Abstract: A stationary position detection circuit and a motor drive circuit capable of more properly detecting the rotor position are disclosed. The stationary position detection circuit supplies an alternating current to each phase load of the motor. The time during which the current flows in a first direction and the time during which the current flows in a second direction opposite to the first direction are converted into electrical signals and amplified. In accordance with the value of the electrical signals, the position of the motor rotor in stationary mode is determined. The use of the alternating current, unlike the kickback voltage, makes it possible to improve the detection accuracy by amplifying the electrical signals with an increased number of alternations. An increased number of alternations can amplify the electrical signals without increasing the value of the alternating current, and therefore, unlike in the case of the kickback voltage, the alternating current of a large value is not required.

Abstract: A stationary position detection circuit and a motor drive circuit capable of more properly detecting the rotor position are disclosed. The stationary position detection circuit supplies an alternating current to each phase load of the motor. The time during which the current flows in a first direction and the time during which the current flows in a second direction opposite to the first direction are converted into electrical signals and amplified. In accordance with the value of the electrical signals, the position of the motor rotor in stationary mode is determined. The use of the alternating current, unlike the kickback voltage, makes it possible to improve the detection accuracy by amplifying the electrical signals with an increased number of alternations. An increased number of alternations can amplify the electrical signals without increasing the value of the alternating current, and therefore, unlike in the case of the kickback voltage, the alternating current of a large value is not required.

Abstract: A carrier and a dummy toner are stored in a developing unit of a process cartridge in a brand new status. A plurality of process cartridges corresponding to a plurality of color toners is used in common. The color toners are respectively supplied to the developing unit from toner supply units after the process cartridges in the brand new status are installed in installation sections in a main unit of an image forming apparatus.

Abstract: A method and apparatus of image forming include a process cartridge detachably mounted therein. The process cartridge includes a photoconductive element and a housing storing the photoconductive element and including a guide portion guiding the process cartridge. The guide portion faces an inner wall of the image forming apparatus or another process cartridge adjoining thereto and guides the adjoining process cartridge. The guide portion slidably engages with a portion of the process adjoining cartridge. The guide portion varies in shape according to its position in the image forming apparatus. The guide portion may be separately formed from or integrated with the housing. A method and apparatus of an image forming includes an image transfer mechanism and a plurality of process cartridges arranged in parallel. Each of the process cartridges includes photoconductive elements and a housing, and forms an image for a single separated color.

Abstract: A motor drive apparatus includes a comparison circuit comparing voltages of 3-phase coil terminals and the voltage of a neutral point terminal of a 3-phase brushless motor to determine which voltage is higher/lower, a zero ampere current detection circuit detecting, based on the comparison result by the comparison circuit, that the coil current of a position detection phase becomes 0 A, a position detection circuit detecting a zero cross point of the voltage of the position detection phase based on the comparison result by the comparison circuit after the coil current becomes 0 A. Therefore, the zero cross point can be accurately detected without introducing a mask period.

Abstract: A motor drive apparatus includes a comparison circuit comparing voltages of 3-phase coil terminals and the voltage of a neutral point terminal of a 3-phase brushless motor to determine which voltage is higher/lower, a zero ampere current detection circuit detecting, based on the comparison result by the comparison circuit, that the coil current of a position detection phase becomes 0 A, a position detection circuit detecting a zero cross point of the voltage of the position detection phase based on the comparison result by the comparison circuit after the coil current becomes 0 A. Therefore, the zero cross point can be accurately detected without introducing a mask period.

Abstract: A powder conveying device of the present invention includes a powder storing portion storing powder, and a pipe configured to guide the powder from the powder storing portion to a destination positioned below the powder storing portion. The pipe extends downward from the powder storing portion toward the destination, then bends with an inclination angle smaller than the preceding inclination angle relative to the horizontal, and then connects to the destination.

Abstract: A toner container for installation in a toner supply device is provided. The toner container includes a toner accommodation member and a cap member freely attachable to and detachable from the toner accommodation member. The toner accommodation member includes a bag member having an opening, and a connection member attached to the opening of the bag member and having a toner supply opening. The cap member is configured to receive toner supplied from the toner supply opening of the connection member of the toner accommodation member and to discharge the received toner. Either of the connection member of the toner accommodation member and the cap member includes a groove part and the other includes a protrusion part to engage with the groove part, and the cap member is attached to the toner accommodation member by engaging the groove part and the protrusion part with each other. The protrusion part elastically deforms to engage with the groove part.

Abstract: An image forming apparatus includes a frame, a plurality of process cartridges, and a guide mounted to the frame. The guide mounted to the frame includes a plurality of guide portions having supporting surfaces arranged at predetermined different heights and on which the plurality of process cartridges are detachably placed, and is configured to guide the plurality of process cartridges placed on the supporting surfaces along a path between respective first positions and respective second positions.

Abstract: A process cartridge is provided with a frame body made up of at least first and second frame bodies that are movable relative to each other to form a space, a frame body positioning member positioning the first and second frame bodies, a latent image bearing member supported by the frame body and replaceable via the space formed by the first and second frame bodies, a developing unit supplying a developing agent to the latent image bearing member, and a developing position determining member. The developing position determining member is disposed at a non-overlapping position relative to the frame body positioning member, and positions the developing unit with respect to the frame body.

Abstract: An image forming process and apparatus, the apparatus including a toner container, a transfer belt below the toner container, a process cartridge below the transfer belt, and an imaging device below the process cartridge. The process cartridge includes a rotating image carrier having an image carrier surface, a brush roller in contact with the image carrier surface, a charging member in contact with the image carrier surface and configured to transfer a charge to the image carrier surface, and a casing including a miler in contact with the image carrier surface and arranged to separate the brush roller from the charging member.

Abstract: An image forming apparatus of the present invention includes a process cartridge including a developing device that includes a developer carrier and a toner storing portion storing toner for replenishment. The developer carrier conveys a developer deposited thereon to a developing zone where the developer carrier faces and image carrier. The developing device feeds the toner from the toner storing portion to the developer carrier or the developer deposited on the developer carrier. A toner container stores toner to be replenished to said the storing section. The process cartridge and toner container each are removably mounted to the apparatus independently of each other. A toner conveying device configured to convey the toner from toner container to toner storing portion by using the weight of the toner is mounted on the image forming apparatus.

Abstract: A carrier and a dummy toner are stored in a developing unit of a process cartridge in a brand new status. A plurality of process cartridges corresponding to a plurality of color toners is used in common. The color toners are respectively supplied to the developing unit from toner supply units after the process cartridges in the brand new status are installed in installation sections in a main unit of an image forming apparatus.

Abstract: A developer container has a main part accommodating a developer therein and is detachably attached to a main part of an image forming apparatus. The developer container comprises an outlet provided at a side of the developer container to discharge the developer from the developer container. An input unit is provided adjacent to the outlet and has a small-diameter portion an inside diameter of which is smaller than a diameter of the container main part wherein, when the developer container is attached to the image forming apparatus, the input unit is engaged with a drive motor of the image forming apparatus to receive a rotating force of the drive motor. A developer guiding unit causes the developer inside the developer container to be moved to the outlet beyond the small-diameter portion of the input unit by rotation of the developer container.

Abstract: A motor driving circuit includes an induced voltage detecting circuit for detecting induced voltages in a motor; a rotation speed/phase detecting circuit and an output matrix circuit for generating a plurality of control signals in response to the detection result of the voltage detecting circuit; a current control circuit for generating current control command values in response to the control signals; and a current detecting circuit for detecting output currents that are driving the motor, and for controlling output transistors in response to its detection result and the current control command values. The motor driving circuit can sharply reduce the driving noise of the motor with improving the efficiency of the motor drive by shaping the output currents in a sinusoidal waveform.

Abstract: A powder conveying device of the present invention includes a powder storing portion storing powder, and a pipe configured to guide the powder from the powder storing portion to a destination positioned below the powder storing portion. The pipe extends downward from the powder storing portion toward the destination, then bends with an inclination angle smaller than the preceding inclination angle relative to the horizontal, and then connects to the destination.

Abstract: A method and apparatus of image forming include a process cartridge detachably mounted therein. The process cartridge includes a photoconductive element and a housing storing the photoconductive element and including a guide portion guiding the process cartridge. The guide portion faces an inner wall of the image forming apparatus or another process cartridge adjoining thereto and guides the adjoining process cartridge. The guide portion slidably engages with a portion of the process adjoining cartridge . The guide portion varies in shape according to its position in the image forming apparatus. The guide portion may be separately formed from or integrated with the housing. A method and apparatus of an image forming includes an image transfer mechanism and a plurality of process cartridges arranged in parallel. Each of the process cartridges includes photoconductive elements and a housing, and forms an image for a single separated color.

Abstract: An image forming apparatus includes a frame, a plurality of process cartridges, and a guide mounted to the frame. The guide mounted to the frame includes a plurality of guide portions having supporting surfaces arranged at predetermined different heights and on which the plurality of process cartridges are detachably placed, and is configured to guide the plurality of process cartridges placed on the supporting surfaces along a path between respective first positions and respective second positions.

Abstract: An image forming process and apparatus, the apparatus including a toner container, a transfer belt below the toner container, a process cartridge below the transfer belt, and an imaging device below the process cartridge. The process cartridge includes a rotating image carrier having an image carrier surface, a brush roller in contact with the image carrier surface, a charging member in contact with the image carrier surface and configured to transfer a charge to the image carrier surface, and a casing including a miler in contact with the image carrier surface and arranged to separate the brush roller from the charging member.

Abstract: A motor driving circuit includes an induced voltage detecting circuit for detecting induced voltages in a motor; a rotation speed/phase detecting circuit and an output matrix circuit for generating a plurality of control signals in response to the detection result of the voltage detecting circuit; a current control circuit for generating current control command values in response to the control signals; and a current detecting circuit for detecting output currents that are driving the motor, and for controlling output transistors in response to its detection result and the current control command values. The motor driving circuit can sharply reduce the driving noise of the motor with improving the efficiency of the motor drive by shaping the output currents in a sinusoidal waveform.