Abstract: One of the two flow passages branches from one of two ink cartridges to one of the two discharging portions and one of the two individual discharging portions. The other flow passage branches from the other ink cartridge to the other discharging portion and the other individual discharging portion. A ratio of frequency of use of each of the discharging portions, Ra, and frequency of use of each of the individual discharging portions, Rb, satisfies Ra:Rb=1:1/2.

Abstract: A charge accumulated on an insulative nozzle plate flows into the ink with which nozzle openings and pressure generation chambers are filled and reaches a vibration plate. The charge that has reached the vibration plate is driven out therethrough because the vibration plate is made of a conductive ceramic material and is grounded. Therefore, it is possible to obtain an ink jet recording head in which insulation breakdown of the vibration plate caused by the charge accumulated on the vibration plate is suppressed from occurring and a driving circuit is suppressed from being damaged.

Abstract: One of the two flow passages branches from one of two ink cartridges to one of the two discharging portions and one of the two individual discharging portions. The other flow passage branches from the other ink cartridge to the other discharging portion and the other individual discharging portion. A ratio of frequency of use of each of the discharging portions, Ra, and frequency of use of each of the individual discharging portions, Rb, satisfies Ra:Rb=1:1/2.

Abstract: A nozzle plate made of conductive ceramics is grounded. Therefore, electric charges do not easily accumulate on the nozzle plate. The migration of electric charges from nozzle orifices to a diaphragm plate through ink filled in pressure generation chambers is unlikely to occur or significantly less likely to occur. Thus, it is possible to prevent the dielectric breakdown of the diaphragm plate caused conventionally by accumulated electric charges and to provide an ink-jet recording head that is substantially free from the damage of a driving circuit.

Abstract: One of the two flow passages branches from one of two ink cartridges to one of the two discharging portions and one of the two individual discharging portions. The other flow passage branches from the other ink cartridge to the other discharging portion and the other individual discharging portion. A ratio of frequency of use of each of the discharging portions, Ra, and frequency of use of each of the individual discharging portions, Rb, satisfies Ra:Rb=1:½.

Abstract: A printer includes first and second ejecting sections of which positions of nozzles are different from each other in a sub scanning direction, and an ejecting section group. The ejecting section group includes first and second individual ejecting sections of which the positions of the nozzles are same in the sub scanning direction. When a frequency of ejecting the liquid using the first and second ejecting sections and the first and second individual ejecting sections are Ra, Rb, Rc and Rd, the first mode in which Ra:Rb:Rc:Rd is 1:1:1:0, a second mode in which Ra:Rb:Rc:Rd is 1:1:0:1 and a third mode in which Ra:Rb:Rc:Rd is 1:1:0.5:0.5 are selected on the basis of the residual amounts of the ink.

Abstract: One of the two flow passages branches from one of two ink cartridges to one of the two discharging portions and one of the two individual discharging portions. The other flow passage branches from the other ink cartridge to the other discharging portion and the other individual discharging portion. A ratio of frequency of use of each of the discharging portions, Ra, and frequency of use of each of the individual discharging portions, Rb, satisfies Ra:Rb=1:½.

Abstract: A liquid ejecting head includes a flow path formation substrate on which individual flow paths communicating with nozzle openings for ejecting liquid are provided, a first member which is provided at one surface side of the flow path formation substrate and has pressure generation units for generating pressure change in liquid in the individual flow paths, and a second member which is provided at a surface side of the flow path formation substrate, which is opposite to the first member. Dummy flow paths are provided on the flow path formation substrate independently of the individual flow paths. Exposure portions which expose a part of wall surfaces of the flow path formation substrate which form the dummy flow paths, are provided at least one of the first member and the second member.

Abstract: A charge accumulated on an insulative nozzle plate flows into the ink with which nozzle openings and pressure generation chambers are filled and reaches a vibration plate. The charge that has reached the vibration plate is driven out therethrough because the vibration plate is made of a conductive ceramic material and is grounded. Therefore, it is possible to obtain an ink jet recording head in which insulation breakdown of the vibration plate caused by the charge accumulated on the vibration plate is suppressed from occurring and a driving circuit is suppressed from being damaged.

Abstract: A nozzle plate made of conductive ceramics is grounded. Therefore, electric charges do not easily accumulate on the nozzle plate. The migration of electric charges from nozzle orifices to a diaphragm plate through ink filled in pressure generation chambers is unlikely to occur or significantly less likely to occur. Thus, it is possible to prevent the dielectric breakdown of the diaphragm plate caused conventionally by accumulated electric charges and to provide an ink-jet recording head that is substantially free from the damage of a driving circuit.

Abstract: A threshold passed signal indicating that a threshold for a remaining liquid amount has been passed is inputted from a threshold sensor that detects the actual remaining liquid amount in the liquid holding unit when the liquid ejection command is being executed, the control apparatus drives the liquid ejecting head so that the liquid continues to be ejected based on the liquid ejection command until the inputted liquid ejection command ends.

Abstract: A printer includes first and second ejecting sections of which positions of nozzles are different from each other in a sub scanning direction, and an ejecting section group. The ejecting section group includes first and second individual ejecting sections of which the positions of the nozzles are same in the sub scanning direction. When a frequency of ejecting the liquid using the first and second ejecting sections and the first and second individual ejecting sections are Ra, Rb, Rc and Rd, the first mode in which Ra:Rb:Rc:Rd is 1:1:1:0, a second mode in which Ra:Rb:Rc:Rd is 1:1:0:1 and a third mode in which Ra:Rb:Rc:Rd is 1:1:0.5:0.5 are selected on the basis of the residual amounts of the ink.

Abstract: One of the two flow passages branches from one of two ink cartridges to one of the two discharging portions and one of the two individual discharging portions. The other flow passage branches from the other ink cartridge to the other discharging portion and the other individual discharging portion. A ratio of frequency of use of each of the discharging portions, Ra, and frequency of use of each of the individual discharging portions, Rb, satisfies Ra:Rb=1:½.

Abstract: An image forming apparatus capable of changing over between black printing and color printing with an intermediate transfer belt being brought into contact with and separated from photoconductors by means of a black transfer member and a three-color-integrated color transfer member. The image forming apparatus has a registration mark former for forming registration marks on the intermediate transfer belt, a registration sensor for reading the registration marks, and a controller for controlling the registration mark former based on the registration marks read by the registration sensor, so as to adjust registration. The controller has an adjustment mode to adjust registration between black and color.

Abstract: An image forming apparatus, includes a plurality of image bearing members, respectively provided with image bearing member pulleys coaxially for rotating in one body with the corresponding image bearing members; an idler pulley, disposed between the image bearing members; a single drive belt, wound over the image bearing member pulleys for rotatively driving the image bearing member pulleys; and a tension pulley, adjusting a tension of the drive belt. An image write-to-transfer time of the image bearing member which is disposed on a side closer to the tension pulley than the idler pulley is set integer times of a rotation period of the idler pulley.

Abstract: A liquid development device has a developer retaining roller having recesses, which are for retaining liquid developer, provided in the surface of the developer retaining roller; and a supplying roller for supplying the liquid developer to the developer retaining roller. The upper edge of the supplying roller is located above the lower edge of the developer retaining roller in the vertical direction, and the supplying roller supplies the liquid developer to the developer retaining roller downwards from above.

Abstract: An image forming apparatus capable of changing over between black printing and color printing with an intermediate transfer belt being brought into contact with and separated from photoconductors by means of a black transfer member and a three-color-integrated color transfer member. The image forming apparatus has a registration mark former for forming registration marks on the intermediate transfer belt, a registration sensor for reading the registration marks, and a controller for controlling the registration mark former based on the registration marks read by the registration sensor, so as to adjust registration. The controller has an adjustment mode to adjust registration between black and color.

Abstract: An image forming apparatus, includes a plurality of image bearing members, respectively provided with image bearing member pulleys coaxially for rotating in one body with the corresponding image bearing members; an idler pulley, disposed between the image bearing members; a single drive belt, wound over the image bearing member pulleys for rotatively driving the image bearing member pulleys; and a tension pulley, adjusting a tension of the drive belt. An image write-to-transfer time of the image bearing member which is disposed on a side closer to the tension pulley than the idler pulley is set integer times of a rotation period of the idler pulley.

Abstract: A liquid development device has a developer retaining roller having recesses, which are for retaining liquid developer, provided in the surface of the developer retaining roller; and a supplying roller for supplying the liquid developer to the developer retaining roller. The upper edge of the supplying roller is located above the lower edge of the developer retaining roller in the vertical direction, and the supplying roller supplies the liquid developer to the developer retaining roller downwards from above.