Abstract: A fixing apparatus includes a roller, a first unit configured to heat the roller, the first unit including a first tubular film, a heating portion forming member to form a heating portion with the roller, and a first guide member dotted with first protruding portions contacting the inner surface of the first tubular film, and a second unit configured to form a nip portion with the roller, the second unit including a second tubular film, a nip portion forming member to form the nip portion with the roller, and a second guide member dotted with second protruding portions contacting the inner surface of the second tubular film, wherein there is a non-overlapping area between the first protruding portions and the second protruding portions in a generatrix direction of the roller.

Abstract: A fixing device configured to fix a toner image on a recording material by heating while conveying the recording material that bears the toner image by a nip portion, the fixing device includes a fixing roller having a rubber layer, a rotating member configured to form a contact portion between the rotating member and the fixing roller, and a pressure member configured to form the nip portion cooperatively with the fixing roller. In the fixing device, heat of the rotating member transfers to the fixing roller from the rotating member via the contact portion, and the contact portion includes a region where the pressure is increased after being decreased on a downstream side further than a center of the contact portion in the rotational direction of the rotating member.

Abstract: An image forming apparatus may include a first and second mode. In the first mode, the image forming apparatus uses a second charging member to charge toner that remains on an intermediate transfer member and then transfers the charged, remaining toner to an image carrier in a primary transfer portion. In the second mode, the image forming apparatus transfers the remaining toner adhered to the second charging member in the first mode to the intermediate transfer member. Also in a second mode, the image forming apparatus controls so that a surface potential of the image carrier that reaches the primary transfer portion at a timing at which the remaining toner transferred to the intermediate transfer member passes through the primary transfer portion has a same polarity as that of a surface potential of the image carrier in the first mode and also has an absolute value smaller than that thereof.

Abstract: The speed at which transfer-material enters a transfer region is controlled to prevent a phenomenon in which a toner image on an intermediate transfer belt is scraped by the leading edge of the transfer-material when the toner image is transferred onto the transfer-material. While the conveying speed of the transfer-material in a transfer nip coincides with the speed of the intermediate transfer belt, the transfer-material is conveyed at a speed lower than the peripheral speed of the intermediate transfer belt when the leading edge of the transfer-material comes into contact with the intermediate transfer belt, and the conveying speed of the transfer-material is increased by the time when the transfer-material enters the transfer nip.

Abstract: An image forming apparatus may include a first and second mode. In the first mode, the image forming apparatus uses a second charging member to charge toner that remains on an intermediate transfer member and then transfers the charged, remaining toner to an image carrier in a primary transfer portion. In the second mode, the image forming apparatus transfers the remaining toner adhered to the second charging member in the first mode to the intermediate transfer member. Also in a second mode, the image forming apparatus controls so that a surface potential of the image carrier that reaches the primary transfer portion at a timing at which the remaining toner transferred to the intermediate transfer member passes through the primary transfer portion has a same polarity as that of a surface potential of the image carrier in the first mode and also has an absolute value smaller than that thereof.

Abstract: An image forming apparatus may include a first and second mode. In the first mode, the image forming apparatus uses a second charging member to charge toner that remains on an intermediate transfer member and then transfers the charged, remaining toner to an image carrier in a primary transfer portion. In the second mode, the image forming apparatus transfers the remaining toner adhered to the second charging member in the first mode to the intermediate transfer member. Also in a second mode, the image forming apparatus controls so that a surface potential of the image carrier that reaches the primary transfer portion at a timing at which the remaining toner transferred to the intermediate transfer member passes through the primary transfer portion has a same polarity as that of a surface potential of the image carrier in the first mode and also has an absolute value smaller than that thereof.

Abstract: An image forming apparatus includes a drum for bearing a toner image; a rotatable belt onto which the toner image is to be transferred from the drum; a primary transfer member for primary transferring the toner image from the drum onto the belt; a secondary transfer member for secondary transferring the toner image from the belt onto a transfer material; and a charging member for electrically charging toner remaining on the belt. The image forming apparatus is capable of executing a belt cleaning mode in which the toner remaining on the belt is electrically charged, and a charging member cleaning mode in which the toner is transferred from the charging member onto the belt and then onto the drum. When the charging member cleaning mode is executed, the charging member is moved at least once from a belt separation position or away from a belt contact position.

Abstract: An image forming apparatus includes an image bearing member, a transfer member, and a power supply unit that outputs a voltage to the transfer member. The power supply unit includes a first voltage generation circuit that includes a piezoelectric transformer driven at a drive frequency within a predetermined frequency area to output a first voltage having a predetermined polarity, and a second voltage generation circuit that outputs a second voltage with a polarity opposite to the predetermined polarity. In addition, a control unit controls the power supply unit to output a superposed voltage as a voltage having the predetermined polarity and corresponding to a voltage output from the piezoelectric transformer by driving the piezoelectric transformer at a driven frequency out of range of the predetermined frequency area, with the superposed voltage being a voltage in which the first voltage and the second voltage are superposed.

Abstract: An image forming apparatus includes an image bearing member that bears a toner image, and a rotatable and endless intermediate transfer member, wherein a toner image is primarily transferred from the image bearing member to the intermediate transfer member in a first primary transfer part, and a toner image is secondarily transferred from the intermediate transfer member to the image bearing member in a secondary primary transfer part. In addition, a charge member is provided upstream of the first primary transfer part and downstream of the secondary primary transfer part in a rotation direction of the intermediate transfer member to charge residual toner remaining on the intermediate transfer member and not being transferred onto the transfer material in the secondary primary transfer part.

Abstract: The image heating apparatus, for heating a toner image while conveying a recording material bearing the toner image at a nip portion, includes a rotary member in contact with the toner image, an endless belt, and a nip portion forming member that is in contact with the inner surface of the belt and forms the nip portion together with the rotary member via the belt. The nip portion forming member is a metal member having a surface which is in contact with the inner surface of the belt and on which an oxide layer is formed by an alumite treatment.

Abstract: A fixing device configured to fix a toner image on a recording material by heating while conveying the recording material that bears the toner image by a nip portion, the fixing device includes a fixing roller having a rubber layer, a rotating member configured to form a contact portion between the rotating member and the fixing roller, and a pressure member configured to form the nip portion cooperatively with the fixing roller. In the fixing device, heat of the rotating member transfers to the fixing roller from the rotating member via the contact portion, and the contact portion includes a region where the pressure is increased after being decreased on a downstream side further than a center of the contact portion in the rotational direction of the rotating member.

Abstract: A fixing apparatus includes a roller, a first unit configured to heat the roller, the first unit including a first tubular film, a heating portion forming member to form a heating portion with the roller, and a first guide member dotted with first protruding portions contacting the inner surface of the first tubular film, and a second unit configured to form a nip portion with the roller, the second unit including a second tubular film, a nip portion forming member to form the nip portion with the roller, and a second guide member dotted with second protruding portions contacting the inner surface of the second tubular film, wherein there is a non-overlapping area between the first protruding portions and the second protruding portions in a generatrix direction of the roller.

Abstract: An image forming apparatus may include a first and second mode. In the first mode, the image forming apparatus uses a second charging member to charge toner that remains on an intermediate transfer member and then transfers the charged, remaining toner to an image carrier in a primary transfer portion. In the second mode, the image forming apparatus transfers the remaining toner adhered to the second charging member in the first mode to the intermediate transfer member. Also in a second mode, the image forming apparatus controls so that a surface potential of the image carrier that reaches the primary transfer portion at a timing at which the remaining toner transferred to the intermediate transfer member passes through the primary transfer portion has a same polarity as that of a surface potential of the image carrier in the first mode and also has an absolute value smaller than that thereof.

Abstract: The image forming apparatus includes an image bearing member, a transfer member, a power supply unit including a first voltage generation circuit and a control unit that controls the power supply unit, wherein in the case where a voltage whose magnitude cannot be output by the first voltage generation circuit is output from the power supply unit to the transfer member in spite of driving the first piezoelectric transformer at the drive frequency in the first drive frequency area, the control unit controls the power supply unit to output the voltage to the transfer member by superposing a voltage output from the first voltage generation circuit by driving the first piezoelectric transformer at a frequency in the first drive frequency area with a voltage output from the second voltage generation circuit by driving the second piezoelectric transformer at a frequency in the second drive frequency area.

Abstract: The image forming apparatus includes a charge member that charges residual toner and is a conductive roller having electrical conductivity and rotates in according to rotation of the intermediate transfer member, and the conductive roller includes a foamed front layer and charges the residual toner upstream and downstream of a contact area in which the conductive roller contacts the intermediate transfer member and charges the residual toner in a void formed on the foamed layer in the contact area. This enables the residual toner on the intermediate transfer member to be sufficiently charged without damaging the intermediate transfer member.

Abstract: An image forming apparatus includes a drum for bearing a toner image; a rotatable belt onto which the toner image is to be transferred from the drum; a primary transfer member for primary transferring the toner image from the drum onto the belt; a secondary transfer member for secondary transferring the toner image from the belt onto a transfer material; and a charging member for electrically charging toner remaining on the belt. The image forming apparatus is capable of executing a belt cleaning mode in which the toner remaining on the belt is electrically charged, and a charging member cleaning mode in which the toner is transferred from the charging member onto the belt and then onto the drum. When the charging member cleaning mode is executed, the charging member is moved at least once from a belt separation position or away from a belt contact position.

Abstract: The speed at which transfer-material enters a transfer region is controlled to prevent a phenomenon in which a toner image on an intermediate transfer belt is scraped by the leading edge of the transfer-material when the toner image is transferred onto the transfer-material. While the conveying speed of the transfer-material in a transfer nip coincides with the speed of the intermediate transfer belt, the transfer-material is conveyed at a speed lower than the peripheral speed of the intermediate transfer belt when the leading edge of the transfer-material comes into contact with the intermediate transfer belt, and the conveying speed of the transfer-material is increased by the time when the transfer-material enters the transfer nip.