Abstract: A three-dimensional object printing method includes a first test printing step of printing a first test pattern in a first region of a workpiece by a head unit while a position of the head unit being changed by a robot, a first detection step of detecting the first test pattern, and a first printing step of printing a first pattern in the first region by the head unit based on a result detected in the first detection step while the position of the head unit being changed by the robot.

Abstract: An ink set including a color ink containing particles including a polymerizable compound, a colorant, and water and an overcoat solution containing particles including a polymerizable compound and water, and an image formation method.

Abstract: A liquid ejecting head includes: a first pressure chamber to which a first liquid is supplied; a first drive element that applies pressure to the first liquid in the first pressure chamber; a second pressure chamber to which a second liquid is supplied; a second drive element that applies pressure to the second liquid in the second pressure chamber; a nozzle channel which has one end communicating with the first pressure chamber and another end communicating with the second pressure chamber and in which the first liquid supplied from the first pressure chamber and the second liquid supplied from the second pressure chamber are mixed; and a nozzle that is provided in the nozzle channel and ejects a mixture of the first liquid and the second liquid.

Abstract: A group management device includes a required information acquisition unit, a supplement instruction unit, a mounting information acquisition unit, and a group update unit. The required information acquisition unit acquires information showing required groups that are groups determined to require supplements of the consumables used in image forming devices that are managed per group. The supplement instruction unit performs a supplement instruction of the consumables for the required groups. The mounting information acquisition unit acquires mounting information showing the image forming device mounted with the consumable supplemented in response to the supplement instruction.

Abstract: Fluid is continuously recirculated through a thermal fluid-ejection printhead. Prior to firing a thermal resistor of the printhead to thermally eject a drop of the fluid through a nozzle of the printhead, the fluid is recirculated on-demand through a chamber of the printhead between the nozzle and the thermal resistor. The thermal resistor is fired to thermally eject the drop of the fluid through the nozzle. The fluid has a concentration of solids greater than 12% by volume.

Abstract: In a board that includes a plurality of contact portions that are arranged to contact corresponding apparatus-side terminals when the board is mounted in a printing apparatus, some contact portions are disposed in a first region, and the remaining contact portions are disposed in a second region. The some contact portions include a first contact portion, a second contact portion, a third contact portion, and a fourth contact portion. The remaining contact portions include a fifth contact portion. The some contact portions are arranged in a first pattern in the first region and the remaining contact portions are arranged in a second pattern in the second region, and the first pattern is asymmetrical to the second pattern with respect to a first virtual line.

Abstract: An inkjet printing apparatus includes a print head ejecting ink, a tank reserving ink to be supplied to the print head and a joint unit being capable of connecting the print head and the tank to each other. The joint unit has a connecting portion for supplying ink to the print head and a shaft that is rotatable by a drive source so as to move in an axial direction. The connecting portion moves together with the shaft. The print head includes a head joint connectable to the connecting portion and an engaging portion engageable with one end of the shaft. The shaft is rotated to be engaged with the engaging portion so that the head joint and the connecting portion are connected to each other.

Abstract: In an embodiment, a method for controlling a printer is provided. The method includes: receiving a set of parameters associated with a printer by a computing device, wherein the printer is depositing ink on a substrate to generate a line; measuring a width of the line by the computing device; receiving a duty cycle associated with the printer by the computing device; using the received duty cycle, the set of parameters, and a model, estimating one or more unknown parameters of the set of parameters by the computing device; receiving a desired width of the line by the computing device; and if the desired width is not the same as the measured width: adjusting the duty cycle associated with the printer based on the set of parameters and the model so that the measured width is closer to the desired width by the computing device.

Abstract: An information processing apparatus includes a processor configured to: acquire physical property information on physical properties of a recording medium and physical properties of ink to be ejected onto the recording medium and setting information on a setting of a device configured to eject the ink onto the recording medium; derive an action amount using the physical property information and the setting information, the action amount relating to action of the recording medium applied by the ink ejected onto the recording medium; and output the action amount.

Abstract: A liquid container device includes: a liquid container having an inlet; a casing in which the liquid container is housed; and a cap lever having a cap configured to seal the inlet. The liquid container has an upper surface, and a visualization surface. The casing includes a cover configured to pivot and that protects the upper surface, a cap lever-engaging portion, a visualization portion having an opening, and a wall portion disposed on the +Z direction side with respect to the visualization portion. The cap lever includes an engageable portion configured to be engaged with the cap lever-engaging portion, and a body extending in the +Y direction from the engageable portion. A surface disposed so as to face the cover of the body is planar, and an end of the body in the +Y direction is separated from an end of the wall portion in the +Z direction.

Abstract: There is provided a printer including: a casing defining an internal space; a conveyor; a head; a tank, a first channel communicating the tank and the head with each other; a first pressure gauge; a first pump; a second channel communicating the tank and the head with each other; a second pressure gauge; and a second pump. The internal space includes a first space defined between a first virtual surface and a second virtual surface which are parallel to a conveyance direction and an up-down direction 7, and a second space which is different from the first space; the head is positioned in the first space; and the tank, the first pressure gauge, the first pump, the second pressure gauge, and the second pump are positioned in the second space.

Abstract: A liquid ejecting head including a nozzle configured to eject a liquid, a liquid flow path communicating with the nozzle, a communication chamber including a communication port configured to communicate with atmospheric air, a partitioning wall portion provided between the liquid flow path and the communication chamber, the partitioning wall portion including an opening portion that communicates the liquid flow path and the communication chamber to each other, and an elastic member closing the opening portion.

Abstract: In one example, a method comprises measuring, by a processor, the flow rate of a cleaning fluid to clean at least a portion of a printing apparatus. The measured flow rate is compared to a desired flow rate. When the measured flow rate is outside of a first deviation from the desired flow rate, but within a second deviation from the desired flow rate, then the method in this example comprises changing the operation of a component of a printing apparatus.

Abstract: In some examples, a controller is to receive sensor data from a sensor associated with a fluid delivery system that delivers fluid from a fluid reservoir to a fluid conduit, determine, based on the sensor data, presence or integrity of a gas purger that is to be fluidically coupled to the fluid conduit, and issue an alert to indicate a gas purger anomaly condition based on the determining.

Abstract: The instant invention is related to a method for replicating an object. The method includes providing an object comprising an outer surface and a channel; applying dry tannin powder to the outer surface of the object wherein at least a portion of the dry tannin powder adheres to the outer surface as imaging tannin; and placing an aqueous solution of an iron salt in the channel wherein the iron salt diffuses through the object to convert said imaging tannin into a replica of the object.

Abstract: A liquid discharge apparatus includes a plurality of head units each of which includes a plurality of heads configured to discharge a liquid, and a plurality of temperature-controlled liquid supply manifolds each of which is configured to distribute the temperature-controlled liquid to the plurality of heads of one of the plurality of head units. The liquid discharge apparatus further includes a conveyor configured to convey a sheet onto which the liquid is applied by the plurality of head units, and the conveyor defines a sheet conveyance passage opposite the plurality of head units. At least one of the plurality of temperature-controlled liquid supply manifolds is disposed between two of the plurality of head units and in a vicinity of the sheet conveyance passage.

Abstract: There is disclosed a fluid container 200 useable with print apparatus. The fluid container comprises a primary module 210 comprising: a primary reservoir 220 to contain print fluid and a regulated chamber 230 to receive the print fluid from the primary reservoir 220. The regulated chamber 203 comprises a regulator unit 232 to actuate a gas control valve 234 to control a flow of relief gas into the fluid container 200 as print fluid is discharged from the fluid container 200. The fluid container comprises a secondary module 250 comprising a secondary reservoir 252 to contain print fluid. The primary reservoir 220 is to receive the print fluid from the secondary reservoir 252 via a re-supply conduit 260 between the secondary reservoir 252 and the primary reservoir 220. The secondary reservoir 252 is to receive the relief gas via the gas control valve 234, and the primary reservoir 220 is to receive the relief gas via the secondary reservoir 252.

Abstract: The liquid L flowed into the bypass communication pipe 93 from the feed reservoir 91f can be returned to the feed reservoir 91f by way of the return reservoir 91r by carrying out the bypass circulation of circulating the liquid L along the bypass circulation channel Cb. Since this bypass communication pipe 93 bypasses the discharge heads H, the liquid L does not pass through the discharge heads H in the bypass circulation. As a result, the liquid L can be circulated between the feed reservoir 91f and the return reservoir 91r while the mixing of foreign substances into the discharge heads H from the respective reservoirs 91f, 91r is suppressed.

Abstract: A droplet ejecting device includes: a first nozzle group consisting of N pieces of first nozzles aligned in a first direction; a second nozzle group consisting of N pieces of second nozzles aligned in the first direction and at the same positions in the first direction as the first nozzles; and a controller. The controller is configured to determine whether an ejection quantity per unit time is not smaller than a first threshold. When the ejection quantity is equal to or greater than the first threshold, a first combination of N pieces of nozzles from among the N pieces of first nozzles and the N pieces of second nozzles is selected. When the ejection quantity is smaller than the first threshold, a second combination of N pieces of nozzles from among the N pieces of first nozzles and the N pieces of second nozzles is selected.

Abstract: A liquid ejecting apparatus includes a liquid supply path through which liquid is supplied to a liquid ejecting head, a liquid discharge path through which the liquid is discharged from the liquid ejecting head, a supply-side pressure adjustment mechanism that adjusts a pressure in a supply-side liquid chamber provided in the liquid supply path to a first pressure at which a gas-liquid interface formed at a nozzle of the liquid ejecting head is maintained, a discharge-side pressure adjustment valve that introduces fluid into a discharge-side liquid chamber when a pressure in the discharge-side liquid chamber provided in the liquid discharge path becomes a second pressure which is lower than the first pressure and at which the gas-liquid interface formed at the nozzle is maintained, and a flow mechanism that discharges the liquid in the liquid ejecting head toward the liquid discharge path via the discharge-side liquid chamber.

Abstract: A liquid supply device includes a liquid discharge head, a main tank, a first sub-tank, a second sub-tank, a first channel, a degassing device, and a second channel. The liquid discharge head is configured to discharge liquid. The main tank is configured to store liquid to be supplied to the liquid discharge head. The first sub-tank is configured to store gas and liquid and connected to the main tank and the liquid discharge head. The second sub-tank is configured to store gas and liquid and connected to the first sub-tank and the liquid discharge head. The first channel connects between the main tank and the first sub-tank. The degassing device is configured to degas liquid in the first channel. The second channel connects between the second sub-tank and the first channel.

Abstract: A differential pressure sensor is used for measuring or identifying a pressure difference, for example to determine a movement or speed of fluid in a fluid conduit or printer re-circulation conduit. The differential pressure sensor determines the difference between an air pressure and a fluid pressure, wherein the fluid is moving in a flow channel. The flow channel includes a surface conveying a fluid between a first port and second port. An opening in the surface of the flow channel provides a fluid communication between the differential pressure sensor and fluid. Moreover, the sensor is arranged in air communication with the pressure box, such as to allow the differential pressure sensor to identify the pressure difference between the air pressure in the pressure box and the fluid pressure in the flow channel.

Abstract: In one example, an article for a replaceable printer component includes an integrated circuit device having a device controller, a conductor to supply power to the device controller and to carry a signal to and from the device controller, and a sensor operatively connected to the device controller to sense a voltage and/or a frequency on the conductor. The device controller to send an indication of a sensed voltage and/or a sensed frequency to the printer controller.

Abstract: A recording apparatus includes: a recording unit that performs a recording by ejecting a liquid on a medium; a carriage that includes the recording unit and is movable in a width direction; a casing that has the carriage therein and constitutes an external appearance of the apparatus; an adapter that is mounted on an upper portion of the recording unit and accommodates the liquid to be supplied to the recording unit; at least one liquid accommodating unit that supplies the liquid to the adapter through a tube and includes a filling port into which the liquid can be filled; and a waste liquid receiving unit that receives the liquid discharged as a waste liquid during a maintenance operation of the recording unit, in which the casing has a cover for covering both the liquid accommodating unit and the waste liquid receiving unit.

Abstract: A liquid ejecting apparatus includes: a pump which is provided for a liquid supply path to supply a liquid stored in a liquid storage portion to a liquid ejection portion; a filter portion which is provided between the pump and the liquid ejection portion as a part of the liquid supply path and which includes a filter and a filter chamber defined by the filter into an upstream filter chamber and a downstream filter chamber; a return path coupled to the upstream filter chamber and the liquid storage portion; and a discharge valve located at the return path. While the pump is driven in a non-communication state between the upstream filter chamber and the liquid storage portion, the non-communication state is switched to a communication state therebetween through the return path using the discharge valve.

Abstract: A liquid ejection head includes pressure chambers arranged in a first direction, first communicating portions, a first common channel extending in the first direction, second communicating portions, a second common channel extending in the first direction, and a damper film. The second common channel includes a first portion and a second portion connecting the first portion and the second communicating portions. The second portion extends from the first portion in a second direction orthogonal to the first direction toward the pressure chambers and is located to a side of the first common channel opposite to the pressure chambers in a third direction orthogonal to the first direction and the second direction. The damper film is located to a side of the second portion opposite in the third direction to the first common channel.

Abstract: The droplet velocities of the nozzles of different groups of nozzles of a print head of an inkjet printing device are determined for different line clock rates. An optimized operating line clock rate is then determined for the operation of the printing device, where the deviation between the droplet velocities of the nozzles of the different groups is reduced (e.g. minimized). The droplet positioning along the transport direction of a recording medium may be advantageously homogenized via the convergence of the droplet velocities.

Abstract: A liquid feeding unit has a first chamber, a second chamber, a wall portion, an opening-closing member, and a filter member. The first chamber has a first feed passage connected to it to receive liquid through the first feed passage. The second chamber receives the liquid from the first chamber, and has a second feed passage for feeding the liquid connected to it. The wall portion has a communication hole through which the first and second chambers communicate with each other. The opening-closing member is arranged in the communication hole to open and close it. The filter member is arranged in the first feed passage or in the first chamber to remove foreign matter in the liquid.

Abstract: The invention describes a facility to provide an indication of level in a container of conductive liquid used in an inkjet printer. The facility comprises an array of nested capacitive sensor pads, the outputs of which can be processed to provide a continuous indication of level. The outputs can also be processed to provide an indication of whether the container is mis-aligned on the printer.

Abstract: Herein is described an inkjet printing system comprising: an aqueous pre-treatment fluid comprising a cationic polymer and a pre-treatment vehicle; an aqueous inkjet ink composition comprising a latex polymer comprising a (meth)acrylate or (meth)acrylamide polymer or copolymer, a pigment and an ink vehicle; and an aqueous inkjet overcoat composition comprising a latex polymer comprising a (meth)acrylate or (meth)acrylamide polymer or copolymer, a wax and an overcoat vehicle.

Abstract: A liquid discharge apparatus includes a case receiving a cartridge having a first chamber, a tank having a second chamber, a head, and a controller to: calculate outflow amount Qa flowed from the second chamber for a time period ?t based on discharge amount Dh; calculate outflow amount Qc flowed from the first chamber toward the second chamber for the time period ?t based on the outflow amount Qa and flow path resistances; read liquid amounts Vc and Vs of the first and second chambers from a memory; subtract the outflow amount Qc from the read liquid amount Vc to calculate new liquid amount Vc; subtract the outflow amount Qa from the read liquid amount Vs and add the outflow amount Qc to calculate new liquid amount Vs; and store the calculated liquid amounts Vc and Vs in the memory.

Abstract: A printing device includes: a controller configured to perform printing wherein in a first case where a first condition is not satisfied, the controller controls the main-scanning unit to perform the main-scanning at a first speed and controls the print head to discharge the ink to correspond to a specific pixel of a partial image to be printed by the partial printing when the print head is at a first position, and in a second case where the first condition is satisfied, the controller controls the main-scanning unit to perform the main-scanning at a second speed slower than the first speed and controls the print head to discharge the ink to correspond to the specific pixel when the print head is at a second position, which is located at a downstream of the first position in the direction of the main-scanning.

Abstract: The image processing apparatus of the present invention includes: an image data acquisition unit configured to acquire image data; a generation unit configured to generate an ejection pattern of ink droplets from the image data, which are ejected for forming dots from a plurality of nozzles of an image forming apparatus; a characteristic acquisition unit configured to acquire an ejection characteristic of ink droplets of the image forming apparatus; and a pattern change processing unit configured to change the ejection pattern based on the ejection characteristic and the ejection pattern, and the pattern change processing unit repeatedly performs, in a case where a gap occurs between dots that should be formed so as to contact each other by the image forming apparatus, the ejection pattern change until the gap is eliminated.

Abstract: An inkjet printing apparatus includes a print head ejecting ink, a tank reserving ink to be supplied to the print head and a joint unit being capable of connecting the print head and the tank to each other. The joint unit has a connecting portion for supplying ink to the print head and a shaft that is rotatable by a drive source so as to move in an axial direction. The connecting portion moves together with the shaft. The print head includes a head joint connectable to the connecting portion and an engaging portion engageable with one end of the shaft. The shaft is rotated to be engaged with the engaging portion so that the head joint and the connecting portion are connected to each other.

Abstract: A liquid circulation device includes a housing having an outlet and an inlet, a circulation unit configured to convey liquid out of the housing through the outlet and recover liquid into the housing through the inlet, a liquid supplying unit configured to supply liquid into the housing, an air conveying unit configured to convey air into and out of the housing, a level detecting unit configured to detect a level of the liquid in the housing, a pressure sensing unit configured to detect a pressure of the air in the housing, and a control unit configured to control a pressure of the liquid in the housing by controlling the liquid supplying unit or the air conveying unit, based on the level and the pressure of the air.

Abstract: An inkjet printing apparatus includes an ink jetting unit to jet ink to a substrate, a stage to movably support the substrate relative to the ink jetting unit, and a pair of air-conditioning units arranged at front and rear ends of the ink jetting unit in a direction in which the stage is moved, the air-conditioning units each including an air blowing unit and a suction unit.

Abstract: A treatment-liquid application device includes a treatment liquid applicator to apply a treatment liquid to an application target object to which a black liquid and a color liquid other than the black liquid are applied. The treatment liquid applicator applies a greater amount of the treatment liquid per unit area to at least a region to which the color liquid is applied than a region to which the black liquid is applied.

Abstract: A coating apparatus is connectable to both an image forming apparatus and a sheet feeder. The coating apparatus includes a coater, a carry-in entrance, and an ejector. The coater coats a recording medium with a treatment liquid. The carry-in entrance is on one of two exterior wall surfaces facing each other. The recording medium is conveyed from the sheet feeder through the carry-in entrance. The ejector is on another of the two exterior wall surfaces. The ejector ejects the recording medium to the image forming apparatus. A position of the carry-in entrance on the one of the exterior wall surfaces matches a position of the ejector on said another of the exterior wall surfaces.

Abstract: An electronic pen includes an ink writing section including a core body and an ink holding section configured to hold an ink that is supplied to the core body, a circuit board, a transmission section which, in operation, transmits a signal, a connection member including a first side that holds an end portion of the ink writing section, on a side of the ink writing section opposite to the core body, and a second side that holds a first end portion of the circuit board, a pen pressure detector provided adjacent to a second end portion of the circuit board, and a casing configured to accommodate the ink writing section, the connection member, the circuit board and the pen pressure detector such that a tip portion of the core body protrudes from the casing.

Abstract: A method for forming an image reproduction is detailed. The method includes: providing a media comprising a first side and a second side wherein the second side is opposite the first side; printing a stock image to be reproduced on the first side with ink from an ink-jet printer to form an image precursor; covering the image precursor with an excess of dry tannin powder wherein a portion of the dry tannin powder adheres to the stock image as imaging tannin and a remainder of the dry tannin powder is unaltered dry tannin powder; removing the unaltered dry tanning powder; and placing an aqueous solution of an iron salt on the second side opposite the imaging tannin wherein the iron salt migrates through the media to convert the imaging tannin into the image reproduction wherein the image reproduction replicates the stock image.

Abstract: A liquid ejection device is disclosed. One device includes a liquid supply member defining a liquid supply channel that is in communication with a common liquid chamber via an outlet of the liquid supply channel. The outlet and the common liquid chamber extend along a longitudinal direction respectively. The liquid supply member includes a plurality of ribs located within the liquid supply channel, the plurality of ribs are disposed side by side in the longitudinal direction. The plurality of ribs includes a first rib, a second rib and a third rib. A distance from the first rib to the third rib in the longitudinal direction is smaller than a distance from the first rib to the second rib in the longitudinal direction.

Abstract: Provided are an image processing apparatus, image processing method, and display apparatus capable of processing a printed image including a color metallic area to be printed by applying color ink containing coloring material and metallic ink containing metal particles on top of each other, into an image displayable on the display apparatus. The image processing apparatus includes: a generation unit that generates preview image data for displaying a preview image on a display apparatus, based on image data for printing a color metallic image including the color metallic area; and a control unit that controls the display apparatus such that the preview image is displayed based on the preview image data generated by the generation unit. A color that expresses the color metallic area in the preview image data is different from a color forming the color metallic area in the image data.

Abstract: A method of calibrating an inkjet printer, which comprises a fluid circuit (4), a print head (1) connected to the fluid circuit through an umbilical (19), this method comprising at least the following functions: calculate a difference between the viscosity of the ink used in the circuit, and a theoretical viscosity of this ink; as a function of this difference, correct data representative of a characteristic function that relates the pressure at a point referred to as the reference point in the fluid circuit or the print head, the ink density, the ink viscosity, the operating temperature and a velocity referred to as the nominal velocity of the ink jet generated by the print head, to form corrected data for said characteristic function.

Abstract: An ejection device includes: ejection portions that eject liquids; supply portions that supply the liquids to the ejection portions respectively; a common pressure applying mechanism that applies pressure onto the liquids at the supply portions; and a pressure difference generating mechanism that generates a relative pressure difference between the ejection portions for the liquids to be supplied from the supply portions to the ejection portions.

Abstract: A method for carrying out a printing operation on an inkjet printing machine compensates for failed printing nozzles by using a computer. After a screening process in which a halftone image is created for an image to be printed, failed printing nozzles are compensated for by increased ink application from neighboring printing nozzles by precalculating at least one corrective halftone image for the adjacent printing nozzles by using the computer, replacing the halftone image created in the screening process by the corrective halftone image in the at least one column of the neighboring printing nozzles, and carrying out the printing operation on the inkjet printing machine using the corrected halftone.

Abstract: A liquid jetting apparatus includes: a head which jets liquid supplied from a liquid tank; a memory which stores pieces of reference data; and a controller which estimates viscosity of the liquid in the liquid tank every time a predefined time passes. The controller acquires a total supply amount or cumulative supply amount of the liquid supplied from the liquid tank and a supply amount of the liquid per unit time within the predefined time, estimates a viscosity change amount of the liquid in the liquid tank based on the cumulative supply amount acquired, the supply amount per unit time acquired, and the pieces of reference data, and estimates the viscosity of the liquid in the liquid tank based on the viscosity change amount estimated and the viscosity of the liquid in the liquid tank at an initial timing point or a most-recent estimation timing point.

Abstract: A liquid supply device includes a first tank to store a liquid, a first pump to supply the liquid from the first tank to a liquid pan, as a first supply operation, a second tank coupled to the first tank, and a second pump to supply the liquid from the second tank to the first tank, as a second supply operation. The liquid supply device further includes circuitry configured to control the first supply operation and the second supply operation. The circuitry accumulates operation time of the first supply operation and starts the second supply operation at a start of the first supply operation under a condition where a cumulative operation time of the first supply operation is equal to or longer than a threshold.

Abstract: A system and method for supplying ink can include an ink supply device with a first end and a second end located along an axis on opposite sides of the ink supply device. In an example, the first end is frustum shaped, and the second end is frustum shaped. In an example, a first ink connector can be attached to the first end. In an example, a second ink connector can be attached to the second end. In an example, a pump can be connected to the second ink connector to move ink accumulating in the second end through the second ink connector into the ink supply system.

Abstract: A liquid supply apparatus includes a liquid container to temporarily store liquid, a vacuum device connected to the liquid container to decompress the liquid container to form a negative pressure in the liquid container and a negative pressure forming device disposed between the liquid container and the vacuum device. The vacuum device includes a gas chamber connected to the liquid container, a flexible member forming a part of wall surface of the gas chamber, a first elastic member to push the flexible member in a first direction to expand the gas chamber, a pressing member to push the flexible member in a second direction opposite the first direction to compress the gas chamber. The gas chamber moves between a connection position and a cutoff position.

Abstract: An inkjet printer includes: a pressurized space and a depressurized space for circulation of ink along a circulation path; a main connection path and an adjustment path connecting the pressurized space and the depressurized space to each other; an air pump configured to send air from the depressurized space to the pressurized space though the main connection path or the adjustment path; a changeover device configured to change over between the main connection path and the adjustment path; and a controller. The controller drives the air pump with the main connection path being set to generate preset pressures respectively in the pressurized space and the depressurized space and then controls the air pump with the adjustment path being changed over to maintain pressures in the pressurized space and the depressurized space respectively at the preset pressures.