Abstract: A heating device includes a planar heater, a rotator, a pressure rotator, a heating device frame, a resistor, and a discharger. The pressure rotator has a conductive outer surface and presses the rotator. The heating device frame holds the pressure rotator. The discharger is in contact with the conductive outer surface of the pressure rotator and grounded via the resistor and the heating device frame.

Abstract: Provided is an image forming apparatus including a toner, and a fixing device configured to fix an image formed with the toner on a recording medium. The fixing device includes a fixing belt that is an endless belt, and a planar member configured to heat the fixing belt. An environmental fluctuation rate X is 45% or greater but 85% or less, and the environmental fluctuation rate X is represented by: Environmental fluctuation rate X=(Q1?Q2)/{(Q1+Q2)/2} where Q1 is a quantity of electric charge of the toner in an environment having a temperature of 10 degrees Celsius and relative humidity of 15%, Q2 is a quantity of electric charge of the toner in an environment having a temperature of 27 degrees Celsius and relative humidity of 80%, and a unit for Q1 and Q2 is ?C/g.

Abstract: A fixing device includes a first rotator, a second rotator, a heater, a nip formation pad, and a separator. The second rotator contacts an outer circumferential surface of the first rotator to form a nip between the first rotator and the second rotator. The heater includes a resistive heat generator to heat the first rotator. The nip formation pad contacts an inner circumferential surface of the first rotator to form the nip. The separator separates a recording medium passing through the nip from the first rotator. The separator includes a separating surface and a contact. The separating surface is separated from the outer circumferential surface of the first rotator and separates the recording medium from the first rotator. The contact contacts the outer circumferential surface of the first rotator at a position where the first rotator is pinchable between the contact and the nip formation pad.

Abstract: A belt device includes a secured member, a belt, a pressure rotator, and lubricant. The belt has an endless shape and slides on a slide surface of the secured member. The belt has an inner portion having an elastic power of 55% or more and a sliding surface sliding on the slide surface of the secured member. The sliding surface has a surface roughness smaller than a surface roughness of the slide surface of the secured member. The pressure rotator presses the secured member via the belt to form a nip between the belt and the pressure rotator. The lubricant is interposed between the sliding surface of the belt and the slide surface of the secured member.

Abstract: A rotator driver includes an endless rotator having an end face in a longitudinal direction thereof. A slide aid contacts an inner circumferential face of the endless rotator. A lubricant is applied between the slide aid and the inner circumferential face of the endless rotator. An end face contact member contacts the end face of the endless rotator and has an end face opposed face contacting the end face of the endless rotator and an opposite face being opposite to the end face opposed face. A helical gear is mounted on the opposite face of the end face contact member. The helical gear has teeth being oriented to generate a force that moves the end face contact member toward the end face of the endless rotator as the helical gear rotates. The helical gear has an outer diameter being not greater than an outer diameter of the endless rotator.

Abstract: A heating device includes: a pair of rotators to form a nip; a heating source having a heat generation area to heat at least one rotator; temperature sensors to detect a temperature of the heating source, a member in contact with the heating source, or one rotator; and a sheet sensor to detect a sheet passing through the nip. The temperature sensors include: a first temperature sensor closer to one end than a center of the heat generation area in the longitudinal direction; and a second temperature sensor closer to the center than the first temperature sensor is. The second temperature sensor is at a position shifted from the center of the heat generation area toward the first temperature sensor. The sheet sensor is on a side opposite a side on which the first temperature sensor is disposed with reference to the center of the heat generation area.

Abstract: A heating device includes a first rotator, a heater including a base having a slide face over which an inner face of the first rotator slides, a second rotator forming an outer face nip between the first rotator and the second rotator and a slide nip between the heater and the inner face, and a lubricant holder disposed between the first rotator and the heater to hold a lubricant. The first rotator, the lubricant holder, and the lubricant satisfy a formula of H×X1×R×G?A?V×G, where H is a height of a roughness of the inner face, X1 is a longitudinal length of the first rotator, R is a circumference of the first rotator, G is a specific gravity of the lubricant, A is an application amount of the lubricant on the slide face or the inner face, and V is a volume of the lubricant holder.

Abstract: A belt device includes a belt, a secured member, a pressure rotator, and lubricant. The belt is rotatable and has an endless shape. The belt includes an inner portion having an inner circumferential surface. The inner portion has an elastic power of 55% or more. The inner circumferential surface of the belt slides on the secured member. The pressure rotator includes a porous elastic body and presses the secured member via the belt to form a nip between the belt and the pressure rotator. The lubricant is interposed between the inner circumferential surface of the belt and the secured member.

Abstract: A conveyance device includes a first temperature detector and a second temperature detector that detect a temperature of a heater. A recording medium detector detects a recording medium. The first temperature detector is separated from a center position of an elastic layer of a pressure rotator farther than the second temperature detector is in an orthogonal direction perpendicular to a recording medium conveyance direction. The first temperature detector is separated from the center position for a first length and disposed in a first span defined by the center position in the orthogonal direction. The recording medium detector is disposed in a second span opposite to the first span, separated from the center position for a second length smaller than the first length, and disposed in a minimum recording medium conveyance span where the recording medium having a minimum width in the orthogonal direction is conveyed.

Abstract: A heating device includes a pair of rotators, a heater, a temperature sensor, a conductor, a conductor support, and a component supporting the conductor. The pair of rotators is in contact with each other to form a nip through which a sheet passes. The heater heats at least one of the pair of rotators. The temperature sensor detects a temperature of the heater. The conductor has flexibility and is coupled to the temperature sensor. The conductor support supports the conductor such that a distance from the conductor to at least one position of the heater outside a predetermined region of the heater in a width direction of the sheet is larger than a distance from the conductor to a position of the heater inside the predetermined region in the width direction. The component has a first side facing the heater and a second side opposite the first side.

Abstract: An image forming apparatus includes a heating device, a rotator, and a blade. The heating device includes a heater extending in a direction orthogonal to a conveyance direction of a recording medium. The heater includes a heat generator and generates a larger heat amount at one end than at a center. The blade includes a rubbing portion extending in the direction. Both ends of the rubbing portion face both ends of the heater. The rotator and the blade are configured such that a friction force between the rotator and one end of the rubbing portion is smaller than a friction force between the rotator and the center of the rubbing portion in the direction.

Abstract: A fixing device includes a fixing belt heated by a heater. A pressure roller presses against the fixing belt to form a nip therebetween, through which a recording medium is conveyed. A holding portion is disposed opposite an inner circumferential face of the fixing belt at each lateral end of the fixing belt in a longitudinal direction thereof. The holding portion rotatably holds the fixing belt. A separator separates the recording medium from the fixing belt. The separator includes a contact portion that contacts the fixing belt and is disposed outboard from a recording medium conveyance region in the longitudinal direction of the fixing belt. The recording medium is conveyed over the fixing belt in the recording medium conveyance region. The contact portion is disposed opposite the holding portion via the fixing belt. The separator further includes a biasing member that presses the contact portion toward the fixing belt.

Abstract: A pressure switching mechanism includes a rotatable support, a biasing member, and a switching rotation member. The rotatable support rotates around a first rotation shaft to support a contact member such that the contact member is movable in a direction toward or away from a contacted member. The biasing member has one end connected to a biased portion of the rotatable support, which is located on a side opposite the first rotation shaft with respect to a virtual line passing through a contact portion between the contact member and the contacted member, and applies a biasing force to the rotatable support. The switching rotation member is connected to another end of the biasing member opposite the one end of the biasing member, rotates around a second rotation shaft, and has a rotation operating end which is on a side opposite the second rotation shaft with respect to the virtual line.

Abstract: A nip forming device includes an endless belt that is flexible and rotates. A nip formation pad is disposed opposite an inner circumferential face of the endless belt. A pressure rotator rotates and presses against the nip formation pad via the endless belt to form a nip between the endless belt and the pressure rotator, through which a conveyed object is conveyed. A housing supports the pressure rotator. A separator is disposed downstream from the nip in a conveyance direction in which the conveyed object is conveyed. The separator separates the conveyed object from the endless belt. The separator moves toward and away from the endless belt. A restrictor restricts motion of the separator that moves toward the endless belt. The restrictor is mounted on the housing.

Abstract: A pressing device includes a rotator, a secured member, a pressure rotator, and lubricant. The rotator has flexibility and a sleeve form and includes an inner portion having a sliding surface. The inner portion has an elastic power of 55% or more. The secured member is inside a loop of the rotator and has a slide surface on which the sliding surface of the rotator is to slide. The slide surface has a smaller surface roughness than a surface roughness of the sliding surface. The pressure rotator presses the rotator against the secured member and forms a nip between the rotator and the pressure rotator. The lubricant between the rotator and the secured member has a consistency of 275 or less.

Abstract: A nip forming device includes an endless film and a pressure rotator that presses against a heater via the endless film. A driver drives and rotates the pressure rotator to cause the pressure rotator to drive and rotate the endless film. A controller controls the driver to drive and rotate the pressure rotator, based on a temperature of the pressure rotator, that is detected by a detector, in a forward direction to convey a conveyed object and to interrupt forward rotation of the pressure rotator. In response to a determination that the temperature of the pressure rotator is higher than a predetermined temperature when a job of the nip forming device is finished, the controller controls the driver to drive and rotate the pressure rotator for a predetermined time in a backward direction opposite to the forward direction and to interrupt backward rotation of the pressure rotator.

Abstract: An image forming apparatus includes a cooler and a heater. The heater includes a heat generation unit, which includes resistive heat generators arranged in a longitudinal direction of the heater, a first electrode, a second electrode, a first conductor that connects the resistive heat generators in parallel with each other to the first electrode, and a second conductor that connects the resistive heat generators in parallel with each other to the second electrode. The first and second conductors are connected to at least one of the resistive heat generators on a first longitudinal end side of the heater from a center of the resistive heat generator in the longitudinal direction of the heater. A cooling ability of the cooler to a second longitudinal end side of the heater opposite the first longitudinal end side of the heater is greater than that to the first longitudinal end side of the heater.

Abstract: A heating device includes a first temperature sensor and a second temperature sensor that detect a temperature of at least one of a first rotator, a second rotator, and a heater that heats at least one of the first rotator and the second rotator. The first temperature sensor is disposed outboard from an increased conveyance span where an increased size sheet having an increased width in a longitudinal direction of the heater is conveyed. The second temperature sensor is disposed outboard from a decreased conveyance span where a decreased size sheet having a decreased width in the longitudinal direction of the heater is conveyed. The decreased conveyance span is smaller than the increased conveyance span. The second temperature sensor is disposed within the increased conveyance span and disposed opposite the first temperature sensor via a center of the increased conveyance span in the longitudinal direction of the heater.

Abstract: A nip forming device includes an endless belt that is flexible and rotates and a nip former that is disposed opposite an inner circumferential face of the endless belt. A pressure rotator presses against the nip former via the endless belt to form a nip between the endless belt and the pressure rotator, through which a conveyed object is conveyed. A separator is disposed downstream from the nip in a conveyance direction of the conveyed object. The separator separates the conveyed object from the endless belt. The separator includes a non-contact portion separated from the endless belt and a contact portion that contacts the endless belt. The contact portion retains a gap having a predetermined size between the non-contact portion and the endless belt.

Abstract: A fixing device includes a rotator, a secured member, a pressure rotator, and lubricant. The rotator has flexibility and a sleeve form. The rotator includes an inner portion having a sliding surface. The inner portion has an elastic power of 55% or more. The secured member is disposed inside a loop of the rotator and has a slide surface on which the sliding surface of the rotator is to slide. The slide surface has a smaller surface roughness in a sliding direction of the rotator than a surface roughness of the sliding surface in the sliding direction of the rotator. The pressure rotator presses the rotator against the secured member and forms a nip between the rotator and the pressure rotator. The lubricant is provided between the rotator and the secured member.