Abstract: An image forming apparatus is provided with: an image forming unit having a photosensitive member, a charger, and a developer carrier, the image forming unit being configured to transfer the developer image to a recording sheet to form an image on the recording sheet; a motor configured to drive the photosensitive member and the developer carrier; a controller configured to control the motor and the charger, and a re-conveyance mechanism configured to reverse the recording sheet discharged from the image forming unit and to convey the recording sheet back towards the image forming unit. The controller is configured to turn off the charger after the motor is turned off, during a time period after the recording sheet is discharged from the image forming unit until the recording sheet is re-conveyed to the image forming unit by the re-conveyance mechanism.

Abstract: In an image forming apparatus, a plurality of light emitting portions arrayed in an array direction. A lens array has a length in the array direction longer than a length in a direction orthogonal to the array direction. A controller is configured to perform: converting a reference printing pattern including a plurality of first linear patterns to a detection pattern including a plurality of second linear patterns, each of the plurality of first linear patterns forming a first angle with respect to a reference line parallel to the array direction, each of the plurality of second linear patterns forming a second angle smaller than the first angle with respect to the reference line; forming a detection pattern image on a transfer medium; detecting a print density of the detection pattern image with a sensor; and setting an image formation condition according to the print density detected by the sensor.

Abstract: In an image forming apparatus, a plurality of light emitting portions arrayed in an array direction. A lens array has a length in the array direction longer than a length in a direction orthogonal to the array direction. A controller is configured to perform: converting a reference printing pattern including a plurality of first linear patterns to a detection pattern including a plurality of second linear patterns, each of the plurality of first linear patterns forming a first angle with respect to a reference line parallel to the array direction, each of the plurality of second linear patterns forming a second angle smaller than the first angle with respect to the reference line; forming a detection pattern image on a transfer medium; detecting a print density of the detection pattern image with a sensor; and setting an image formation condition according to the print density detected by the sensor.

Abstract: An apparatus for measuring for measuring coefficient of restitution which is capable of reducing a mass effect and performing tests in free directions, is disclosed. The apparatus for measuring coefficient of restitution includes a holder for holding a spherical indenter, an ejection mechanism configured to eject the indenter held by the holder from the holder to a specimen, a speed measuring unit configured to measure an impact speed that is a speed of the indenter before the indenter impacts against the specimen, and a rebound speed that is a speed of the indenter after the indenter is rebounded from the specimen; and an arithmetic unit configured to calculate a coefficient of restitution that is a ratio of the rebound speed to the impact speed.

Abstract: An apparatus for measuring for measuring coefficient of restitution which is capable of reducing a mass effect and performing tests in free directions, is disclosed. The apparatus for measuring coefficient of restitution includes a holder for holding a spherical indenter, an ejection mechanism configured to eject the indenter held by the holder from the holder to a specimen, a speed measuring unit configured to measure an impact speed that is a speed of the indenter before the indenter impacts against the specimen, and a rebound speed that is a speed of the indenter after the indenter is rebounded from the specimen; and an arithmetic unit configured to calculate a coefficient of restitution that is a ratio of the rebound speed to the impact speed.

Abstract: An image forming apparatus includes: an image forming unit configured to transfer a developer image; a processor; and memory storing computer readable instructions that, when executed by the processor, causing the image forming apparatus to: perform an image forming operation of forming an image; perform a cleaning operation of cleaning unnecessary developer of the image forming unit; in a case where existence of data of an image which is to be formed is recognized after activation of the image forming apparatus before a first image forming operation, determine whether to perform the cleaning operation; and in a case where existence of data of the image which is to be formed is not recognized after the activation of the image forming apparatus before the first image forming operation, not to perform the cleaning operation.

Abstract: An image forming apparatus is provided with: an image forming unit having a photosensitive member, a charger, and a developer carrier, the image forming unit being configured to transfer the developer image to a recording sheet to form an image on the recording sheet; a motor configured to drive the photosensitive member and the developer carrier; a controller configured to control the motor and the charger, and a re-conveyance mechanism configured to reverse the recording sheet discharged from the image forming unit and to convey the recording sheet back towards the image forming unit. The controller is configured to turn off the charger after the motor is turned off, during a time period after the recording sheet is discharged from the image forming unit until the recording sheet is re-conveyed to the image forming unit by the re-conveyance mechanism.

Abstract: An image forming apparatus includes a control device executing: a holding process of holding developer attached on an image carrier at a holding member; a moving process of moving the developer from the holding member to the image carrier; and a collection process of collecting the developer attached on the image carrier into a collection member. The control device executes the moving process and the collection process after completing printing. The control device sets a first flag when predetermined time period elapses from start of the moving process and unsets the first flag at start of the printing. When the first flag is not set at a startup time, the control device executes the moving process and the collection process before the printing. When the first flag is set, the control device omits the moving process before the printing.

Abstract: A developing unit includes a developer casing, a developer carrying member, and a receptacle. The developer carrying member is mounted on the developer casing. The receptacle is supported on the developer casing to be slidable linearly with respect to the developing casing, and is configured to accommodate a waste developer.

Abstract: An image forming apparatus includes: a first cartridge configured to contain developer of a first color; a second cartridge configured to contain developer of a second color; a processor; and memory storing computer readable instructions that, when executed by the processor, causing the image forming apparatus to: indicate the necessity to replace the first cartridge by using at least information based on a first use amount and information based on a number of printed sheets; and indicate the necessity to replace the second cartridge by using at least information based on a second use amount without using the information based on the number of printed sheets.

Abstract: An image forming apparatus includes: a first image forming unit for a monochrome printing including a first photosensitive member for black, a first charging member and a first collection member; a second image forming unit for a multi-color printing including a second photosensitive member for a color, a second charging member and a second collection member; and a control device configured to, at the color printing mode, apply a first charging bias to the second charging member and apply a first bias having a reverse polarity to a charged polarity of developer to the first and second collection members, and at the monochrome printing mode, apply a second charging bias to the second charging member, apply a second bias having the reverse polarity to the first collection member and apply a third bias to the second collection member.

Abstract: An image forming apparatus includes: a first photosensitive drum for a monochrome printing mode; second and third photosensitive drums for a color printing mode; a moving unit moving a medium from the first photosensitive drum via the second photosensitive drum to the third photosensitive drum; charger devices for charging the photosensitive drums; transfer devices for transferring developer images on the photosensitive drums to the medium; and a control unit configured to control charging biases of the charger devices and transfer biases of the transfer devices. The control unit executes, in the monochrome printing mode, an energy saving control in which an absolute value of a charging bias applied to the charger device for the third photosensitive drum is smaller than an absolute value of a charging bias applied to the charger device corresponding to the second photosensitive drum.

Abstract: An image forming apparatus includes: a first cartridge configured to contain developer of a first color; a second cartridge configured to contain developer of a second color; a processor; and memory storing computer readable instructions that, when executed by the processor, causing the image forming apparatus to: indicate the necessity to replace the first cartridge by using at least information based on a first use amount and information based on a number of printed sheets; and indicate the necessity to replace the second cartridge by using at least information based on a second use amount without using the information based on the number of printed sheets.

Abstract: An image forming apparatus includes: an image forming unit configured to transfer a developer image; a processor; and memory storing computer readable instructions that, when executed by the processor, causing the image forming apparatus to: perform an image forming operation of forming an image; perform a cleaning operation of cleaning unnecessary developer of the image forming unit; in a case where existence of data of an image which is to be formed is recognized after activation of the image forming apparatus before a first image forming operation, determine whether to perform the cleaning operation; and in a case where existence of data of the image which is to be formed is not recognized after the activation of the image forming apparatus before the first image forming operation, not to perform the cleaning operation.

Abstract: An image forming apparatus includes first photosensitive members, first chargers for charging the first photosensitive members, developer carriers for supplying developer to the first photosensitive members, a first charging-bias applying unit that applies charging biases to the first chargers, development-bias applying units for applying development biases to the corresponding developer carriers, a charging-current sensing unit that separately senses a charging current flowing in each of the first chargers, and a control unit that controls the development biases based on the sensed charging current. When a difference between a reference charging-current value and a detected charging-current value exceeds a predetermined value, if the detected charging-current value is larger than the reference charging-current value, the control unit increases an absolute value of a development bias applied to a developer carrier corresponding to the charger having the difference exceeding the predetermined value.

Abstract: An image forming apparatus includes: a first image forming unit for a monochrome printing including a first photosensitive member for black, a first charging member and a first collection member; a second image forming unit for a multi-color printing including a second photosensitive member for a color, a second charging member and a second collection member; and a control device configured to, at the color printing mode, apply a first charging bias to the second charging member and apply a first bias having a reverse polarity to a charged polarity of developer to the first and second collection members, and at the monochrome printing mode, apply a second charging bias to the second charging member, apply a second bias having the reverse polarity to the first collection member and apply a third bias to the second collection member.

Abstract: An image forming device performs an image forming operation in either one of a color mode or a monochrome mode. The image forming device includes a plurality of photosensitive members, a plurality of collecting members configured to collect excrescences from the corresponding photosensitive members, and a reverse-transfer member that performs a reverse-transfer operation to transfer the excrescences collected by the collecting members back onto the photosensitive members and further onto an endless bearing member. A control unit controls the reverse-transfer member to perform the reverse-transfer operation at a frequency when image forming operations are performed in succession in the monochrome mode. The control unit sets the frequency based on an image forming condition.

Abstract: An image forming apparatus includes a control device executing: a holding process of holding developer attached on an image carrier at a holding member; a moving process of moving the developer from the holding member to the image carrier; and a collection process of collecting the developer attached on the image carrier into a collection member. The control device executes the moving process and the collection process after completing printing. The control device sets a first flag when predetermined time period elapses from start of the moving process and unsets the first flag at start of the printing. When the first flag is not set at a startup time, the control device executes the moving process and the collection process before the printing. When the first flag is set, the control device omits the moving process before the printing.

Abstract: An electrophotographic image forming apparatus is provided. The image forming apparatus includes an image forming unit configured to form an image on a recording medium; a fixing unit configured to fix the image onto the recording medium by applying heat and pressure; a re-transport unit configured to re-transport the recording medium which has passed through the fixing unit, to the image forming unit along a re-transport path; a cooling unit provided between the fixing unit and the image forming unit along the re-transport path and configured to cool the recording medium transported by the re-transport unit; a parameter signal output unit configured to output a signal corresponding to a parameter for controlling the cooling unit; and a controller configured to control the cooling unit according to the signal output from the parameter signal output unit.

Abstract: An image forming apparatus includes: photosensitive members; an endless belt facing the photosensitive members; developing rollers respectively supplying, to the photosensitive members, developer of different colors which is charged to a first polarity; cleaning rollers adjacent to the photosensitive members; a separating mechanism separating the developing roller from the photosensitive member in a single color printing. If in a multi color printing, a control unit applies a cleaning bias whose polarity is a second polarity opposite to the first polarity and which holds a first electric potential to each cleaning roller. If in the single color printing, the control unit executes a bias reduction control in which a cleaning bias applied to the cleaning roller not used in the single color printing is given the second polarity and is made to hold a second electric potential whose absolute value is smaller than that of the first electric potential.