Abstract: An image forming apparatus provided with a charging member to charge a surface of a photoreceptor, includes: a power supply that applies to the charging member a first bias in which an AC voltage is superimposed on a DC voltage or a second bias which is a simple DC voltage; and a hardware processor that causes the power supply to apply the first bias until an amount used of the photoreceptor reaches a predetermined value, and causes the power supply to apply the second bias when the amount used of the photoreceptor reaches the predetermined value.

Abstract: An image forming apparatus provided with a charging member to charge a surface of a photoreceptor, includes: a power supply that applies to the charging member a first bias in which an AC voltage is superimposed on a DC voltage or a second bias which is a simple DC voltage; and a hardware processor that causes the power supply to apply the first bias until an amount used of the photoreceptor reaches a predetermined value, and causes the power supply to apply the second bias when the amount used of the photoreceptor reaches the predetermined value.

Abstract: A toner conveyance member includes a shaft, a first blade member, at least one paddle member, and a pressure relief path. The shaft extends in a first direction and rotates in a second direction. The first blade member winds around the shaft and continues to extend helically in the first direction. The paddle member is in the form of a plate protruding from a surface of the shaft and having a first principal face and a second principal face positioned opposite to and forward from the first principal face in the second direction. The pressure relief path has an opening. The opening is provided within a predetermined distance range from an intersection point of the shaft, the first blade member, and the second principal face of the paddle member.

Abstract: A toner conveyance member includes a shaft, a first blade member, at least one paddle member, and a pressure relief path. The shaft extends in a first direction and rotates in a second direction. The first blade member winds around the shaft and continues to extend helically in the first direction. The paddle member is in the form of a plate protruding from a surface of the shaft and having a first principal face and a second principal face positioned opposite to and forward from the first principal face in the second direction. The pressure relief path has an opening. The opening is provided within a predetermined distance range from an intersection point of the shaft, the first blade member, and the second principal face of the paddle member.

Abstract: An image forming apparatus having; a latent image support member; a latent image forming unit for forming an electrostatic latent image on the latent image support member; a developer support member for supplying toner to the latent image support member to develop the electrostatic latent image; a voltage applying device for applying a developing bias, which is a superimposed voltage of a DC voltage and an AC voltage, to the developer support member; a first selecting device for selecting a screen ruling; and a second selecting device for selecting a frequency of the AC voltage. The second selecting device selects a first frequency when the first selecting device selects a first screen ruling, and selects a second frequency lower than the first frequency when the first selecting device selects a second screen ruling higher than the first screen ruling.

Abstract: An image forming apparatus having: an electrostatic latent image support member; an electrostatic latent image forming section; a developer support member; a first voltage applying device for applying a developing bias voltage that is a superimposed voltage of a first DC voltage and a first AC voltage to the developer support member; and a controller for controlling the first voltage applying device. The first voltage applying device is controlled to stop an output of the first AC voltage at a first frequency, to change the first DC voltage outputted therefrom from a first voltage value to a second voltage value and to start an output of the first AC voltage at a second frequency, in this order. The controller selects a screen ruling for each page in accordance with image data and determines the output from the first voltage applying device in accordance with the selected screen ruling.

Abstract: In an image forming apparatus, a control circuit rotationally drives a development roller at a predetermined rotation speed during a development process, in which the development roller has depression portions and land portions on a circumferential surface. The depression portions and the land portions are oblique grooves in the surface. While the development roller is rotationally driven, the control circuit controls the predetermined rotation speed such that a crossing angle approximates 90°. The crossing angle is formed by a screen line in the electrostatic latent image on the circumferential surface of the latent image support and an area where the land portion of the development roller substantially passes over the circumferential surface of the latent image support.

Abstract: If image stabilization becomes necessary while an MFP is executing a print job received from a user, the MFP performs the image stabilization while emitting an operation sound if the user has not moved away from the MFP. Also, if the user has moved away from the MFP, the MFP stops the print job and logs the user out.

Abstract: An image forming device includes a power source unit, motors supplied with and driven by electric power from the power source unit, and a control device for controlling the motors' operations. A CPU in the control device monitors presence/absence of power supply from the power source unit. When power is cut off during image forming, the CPU causes regenerative braking of the motors. The regenerated power is voltage-converted by a second DC-DC converter in the power source unit and supplied to the control device for continuously driving the CPU, which in turn backs up operating information. This eliminates inconsistency between the actual life status and the backed-up information when power is off, with no need of frequent backup during image forming. It is thus possible to provide the image forming device which can reliably manage operating information even if power supply to the motors is stopped during printing.

Abstract: In an image forming apparatus, a control circuit rotationally drives a development roller at a predetermined rotation speed during a development process, in which the development roller has depression portions and land portions on a circumferential surface. The depression portions and the land portions are oblique grooves in the surface. While the development roller is rotationally driven, the control circuit controls the predetermined rotation speed such that a crossing angle approximates 90°. The crossing angle is formed by a screen line in the electrostatic latent image on the circumferential surface of the latent image support and an area where the land portion of the development roller substantially passes over the circumferential surface of the latent image support.

Abstract: An image forming apparatus having; a latent image support member; a latent image forming unit for forming an electrostatic latent image on the latent image support member; a developer support member for supplying toner to the latent image support member to develop the electrostatic latent image; a voltage applying device for applying a developing bias, which is a superimposed voltage of a DC voltage and an AC voltage, to the developer support member; a first selecting device for selecting a screen ruling; and a second selecting device for selecting a frequency of the AC voltage. The second selecting device selects a first frequency when the first selecting device selects a first screen ruling, and selects a second frequency lower than the first frequency when the first selecting device selects a second screen ruling higher than the first screen ruling.

Abstract: An image forming apparatus having; an electrostatic latent image support member; an electrostatic latent image forming section; a developer support member; a first voltage applying device for applying a developing bias voltage that is a superimposed voltage of a first DC voltage and a first AC voltage to the developer support member; and a controller for controlling the first voltage applying device. The first voltage applying device is controlled to stop an output of the first AC voltage at a first frequency, to change the first DC voltage outputted therefrom from a first voltage value to a second voltage value and to start an output of the first AC voltage at a second frequency, in this order. The controller selects a screen ruling for each page in accordance with image data and determines the output from the first voltage applying device in accordance with the selected screen ruling.

Abstract: A power supply control device controls a power supply connected to a motor and includes: an AC/DC converter that makes a first DC power supply; a DC/DC converter that makes a second DC power supply out of the first DC power supply; a first rectifying element that allows current to flow from the first DC power supply toward the motor; a second rectifying element that allows current to flow from the first DC power supply toward the DC/DC converter; and a third rectifying element that allows current to flow from the motor toward the DC/DC converter. In this way, a power supply connected to a motor can be suitably controlled.

Abstract: An image forming device includes a motor which generates motive power by current, a component driven by the motive power of the motor, and a motor current waveform determining unit which determines a condition of the image forming device on the basis of a current waveform of the current flowing through the motor while the motor is being driven. Accordingly, the image forming device which is capable of determining the condition of the device while suppressing an increase in the number of components and preventing reduction of productivity can be provided.

Abstract: A power supply control device controls a power supply connected to a motor and includes: an AC/DC converter that makes a first DC power supply; a DC/DC converter that makes a second DC power supply out of the first DC power supply; a first rectifying element that allows current to flow from the first DC power supply toward the motor; a second rectifying element that allows current to flow from the first DC power supply toward the DC/DC converter; and a third rectifying element that allows current to flow from the motor toward the DC/DC converter. In this way, a power supply connected to a motor can be suitably controlled.

Abstract: An image forming device includes a power source unit, motors supplied with and driven by electric power from the power source unit, and a control device for controlling the motors' operations. A CPU in the control device monitors presence/absence of power supply from the power source unit. When power is cut off during image forming, the CPU causes regenerative braking of the motors. The regenerated power is voltage-converted by a second DC-DC converter in the power source unit and supplied to the control device for continuously driving the CPU, which in turn backs up operating information. This eliminates inconsistency between the actual life status and the backed-up information when power is off, with no need of frequent backup during image forming. It is thus possible to provide the image forming device which can reliably manage operating information even if power supply to the motors is stopped during printing.

Abstract: Upon completing a preparation operation including different processes, an image formation apparatus shifts to ready state in which image formation is executable, the processes including at least one process executed using a corresponding motor. The image formation apparatus comprises: an obtainer for obtaining, for each process, an estimated time period between start and completion thereof; and a controller for starting execution of, out of the processes, (i) one process whose estimated time period is the longest, then (ii) any other process so that any other process is executed in parallel with said one process. When said one process is included in the at least one process, the controller initiates the motor by high-speed initiation by applying thereto first voltage that is higher than second voltage. When any other process is included in the at least one process, the controller initiates the motor by normal initiation by applying thereto first voltage.

Abstract: In a PC connected to an image forming apparatus, an image formation assist program starts at power-on (S101). Print modes are set in advance. In a mode for collectively performing printing when an application having produced print jobs ends, an accepted print instruction provided by an user's operation and the like is temporarily accumulated (S109), and the print jobs produced by the application will be collectively transmitted to the image forming apparatus (S115) when the ending of the application is sensed. In a mode for collectively performing the printing when all the applications end, all the accumulated print jobs are transmitted to the image forming apparatus (S119) when the ending of all the applications is sensed.

Abstract: Upon completing a preparation operation including different processes, an image formation apparatus shifts to ready state in which image formation is executable, the processes including at least one process executed using a corresponding motor. The image formation apparatus comprises: an obtainer for obtaining, for each process, an estimated time period between start and completion thereof; and a controller for starting execution of, out of the processes, (i) one process whose estimated time period is the longest, then (ii) any other process so that any other process is executed in parallel with said one process. When said one process is included in the at least one process, the controller initiates the motor by high-speed initiation by applying thereto first voltage that is higher than second voltage. When any other process is included in the at least one process, the controller initiates the motor by normal initiation by applying thereto first voltage.

Abstract: An image forming apparatus includes a cartridge loading portion removably loaded with a first cartridge containing therein a consumable but carrying no memory storing information on the consumable, or with a second cartridge containing therein the consumable and carrying a memory storing information on the consumable; a controller; and a first memory storing the information on the consumable contained in the first cartridge, and is characterized in that the controller includes: a first consumption calculating/storing portion operating when the first cartridge is loaded in the cartridge loading portion, calculating a consumption of the consumable in the first cartridge and storing the calculation result in the first memory; and a second consumption calculating/storing portion for calculating a consumable consumption of the second cartridge and for storing the calculation result in the memory installed in the second cartridge.