Abstract: A voltage maintenance element is connected to a contact member that contacts a primary transfer surface area of an intermediate transfer belt to which toner images are transferred from a plurality of image carriers between stretch members, in such a way as to prevent the electric potential of the intermediate transfer belt from varying between respective image forming stations.

Abstract: An image forming apparatus includes a main body of the apparatus, a plurality of cartridges each including a photosensitive member, and a transfer unit detachably mounted on the main body of the apparatus. The transfer unit includes an endless belt opposing the photosensitive member, a plurality of stretching members configured for stretching the belt, and a frame configured to axially support a plurality of rollers. The frame is provided with a plurality of positioning portions configured to allow abutment of the plurality of cartridges and determine the positions of the plurality of cartridges in the main body of the apparatus.

Abstract: A voltage maintenance element is connected to a contact member that contacts a primary transfer surface area of an intermediate transfer belt to which toner images are transferred from a plurality of image carriers between stretch members, in such a way as to prevent the electric potential of the intermediate transfer belt from varying between respective stations.

Abstract: A voltage maintenance element is connected to a contact member that contacts a primary transfer surface area of an intermediate transfer belt to which toner images are transferred from a plurality of image carriers between stretch members, in such a way as to prevent the electric potential of the intermediate transfer belt from varying between respective image forming stations.

Abstract: An image forming apparatus includes a main body of the apparatus, a plurality of cartridges each including a photosensitive member, and a transfer unit detachably mounted on the main body of the apparatus. The transfer unit includes an endless belt opposing the photosensitive member, a plurality of stretching members configured to stretch the belt, and a frame configured to axially support a plurality of rollers. The frame is provided with a plurality of positioning portions configured to allow abutment of the plurality of cartridges and determine the positions of the plurality of cartridges in the main body of the apparatus.

Abstract: An imaging forming apparatus includes a positive high-voltage circuit that generates voltage having a positive polarity, a negative high-voltage circuit connected in series with the positive high-voltage circuit and generates voltage having a negative polarity, a transfer roller to which the voltage generated by the positive high-voltage circuit or the negative high-voltage circuit is supplied, neutralizing pins to which the voltage generated by the negative high-voltage circuit is supplied, a current detection circuit that detects current flowing into the transfer roller, and a diode connected between the transfer roller and the neutralizing pins and that separates a path for the current flowing into the transfer roller and a path for current flowing into the neutralizing pins from each other.

Abstract: An image forming apparatus includes an apparatus main body, an image bearing member capable of bearing a toner image, a current supply member, and an intermediate transfer unit which is removably mounted to the apparatus main body. When the intermediate transfer unit is attached to the apparatus main body, the intermediate transfer unit includes an endless belt whose outer peripheral surface is configured to contact the current supply member, onto which the toner image is transferred from the image bearing member by current supplied from the current supply member, a contact member configured to contact an inner peripheral surface of the endless belt at a position opposed to the image bearing member through the endless belt, an opposing member configured to contact the inner peripheral surface of the endless belt at a position opposed to the current supply member through the endless belt, and a voltage maintaining element which is connected to the opposing member and the contact member.

Abstract: A high-voltage power source includes a switching unit configured to be driven according to a frequency signal, a voltage resonance unit configured to generate a voltage according to driving of the switching unit, a rectification unit configured to rectify and amplify the voltage generated by the voltage resonance unit, a separation unit configured to separate an alternating current generated by the voltage resonance unit and a direct current generated by the rectification unit from each other, and a current detection unit configured to detect the current generated by the voltage resonance unit.

Abstract: The power supply apparatus is configured to detect the output voltage of a piezoelectric transformer and controls the frequency of a pulse signal to drive the piezoelectric transformer based on the detected output voltage and a preset target voltage so as to perform feedback control of the output voltage of the piezoelectric transformer, the gain when performing the feedback control is switched in accordance with the target voltage.

Abstract: The intermediate transfer unit removably mounted to an apparatus main body of an image forming apparatus, includes a contact roller is disposed so as to come into contact with an intermediate transfer belt correspondingly to a photosensitive drum, an opposing member, and a voltage maintaining element which is connected to the opposing member and the contact roller. The number of electric contacts between the intermediate transfer unit and the apparatus main body is decreased so that the apparatus can be downsized, and its cost can be lowered.

Abstract: A voltage maintenance element is connected to a contact member that contacts a primary transfer surface area of an intermediate transfer belt to which toner images are transferred from a plurality of image carriers between stretch members, in such a way as to prevent the electric potential of the intermediate transfer belt from varying between respective stations.

Abstract: A high-voltage power source includes a switching unit configured to be driven according to a frequency signal, a voltage resonance unit configured to generate a voltage according to driving of the switching unit, a rectification unit configured to rectify and amplify the voltage generated by the voltage resonance unit, a separation unit configured to separate an alternating current generated by the voltage resonance unit and a direct current generated by the rectification unit from each other, and a current detection unit configured to detect the current generated by the voltage resonance unit.