Abstract: An inkjet recording apparatus is provided, wherein the inkjet recording apparatus comprises a recording head with a filter, an ink that comprises a colorant, a humectant, a surfactant, and a wetting agent is discharged from the recording head, the viscosity of the ink at 25° C. is 6 mPa·s to 13 mPa·s, and the fluid resistance of the filter against the ink is 4.4×109 Pa·s/m3 and 2.2×1010 Pa·s/m3.

Abstract: A pressure adjustment mechanism can provide ink to a subtank with the inside of the subtank being opened to outside air, by using a low driving force. A liquid tank holds liquid to be used by a printing apparatus. The liquid tank has a structure in which a capacity of the liquid tank can be changed so as to generate a negative pressure in the liquid tank. The liquid tank includes a case having an opening at one side of the tank, and a flexible film that covers the opening, and a compressed spring in the tank for pressing the film outwards.

Abstract: A powder conveying device includes a powder container, a powder conveying tube, a powder conveying member, and a detecting unit. The powder container is configured to contain powder. The powder conveying tube guides the powder from the powder container to a conveyance destination located downward from the powder container. The powder conveying member is located inside the powder conveying tube, and moves to convey the powder toward downstream in a conveying direction. The detecting unit is located in the powder conveying tube, and detects a remaining amount of powder. Time t2 taken to convey the maximum amount of powder satisfies t2<t1 where t1 is the sum of time required to feed recording sheets and time interval between feeding of the recording sheets.

Abstract: A sub tank is provided that includes a case at which an air flow path is formed, the air flow path including an entrance flow path portion that is connected to an ink accommodating portion of the case, and a cross flow path portion that continues from the entrance flow path portion. The cross flow path portion extends in an upper diagonal direction with respect to a reference plane corresponding to the ink liquid level at a standstill state. Another sub tank is provided that includes a case forming an ink accommodating portion, on which case a flexible film member is attached through bonding or welding to seal an opening of the ink accommodating portion and to form one side of the sub tank. A spring is disposed within the ink accommodating portion between the case and the flexible film member, the spring forcing the flexible film member outward.

Abstract: A pressure adjustment mechanism can provide ink to a subtank with the inside of the subtank being opened to outside air, by using a low driving force. A liquid tank holds liquid to be used by a printing apparatus. The liquid tank has a structure in which a capacity of the liquid tank can be changed so as to generate a negative pressure in the liquid tank. The liquid tank includes a case having an opening at one side of the tank, and a flexible film that covers the opening, and a compressed spring in the tank for pressing the film outwards.

Abstract: An image forming apparatus of the present invention includes an endless belt for conveying a recording medium. The belt is passed over four support rollers each being formed with an annular guide groove that receives a guide formed on the belt. Assume that a biasing force F2 acts on one end of at least one support roller remote from the guide of the belt, and a biasing force F1 acts on the other side close to the guide member. Then, a relation of F1<F2<1.5×F1 holds. This frees the image transfer surface of the belt from slackening and creasing.

Abstract: An image forming apparatus of the present invention includes an endless belt for conveying a recording medium. The belt is passed over four support rollers each being formed with an annular guide groove that receives a guide formed on the belt. Assume that a biasing force F2 acts on one end of at least one support roller remote from the guide of the belt, and a biasing force F1 acts on the other side close to the guide member. Then, a relation of F1<F2<1.5×F1 holds. This frees the image transfer surface of the belt from slackening and creasing.