Abstract: An object of the present invention is to provide an image forming unit detachably attachable to an image forming apparatus, which has an image bearing body, charging device for charging the image bearing body, a first unit having the image bearing body and the charging device, an intermediate transferring body, transferring device for transferring a toner image on the image bearing body to the intermediate transferring body, and a second unit having the intermediate transferring body and the transferring device, wherein one of the first unit and the second unit is supplied with electric power through the other unit.

Abstract: In a contact type charger including a charge roller which comes into contact with a photosensitive body and a power supply circuit which applies a direct-current fixed voltage to the charge roller, the power supply circuit further includes a resistor and applies the voltage to the charge roller through the resistor. Further, the power supply circuit includes a rectifying circuit and the resistor is disposed closer to the charge roller side than the rectifying circuit. Due to such a constitution, in response to an impedance between the photosensitive body and the charge roller, a current which flows into the charge roller is changed and an output voltage value is changed and hence, a fog on a background which is generated due to the change of the environment or change of the charge potential derived from the change of the film thickness of the photosensitive body can be prevented.

Abstract: An image forming apparatus includes an image bearing member; a charge member for electrically charging the image bearing member while contacting to the image bearing member: voltage applying means for applying an oscillating voltage including a component of AC voltage to the charge member; first detecting means for detecting an average of the AC current applied to the charge member from the voltage applying means; second detecting means for detection a value of the AC current corresponding to a peak of the AC voltage; and control means for effecting control such that when a detected current value of the detecting means is smaller than a first predetermined value, the detected current value of the first detecting means is at the first predetermined value, and when the detected current value of the first detecting means is larger than the first predetermined value, a current value of the second detecting means is at a second predetermined value.

Abstract: A charging device for charging a charged member includes a charging member for contacting the charged member to charge the charged member. A contact-separation device is provided for contacting/separating the charging member to/from the charged member. A power supply device supplies power to the charging member, in which a power supply path can be opened. The power supply device is constituted so that when the charging member contacts the charged member, the power supply path is closed, and when the charging member is separated from the charged member, the power supply path is opened.

Abstract: A charging device comprises a conductor, which is in contact with a photoconductor, and a power source circuit, which applies a voltage to the conductor and electrically charges the photoconductor as to have a predetermined level of potential. The power source circuit includes a resistor having a predetermined level of resistance, and provides the conductor with a voltage through the resistor, thereby to stabilize the charged potential of the photoconductor.

Abstract: An electrical component including: a plurality of long fibers and a matrix, wherein at least one of the fibers is electrically conductive, wherein the plurality of long fibers includes a first fiber group extending in a manner generally parallel to a first axis, and a second fiber group extending in a manner generally parallel to a different second axis.

Abstract: Contactless power and communications links are established between a printer engine and a peripheral device installed on a replaceable printer component. For peripheral devices incorporated within or on the replaceable component, power is inductively transferred from a primary winding on the printer engine to an adjacent secondary winding on the replaceable component without the use of direct physical contact between electrical conductors. In addition, communications between the printer engine and at least one peripheral device on board the replaceable component are provided without making direct physical contact between electrical conductors. The communication task is accomplished in one of several ways. For a first embodiment of the invention, control signals are sent from the printer engine to the replaceable component over the inductive power coupling circuit by switching between two frequencies of alternating current applied to the primary winding on the printing engine.

Abstract: It is an exemplified object of the present invention to provide a transfer-current control circuit that may reduce the smaller number of current control circuits and wires than the conventional while maintaining the controllable number of currents. The present invention divides the transfer output circuit into main and auxiliary controller modules. The main controller module has a configuration similar to the conventional transfer output circuit. The auxiliary controller module provides the same number of current control circuits as the number of input signal lines. The main controller module is connected to the auxiliary controller module in a wired-OR manner. A method of controlling the transfer-current control circuit based on first and second parameters forms part of the invention.

Abstract: An image recording apparatus operates a counter acting as a print timer in a printing operation. In a case where a counted value reaches a predetermined value, the image recording apparatus sets a waiting state, stops power supply from a high voltage power supply unit according to a predetermined sequence, starts to operate a nonvolatile memory in a cartridge according to a predetermined procedure, reads data from the memory, adds the read data to the counted value of the print timer, and then writes an added result.

Abstract: An improved printer is provided which includes a print engine control program that minimizes the power consumption of the paper-handling devices to allow for a smaller DC power supply. Some of the paper-handling devices are input paper trays, output paper stackers, and a duplexer, which all preferably contain a microcontroller and an individual electric motor drive. The base printer also contains a microcontroller in the print engine that controls the printer's mechanisms and various subassemblies that are used in the laser electrophotographic printing process. To maintain control of the entire paper path, the print engine sends commands to the paper-handling devices, and these devices send responses to these commands. Most of the printer's paper-handling devices receive their electrical power entirely from the base printer, which is supplied as a DC voltage. The print engine avoids the concurrent running of subsystems in cases where the functionality of the printer is not compromised.

Abstract: The transfer voltage supplied to the transfer roller in an electrophotographic printer is determined by feeding current to the transfer roller and reading the voltage produced by passage of the current through the transfer roller. Whether the transfer roller is adequately charged is determined by comparing the voltage reading with a previous voltage reading. The voltage reading is preferably an average reading taken over one revolution of the transfer roller. Alternatively, separate voltage readings are taken for different radial sectors of the transfer roller, and the transfer voltage is determined separately for each radial sector.

Abstract: A corona charger for depositing an electrostatic charge on a charge retentive surface, without the creation of sheeting defects, the charger includes a coronode, and a power supply operating in cycles and providing in each of the cycles electrical power to the coronode to produce a net positive charging current with voltage to the coronode from the power supply operating in a portion of each cycle with a positive polarity to generate positive corona emissions. The power supply operates so that an AC component of the voltage provided by the power supply has a positive polarity in the range of about 60% to about 85% of each cycle. When operating in a broader range of greater than 50% but less than 100%, DC equivalent current to the coronode is controlled below a value causing sheeting.

Abstract: This invention pertains to a sawtooth AC charger (10) in which an AC voltage signal applied to sawtooth blades (12) has a duty cycle greater than 50%. Duty cycles above about 70% increase the uniformity of negative charging without significantly increasing the peak voltage to the sawtooth blades.

Abstract: This invention pertains to an AC charger (10) in which an AC voltage waveform applied to a corona wires (12) has a duty cycle of between 50% and 90%. This increases the efficiency of the charger without increasing the signal-to-noise ratio. In one embodiment, the AC voltage waveform is asymmetric.

Abstract: An apparatus for applying an electrical charge to a charge retentive surface, wherein a bias contact roll member is situated in contact with a surface of the photoreceptor. The bias contact roll member is supplied with an electrical bias including an oscillating voltage signal having a DC offset, wherein the oscillating voltage is clipped via a rectifier circuit to remove a predetermined polarity component thereof.

Abstract: In a multi-color imaging apparatus utilizing a recharge step between two image creation steps for recharging a charge retentive surface to a predetermined potential pursuant to forming the second of the two images, a first corona generating device recharges the charge retentive surface to a higher absolute potential than a predetermined potential, and then a second corona generating device recharges the charge retentive surface to the predetermined potential. An electrical charge associated with the first image is substantially neutralized after being recharged by the first and second corona generating device.

Abstract: An image forming apparatus includes image bearing member or members for bearing an image; charging member for sequentially charging a surface of the image bearing member or members to form an image thereon; a voltage source for applying an oscillating voltage to the charging member, the oscillating voltage including a first frequency and a second frequency which is different from the first frequency during charging by the charging member.