Patent Description:
A so-called inkjet liquid discharge apparatus may not normally discharge ink (i.e., a liquid) from a discharge head when the ink is thickened or dried. The discharge head may be referred to simply as a "head" in the following description. For example, a discharge failure in which the ink is not discharged from the head, or an abnormal discharge in which the ink is discharged in a direction different from a desired direction may occur. In the related art, a liquid discharge apparatus has a head cleaning function of periodically cleaning the head to prevent the discharge failure and the abnormal discharge.

Specifically, the liquid discharge apparatus includes a cap, a first path, and a second path. The head has a discharge port (i.e., a nozzle or an opening from which the ink is discharged). The cap covers the discharge port of the head. The first path and the second path are connected to a lower face of the cap. The ink remaining in the discharge port is sucked through the multiple paths, such as the first path and the second path, to perform a head cleaning. In a comparative example, a suction pump is connected to the first path in the head cleaning.

The suction pump sucks the ink in the discharge port to perform the head cleaning. On the other hand, air is sent to a sealed space between a nozzle face and the cap through the second path. A check valve is disposed on the second path. The check valve supplies the air from the outside into the cap and prevents backflow of the air and the ink. Accordingly, the ink is prevented from flowing out to the outside even when an air release valve disposed below the cap is opened, for example, in a technique in <CIT>.

Document <CIT> discloses a liquid discharge apparatus according to the preamble of claim <NUM>.

In the comparative examples, a liquid such as ink may overflow from a storage of the cap to the outside. In particular, when the head is removed from the storage, the liquid is likely to overflow from the storage to the outside. Even when a path through which the liquid flows is provided separately from the path for suction, if the liquid remains on the path, the liquid may be difficult to flow and may overflow from the storage to the outside.

The present disclosure has been made in view of the above situation, and an object of the present disclosure is to prevent a liquid from overflowing from the storage.

Embodiments of the present disclosure describe an improved liquid discharge apparatus that includes a head, a suction cap, a tank, a first path, a suction device, a second path, a first atmosphere path, a second atmosphere path, an atmosphere switch. The head discharges a liquid. The suction cap detachably contacts the head and stores the liquid suctioned from the head. The tank is connected to the suction cap to store the liquid fed from the suction cap. The first path connects the suction cap and the tank. The suction device is disposed in the first path between the suction cap and the tank to suck the liquid from the head to the suction cap. The second path is connected to the suction cap. The first atmosphere path having a first diameter connects the second path to atmosphere. The second atmosphere path having a second diameter smaller than the first diameter connects the second path to the atmosphere. The atmosphere switch is disposed between the second path, the first atmosphere path, and the second atmosphere path to switch to connect the second path with the first atmosphere path or connect the second path with the second atmosphere path.

As a result, according to the present disclosure, the liquid can be prevented from overflowing from the storage to the outside.

However, the disclosure of this specification is not intended to be limited to the specific terminology so selected and it is to be understood that the invention is defined by the claims.

Embodiments of the present disclosure are described below with reference to the accompanying drawings. The embodiments are not limited to the specific examples described below.

<FIG> is a schematic view of an image forming apparatus <NUM>. The image forming apparatus <NUM> illustrated in <FIG> is described as a liquid discharge apparatus according to an embodiment of the present disclosure. The image forming apparatus <NUM> discharges ink onto a sheet to form an image. The image forming apparatus <NUM> includes a sheet feeding unit <NUM>, a pretreatment unit <NUM>, an image forming unit <NUM>, a drying unit <NUM>, a post-processing unit <NUM>, a sheet ejection unit <NUM>, an operation unit <NUM>, and a controller <NUM>.

In the image forming apparatus <NUM>, the pretreatment unit <NUM> performs pretreatment on a sheet P fed by the sheet feeding unit <NUM>. After the pretreatment, the image forming unit <NUM> discharges ink onto the sheet P to form an image on the sheet P. The drying unit <NUM> dries the ink adhering to the sheet P. After drying, the post-processing unit <NUM> performs post-processing on the sheet P. After the post-processing, the sheet ejection unit <NUM> ejects the sheet P. Each unit is individually described below.

The sheet feeding unit <NUM> includes a sheet feeding tray 11A, a sheet feeding tray 11B, a sheet feeding device 12A, and a sheet feeding device 12B. Multiple sheets P are stacked on the sheet feed tray 11A and the sheet feed tray 11B. The sheet feeding device 12A and the sheet feeding device 12B separate and feed the sheets P one by one. As the sheet feeding devices 12A and 12B, a device using a roller, a device using air suction, and the like may be used. The sheet P is conveyed in a conveyance direction <NUM> and forwarded to the pretreatment unit <NUM>.

The pretreatment unit <NUM> performs the pretreatment on the sheet P fed from the sheet feeding unit <NUM>. Examples of the pretreatment include applying a treatment liquid, which reacts with ink, to the sheet P to reduce bleeding of the ink. The sheet P may be processed in the pretreatment. The pretreatment unit <NUM> includes a registration roller pair <NUM> that feeds the sheet P to the image forming unit <NUM>. After the pretreatment, the sheet P is conveyed to the registration roller pair <NUM>. After the sheet P reaches the registration roller pair <NUM>, the registration roller pair <NUM> adjusts the timing to send the sheet P to the image forming unit <NUM>.

The drying unit <NUM> includes a conveyor <NUM> and a heater <NUM>. The conveyor <NUM> conveys the sheet P. The heater <NUM> dries the ink adhering to the sheet P. For example, the heater <NUM> is a halogen heater, a ceramic heater, or the like. The conveyor <NUM> receives the sheet P conveyed from the image forming unit <NUM>. Then, the conveyor <NUM> conveys the sheet P to the heater <NUM>. After drying, the sheet P is conveyed to the post-processing unit <NUM>. The ink on the sheet P is heated by the heater <NUM> while the sheet P passes through the heater <NUM>. As a result, liquid components such as moisture in the ink are evaporated and the ink is fixed on the sheet P.

The post-processing unit <NUM> performs the post-processing on the sheet P. The post-processing unit <NUM> includes a sheet reverse unit <NUM>. The sheet reverse unit <NUM> reverses the sheet P and sends the sheet P to the image forming unit <NUM> again through a reverse passage <NUM>. Thus, the image forming apparatus <NUM> forms images on both sides of the sheet P. The image forming apparatus <NUM> may perform post-processing such as reversal, binding, correction, and cooling of the sheet P. Specifically, the binding is a process of binding a plurality of sheets P. The correction is a process of correcting deformation of the sheet P. The cooling is a process of cooling the sheet P.

The sheet ejection unit <NUM> includes a sheet ejection tray <NUM> on which multiple sheets P is stacked. The sheets P conveyed from the post-processing unit <NUM> are sequentially stacked on the sheet ejection tray <NUM>.

The operation unit <NUM> includes a touch panel, a keyboard, or the like. The operation unit <NUM> accepts an operation input by an operator. The operation unit <NUM> may include a display that displays information for the operator. The operation unit <NUM> may be installed at any position inside or outside the image forming apparatus <NUM>.

The controller <NUM> controls the entire image forming apparatus <NUM>. The controller <NUM> may be installed at any position inside or outside the image forming apparatus <NUM>.

<FIG> is a diagram illustrating an example of a configuration of the image forming unit <NUM>. The image forming apparatus <NUM> includes a device including the image forming unit <NUM> described below. The image forming unit <NUM> includes a receiving cylinder <NUM>, a drum <NUM>, heads <NUM>, a transfer cylinder <NUM>, a cleaning unit <NUM>, and an in-line sensor <NUM>. The receiving cylinder <NUM> receives the sheet P conveyed by the pretreatment unit <NUM>. The drum <NUM> carries the sheet P on an outer circumferential surface thereof to convey the sheet P. The head <NUM> discharges ink onto the sheet P carried by the drum <NUM>. The transfer cylinder <NUM> conveys the sheet P to the drying unit <NUM>.

A leading end of the sheet P is gripped by a sheet gripper disposed on the surface of the receiving cylinder <NUM>, and the sheet P is conveyed along with the movement of the surface of the receiving cylinder <NUM>. The sheet P is transferred to the drum <NUM> at a position facing the drum <NUM>. A sheet gripper is disposed on the surface of the drum <NUM>. The leading end of the sheet P is gripped by the sheet gripper of the drum <NUM>. A plurality of suction holes is formed on the surface of the drum <NUM>. A suction unit inside the drum <NUM> generates a suction airflow through the plurality of suction holes toward an interior of the drum <NUM>. The leading end of the sheet P is gripped by the sheet gripper, and the sheet P is attracted to the surface of the drum <NUM> by the suction airflow. The sheet P is conveyed as the drum <NUM> rotates.

The heads <NUM> discharge ink of four colors of C (cyan), M (magenta), Y (yellow), and K (black) to form an image. The heads <NUM> includes a liquid discharge head 33A, a liquid discharge head 33B, a liquid discharge head 33C, and a liquid discharge head 33D in accordance with the types of color. The liquid discharge head 33A, the liquid discharge head 33B, the liquid discharge head 33C, and the liquid discharge head 33D are collectively referred to as the "heads <NUM>," each of which is referred to as a "head <NUM>" unless distinguished.

The head <NUM> has multiple nozzles arranged over the entire width of the sheet P in a width direction <NUM> of the sheet P to form an image on the entire sheet P in the width direction <NUM>. The width direction <NUM> is substantially orthogonal to the conveyance direction <NUM>. As described above, the image forming unit <NUM> has a line-type configuration that does not move the head <NUM> (i.e., a full-width head). The head <NUM> may use a special ink such as white, gold, or silver. The head <NUM> may perform processing other than image formation by using a surface coating liquid or the like.

The cleaning unit <NUM> cleans the head <NUM>. For example, the cleaning unit <NUM> includes a suction cap, a suction pump, a web, a rubber blade, and the like. The head <NUM> may be stained by mist of ink. When the head <NUM> is stained, the cleaning unit <NUM> cleans the head <NUM>. The cleaning unit <NUM> is provided for each head <NUM>.

The head <NUM> discharge ink based on image data. When the sheet P passes through a position facing the head <NUM>, the head <NUM> discharges the ink of each color. As the ink is discharged as described above, an image corresponding to the image data is formed on the sheet P.

The in-line sensor <NUM> is disposed downstream from the heads <NUM> in the conveyance direction <NUM>. The in-line sensor <NUM> scans an image formed on the sheet P. The conveyance direction <NUM> is a rotation direction of the drum <NUM>. For example, the in-line sensor <NUM> includes an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS). The in-line sensor <NUM> outputs a color scanned image.

<FIG> is a block diagram illustrating an example of a hardware configuration of the controller <NUM>. Specifically, the controller <NUM> as circuitry includes a central processing unit (CPU) <NUM> and a read only memory (ROM) <NUM>. The controller <NUM> further includes a random access memory (RAM) <NUM> and a hard disk drive (HDD) / solid state drive (SSD) <NUM>. The controller <NUM> further includes an interface (I/F) <NUM>. The hardware resources described above are electrically connected to each other via a system bus B. Each resource transmits and receives data and signals to and from each of the head <NUM>, the in-line sensor <NUM>, the cleaning unit <NUM>, and the operation unit <NUM> via the system bus B.

The CPU <NUM> uses the RAM <NUM> as a work area and executes a program stored in the ROM <NUM>. The HDD/SSD <NUM> is a storage device. The HDD/SSD <NUM> stores programs, setting values, and data read by the CPU <NUM>. The I/F <NUM> is an interface with an external personal computer (PC) <NUM>. The controller <NUM> may further include a calculation device, a control device, a storage device, an input device, an output device, and an auxiliary device inside or outside thereof in addition to the above-described resources.

<FIG> is a diagram illustrating an example of an internal structure of the image forming apparatus <NUM>. Specifically, the image forming apparatus <NUM> includes a storage <NUM>, a first path <NUM>, a second path <NUM>, a third path <NUM>, a fourth path <NUM>, and a suction device <NUM>. The storage <NUM> is the suction cap. The storage <NUM> stores ink. The head <NUM> is detachably contacts the storage <NUM>. A description is given below of the storage <NUM> and the surrounding thereof when the head <NUM> is removed from the storage <NUM>. The first path <NUM> and the second path <NUM> are connected to the storage <NUM>.

The first path <NUM> is a path through which the ink is sucked from a suction port of the storage <NUM>. The suction port is disposed in a bottom face of the storage <NUM>. The first path <NUM> is connected to the suction device <NUM>. The suction device <NUM> is a suction pump. The ink sucked by the suction device <NUM> is drained to a tank <NUM>. Thus, the tank <NUM> collects the ink as a waste ink (waste liquid).

Specifically, the ink is discharged from the head <NUM> into the suction cap (i.e., the storage <NUM>) by driving the suction pump (i.e., the suction device <NUM>) and applying a negative pressure to a nozzle face, in which the multiple nozzles are arranged, of the head <NUM>. Foreign substances, bubbles, or the like in the head <NUM> is discharged together with the ink.

The second path <NUM> is a path connected to an opening different from the suction port disposed in the bottom face of the storage <NUM>. The opening is referred to as an "atmospheric port" communicating with an atmosphere. The second path <NUM> and the third path <NUM> are connected to each other. The second path <NUM> and the third path <NUM> is not necessarily separate paths and may be integrated into a single body. Accordingly, the second path <NUM> and the third path <NUM> may be collectively referred to as the second path <NUM> and <NUM>, the second path <NUM> may be referred to as a first part of the second path <NUM> and <NUM>, and the third path <NUM> may be referred to as a second part of the second path <NUM> and <NUM>.

The third path <NUM> is connected to a first atmosphere path <NUM> or the fourth path <NUM> (i.e., a second atmosphere path) via an atmosphere switch <NUM>. The first atmosphere path <NUM> is opened to the atmosphere. The fourth path <NUM> is a joint or a tube opened to the atmosphere. The first atmosphere path <NUM> has a first diameter, for example, substantially the same diameter with the third path <NUM>. The fourth path <NUM> has a second diameter smaller than the first diameter, for example, smaller than a diameter of each of the first path <NUM>, the second path <NUM>, and the third path <NUM>. The first path <NUM> and the second path <NUM> may have any diameter. For example, the fourth path <NUM> preferably has an inner diameter (the second diameter) of <NUM> or less and <NUM> or more.

The fourth path <NUM> preferably has an inner diameter as small as possible. On the other hand, a component having a path less than <NUM> is difficult to manufacture and is often difficult to obtain. Accordingly, when the diameter of the fourth path <NUM> is <NUM> or less and <NUM> or more, the fourth path <NUM> can be made of an easily available component. Further, with the fourth path <NUM> having a small inner diameter, when the suction device <NUM> is driven, the ink can be sucked from the head <NUM> while air is taken into the second path <NUM> and the third path <NUM> through the fourth path <NUM>. Specifically, the fourth path <NUM> having the diameter of <NUM> or less can generate a flow path resistance sufficient to suck the ink from the head <NUM>.

The atmosphere switch <NUM> is disposed between the third path <NUM>, the fourth path <NUM>, the first atmosphere path <NUM>. The atmosphere switch <NUM> switches to connect the third path <NUM> with the fourth path <NUM> or connect the third path <NUM> with the first atmosphere path <NUM> to take air into the second path <NUM> and the third path <NUM>.

The paths including the fourth path <NUM> have the flow path resistance satisfying a condition that a negative pressure applied to the nozzle face of the head <NUM> during suction reaches the negative pressure sufficient for suction maintenance to suck the ink from the head <NUM>. With the paths satisfying this condition, when the suction device <NUM> (suction pump) sucks the ink, the third path <NUM> is connected to the fourth path <NUM> which is open to the atmosphere. As a result, the air taken into the second path <NUM> and the third path <NUM> through the fourth path <NUM> prevents the ink from flowing into the second path <NUM> when the suction device <NUM> sucks the ink before the third path is connected to the first atmosphere path <NUM> directly opened to the atmosphere.

In this path, the pressure distribution in the second path <NUM> and the third path <NUM> causes the air to flow from the outside toward the atmospheric port, which is an opposite direction to the ink flowing into the second path <NUM> through the atmospheric port, thereby preventing the backflow of the air and the ink. As described above, with the configuration including the fourth path <NUM>, ink is prevented from overflowing.

In the image forming apparatus <NUM>, a conveyance unit that conveys the sheet P is a rotator such as the drum <NUM> illustrated in <FIG>. Alternatively, the conveyance unit may be a conveyance belt. The present embodiment can be applied to both a configuration in which the conveyance unit conveys the sheet P with the rotator and a configuration in which the conveyance unit conveys the sheet P with the conveyance belt.

<FIG> is a diagram illustrating an example of a configuration of the image forming unit <NUM> when the head <NUM> (and the storage <NUM>) is inclined. Similarly to <FIG>, the drum <NUM> conveys the sheet P in <FIG>. When the sheet P is conveyed by a rotator such as the drum <NUM>, a surface on which the sheet P is conveyed is not a flat surface like when the sheet P is conveyed on a belt, but a curved surface. Accordingly, the head <NUM> is installed so as to be inclined with respect to a horizontal plane <NUM> in accordance with the shape of the drum <NUM>.

Specifically, the liquid discharge head 33A is installed so as to be inclined at an angle θ with respect to the horizontal plane <NUM>. The angle θ is adjusted and set according to a curvature of the drum <NUM>, an installation position of the head <NUM>, or the like. When the sheet P is conveyed by the drum <NUM> as described above, the storage <NUM> further has the following configuration.

<FIG> is a schematic view of the storage <NUM> to which the head <NUM> is attached. The storage <NUM> stores ink <NUM>. A path such as the first path <NUM> is connected to the bottom face of the storage <NUM> to suck the ink <NUM>. A nozzle row <NUM>, in which the multiple nozzles are arranged, is integrated with the head <NUM> as a single body. Thus, when the head <NUM> is attached to and detached from the storage <NUM>, the nozzle row <NUM> is also attached and detached together with the head <NUM>. A user removes the head <NUM> from the storage <NUM> as illustrated in <FIG>. Alternatively, the image forming apparatus <NUM> may automatically remove the head <NUM> from the storage <NUM>.

<FIG> is a schematic view of the storage <NUM> from which the head <NUM> is removed. <FIG> is different from <FIG> in that the head <NUM> is removed from the storage <NUM>. As illustrated in <FIG> and <FIG>, the head <NUM> is attachable to and detachable from the storage <NUM> by operations of the user or the image forming apparatus <NUM>. When the head <NUM> is removed from the storage <NUM> as illustrated in <FIG>, the ink <NUM> is likely to overflow to the outside of the storage <NUM>. In particular, when the storage <NUM> is inclined at the angle θ with respect to the horizontal plane <NUM>, the sucked ink <NUM> remaining in the storage <NUM> is more likely to overflow to the outside of the storage <NUM> as compared with a storage horizontally installed.

Accordingly, the present embodiment is preferably applied to the storage <NUM> inclined with respect to the horizontal plane <NUM> in accordance with the shape of the rotator. The configuration according to the present embodiment can omit a process of lowering the level of the ink <NUM>. The process prevents the ink <NUM> from overflowing to the outside of the storage <NUM>. In addition, the configuration having the fourth path <NUM> according to the present embodiment prevents the ink <NUM> from flowing backward even when the ink <NUM> is sucked from the head <NUM>.

<FIG> is a diagram illustrating an example of an internal structure of the image forming apparatus <NUM> according to a second embodiment. The second embodiment is different from the first embodiment in that a fifth path <NUM> and a path switch <NUM> are added. Different points are described below, and a redundant description may be omitted.

The fifth path <NUM> (i.e., a connection path) is connected to the first path <NUM>. The path switch <NUM> is a switching valve. The path switch <NUM> is disposed between the second path <NUM>, the third path <NUM>, and the fifth path <NUM>. The path switch <NUM> switches between connecting the fifth path <NUM> and the second path <NUM> and connecting the third path <NUM> and the second path <NUM>. Since the path switch <NUM> contacts the ink <NUM>, a material of the path switch <NUM> is preferably resistant to the ink <NUM>.

<FIG> is a flowchart illustrating an operation example of the suction maintenance. For example, when the ink <NUM> is thickened or bubbles are generated in the ink <NUM>, the suction maintenance starts. The image forming apparatus <NUM> performs the suction maintenance in the following suction procedure based on the result of scanning an image formed with the ink <NUM> by the image forming apparatus <NUM>.

In step S0901, after attaching the head <NUM> to the storage <NUM>, the image forming apparatus <NUM> sucks the ink <NUM> from the head <NUM>. <FIG> is a schematic view of the storage <NUM> in the suction procedure. <FIG> illustrates the operation example in step S0901. Step S0901 is executed in a state in which the head <NUM> is attached to the storage <NUM>.

The path switch <NUM> connects the third path <NUM> and the second path <NUM>. Further, the atmosphere switch <NUM> connects the third path <NUM> to the fourth path <NUM> to take air into the second path <NUM> and the third path <NUM> through the fourth path <NUM>. In this state, the suction device <NUM> sucks the ink <NUM>. The ink <NUM> is sucked from the head <NUM> by the suction device <NUM>.

In step S0902, the image forming apparatus <NUM> opens the third path <NUM> directly to the atmosphere through the first atmosphere path <NUM> and sucks the ink <NUM>. <FIG> is a schematic view of the storage <NUM> to which the head <NUM> is attached when the third path <NUM> is opened to the atmosphere and the ink <NUM> is sucked from the storage <NUM>. <FIG> is different from <FIG> in that the atmosphere switch <NUM> switches to connect the third path <NUM> with the first atmosphere path <NUM> directly opened to the atmosphere to take air into the second path <NUM> and the third path <NUM>.

In such a state, the air is directly taken into the second path <NUM> and the third path <NUM> through the first atmosphere path <NUM>. The suction device <NUM> sucks the ink <NUM> similarly to step S0901. The suction device <NUM> sucks the ink <NUM> remaining in the storage <NUM>.

The atmosphere switch <NUM> is operated for draining the ink <NUM> in the storage <NUM> (i.e., the suction cap) while the storage <NUM> caps the head <NUM>. Specifically, when the suction device <NUM> is driven with the third path <NUM> connected to the fourth path <NUM> having the smaller inner diameter, since the fourth path <NUM> is a resistance, the ink <NUM> in the storage <NUM> and the paths is drained, and the ink <NUM> is newly sucked from the head <NUM> at the same time.

On the other hand, when the suction device <NUM> is driven with the third path <NUM> directly opened to the atmosphere through the first atmosphere path <NUM> by the atmosphere switch <NUM>, the resistance is small, and air can be actively taken into the third path <NUM>. Accordingly, the suction device <NUM> can drain the ink <NUM> in the storage <NUM> and the path (e.g., the first path <NUM>) without newly sucking the ink <NUM> from the head <NUM>.

In step S0903, the head <NUM> is removed from the storage <NUM>. In step S0904, the image forming apparatus <NUM> switches paths and suck the ink <NUM>. <FIG> is a schematic view of the storage <NUM> from which the head <NUM> is removed after the path switch <NUM> switches the paths in the suction procedure. <FIG> is different from <FIG> in that the paths are switched by the path switch <NUM>. <FIG> illustrates the storage <NUM> from which the head <NUM> is removed in step S0903.

Accordingly, the ink <NUM> in each path (i.e., the second path <NUM>, the fifth path <NUM>, and the first path <NUM>) is drained by the suction device <NUM>. The image forming apparatus <NUM> may perform the suction maintenance periodically. Alternatively, an artificial intelligence (AI) may determine to start the suction maintenance based on an operation by a user or the result of scanning an image.

As illustrated in <FIG>, <FIG>, and <FIG>, the storage <NUM> may include an absorber <NUM>. <FIG> is a schematic view of the storage <NUM> in the suction procedure, illustrating effects of suction. <FIG> is different from <FIG> in that an ink residue <NUM> remains in the second path <NUM>. The ink residue <NUM> is generated when the ink <NUM> flows into the second path <NUM>. In particular, in step S0902, a pressure in the second path <NUM> and the third path <NUM> is negative, and thus the ink <NUM> is likely to flow in the second path <NUM>.

In addition, when the ink <NUM> drips from the nozzle row <NUM>, the ink <NUM> may adhere to the atmospheric port and the ink <NUM> may flow into the second path <NUM> and the third path <NUM>. For this reason, as illustrated in <FIG>, after the head <NUM> is removed, the suction device <NUM> is driven with the atmospheric port communicating with the suction device <NUM> through the second path <NUM>, the fifth path <NUM>, and the first path <NUM>. As a result, the ink residue <NUM> in the path can be drained by suction.

When the ink residue <NUM> remains in the path, the path may be clogged with the ink residue <NUM>, thereby hindering air from being taken in. In particular, when the ink <NUM> is thickened, the air is more difficult to flow due to the ink residue <NUM>, and the hindrance is likely to increase.

When the absorber <NUM> is disposed in the storage <NUM> or paths, the suction force of the suction device <NUM> for sucking the ink residue <NUM> may be reduced. For this reason, in the present embodiment, the ink residue <NUM> remaining in the path can be sucked and drained through the fifth path <NUM>. A pressure applied to the ink residue <NUM> is higher when the suction device <NUM> sucks through the fifth path <NUM> than when air is taken into the second path <NUM> and the third path <NUM>, thereby draining the ink residue <NUM> more effectively.

<FIG> is a diagram illustrating an example of a configuration for wiping the nozzle row <NUM>. The image forming apparatus <NUM> may include a blade <NUM> and a web <NUM> to wipe the nozzle row <NUM>. The blade <NUM> cleans the nozzle face after the web <NUM> wipes the nozzle face. The web <NUM> absorbs the ink <NUM> remaining on the nozzle face after the suction.

The recording medium is, for example, a sheet of paper (also referred to as "plain paper"). However, the recording medium may be an overhead projector sheet, a film, a flexible thin plate, or the like in addition to coated paper, label paper, or the like other than the sheet of paper. In other words, the recording medium is made of a material onto which droplets of ink are at least temporarily adherable, a material onto which droplets of ink adhere and fix, or a material to which droplets of ink adhere and permeate. Specific examples of the recording medium include, but are not limited to, a recording medium such as a sheet, a film, or cloth, an electronic component such as an electronic substrate or a piezoelectric element (which may be referred to as a piezoelectric component), layered powder, an organ model, and a testing cell. In short, the recording medium is made of any material onto which liquid can adhere, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramic, or a combination thereof. The liquid may be any fluid other than the ink in accordance with the above-described application.

The control method described above is implemented by, for example, causing a computer to execute the processes described above. The control method according to the present disclosure may include processes other than those described above. The control method includes a method in which a part of processes is executed by an external device.

The above-described control method may be implemented by a program (including firmware and program equivalents, which are referred to simply as the "program") that executes the above-described processes or processing equivalent to the above-described processes.

In other words, the above-described control method may be implemented by the program written in a programming language or the like so as to obtain a predetermined result by instructing a computer to execute the processes. A part of the processes executed by the program may be implemented by hardware such as an integrated circuit (IC).

The program causes an arithmetic device, a control device, a storage device, and the like, which are cooperated with each other, included in a computer to execute the above-described processes. The program is loaded into the storage device and issues a command to the arithmetic device to cause the arithmetic device to perform an arithmetic operation, thereby operating the computer. The program may be provided via a computer-readable storage medium or an electric communication line such as a network.

Aspects of the present disclosure are, for example, as follows.

A liquid discharge apparatus includes a head, a suction cap, a tank, a first path, a suction device, a second path, a first atmosphere path, a second atmosphere path, an atmosphere switch. The head discharges a liquid. The suction cap detachably contacts the head and stores the liquid suctioned from the head. The tank is connected to the suction cap to store the liquid fed from the suction cap. The first path connects the suction cap and the tank. The suction device is disposed in the first path between the suction cap and the tank to suck the liquid from the head to the suction cap. The second path is connected to the suction cap. The first atmosphere path having a first diameter connects the second path to atmosphere. The second atmosphere path having a second diameter smaller than the first diameter connects the second path to the atmosphere. The atmosphere switch is disposed between the second path, the first atmosphere path, and the second atmosphere path to switch to connect the second path with the first atmosphere path or connect the second path with the second atmosphere path.

In Aspect <NUM>, the second atmosphere path has the second diameter of <NUM> or less and <NUM> or more.

In Aspect <NUM> or <NUM>, the liquid discharge apparatus further includes a connection path and a path switch. The connection path connects the first path with a first part of the second path connected to the suction cap. A second part of the second path (<NUM>, <NUM>) is connected to the atmosphere switch. The path switch is disposed between the first part and the second part of the second path and connected to the connection path to switch to connect the first path with the first part of the second path through the connection path or connect the first part with the second part of the second path.

In any one of Aspects <NUM> to <NUM>, the liquid discharge apparatus further includes a drum to convey, to the head, a recording medium on an outer circumferential surface of the drum. The suction cap is inclined with respect to a horizontal plane in accordance with the outer circumferential surface of the drum.

In any one of Aspects <NUM> to <NUM>, the liquid discharge apparatus further includes an image forming unit including the head to discharge the liquid onto a recording medium to form an image.

In Aspect <NUM>, the liquid discharge apparatus further includes circuitry causes the suction cap to contact the head, causes the atmosphere switch to connect the second path and the second atmosphere path to connect the second atmosphere path to the suction cap, and causes the suction device to suck the liquid from the head with the suction cap, and drain the liquid in the suction cap to the tank through the first path.

In Aspect <NUM>, the circuitry further causes the atmosphere switch to connect the second path and the first atmosphere path to connect the first atmosphere path to the suction cap and causes the suction device to drain the liquid in the suction cap to the tank through the first path.

In Aspect <NUM>, the liquid discharge apparatus further includes circuitry causes the suction cap to contact the head, causes the path switch to connect the first part and the second part of the second path, causes the atmosphere switch to connect the second part of the second path and the second atmosphere path to connect the second atmosphere path to the suction cap, and causes the suction device to suck the liquid from the head with the suction cap, and drain the liquid in the suction cap to the tank through the first path.

In Aspect <NUM>, the circuitry further causes the path switch to connect the first part and the second part of the second path, causes the atmosphere switch to connect the second part of the second path and the first atmosphere path to connect the first atmosphere path to the suction cap, and causes the suction device to drain the liquid in the suction cap to the tank through the first path.

In Aspect <NUM>, the circuitry further causes the suction cap to detach from the head, causes the path switch to connect the first part of the second path to the first path through the connection path and disconnect the first part and the second part of the second path, and causes the suction device to drain the liquid in the suction cap to the tank through the first path and the first part of the second path through the connection path.

Claim 1:
A liquid discharge apparatus (<NUM>) comprising:
a head (<NUM>) to discharge a liquid;
a suction cap (<NUM>) to detachably contact the head (<NUM>) and store the liquid suctioned from the head (<NUM>);
a tank (<NUM>) connected to the suction cap (<NUM>) to store the liquid fed from the suction cap (<NUM>);
a first path (<NUM>) connecting the suction cap (<NUM>) and the tank (<NUM>);
a suction device (<NUM>) in the first path (<NUM>) between the suction cap (<NUM>) and the tank (<NUM>), the suction device (<NUM>) to suck the liquid from the head (<NUM>) to the suction cap (<NUM>);
a second path (<NUM>, <NUM>) connected to the suction cap (<NUM>);
a first atmosphere path (<NUM>) to connect the second path (<NUM>, <NUM>) to atmosphere, the first atmosphere path (<NUM>) having a first diameter;
a second atmosphere path (<NUM>), characterized in that
the second atmosphere path is to connect the second path (<NUM>, <NUM>) to the atmosphere, the second atmosphere path (<NUM>) having a second diameter smaller than the first diameter;
and that the liquid discharge apparatus (<NUM>) comprises an atmosphere switch (<NUM>) between the second path (<NUM>, <NUM>), the first atmosphere path (<NUM>), and the second atmosphere path (<NUM>), the atmosphere switch (<NUM>) to switch to:
connect the second path (<NUM>, <NUM>) with the first atmosphere path (<NUM>); or
connect the second path (<NUM>, <NUM>) with the second atmosphere path (<NUM>).