance for a long period of time.

[Second Embodiment]
Hereinafter, other embodiments of the liquid circulation mechanism 200 in the device for discharging the liquid according to the present invention will be described. The description of the same points as in the above embodiment will be omitted as appropriate.

9A and 9B are explanatory views of the configuration of the head tank 300 in the liquid circulation mechanism 200 according to the second embodiment, where FIG. 9A is a front view and FIG. 9B is a sectional view taken along the line AA of FIG. 9A. ..

In the head tank 300 according to the second embodiment, the casing 303 is made of a transparent resin, and photosensors 308a and 308b as displacement detecting members of the diaphragm 302 are provided at positions facing the casing 303. The positions of the diaphragm 302 inside the head tank 300 can be detected by these two photosensors 308a and 308b.

Here, when the liquid is discharged from the head 100, the first liquid feeding pump 202 and the second feeding pump 202 and the second liquid feeding pump 202 and the second liquid feeding pump 202 and the second liquid feeding pump 202 are in order to circulate the liquid in the head, replenish the discharged liquid, and keep the pressure of the liquid as constant as possible. Although the liquid pump 203 is controlled, the response of the liquid refill from the sub tank to the liquid consumption of the head 100 is delayed.

During the period of the response delay, the diaphragm 302 of the head tank 300 is a liquid with almost no pressure change so that the head tank 300 supplies the head 100 to prevent problems such as insufficient supply and oversupply. It is desirable that the volume of the chamber 304 can be expanded or contracted.

That is, in FIG. 9B, if the diaphragm 302 is in the state of the diaphragm 302M, the ink in the head tank 300 is taken in and out of the head 100, and the pressure fluctuation can be satisfactorily prevented.

Therefore, the head tank 300 according to the second embodiment has a configuration in which it is possible to detect whether or not the position of the diaphragm 302 is in the ideal position by the two photo sensors 308a and 308b.

FIG. 10A is an explanatory diagram of the behavior of the diaphragm and the detection area of the photosensor, and FIG. 10B is an explanatory diagram of driving the air pump.

In the present embodiment, the photosensors 308a and 308b are reflective photosensors and are arranged at different distances from the diaphragm 302. As a result, for example, as shown in FIG. 10A, the diaphragm 302 of the photosensor 308a is turned ON between the vicinity of the target position and the proximity limit position (diaphragm 302H of FIG. 9B), and the photosensor 308b is the diaphragm. It is possible to turn the 302 ON between the vicinity of the target position and the separation limit position (diaphragm 302L in FIG. 9B).

At this time, the position where both the photosensors 308a and 308b are turned on is the target position of the diaphragm 302. Therefore, when one of the photosensors 308 is turned off, the air pump (described later) is driven to drive the head tank 300. Air should be taken in and out of the air chamber 305 to adjust the position of the diaphragm 302.

FIG. 11 shows a connection mode of the head tank 300 in the liquid circulation mechanism 200 according to the second embodiment. FIG. 11 is an explanatory view obtained by cutting out a part of the piping explanatory view shown in FIG. 5, and is an explanatory view of a liquid circulation path from the first manifold 230 to the head 100 and from the head 100 to the second manifold 240. Also in the second embodiment, since the number of heads is 3, the number of head tanks 300 is as follows: three first head tanks connected to the first manifold 230 and a second head tank connected to the second manifold 240. There are three head tanks, and a total of six are arranged.

In FIG. 11, as in FIG. 8, the first head tanks 300a, 300c, 300e are shown as the first head tank, and the second head tanks 300b, 300d, are shown as the second head tank. Although 300f is shown, it is not limited to this.

In the liquid circulation mechanism 200 shown in FIG. 11, at least one of the head tanks 300a, 300c, 300e and at least one of the head tanks 300b, 300d, 300f are provided with photosensors 308a, 308b (a configuration in which the photosensors 308a, 308b are provided. 9), and the other four head tanks 300 do not have the photosensors 308a and 308b (FIG. 7).

Similar to the first embodiment, all three first head tanks 300a, 300c, 300e communicate with each other via the connection path 602, and a first air release valve 320 is provided on one end side and a cap 321 is provided on the other end side. Has been done. When the first atmospheric release valve 320 is closed, the three first head tanks 300a, 300c, and 300e have a common closed space.

Further, all three second head tanks 300b, 300d, and 300f are also communicated with each other via the connection path 602, and a second atmospheric release valve 330 is provided on one end side and a cap 331 is provided on the other end side. When the second atmospheric release valve 330 is closed, the three second head tanks 300b, 300d, and 300f have a common closed space.

Further, a part of the pipe communicating with the air chamber 305 of the first head tank 300a is branched to connect the first intake air pump 322 (P1) and the first exhaust air pump 323 (P2). ing. When the first intake air pump 322 is driven, air is sent from the outside to the air chamber 305 of the first head tank 300a, and when the first exhaust air pump 323 is driven, air is sent from the air chamber 305 of the first head tank 300a. Acts to suck out.

Similarly, a part of the pipe communicating with the air chamber 305 of the second head tank 300b is branched to connect the second intake air pump 332 (P1) and the second exhaust air pump 333 (P2). Has been done. When the second intake air pump 332 is driven, air is sent from the outside to the air chamber 305 of the second head tank 300b, and when the second exhaust air pump 333 is driven, air is sent from the air chamber 305 of the second head tank 300b. Acts to suck out.

The operation of the liquid circulation mechanism 200 according to the second embodiment will be described with reference to FIGS. 9 to 11.

In the stopped state, the diaphragm 302 of the first head tank and the second head tank is in the vicinity of the position indicated by the diaphragm 302M in FIG. 9B. In the liquid circulation mechanism 200, there are three first head tanks and three second head tanks, but since the liquid chamber 304 and the air chamber 305 communicate with each other, each head tank The diaphragm positions of 300 are approximately the same.

From here, the first liquid feeding pump 202 and the second liquid feeding pump 203 are driven to circulate the liquid, the liquid is discharged from the head 100, and the liquid discharged from each head 100 is refilled. The first liquid feed pump 202 and the second liquid feed pump 203 (third liquid feed pump 209, if necessary) are controlled.

When the intake air pump P1 (322, 332) and the exhaust air pump P2 (323,333) are not controlled, there is a delay in pump control with respect to the discharge of the head 100 as described above. As shown by the solid line in a), the diaphragm 302 is greatly dented or greatly bulged.

Due to such a large fluctuation of the diaphragm 302, the diaphragm 302 may be stretched, the compliance of the liquid chamber 304 may be lowered, and the damping effect of the pressure fluctuation may be lowered.

On the other hand, in the head tank 300 in the second embodiment, since the position of the diaphragm 302 is detected by the photo sensor 308, the diaphragm 302 becomes the separation limit position indicated by 302L as shown in FIG. 10 (a). When the photosensor 308b detects that the air is present, as shown in FIG. 10B, the exhaust air pump P2 is driven to suck air from the air chamber 305.

On the contrary, when the photo sensor 308a detects that the diaphragm 302 is at the proximity limit position indicated by 302H, the intake air pump P1 is driven as shown in FIG. 10 (b). Air is sent to the air chamber 305.

With the above control, the position of the diaphragm 302 can be maintained in the vicinity of the target position as shown by the alternate long and short dash line in FIG. 10A.

According to the head tank 300 according to the second embodiment described above, the photo sensor 308 that detects the displacement of the diaphragm 302 and the air pumps P1 and P2 that are connected to the air chamber 305 of the head tank 300 and can take in and out air. The compliance of the head tank 300 can be kept high at all times. Therefore, it is possible to maintain the damping performance of the pressure fluctuation in the maximum state.

In the second embodiment, one head tank of each of the first head tank and the second head tank is configured to have the photo sensors 308a and 308b, but all the head tanks are photographed. The highest pressure fluctuation performance can be obtained by providing the sensors 308a and 308b and independently controlling the diaphragm 302 based on the detection results of the photosensors 308a and 308b. However, since the air chambers 305 of the first head tanks 300a, 300c, and 300e and the air chambers 305 of the second head tanks 300b, 300d, and 300f communicate with each other, the photosensor 308a is used for each one of the head tanks 300. , 308b is provided, and the diaphragm 302 is controlled based on the detection results of the photosensors 308a and 308b, so that the same pressure fluctuation performance can be obtained easily and at low cost.

[Third Embodiment]
12A and 12B are explanatory views of the configuration of the head tank 300 according to the third embodiment, where FIG. 12A is a front view and FIG. 12B is a sectional view taken along the line AA of FIG. 12A. FIG. 13 is an explanatory diagram showing a connection mode of the head tank 300 in the liquid circulation mechanism 200 according to the third embodiment.

In the head tank 300 according to the third embodiment, a cylindrical target 309 is attached to the diaphragm 302 as a detection target member, and a guide member 310 for guiding the target 309 is provided on the inner surface of the casing 303. There is.

Photosensors 308a and 308b as displacement detecting members of the diaphragm 302 are provided at positions facing the casing 303. The position of the diaphragm 302 can be detected by detecting the position of the target 309 by the two photo sensors 308a and 308b.

In the liquid circulation mechanism 200 shown in FIG. 13, at least one of the first head tanks 300a, 300c, 300e and at least one of the second head tanks 300b, 300d, 300f are photographed. The configuration has the sensors 308a and 308b and the target 309 (FIG. 12), and the other four head tanks do not have the photo sensors 308a and 308b (FIG. 7). Note that in FIG. 13, the photo sensors 308a and 308b are not shown. At this time, the head tank 300 having the photosensors 308a and 308b and the target 309 is preferably located farthest from the air pumps P1 and P2.

Further, as in the above embodiment, all three first head tanks 300a, 300c, 300e communicate with each other via the connection path 602, and a first atmospheric release valve 320 is provided on one end side and a cap 321 is provided on the other end side. Has been done. When the first atmospheric release valve 320 is closed, the three first head tanks 300a, 300c, and 300e have a common closed space.

Further, all three second head tanks 300b, 300d, and 300f are also communicated with each other via the connection path 602, and a second atmospheric release valve 330 is provided on one end side and a cap 331 is provided on the other end side. When the second atmospheric release valve 330 is closed, the three second head tanks 300b, 300d, and 300f have a common closed space.

Further, a part of the pipe communicating with the air chamber 305 of the first head tank 300a is branched to connect the first intake air pump 322 (P1) and the first exhaust air pump 323 (P2). ing.

Similarly, a part of the pipe communicating with the air chamber 305 of the second head tank 300b is branched to connect the second intake air pump 332 (P1) and the second exhaust air pump 333 (P2). Has been done.

Further, the diaphragm 302 of the head tank 300 (first head tank 300e, second head tank 300f) having the target 309 has a lower rigidity than the diaphragm 302 of the other head tank 300 having no target 309. , It is assumed that the connection pipe is connected to the farthest place from the air pumps P1 and P2. The diaphragm 302 of the head tank 300 having the target 309 can be made low in rigidity, for example, by using a material having lower elasticity than the diaphragm 302 of another head tank 300 or by reducing the wall thickness.

In the head tank 300 (first head tank 300e, second head tank 300f) according to the third embodiment described above, the diaphragm 302 of the head tank 300 capable of detecting the displacement of the diaphragm 302 is used as the other head tank. It has a lower rigidity than the 300 diaphragm 302. Therefore, as compared with other head tanks 300, the diaphragm 302 moves with higher sensitivity to the pressure of the liquid chamber 304, so that the displacement detection sensitivity of the diaphragm 302 can be increased. Therefore, the pressure damping control can be performed with high accuracy.

Further, since the target 309 that moves in conjunction with the diaphragm 302 and the guide member 310 that guides and supports the target 309 are provided, the displacement can be stabilized even if the diaphragm 302 has low rigidity. Stable pressure damping performance can be obtained.

Further, by piping the head tank 300 (first head tank 300e, second head tank 300f) capable of detecting the displacement of the diaphragm 302 to the farthest place from the air pumps P1 and P2, the head tank 300 can be connected to another head tank 300. Since the supplied working fluid is taken in and out in a shorter time, it becomes easy to bring the pressure damping performance of all the head tanks 300 closer to the target.

[Fourth Embodiment]
FIG. 14 is a head and head connection diagram according to the fourth embodiment. This embodiment differs from each of the above-described embodiments in that the head used is not a circulation type. Since the pressure fluctuation in the head can occur even when such a non-circulating head is used, the pressure fluctuation suppressing effect can be obtained by connecting the air ports 307a and 307b through the connection path 602.

[Fifth Embodiment]
FIG. 15 is a head and head connection diagram according to the fifth embodiment. In this embodiment, the connection destination of the connection path 602 is different from that in the first to third embodiments described above. Specifically, the connection path 602 connects the air port 307a of the first head tank 300a and the air port 307b of the second head tank 300b. That is, the connection destination of the connection path 602 is not limited to the first head tanks and the second head tanks, and may be configured in this way.

The pressure fluctuations of the head tank on the supply side (first head tank 300a) and the head tank on the discharge side (second head tank 300b) are often reversed in positive and negative directions. Therefore, with the above configuration, the pressure fluctuation of the supply side head tank (first head tank 300a) can be efficiently damped by the discharge side head tank (second head tank 300b).

[Sixth Embodiment]
FIG. 16 is a head and head connection diagram according to the sixth embodiment. This embodiment is different from the fifth embodiment described above in that adjacent head tanks are further connected to each other by a connection path 602 (note that the sub tanks are described so as to be adjacent to each other in the drawings). However, it does not limit the actual placement.) In other words, the connection path 602 connects the air port 307a of the first head tank 300a and the air port 307a of the second head tank 300b, and at yet another connection path 602, the first head tank 300c. The air port 307b of the second head tank 300b is connected to the air port 307a of the second head tank 300b. Further, any one of the head tanks is provided with an atmospheric release valve 320. With this configuration, only one air release valve is required, and a damping effect can be obtained with a simpler configuration.

In the present application, the "liquid" to be discharged may have a viscosity and surface tension that can be discharged from the head, and is not particularly limited, but has a viscosity of 30 mPa · s or less at room temperature, under normal pressure, or by heating or cooling. It is preferable that More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functionalizing materials such as surfactants, biocompatible materials such as DNA, amino acids and proteins, and calcium. , Solvents, suspensions, emulsions, etc. containing edible materials such as natural pigments, etc., for example, inks for inkjets, surface treatment liquids, components of electronic elements and light emitting elements, and formation of electronic circuit resist patterns. It can be used for applications such as a liquid for use and a material liquid for three-dimensional modeling.

The "liquid discharge head" includes a piezoelectric actuator (laminated piezoelectric element and thin film piezoelectric element), a thermal actuator that uses an electrothermal conversion element such as a heat generating resistor, a vibrating plate and a counter electrode as an energy generation source for discharging liquid. Includes those that use electrostatic actuators and the like.

The "device for discharging a liquid" includes a device for driving a liquid discharge head to discharge a liquid. The device for discharging the liquid includes not only a device capable of discharging the liquid to a device to which the liquid can adhere, but also a device for discharging the liquid toward the air or the liquid.

The "device for discharging the liquid" can also include means for feeding, transporting, and discharging paper to which the liquid can adhere, as well as a pretreatment device, a posttreatment device, and the like.

For example, as a "device that ejects a liquid", an image forming apparatus that ejects ink to form an image on paper, and a powder is formed in layers in order to form a three-dimensional model (three-dimensional model). There is a three-dimensional modeling device (three-dimensional modeling device) that discharges the modeling liquid into the powder layer.

Further, the "device for discharging a liquid" is not limited to a device in which a significant image such as characters and figures is visualized by the discharged liquid. For example, those that form patterns that have no meaning in themselves and those that form a three-dimensional image are also included.

The above-mentioned "material to which a liquid can adhere" means a material to which a liquid can adhere at least temporarily, such as one that adheres and adheres, and one that adheres and permeates. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic substrates, electronic components such as piezoelectric elements, powder layers (powder layers), organ models, and media such as inspection cells. Yes, including anything to which the liquid adheres, unless otherwise specified.

The material of the above-mentioned "material to which a liquid can be attached" may be paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramics, or the like as long as the liquid can be attached even temporarily.

Further, the "device for discharging the liquid" includes, but is not limited to, a device in which the liquid discharge head and the device to which the liquid can adhere move relatively. Specific examples include a serial type device that moves the liquid discharge head, a line type device that does not move the liquid discharge head, and the like.

In addition, as a "device for ejecting a liquid", a treatment liquid coating device for ejecting a treatment liquid to a paper in order to apply the treatment liquid to the surface of the paper for the purpose of modifying the surface of the paper, etc. There is an injection granulator that injects a composition liquid in which a raw material is dispersed in a solution through a nozzle to granulate fine particles of the raw material.

In addition, image formation, recording, printing, printing, printing, modeling, etc. in the terms of the present application are all synonymous.

Although the above-described embodiment is a preferred example of the present invention, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

1 Carry-in means 11 Original winding roller 3 Guide transport means 5 Printing means 50 Head unit 51 Head array 52 Base member 55 Head unit 59 Transport guide member 7 Drying means 9 Discharge means 91 Winding roller 10 Continuity 100 Liquid discharge head 101 Nozzle plate 102 Flow path plate 103 Vibrating plate member 104 Nozzle 105 Nozzle communication passage 106 Individual liquid chamber 107 Supply side fluid resistance part 108 Liquid introduction part 109 Opening 110 Supply side common liquid chamber 110A Downstream side common liquid chamber 110B Upstream side common liquid chamber 111 piezoelectric Actuator 112 piezoelectric element 113 base member 115 flexible wiring member 120 common liquid chamber member 121 first common liquid chamber member 122 second common liquid chamber member 129 cover 130 vibration region 130a convex part 140 flow path member 150 discharge side common liquid chamber 151 discharge Flow path 171 Supply port (supply port)
181 Discharge port (Discharge port)
200 Liquid circulation mechanism 201 Main tank 202 1st liquid feed pump 203 2nd liquid feed pump 205 Filter 209 3rd liquid feed pump 210 2nd sub tank 210a Gas chamber 211 Liquid level detection means 212 Electromagnetic valve 220 1st sub tank 220a Gas chamber 221 Liquid level detection means 222 Electromagnetic valve 230 1st manifold 231 Supply path 232 Electromagnetic valve 233 Pressure sensor 240 2nd manifold 241 Discharge path 242 Electromagnetic valve 243 Pressure sensor 260 Degassing device 261 Filter 270 Bypass path 271 Electromagnetic valve 272 Electromagnetic valve 281 Liquid Route 282 Liquid path 283 Liquid path 284 Liquid path 285 Backflow liquid path 286 Backflow liquid path 287 Electromagnetic valve 288 Electromagnetic valve 289 Liquid path 290 Third subtank 291 Liquid level detection means 292 Electromagnetic valve 300 Head tank 300a, 300c, 300e First Head tank 300b, 300d, 300f Second head tank 302 Diaphragm 303 Casing 304 Liquid chamber 305 Air chamber 306a, 306b Liquid port 307 (307a, 307b) Air port 308 (308a, 308b) Photosensor 309 Target 310 Guide member 320 1 Air release valve 321 Cap 322 First intake air pump (P1)
323 First exhaust air pump (P2)
330 Second atmosphere release valve 331 Cap 332 Second intake air pump (P1)
333 Second exhaust air pump (P2)
500 Control unit 500A Main control unit 501 CPU
502 ROM
503 RAM
504 Non-volatile memory 505 ASIC
506 Host I / F
508 Print control unit 509 Head driver 510 Solenoid valve control unit 511 Supply system control unit 512 Pressure system control unit 513 I / O unit 514 Operation panel 515 Sensor group 550 Solenoid valve group 590 Printer driver 602 Connection path 1000 Printing device

Japanese Patent No. 5814162

Claims (10)

With multiple liquid discharge heads that discharge liquid,
A plurality of head tanks through which the liquid passes through the liquid discharge head, and
A liquid path through which the liquid circulates through the liquid discharge head .
The head tank includes a liquid chamber for storing the liquid and a gas chamber adjacent to the liquid chamber via a wall member.
For each of the plurality of liquid discharge heads, the first head tank provided in the liquid path leading to the liquid supply port to the liquid discharge head and the liquid discharge port provided in the liquid discharge head. Equipped with a second head tank that leads
A device for discharging a liquid , wherein the gas chamber of the first head tank communicates with the gas chamber of another first head tank . The device for discharging a liquid according to claim 1 , wherein the gas chamber of the second head tank communicates with the gas chamber of another second head tank. A first manifold provided upstream of the plurality of first head tanks in the liquid circulation direction.
The device for discharging a liquid according to claim 1 or 2 , further comprising a second manifold provided downstream of the second head tank in the liquid circulation direction. At least one of the gas chambers of the plurality of first head tanks and the gas chambers of the plurality of second head tanks is capable of communicating with the atmosphere through a valve. The device for discharging the liquid according to any one of claims 1 to 3 . With multiple liquid discharge heads that discharge liquid,
A plurality of head tanks through which the liquid passes through the liquid discharge head, and
A liquid path through which the liquid circulates through the liquid discharge head.
The head tank includes a liquid chamber for storing the liquid and a gas chamber adjacent to the liquid chamber via a wall member.
For each of the plurality of liquid discharge heads, the first head tank provided in the liquid path leading to the liquid supply port to the liquid discharge head and the liquid discharge port provided in the liquid discharge head. Equipped with a second head tank that leads
The gas chamber of the first head tank communicates with the gas chamber of the second head tank.
At least one of the gas chambers of the plurality of first head tanks and the gas chambers of the plurality of second head tanks is capable of communicating with the atmosphere through a valve. A device that discharges liquid. A first manifold provided upstream of the plurality of first head tanks in the liquid circulation direction.
The device for discharging a liquid according to claim 5, further comprising a second manifold provided downstream of the second head tank in the liquid circulation direction. With multiple liquid discharge heads that discharge liquid,
Each of the liquid discharge heads is provided with a plurality of head tanks through which the liquid passes.
The head tank includes a liquid chamber for storing the liquid and a gas chamber adjacent to the liquid chamber via a wall member.
The gas chamber of the head tank communicates with the gas chamber of another head tank.
The wall member is made of a flexible member and is made of a flexible member.
A displacement detection member that detects the displacement of the flexible member, and
A device for discharging a liquid, which comprises an air pump connected to the gas chamber for intake and exhaust. The detection target member provided on the flexible member and
A guide member that guides the fluctuation of the detection target member due to the displacement of the flexible member is provided.
The device for discharging a liquid according to claim 7 , wherein the displacement detecting member detects the displacement of the flexible member by detecting the position of the detection target member. The plurality of head tanks
A head tank provided with the displacement detecting member and a head tank not provided with the displacement detecting member are mixed.
The liquid according to claim 7 or 8 , wherein the flexible member of the head tank provided with the displacement detecting member has lower rigidity than the flexible member of the head tank not provided with the displacement detecting member. Displacement device. The plurality of head tanks
A head tank provided with the displacement detecting member and a head tank not provided with the displacement detecting member are mixed.
The liquid according to any one of claims 7 to 9 , wherein the head tank provided with the displacement detecting member is piped at a position farther from the air pump than the head tank without the displacement detecting member. A device that discharges.

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