Abstract: A maintenance device used in a liquid discharge head includes a first cap to seal a nozzle face of the liquid discharge head, a second cap disposed outside the first cap, and a humidity conditioner disposed outside the first cap and inside the second cap. The second cap seals the first cap and at least a contact portion between the nozzle face of the liquid discharge head and the first cap. The humidity conditioner adjusts humidity in a space between the first cap and the second cap.

Abstract: A maintenance device used in a liquid discharge head includes a first cap to seal a nozzle face of the liquid discharge head, a second cap disposed outside the first cap, and a humidity conditioner disposed outside the first cap and inside the second cap. The second cap seals the first cap and at least a contact portion between the nozzle face of the liquid discharge head and the first cap. The humidity conditioner adjusts humidity in a space between the first cap and the second cap.

Abstract: A curl straightening method in an image apparatus including a fixing apparatus and a curl straightening apparatus is disclosed. The method includes calculating moisture content of a sheet before being supplied to the fixing apparatus; measuring a temperature of a heating unit and a pressurizing unit; calculating a temperature and moisture content of the sheet in the respective conveying sections; calculating a conveying time of the sheet in the respective conveying sections; calculating a residual strain of the sheet in the respective conveying sections from the calculated temperature and the moisture content of the sheet in the respective conveying sections, the calculated conveying time, and the stress relaxation characteristics of the sheet; calculating a final curl amount using the calculated residual strain of the sheet in the respective conveying sections; and controlling the curl straightening apparatus based on the final curl amount obtained.

Abstract: An image forming apparatus includes: a curl correction device which corrects curl generated in a recording medium having passed through a fixing device; a temperature/humidity sensor unit which is installed in a conveying path between the fixing device and the curl correction device, and detects and outputs temperature and humidity near a surface of the recording medium; a calculation unit which calculates temperature and moisture content of the recording medium from the temperature and humidity output values output from the temperature/humidity sensor unit, and calculates curl correction efficiency of the curl correction device from the temperature and moisture content of the recording medium; a control value determination unit which determines a control value to perform a curl correction in the curl correction device, based on the curl correction efficiency calculated by the calculation unit; and a control unit which controls the curl correction device by the control value.

Abstract: A fixing device including an endless belt; a pressing pad located inside the endless belt; a pressing roller pressed toward the pressing pad with the endless belt therebetween to form a fixing nip; an internal guide to position the endless belt; and an external guide, which is contacted with an outer surface of the endless belt at the exit side of the fixing nip to deform the endless belt. The pressing roller drives the endless belt to rotate.

Abstract: A curl straightening method in an image apparatus including a fixing apparatus and a curl straightening apparatus is disclosed. The method includes calculating moisture content of a sheet before being supplied to the fixing apparatus; measuring a temperature of a heating unit and a pressurizing unit; calculating a temperature and moisture content of the sheet in the respective conveying sections; calculating a conveying time of the sheet in the respective conveying sections; calculating a residual strain of the sheet in the respective conveying sections from the calculated temperature and the moisture content of the sheet in the respective conveying sections, the calculated conveying time, and the stress relaxation characteristics of the sheet; calculating a final curl amount using the calculated residual strain of the sheet in the respective conveying sections; and controlling the curl straightening apparatus based on the final curl amount obtained.

Abstract: A fixing device including an endless belt; a pressing pad located inside the endless belt; a pressing roller pressed toward the pressing pad with the endless belt therebetween to form a fixing nip; an internal guide to position the endless belt; and an external guide, which is contacted with an outer surface of the endless belt at the exit side of the fixing nip to deform the endless belt. The pressing roller drives the endless belt to rotate.

Abstract: An image forming apparatus includes: a curl correction device which corrects curl generated in a recording medium having passed through a fixing device; a temperature/humidity sensor unit which is installed in a conveying path between the fixing device and the curl correction device, and detects and outputs temperature and humidity near a surface of the recording medium; a calculation unit which calculates temperature and moisture content of the recording medium from the temperature and humidity output values output from the temperature/humidity sensor unit, and calculates curl correction efficiency of the curl correction device from the temperature and moisture content of the recording medium; a control value determination unit which determines a control value to perform a curl correction in the curl correction device, based on the curl correction efficiency calculated by the calculation unit; and a control unit which controls the curl correction device by the control value.

Abstract: An image forming apparatus includes a controller, a database, an image carrier, a transfer unit, a fixing device including a temperature detector and a first drive device, a speed changer, and an electric-current detector. The controller calculates a toner adhesion amount of a recording medium, identifies a type of the recording medium, detects a temperature of the fixing device, determines a moisture content of the recording medium, calculates a reaction force of the recording medium, calculates a toner adhesion force, compares the reaction force and the toner adhesion force, determines a fixing nip angle, drives the first drive device to set the fixing device to the fixing nip angle, determines a target feed speed of the recording medium, and drives the speed changer to change a feed speed of the recording medium to match the target speed.

Abstract: A driving force transmission device superior in reliability with suppressed rotation fluctuation. The driving force transmission device has gearing reception portions, three arm portions and a press member. The gearing reception portions are formed in the inner circumference of a rotor. The arm portions extend from a shaft radially. The arm portions can be elastically deformed. The arm portions have engagement tooth portions for transmitting a driving force of the shaft to the rotor. The press member presses the rotor to bend the arm portions in the direction where the rotor is pressed. In that state, the gearing reception portions gear with the engagement tooth portions.

Abstract: A transfer apparatus comprises a toner image supporting body and a corona transfer means, which are oppositely disposed, and a vibrating unit for exerting vibration force to the rear face of a toner supporting body, disposed opposite to the corona transfer means, wherein the vibrating unit has a cantilever structure for holding an end of a piezoelectric bimorph element in which a pair of piezoelectric bodies each having an electrode, are bonded to both sides of a conductive elastic member (a shim member). A protrusion portion is provided on the other end of the piezoelectric bimorph element.

Abstract: The invention provides a double feed sensing device capable of sensing double feed of paper sent out for the first time. The double feed sensing device includes a thickness sensing unit for sensing thickness of cut paper conveyed, a rigidity sensing unit for sensing bending rigidity of the conveyed paper, and a double feed determining unit for comparing a value of the thickness of the paper sensed by the thickness sensing unit and a value of the bending rigidity of the paper sensed by the rigidity sensing unit with threshold values of thickness and rigidity of the paper set based on values of thickness and bending rigidity of one sheet of the paper and values of thickness and bending rigidity of stacked sheets of the paper, so as to determine whether the paper is double-fed or not.

Abstract: A velocity correction device of an image forming apparatus capable of obtaining a high-quality image. The image forming apparatus includes a rotor, a motor, a motor control unit, and a velocity command memory. The velocity correction device includes a velocity measuring unit, an arithmetic unit, and an interface unit. The velocity correction device is attached to the image forming apparatus. The velocity measuring unit measures the rotational velocity of the rotor when the motor is rotating at a reference rotational velocity which is a fixed velocity. The arithmetic unit compares the measured velocity with a no-velocity-fluctuation velocity of the rotor calculated by the reference rotational velocity of the motor, extracts a velocity fluctuation component of the rotor, and generates the velocity command data to cancel the extracted velocity fluctuation component. The generated velocity command data are transmitted to the velocity command memory through the interface unit, and stored therein.

Abstract: A belt-conveyor device includes a detecting unit that detects a belt position in a width direction of the endless belt for a plurality of times within more than a cycle of the endless belt, the width direction being a direction orthogonal to direction of travel of the endless belt; an average calculating unit that calculates an average belt position from the belt positions detected by the detecting unit; a storing unit that stores therein a plural sets of correction values and belt positions; and a meander correcting unit that corrects meander of the endless belt based on a correction value that corresponds with the average belt position in the storing unit.

Abstract: An image forming apparatus includes a controller, a database, an image carrier, a transfer unit, a fixing device including a temperature detector and a first drive device, a speed changer, and an electric-current detector. The controller calculates a toner adhesion amount of a recording medium, identifies a type of the recording medium, detects a temperature of the fixing device, determines a moisture content of the recording medium, calculates a reaction force of the recording medium, calculates a toner adhesion force, compares the reaction force and the toner adhesion force, determines a fixing nip angle, drives the first drive device to set the fixing device to the fixing nip angle, determines a target feed speed of the recording medium, and drives the speed changer to change a feed speed of the recording medium to match the target speed.

Abstract: A driving force transmission device superior in reliability with suppressed rotation fluctuation. The driving force transmission device has gearing reception portions, three arm portions and a press member. The gearing reception portions are formed in the inner circumference of a rotor. The arm portions extend from a shaft radially. The arm portions can be elastically deformed. The arm portions have engagement tooth portions for transmitting a driving force of the shaft to the rotor. The press member presses the rotor to bend the arm portions in the direction where the rotor is pressed. In that state, the gearing reception portions gear with the engagement tooth portions.

Abstract: To accomplish high-speed fixing which requires high-precision temperature control, or fixing of high-quality color images on various kinds of paper without increasing the size and production cost of the temperature detecting means and contaminating the back sides of paper by toner that comes off from the temperature detecting element, an image forming device is equipped with a fixing device comprising a heating roller, a pressing belt which forcibly contacts the heating roller, and a temperature detecting means which touches the surface of the heating roller to sense the surface temperature of the heating roller, wherein a cleaning means to clean the belt surface is provided on a place which is corresponding to a place at which the contact-type thermistor touches the heating roller.

Abstract: A paper feeder is capable of minimizing abnormal noise produced at a separation pad during paper feed, without reducing the paper feed capability, for use in an image forming apparatus using the same. Buffers are mounted on the separation pad. This arrangement ensures that, when a stick-slip condition occurs between the paper and separation pad during paper feed, and the separation pad is vibrated by the paper, the buffer vibrates so as to dissipate the vibration energy of the separation pad, with the result that the vibration of the separation pad is minimized, thereby to reduce any abnormal noise.

Abstract: In a fixing apparatus including heating member having an elastic layer and a heat source and pressing member having an endless shape member and a pressing member for transporting a record medium in a cut sheet shape while being adhered with an unfixed toner image to pass a nip portion formed by the endless shape member and the heating member and fixing the unfixed toner image on the record medium, the fixing apparatus is constructed by a constitution in which a space between the toner image on the record medium and a surface of the heating member is widened immediately after the record medium is projected from an outlet of the nip portion.

Abstract: An electronic color photography apparatus includes a photosensitive body and a plurality of detachable developing devices. A power for moving the developing devices close to the photosensitive body is created by a retracting force of a slanted teeth gear which is driven at one side of a body of the electronic color photography apparatus.