Abstract: An image forming device includes a photosensitive drum, a development roller, a current detection circuit, a power supply part and a power supply control part. The development roller develops an electrostatic latent image formed on the photosensitive drum and forms a toner image on the photosensitive drum. The current detection circuit detects a development current flowing between the photosensitive drum and the development roller when the toner image is formed and outputs a detection signal showing a current value of the development current. The power supply part applies a voltage on the development roller. The power supply control part controls the power supply part such that a variation of the voltage has a negative correlation with a variation of the current value shown in the detection signal.

Abstract: An image forming device includes a photosensitive drum, a development roller, a current detection circuit, a power supply part and a power supply control part. The development roller develops an electrostatic latent image formed on the photosensitive drum and forms a toner image on the photosensitive drum. The current detection circuit detects a development current flowing between the photosensitive drum and the development roller when the toner image is formed and outputs a detection signal showing a current value of the development current. The power supply part applies a voltage on the development roller. The power supply control part controls the power supply part such that a variation of the voltage has a negative correlation with a variation of the current value shown in the detection signal.

Abstract: An image forming apparatus includes a photosensitive drum, a developing section, a voltage applicator, a detector, a calculating section, and an evaluating section. The detector detects values of first and second currents. The first current flows between the photosensitive drum and the developing section during formation of an electrostatic latent image. The second current flows between the photosensitive drum and the developing section when the electrostatic latent image is not being formed. The calculating section calculates a toner charge-to-mass ratio. The evaluating section evaluates reliability of a calculation result of the toner charge-to-mass ratio by comparing the second current value to a reference value. The reference value is of a reference current flowing between the photosensitive drum and the developing section when the electrostatic latent image is not being formed, and indicates a current value detected after adjustment to at least one of the photosensitive drum and the developing section.

Abstract: An image forming apparatus includes a photosensitive drum, a developing section, a voltage applicator, a detector, a calculating section, and an evaluating section. The detector detects values of first and second currents. The first current flows between the photosensitive drum and the developing section during formation of an electrostatic latent image. The second current flows between the photosensitive drum and the developing section when the electrostatic latent image is not being formed. The calculating section calculates a toner charge-to-mass ratio. The evaluating section evaluates reliability of a calculation result of the toner charge-to-mass ratio by comparing the second current value to a reference value. The reference value is of a reference current flowing between the photosensitive drum and the developing section when the electrostatic latent image is not being formed, and indicates a current value detected after adjustment to at least one of the photosensitive drum and the developing section.

Abstract: A processor causes a transmission circuit to output a carrier signal intermittently. Each time the carrier signal is output, the processor determines whether or not a level of a detection signal is in a satisfactory state. In a first case where the level of the detection signal is determined to be in the satisfactory state, the processor performs a read control to cause the transmission circuit to perform a precharge process and a transmission process. In a second case where the level of the detection signal is not determined to be in the satisfactory state, the processor determines that the unit attachment portion is in a unit non-attachment state. In the first case, when the processor succeeds in identifying the developer information, the processor determines that the unit attachment portion is in a unit attachment state, and otherwise, determines that the unit attachment portion is in an exceptional state.

Abstract: In an image forming apparatus, a recognition tag is an electronic tag in which recognition information is recorded in advance. A displacement mechanism holds a displacement portion at a first position so as to make a communication access from a tag reader to a recognition tag possible in a case where a replenishment unit is not attached to a unit attachment portion, and holds the displacement portion at a second position so as to make the communication access from the tag reader to the recognition tag impossible in a case where the replenishment unit is attached to the unit attachment portion. The state determining portion determines a state from among a unit attachment state, a unit non-attachment state, and an exceptional state based on information obtained via the tag reader.

Abstract: A toner container attachment detecting device includes a reader-writer, a shutter made with an electrically conductive material and provided movably between an open position where the shutter is kept from influencing a carrier wave radiated from an antenna of the reader-writer and a covering position where the shutter influences the carrier wave, and first and second displacing portions. When the toner container is attached to an apparatus body, the first displacing portion displaces the shutter to the open position. When the toner container is removed from the apparatus body, the second displacing portion displaces the shutter to the covering position. A radio field intensity detecting section of the reader-writer detects a radio field intensity of the carrier wave and a determining section of the reader-writer determines, based on a detection result of the radio field intensity detecting section, whether or not the toner container is attached to the apparatus body.

Abstract: A processor causes a transmission circuit to output a carrier signal intermittently. Each time the carrier signal is output, the processor determines whether or not a level of a detection signal is in a satisfactory state. In a first case where the level of the detection signal is determined to be in the satisfactory state, the processor performs a read control to cause the transmission circuit to perform a precharge process and a transmission process. In a second case where the level of the detection signal is not determined to be in the satisfactory state, the processor determines that the unit attachment portion is in a unit non-attachment state. In the first case, when the processor succeeds in identifying the developer information, the processor determines that the unit attachment portion is in a unit attachment state, and otherwise, determines that the unit attachment portion is in an exceptional state.

Abstract: In an image forming apparatus, a recognition tag is an electronic tag in which recognition information is recorded in advance. A displacement mechanism holds a displacement portion at a first position so as to make a communication access from a tag reader to a recognition tag possible in a case where a replenishment unit is not attached to a unit attachment portion, and holds the displacement portion at a second position so as to make the communication access from the tag reader to the recognition tag impossible in a case where the replenishment unit is attached to the unit attachment portion. The state determining portion determines a state from among a unit attachment state, a unit non-attachment state, and an exceptional state based on information obtained via the tag reader.

Abstract: A toner container attachment detecting device includes a reader-writer, a shutter made with an electrically conductive material and provided movably between an open position where the shutter is kept from influencing a carrier wave radiated from an antenna of the reader-writer and a covering position where the shutter influences the carrier wave, and first and second displacing portions. When the toner container is attached to an apparatus body, the first displacing portion displaces the shutter to the open position. When the toner container is removed from the apparatus body, the second displacing portion displaces the shutter to the covering position. A radio field intensity detecting section of the reader-writer detects a radio field intensity of the carrier wave and a determining section of the reader-writer determines, based on a detection result of the radio field intensity detecting section, whether or not the toner container is attached to the apparatus body.

Abstract: An image forming apparatus is connected to a plurality of computers via a network, and the image forming apparatus which spools and sequentially processes each of jobs received from the plurality of computers includes: a job management section receiving and managing the jobs transmitted from the computers; and a control section, upon reception of a new job from the computer by the job management section, calculating a scheduled end time of the new job based on a number of prints required for executing the new job, a print speed of the image forming apparatus, and a scheduled end time of the job on standby, and notifying the calculated scheduled end time to the computer which has transmitted the new job.

Abstract: An image forming apparatus is connected to a plurality of computers via a network, and the image forming apparatus which spools and sequentially processes each of jobs received from the plurality of computers includes: a job management section receiving and managing the jobs transmitted from the computers; and a control section, upon reception of a new job from the computer by the job management section, calculating a scheduled end time of the new job based on a number of prints required for executing the new job, a print speed of the image forming apparatus, and a scheduled end time of the job on standby, and notifying the calculated scheduled end time to the computer which has transmitted the new job.