Abstract: This invention provides a small and simple construction to drive a mechanism for maintaining a printing performance of a print head. In one preferred mode of the invention, a recovery device to maintain the printing performance of the print head has a suction pump unit, a capping unit and a wiping unit. The suction pump unit is driven through a spring clutch mechanism by an LF motor in the print sheet transport unit as a drive source. The capping unit and the wiping unit are driven by an AP motor as a drive source in a rotary dead zone set for a paper feed unit that feeds the print sheet to a transport unit. A piston pump is suited for use in a recovery operation to maintain the function of the print head.

Abstract: In a supply system which includes an ink container for reserving a predetermined amount of ink to be supplied to a printing head and which is configured such that ink is intermittently supplied to the container from an ink tank, there is provided a structure that fundamentally eliminates waste of ink associated with an operation of charging the container to apply a required negative pressure to the head. An ink containing body in which a negative pressure can be generated because of its elasticity is provided in the container. After the ink containing body is expanded to introduce ink into the same by depressurizing the interior of the container, the interior of the container is pressurized to contract the ink containing body, thereby returning a predetermined amount of ink to the tank. A negative pressure is thus generated in equilibrium with an ink meniscus holding ability of the head.

Abstract: For eliminating waste of ink and achieving high charging efficiency with a reduced charging time where a printing head is equipped with a second tank for reserving a predetermined amount of ink and a supply system is configured to supply ink from a first tank to the second tank intermittently, the second tank is provided with a variable internal volume. The internal volume is varied to cause the second tank itself to function as an actuator for charging ink and performing a venting process. Specifically, the internal volume is forcibly reduced to cause a reverse flow of a gas residing in the second tank along with ink into the first tank, which makes it possible to generate of waste ink that is released to the outside. A normal charging operation can be completed simply by causing a change in the opposite direction (the direction of increasing the internal volume). Relatedly, the second tank may be provided with a member for holding ink and generating a negative pressure originating from an elastic force.

Abstract: There is provided an inkjet printing head carrying a sub-tank from which accumulated gases can be easily discharged. The inkjet printing head includes a sub-tank which has a movable section constituted by a deformable film sheet, a spring for generating a negative pressure, and a supply/discharge channel for supplying ink and discharging accumulated gases. The sub-tank is intermittently supplied with ink from a main tank and reserving the ink. The supply/discharge channel is provided in a position where it does not interfere with the movable section and the spring, e.g., in a frame of the sub-tank. The supply/discharge channel is preferably formed in an upper part of the sub-tank, e.g., a ceiling section of the sub-tank.

Abstract: The present invention provides an image forming apparatus for forming an image by discharging liquid from a recording head onto a recording medium, comprising a carriage to which the recording head and a sub-tank for storing the liquid to be supplied to the recording head are mounted and which can be shifted reciprocally, a main tank disposed out of the carriage and adapted to store the liquid, a liquid flow passage connected between the main tank and the sub-tank in order to supply the liquid from the main tank to the sub-tank, a flow passage opening/closing valve disposed in the liquid flow passage on the way and adapted to open and close the liquid flow passage, and control means for controlling opening/closing of the flow passage opening/closing valve in accordance with an image forming condition during image formation using the recording head.

Abstract: In a structure which includes a second tank for reserving a predetermined amount of ink to be supplied to a printing head and in which a supply system is configured such that ink is intermittently supplied to the second tank from a first tank, a high charging efficiency to and shortened processing time for charging the second tank, and high overall usability of ink are achieved. In an orientation upon using the printing apparatus, a port of a channel located at the second tank side for supplying ink from the first tank to the second tank is arranged relatively high position and an outlet port for supplying ink from the second tank to the head is arranged relatively low position in relation to the direction of gravity, and a port of the channel located at the first tank side is arranged at the bottom of the first tank.

Abstract: An ink tank is formed having a generally rectangular parallelepiped shape, and air/fluid separating members having air pores are provided around at least the corner portions of the generally rectangular parallelepiped. The inner faces of wall members forming the outer faces of the generally rectangular parallelepiped are formed with an inclination of a predetermined angle as to the outer face of the wall member which it faces.

Abstract: In a supply system which includes an ink container for reserving a predetermined amount of ink to be supplied to a printing head and which is configured such that ink is intermittently supplied to the container from an ink tank, there is provided a structure that fundamentally eliminates waste of ink associated with an operation of charging the container to apply a required negative pressure to the head. An ink containing body in which a negative pressure can be generated because of its elasticity is provided in the container. After the ink containing body is expanded to introduce ink into the same by depressurizing the interior of the container, the interior of the container is pressurized to contract the ink containing body, thereby returning a predetermined amount of ink to the tank. A negative pressure is thus generated in equilibrium with an ink meniscus holding ability of the head.

Abstract: A high-intensity discharge lamp includes an arc tube having a pair of main electrodes, a starting circuit having a thermally-actuated switch for disconnecting the starting circuit, and an outer tube for containing the arc tube and the starting circuit, and the lamp is lighted by means of a reactance ballast. The thermally-actuated switch includes an envelope bulb that covers contacts of the thermally-actuated switch. Thereby, occurrence of sustained arc discharge in the outer tube is prevented in the case of a starting failure or a break-off of the arc tube at the end of the lamp's life.

Abstract: The present invention provides an image forming apparatus for forming an image by discharging liquid from a recording head onto a recording medium, comprising a carriage to which the recording head and a sub-tank for storing the liquid to be supplied to the recording head are mounted and which can be shifted reciprocally, a main tank disposed out of the carriage and adapted to store the liquid, a liquid flow passage connected between the main tank and the sub-tank in order to supply the liquid from the main tank to the sub-tank, a flow passage opening/closing valve disposed in the liquid flow passage on the way and adapted to open and close the liquid flow passage, and control means for controlling opening/closing of the flow passage opening/closing valve in accordance with an image forming condition during image formation using the recording head.

Abstract: There is provided an inkjet printing head carrying a sub-tank from which accumulated gases can be easily discharged. The inkjet printing head includes a sub-tank which has a movable section constituted by a deformable film sheet, a spring for generating a negative pressure, and a supply/discharge channel for supplying ink and discharging accumulated gases. The sub-tank is intermittently supplied with ink from a main tank and reserving the ink. The supply/discharge channel is provided in a position where it does not interfere with the movable section and the spring, e.g., in a frame of the sub-tank. The supply/discharge channel is preferably formed in an upper part of the sub-tank, e.g., a ceiling section of the sub-tank.

Abstract: According to an image forming apparatus, a simple arrangement is used to switch the transmission of drive forces, produced by drive sources that are used in common by multiple drive mechanisms, without depending on the movement of a carriage, for example. The drive force produced by a line feed (LF) motor to drive feed rollers is transmitted to a pump cam in a recovery system via a pendulum drive force transmission mechanism, which is provided at one end close to the feed rollers. And the drive force produced by another motor to drive paper supply rollers is transmitted via the same pendulum drive force transmission mechanism to the paper supply rollers, or to a blade holder and a cap holder in the recovery system. Therefore, the transmission of the drive forces can be switched by controlling the rotational directions of the motors.

Abstract: The present invention provides a compact pump capable of simultaneous sucking/discharging desired volumes of fluid in a plurality of systems, which includes a separating wall dividing a cylinder into a plurality of fluid compartments, discharging ports and sucking ports mutually arranged at opposite sides of the respective fluid compartments with respect to longitudinal direction, a plurality of pistons accommodated in the respective fluid compartments so as to slide in the respective fluid compartments and to divide respective fluid compartments into two rooms, and a common piston rod for the pistons passing through the separating wall to reciprocate the pistons in fluid compartments respectively.

Abstract: A structure which includes a container for reserving a predetermined amount of ink to be supplied to a printing head and in which a supply system is configured such that ink is intermittently supplied to the container from an ink tank makes it possible to reduce the time for charging the container with ink. A member for holding ink and generating a negative pressure is provided in the container. With connecting the tank and the member, the pressure in the container is reduced to cause the member to expand, thereby introducing ink into the same. This introduction is stopped by regulating the expansion with a displaceable unit which expands when the pressure is reduced. The regulation is performed at such a position that the negative pressure generated in the member by canceling regulation is in equilibrium with an ink meniscus holding ability of the printing head.

Abstract: For eliminating waste of ink and achieving high charging efficiency with a reduced charging time where a printing head is equipped with a second tank for reserving a predetermined amount of ink and a supply system is configured to supply ink from a first tank to the second tank intermittently, a second tank having a variable internal volume is provided, and the internal volume is varied to cause the second tank itself functions as an actuator for charging ink and performing a venting process. Specifically, the internal volume is forcibly reduced to cause a reverse flow of a gas residing in the second tank along with ink into the first tank, which makes it possible to generation of waste ink that is released to the outside. A normal charging operation can be completed simply by causing a change in the opposite direction (the direction of increasing the internal volume).

Abstract: A structure which includes a container for reserving a predetermined amount of ink to be supplied to a printing head and in which a supply system is configured such that ink is intermittently supplied to the container from an ink tank as an ink supply source makes it possible to reduce the time for charging the container with ink. A member for holding ink and generating a negative pressure originating from an elastic force is provided in the container. With connecting the tank and the member, the pressure in the container is reduced to cause the member to expand, thereby introducing ink into the same. This introduction is stopped by regulating the expansion with a displaceable unit. A negative pressure is generated in the member by canceling regulation by the unit to put it in equilibrium with an ink meniscus holding ability of the printing head.

Abstract: In a structure which includes a second tank for reserving a predetermined amount of ink to be supplied to a printing head and in which a supply system is configured such that ink is intermittently supplied to the second tank from a first tank, a high charging efficiency to and shortened processing time for charging the second tank, and high overall usability of ink are achieved. In an orientation upon using the printing apparatus, a port of a channel located at the second tank side for supplying ink from the first tank to the second tank is arranged relatively high position and an outlet port for supplying ink from the second tank to the head is arranged relatively low position in relation to the direction of gravity, and a port of the channel located at the first tank side is arranged at the bottom of the first tank.

Abstract: A high-intensity discharge lamp includes an arc tube having a pair of main electrodes, a starting circuit having a thermally-actuated switch for disconnecting the starting circuit, and an outer tube for containing the arc tube and the starting circuit, and the lamp is lighted by means of a reactance ballast. The thermally-actuated switch includes an envelope bulb that covers contacts of the thermally-actuated switch. Thereby, occurrence of sustained arc discharge in the outer tube is prevented in the case of a starting failure or a break-off of the arc tube at the end of the lamp's life.

Abstract: The objective of the present invention is to provide a compact pump capable of simultaneous sucking/discharging desired volumes of fluid in a plurality of systems, which does not exist up to now. The pump comprises as follows attains the objective; a separating wall dividing a cylinder into a plurality of fluid compartments, discharging ports and sucking ports mutually arranged at opposite sides of the respective fluid compartments with respect to longitudinal direction, a plurality of pistons accommodated in the respective fluid compartments so as to slide in the respective fluid compartments and to divide respective fluid compartments into two rooms and a common piston rod for the pistons passing through the separating wall to reciprocate the pistons in fluid compartments respectively.

Abstract: According to an image forming apparatus, a simple arrangement is used to switch the transmission of drive forces, produced by drive sources that are used in common by multiple drive mechanisms, without depending on the movement of a carriage, for example.