Abstract: An image forming apparatus includes a photoconductive element including a conductive support rotatably supported and a charge injection layer and a surface protection layer sequentially laminated on the conductive support. A charger includes a conductive body for injecting, when a preselected voltage is applied thereto, a charge in the charge injection layer in contact with the surface protection layer. A writing unit exposes the charged surface of the photoconductive element imagewise to thereby locally vary the potential deposited on the photoconductive element and electrostatically form a latent image. A developing unit develops the latent image to thereby produce a corresponding toner image. The toner image is transferred from the photoconductive element to a recording medium.

Abstract: By using a duct, an image forming device in which an upper portion of a thermal fixing mechanism and an optical mechanism can be cooled. A fixing unit is disposed on the left side of the duct. A first auxiliary plate, which supports a scanner unit having a drive motor, is disposed above an upper opening of the duct. A process cartridge is disposed with its end next to the right side of the duct, and a second auxiliary plate is disposed below the duct. A power source is placed under the second auxiliary plate. Accordingly, cooling air from an intake fan is directed to four directions: between an upper portion of the fixing unit and the first auxiliary plate, to the underside of the first auxiliary plate, to the end of the process cartridge, and to the power source.

Abstract: A power control circuit for controlling an output of a power supply is provided with a setting section which variably sets a maximum rated output based on input temperature information.

Abstract: An image forming apparatus includes a photoconductive element including a conductive support rotatably supported and a charge injection layer and a surface protection layer sequentially laminated on the conductive support. A charger includes a conductive body for injecting, when a preselected voltage is applied thereto, a charge in the charge injection layer in contact with the surface protection layer. A writing unit exposes the charged surface of the photoconductive element imagewise to thereby locally vary the potential deposited on the photoconductive element and electrostatically form a latent image. A developing unit develops the latent image to thereby produce a corresponding toner image. The toner image is transferred from the photoconductive element to a recording medium.

Abstract: A power supply control circuit connectable with an input power monitor that monitors an input power value to the power supply, an output power monitor that monitors an output power value from the power supply, and an output power controller that varies the output power value from the power supply, the power supply control circuit having an output power determiner that determines a determined output power value depending on the input power value and a power adjuster that adjusts the output power value to the determined output power value by controlling the output power controller.

Abstract: A power control circuit for controlling an output of a power supply is provided with a setting section which variably sets a maximum rated output based on input temperature information.

Abstract: To avoid burning out a capacitor in a synchronous rectification type DC-to-DC converter due to overvoltages, the synchronous rectification type DC-to-DC converter includes a storage unit storing therein power derived from a power supply, switching elements connecting and disconnecting respective signal paths from power and ground, and a control unit controlling the connecting/disconnecting operations of the switching elements to maintain a voltage output from the storage unit at a predetermined value.

Abstract: A direct-current to direct-current conversion (DC/DC) apparatus includes a control circuit having an error amplifier for voltage control and controlling a direct-current to direct-current conversion based on a pulse width modulation control using an output of the error amplifier. The error amplifier inputs a voltage signal corresponding to an output voltage of a DC/DC result and a plurality of reference voltage signals. The DC/DC apparatus also includes a soft start capacitor to provide one of the plurality of reference voltage signals. The error amplifier amplifies a difference between the voltage signal corresponding to the output voltage of a DC/DC result and a voltage signal of a lower potential among the plurality of reference voltage signals and, based on the amplified output, carries out the pulse width modulation control.

Abstract: To avoid burning out a capacitor in a synchronous rectification type DC-to-DC converter due to overvoltages, the synchronous rectification type DC-to-DC converter includes a storage unit storing therein power derived from a power supply, switching elements connecting and disconnecting respective signal paths from power and ground, and a control unit controlling the connecting/disconnecting operations of the switching elements to maintain a voltage output from the storage unit at a predetermined value.

Abstract: To avoid burning out a capacitor in a synchronous rectification type DC-to-DC converter due to overvoltages, the synchronous rectification type DC-to-DC converter includes a storage unit storing therein power derived from a power supply, switching elements connecting and disconnecting respective signal paths from power and ground, and a control unit controlling the connecting/disconnecting operations of the switching elements to maintain a voltage output from the storage unit at a predetermined value.

Abstract: A charging-and-discharging device in an electronic apparatus includes a rechargeable battery and a charging device for charging the battery. The charging-and-discharging device includes a switching circuit electrically isolating one terminal side of the battery from a ground side of the electronic apparatus. The charging-and-discharging device further includes a charge control section controlling the isolating of the one terminal side of the battery from the ground side of the electronic apparatus by turning off the switching circuit during charging of the battery. In the charging-and-discharging device, the one terminal side of the battery is isolated from the ground side of the electronic apparatus by the switching circuit during charging of the battery and a closed loop including the charging device and the battery is established to charge the battery.

Abstract: An image forming apparatus includes a rotatable image bearing member and a contact-charging member which contacts a surface of the image bearing member. The contact-charging member can charge the image bearing member by applying a predetermined voltage to the contact-charging member so that a potential of the contact-charging member is changed to a required potential for transferring a residual toner that is stuck on a surface of the contact-charging member facing the image bearing member onto the image bearing member while the image bearing member stops rotating. A method for removing residual toner sticking onto a contact-charging member that contacts a surface of the image bearing member changes a potential of the contact charging member to a required cleaning potential for transferring the residual toner sticking to a surface of the contact-charging member facing the image bearing member onto the contact-charging member while the image bearing member stops rotating.

Abstract: In a printer for facsimile machines or the like, a forward end of paper to be fed is temporarily fixed between a platen roller and a print head before printing by the print head is started. A paper feed roller is then rotated so that an inclination of the paper is corrected. Guides are provided so that the paper is fed in a direction of a tangential line of the platen roller at a holding point between the platen roller and the print head.

Abstract: A power supply device includes a secondary battery and a charger, and can further utilize an external D.C. power supply. A switch is interposed between a negative electrode of the secondary battery and the ground. This switch is turned OFF when the external D.C. power supply is connected to the power supply device, and is turned ON when the external D.C. power supply is removed from the power supply device. The charger controls the charge of the secondary battery from the external D.C. power supply by regulating the potential of the negative electrode of the battery. A contact remains OFF while the external D.C. power supply is connected to the power supply device. In consequence, a current does not directly flow from the external D.C. power supply to the secondary battery. Therefore, a back-flow prevention diode, which otherwise results in power consumption, need not be disposed between the secondary battery and the load.

Abstract: A charging-and-discharging device in an electronic apparatus includes a rechargeable battery and a charging device for charging the battery. The charging-and-discharging device includes a switching circuit electrically isolating one terminal side of the battery from a ground side of the electronic apparatus. The charging-and-discharging device further includes a charge control section controlling the isolating of the one terminal side of the battery from the ground side of the electronic apparatus by turning off the switching circuit during charging of the battery. In the charging-and-discharging device, the one terminal side of the battery is isolated from the ground side of the electronic apparatus by the switching circuit during charging of the battery and a closed loop including the charging device and the battery is established to charge the battery.

Abstract: In a power control unit according to the present invention, an output voltage of a power circuit is detected as a control voltage by an output voltage detector and a selector selects one of an internal reference voltage supplied from a built-in reference voltage source and an external reference voltage applied from the external as a selected reference voltage. Further, a control signal generating unit generates a control signal for adjusting the output voltage of said power circuit to voltage corresponding to the selected reference voltage on the basis of the comparison result of said selected reference voltage and said control voltage.

Abstract: The color image forming method of the kind sequentially forming toner images of different colors on an image carrier with developers of corresponding colors stored in a plurality of developing devices, sequentially transferring the toner images to a single paper or similar recording medium one above the other, and returning the toner left on the image carrier after the image transfer to the developing devices color by color, and an image forming apparatus practicable therewith. After the transfer of a toner image of any particular color to the paper wrapped around a transfer drum, a cleaning roller assigned to the above color each collects the toner remaining on the drum and again deposits it on the drum. The drum conveys the redeposited toner to one of the developing devices storing a developer of the same color as the toner.

Abstract: An image forming apparatus includes a cleaning member for collecting toner left on an image carrier after image transfer, and then redepositing it on the carrier, so that a developing unit can collect the redeposited toner to reuse it. Even when the frictional charging ability of the cleaning member falls due to aging or varying environment, the charge of the toner left on the image carrier is regulated to preselected polarity before the toner reaches the cleaning member, thereby enhancing a toner collecting efficiency and a toner redepositing efficiency. The charge of the toner redeposited on the image carrier and moved away from the cleaning member is regulated to preselected polarity while being increased, thereby reducing a load to act on the developing unit. The toner is redeposited on the image carrier efficiently without regard to the polarity of the toner collected by the cleaning member.

Abstract: A power supply apparatus includes a battery, a voltage converter for converting the output of the battery to a different D.C. voltage by ON/OFF action of a main voltage converter control switch circuit, and a device for estimating a remaining capacity of the battery. The remaining battery capacity estimation device detects a non-load voltage of the battery when the main voltage converter control switch circuit is OFF, and estimates the remaining capacity of the battery.

Abstract: FET's lying on a switching circuit are used to execute a switched capacitor action. The FET's connect a first capacitor to a battery to charge the former at an input power voltage, and after charging, disconnect the first capacitor from the battery but simultaneously connect the first capacitor to a second capacitor to transfer accumulated electric charges to the latter. A control circuit including a comparator and a voltage controlled oscillator monitors an output voltage from the second capacitor and performs a switching control so that the output voltage is maintained at a specific level.