Abstract: A valve body has an inflow passage for a working fluid, an outflow passage for the working fluid, and a pressure relief passage, which connects the inflow passage and the outflow passage by bypassing a normally close valve seat. A pressure relief valve is located in the pressure relief passage. The pressure relief valve closes the pressure relief passage, if a pressure of the working fluid in the outflow passage is lower than, is equal to, and is higher by a pressure difference less than a predetermined relief pressure than a pressure of the working fluid in the inflow passage. The pressure relief valve opens the pressure relief passage, if the pressure of the working fluid in the outflow passage is higher by a pressure difference equal to or higher than the relief pressure than a pressure of the working fluid in the inflow passage.

Abstract: An electromagnetic valve is configured with an electromagnetic section, a flow path section, and a sealing member between them. This separate arrangement improves a degree of freedom for arranging inflow and/or outflow passage. This separate arrangement also enables to reduce a size of the electromagnetic section. A plunger comes in contact with a central portion of a spherical portion of a valve member. A normally open compression spring comes in contact with a peripheral portion of the valve member. The valve member can be reliably seated on the normally close valve seat even if the plunger is slightly tilted.

Abstract: An image forming apparatus includes a sensor that acquires first and second data groups of paper characteristics by measuring a recording medium; a processor that determines a parameter for controlling at least one of image formation and conveyance of a recording medium on a conveyance path based on the first and second data groups acquired by the sensor; an image former that forms an image on a recording medium conveyed on the conveyance path based on the parameter. The processor compares the first and second paper characteristic data groups, the first paper characteristic data group has been measured at a first time period and the second paper characteristic data group has been measured at a second time period nearer to a present time than the first time period, and the processor controls the image formation based on a the comparison result.

Abstract: Provided is a recording medium detection device which prevents a recording medium from jamming. The device comprises: a first roller and a second roller which nip and transport a recording medium; a roller shaft which rotatably supports the second roller; a shaft support; and a displacement detector. The shaft support supports the roller shaft movably in the thickness direction of the recording medium. The displacement detector detects displacement of the second roller in the thickness direction. The shaft support further supports the second roller movably in the transportation direction of the recording medium through the roller shaft.

Abstract: Provided is a recording medium detection device which prevents the decline in productivity. The recording medium detection device comprises a first detecting section and a second detecting section. The first detecting section performs a first adjustment process and makes a detection of a recording medium being transported. The second detecting section is located more downstream than the first detecting section in the transportation direction of the recording medium, performs a second adjustment process which takes a longer time than the first adjustment process, and makes a detection of the recording medium being transported.

Abstract: An image forming apparatus includes a high-voltage power supply board utilized for electrophotographic image formation, wherein a converter that generates high voltage is arranged on the high-voltage power supply board, and a drive coil and a high-voltage generation coil in the converter are insulated from each other, a first hardware processor that generates a control signal to control the drive coil is provided, the first hardware processor generates the control signal suitably adjusted in accordance with each of various alternating waveforms, and high voltage having various alternating waveforms is output from one output terminal of the converter of the high-voltage power supply board.

Abstract: A heating device includes rollers, a heating belt, a heater and a hardware processor. The heating belt is in partial contact with an image generation face of a recording medium and extends over the rollers and circulating in cooperation with the rollers. The heater heats the heating belt. The hardware processor modifies an area of contact between the recording medium and the heating belt. At least two rollers are disposed along a traveling direction of the heating belt and are urged to the recording medium with intermediation of the heating belt. The hardware processor modifies the area of the contact by modifying a distance between a first roller and a second roller among the at least two rollers, the first and second rollers being respectively disposed most upstream and most downstream in the travelling direction of the heating belt.

Abstract: A heating device includes rollers, a heating belt, a heater and a hardware processor. The heating belt is in partial contact with an image generation face of a recording medium and extends over the rollers and circulating in cooperation with the rollers. The heater heats the heating belt. The hardware processor modifies an area of contact between the recording medium and the heating belt. At least two rollers are disposed along a traveling direction of the heating belt and are urged to the recording medium with intermediation of the heating belt. The hardware processor modifies the area of the contact by modifying a distance between a first roller and a second roller among the at least two rollers, the first and second rollers being respectively disposed most upstream and most downstream in the travelling direction of the heating belt.

Abstract: An electromagnetic valve includes a valve compartment inside an end tubular portion of a housing, a valve element provided in the valve compartment and movable to open or close a valve port, a guide member slidably supporting the valve element, a shaft contacting an end of the valve element to move the valve element, and a pressure release passage through which an inner compartment of the valve element communicates with the valve port in a closed state of the valve element.

Abstract: A fixing apparatus configured to fix a coloring material attached to a recording medium by heating the recording medium by using a fixing member includes: a heater configured to heat the fixing member; an AC power source configured to apply AC voltage to the heater; a temperature detection unit configure to detect a temperature of the heater; and a power control unit configured to control drive power supplied to the heater from the AC power source by calculating an application pattern of AC voltage to be applied to the heater based on an output of the temperature detection unit, and by appropriately selecting a half wave of AC waveform from the AC power source based on the application pattern, wherein the power control unit supplies power equivalent to a waveform with a predetermined phase angle on a non-selected half wave from the AC power source to the heater.

Abstract: An electromagnetic valve includes a valve compartment inside an end tubular portion of a housing, a valve element provided in the valve compartment and movable to open or close a valve port, a guide member slidably supporting the valve element, a shaft contacting an end of the valve element to move the valve element, and a pressure release passage through which an inner compartment of the valve element communicates with the valve port in a closed state of the valve element.

Abstract: An electromagnetic valve includes a valve compartment inside an end tubular portion of a housing, a valve element provided in the valve compartment and movable to open or close a valve port, a guide member slidably supporting the valve element, a shaft contacting an end of the valve element to move the valve element, and a pressure release passage extending through a part of the end of the valve element which does not contact the shaft. An inner compartment of the valve element communicates with the valve port through the pressure release passage in a closed state of the valve element.

Abstract: An electromagnetic valve includes a valve compartment inside an end tubular portion of a housing, a valve element provided in the valve compartment and movable to open or close an inlet passage, a support member slidably supporting the valve element, a shaft contacting an end of the valve element to move the valve element, and a pressure release passage extending through a part of the end of the valve element which does not contact the shaft. An inner compartment of the valve element communicates with a drainage passage through the pressure release passage in an open state of the valve element where the inlet passage is open to allow a working fluid flows from an upstream passage to a downstream passage through the inlet passage.

Abstract: An electromagnetic valve includes a valve compartment inside an end tubular portion of a housing, a valve element provided in the valve compartment and movable to open or close an inlet passage, a support member slidably supporting the valve element, a shaft contacting an end of the valve element to move the valve element, and a pressure release passage extending through a part of the end of the valve element which does not contact the shaft. An inner compartment of the valve element communicates with a drainage passage through the pressure release passage in an open state of the valve element where the inlet passage is open to allow a working fluid flows from an upstream passage to a downstream passage through the inlet passage.

Abstract: An electromagnetic valve includes a valve compartment inside an end tubular portion of a housing, a valve element provided in the valve compartment and movable to open or close a valve port, a guide member slidably supporting the valve element, a shaft contacting an end of the valve element to move the valve element, and a pressure release passage extending through a part of the end of the valve element which does not contact the shaft. An inner compartment of the valve element communicates with the valve port through the pressure release passage in a closed state of the valve element.

Abstract: A fixing apparatus configured to fix a coloring material attached to a recording medium by heating the recording medium by using a fixing member includes: a heater configured to heat the fixing member; an AC power source configured to apply AC voltage to the heater; a temperature detection unit configure to detect a temperature of the heater; and a power control unit configured to control drive power supplied to the heater from the AC power source by calculating an application pattern of AC voltage to be applied to the heater based on an output of the temperature detection unit, and by appropriately selecting a half wave of AC waveform from the AC power source based on the application pattern, wherein the power control unit supplies power equivalent to a waveform with a predetermined phase angle on a non-selected half wave from the AC power source to the heater.

Abstract: An image forming apparatus including, a photosensitive body for carrying toner images, a transfer section for nipping the recording sheet at a position facing the photosensitive body and transferring the toner images carried on the photosensitive body onto a recording sheet, a driving section for driving the photosensitive body, and a control section for giving instructions to the driving section to conduct a velocity control to rotate the photosensitive body at a predetermined velocity, wherein the control section sets a gain of velocity control to be greater than normal condition, at a time which is at least one of a time when the recording sheet enters the transfer section, or a time when the recording sheet separates from the transfer section.

Abstract: In order that the air surrounding a fixing member is prevented from entering a blowing section for blowing separation air, a wind speed setting section is provided with switchable control modes, namely, a first control mode (control mode for operating the blower fan at a wind speed for separation) and a second control mode (control mode for operating the blower fan at a low speed). This structure allows the blower fan to be controlled in conformity to any one of these first and second control modes.

Abstract: An image forming apparatus including: a photoreceptor for bearing a toner image; a transfer body onto which the toner image borne by the photoreceptor is transferred; a drive section for driving the photoreceptor and transfer body respectively, and a control section for controlling the drive section so as to drive the photoreceptor and transfer body at a predetermined driving speed, wherein the control section, under a state in which the control section controls to drive the transfer body at the predetermined driving speed, controls to: a) drive the photoreceptor while changing the driving speed of the photoreceptor within a range of driving speeds between low speed and high speed, including the predetermined driving speed, b) extract torque characteristics under the control which includes the change of driving speed of the photoreceptor, and c) determine the driving speed of the photoreceptor based on the extracted torque characteristics.

Abstract: Disclosed is a fixing device, which makes it possible to prevent the air blasting section from deterioration, caused by heat transferred from the duct to the air blasting section. The fixing device includes a fixing section to fix the toner image onto the paper sheet; a heat source; and a separating section to separate the paper sheet from the pair of fixing members. On the other hand, the separating section includes: a gas blasting section to blast a gas; and a duct to guide the gas towards the pair of fixing members, and that is provided with a duct wall serving as a heat receiving surface to receive radiation heat irradiated from the fixing section, and at least one of the gas blasting section and the duct is provided with such a connection structure that suppresses heat transferring action from the duct to the gas blasting section.