Abstract: An optical sensor attached to an apparatus includes a substrate and a light emitting element mounted on a first surface of the substrate. The light emitting element emits a light to a detection object in parallel to the substrate. A light receiving element is mounted on the first surface of the substrate. The light receiving element receives a regular reflection light reflected by the detection object. The said first surface serves as a positioning reference for positioning the optical sensor on an optical sensor mounting member provided in the apparatus.

Abstract: An image forming apparatus includes a developer unit to store two-component developer which includes toner and carrier and develop an electrostatic latent image formed on the image carrier, a toner concentration detector to detect toner concentration in the developer unit, a toner supply unit to supply toner to the developer unit, and a controller to control toner supply amount by controlling the toner supply unit by comparing an output value of the toner concentration detector with a reference value stored in a memory and correcting difference between output values of the toner concentration detector at two or more process linear velocities in accordance with the toner concentration in the developer unit. A compensation amount for correcting difference between output values of the toner concentration detector that differ depending on the process linear velocity is adjustable in accordance with the toner concentration in the development unit.

Abstract: An optical sensor includes: a light-emitting unit; a light-receiving unit that receives light radiated from the light-emitting unit and reflected from a detection target and that outputs an output value in response to the light received; and a correcting unit that corrects the output value of the light-receiving unit when receiving the light reflected from the detection target based on the output value of the light-receiving unit obtained by irradiating a detection area of the optical sensor with light without any light reflective objects being present in the detection area.

Abstract: An image forming apparatus forms a plurality of tone patterns of different colors, each of which containing a plurality of toner patches having different toner densities. Some of the toner patches in each of the tone patterns are formed with a predetermined fixed developing bias and the rest of the toner patches in each of the tone patterns are formed with developing biases set based on previous developing biases that have been obtained through a previous control process. The largest toner density of the toner patches in each of the tone patterns is determined based on a magnitude relation of previous index values obtained through the previous control process.

Abstract: A process cartridge for use in an image forming apparatus includes an image bearing member and a developing unit. The developing unit includes a developer bearing member to bear developer including toner and carrier, a casing forming a developer container containing the developer, a screw having a shaft with a spiral screw blade, a toner density sensor to detect a density of the toner on a detection surface, and a detection surface agitating member fixedly mounted on the shaft of the screw at a position facing a detection surface to scrape away the developer accumulated on the detection surface as the screw rotates. The detection surface agitating member includes an elastic sheet elastically deformable to scrape away the developer accumulated on the detection surface and disposed at a substantially same angle to an axial direction of the shaft of the screw as the spiral screw blade.

Abstract: An image forming apparatus includes a control device that calculates a developing ability of the developing device based on a detection value detected by an optical detection device from the plural toner patches. The control device adjusts an image formation condition based on the calculated developing ability. A factor detection device is provided to detect a contributing factor that causes the developing ability to largely change after the last adjustment of the image formation condition. The control device controls image formation such that when the factor detection device does not detect the contribution factor and a developing ability calculated this time is different from that calculated last time (as to a part of the plural toner patches), the plural toner patches are formed based on a prescribed fixed image formation condition so that an attraction amount of toner attracting to the plural toner patches enter a prescribed range detectable for the optical detection device.

Abstract: An optical sensor attached to an apparatus includes a substrate and a light emitting element mounted on a first surface of the substrate. The light emitting element emits a light to a detection object in parallel to the substrate. A light receiving element is mounted on the first surface of the substrate. The light receiving element receives a regular reflection light reflected by the detection object. The said first surface serves as a positioning reference for positioning the optical sensor on an optical sensor mounting member provided in the apparatus.

Abstract: An optical sensor includes: a light-emitting unit; a light-receiving unit that receives light radiated from the light-emitting unit and reflected from a detection target and that outputs an output value in response to the light received; and a correcting unit that corrects the output value of the light-receiving unit when receiving the light reflected from the detection target based on the output value of the light-receiving unit obtained by irradiating a detection area of the optical sensor with light without any light reflective objects being present in the detection area.

Abstract: An image forming apparatus includes a developer unit to store two-component developer which includes toner and carrier and develop an electrostatic latent image formed on the image carrier, a toner concentration detector to detect toner concentration in the developer unit, a toner supply unit to supply toner to the developer unit, and a controller to control toner supply amount by controlling the toner supply unit by comparing an output value of the toner concentration detector with a reference value stored in a memory and correcting difference between output values of the toner concentration detector at two or more process linear velocities in accordance with the toner concentration in the developer unit. A compensation amount for correcting difference between output values of the toner concentration detector that differ depending on the process linear velocity is adjustable in accordance with the toner concentration in the development unit.

Abstract: A printer in which, while achieving a stabilization of image quality by process control processing, the generation of unnecessary wait time to the user, shortening of lifespan of the apparatus and needless consumption of toner caused by unnecessary execution of the process control processing can be better suppressed than in the prior art. An NVRAM serving as non-volatile information storage device in which stored information is retained even if the supply of power from an engine unit power source circuit is cutoff is provided in an engine unit, and timing signal information output from a timing circuit when the process control processing is executed is stored in the NVRAM, the engine unit being configured so as to judge, when power supply from the engine unit power source circuit starts, whether or not process control processing is to be executed in accordance with the timing signal information stored in the NVRAM and the timing signal output from the timing circuit.

Abstract: An image forming apparatus forms a plurality of tone patterns of different colors, each of which containing a plurality of toner patches having different toner densities. Some of the toner patches in each of the tone patterns are formed with a predetermined fixed developing bias and the rest of the toner patches in each of the tone patterns are formed with developing biases set based on previous developing biases that have been obtained through a previous control process. The largest toner density of the toner patches in each of the tone patterns is determined based on a magnitude relation of previous index values obtained through the previous control process.

Abstract: An image forming apparatus includes a control device that calculates a developing ability of the developing device based on a detection value detected by an optical detection device from the plural toner patches. The control device adjusts an image formation condition based on the calculated developing ability. A factor detection device is provided to detect a contributing factor that causes the developing ability to largely change after the last adjustment of the image formation condition. The control device controls image formation such that when the factor detection device does not detect the contribution factor and a developing ability calculated this time is different from that calculated last time (as to a part of the plural toner patches), the plural toner patches are formed based on a prescribed fixed image formation condition so that an attraction amount of toner attracting to the plural toner patches enter a prescribed range detectable for the optical detection device.

Abstract: A process cartridge for use in an image forming apparatus includes an image bearing member and a developing unit. The developing unit includes a developer bearing member to bear developer including toner and carrier, a casing forming a developer container containing the developer, a screw having a shaft with a spiral screw blade, a toner density sensor to detect a density of the toner on a detection surface, and a detection surface agitating member fixedly mounted on the shaft of the screw at a position facing a detection surface to scrape away the developer accumulated on the detection surface as the screw rotates. The detection surface agitating member includes an elastic sheet elastically deformable to scrape away the developer accumulated on the detection surface and disposed at a substantially same angle to an axial direction of the shaft of the screw as the spiral screw blade.

Abstract: A printer in which, while achieving a stabilization of image quality by process control processing, the generation of unnecessary wait time to the user, shortening of lifespan of the apparatus and needless consumption of toner caused by unnecessary execution of the process control processing can be better suppressed than in the prior art. An NVRAM serving as non-volatile information storage device in which stored information is retained even if the supply of power from an engine unit power source circuit is cutoff is provided in an engine unit, and timing signal information output from a timing circuit when the process control processing is executed is stored in the NVRAM, the engine unit being configured so as to judge, when power supply from the engine unit power source circuit starts, whether or not process control processing is to be executed in accordance with the timing signal information stored in the NVRAM and the timing signal output from the timing circuit.

Abstract: A lens mounting plate to which a projection lens unit is fixed is brought into contact with a sliding base. The lens mounting plate is pressed against the sliding base by the urging of a coiled spring. The pressing force is set such that the position of the projection lens unit can be held and shifted. A cover is provided with a pipe-shaped projection so as to surround the projection lens unit with a clearance corresponding to the shifting width of the projection lens unit between the pipe-shaped projection and the projection lens unit. A user shifts the position of the projection lens unit with his or her fingers laid on the pipe-shaped projection and the projection lens unit.

Abstract: An image forming apparatus of the present invention includes an image carrier on which a developer is to be deposited by an electrophotographic system. A controller controls the amount of the developer to deposit on the image carrier by varying a potential for development. A reflection type sensor for sensing the amount of the developer deposited on the image carrier is made up of a light source and a light-sensitive device for. An adjusting device adjusts a set value set in the controller for controlling the amount of the developer to a target value. The sensor is of a diffuse reflection system and has a correcting function. The adjusting device causes the sensor to sense the amount of the developer deposited on a test patch, which is formed on the basis of a preselected set value, and then calculates an adjustment value of the set value on the basis of the amount sensed by the sensor and the target value.

Abstract: A lens mounting plate to which a projection lens unit is fixed is brought into contact with a sliding base. The lens mounting plate is pressed against the sliding base by the urging of a coiled spring. The pressing force is set such that the position of the projection lens unit can be held and shifted. A cover is provided with a pipe-shaped projection so as to surround the projection lens unit with a clearance corresponding to the shifting width of the projection lens unit between the pipe-shaped projection and the projection lens unit. A user shifts the position of the projection lens unit with his or her fingers laid on the pipe-shaped projection and the projection lens unit.

Abstract: An image forming apparatus of the present invention includes an image carrier on which a developer is to be deposited by an electrophotographic system. A controller controls the amount of the developer to deposit on the image carrier by varying a potential for development. A reflection type sensor for sensing the amount of the developer deposited on the image carrier is made up of a light source and a light-sensitive device for. An adjusting device adjusts a set value set in the controller for controlling the amount of the developer to a target value. The sensor is of a diffuse reflection system and has a correcting function. The adjusting device causes the sensor to sense the amount of the developer deposited on a test patch, which is formed on the basis of a preselected set value, and then calculates an adjustment value of the set value on the basis of the amount sensed by the sensor and the target value.

Abstract: In a method and an apparatus for removing an image forming substance such as toner from an image holding member such as a sheet of transfer paper, an unstabilizing agent is provided to the image holding member. An attaching state between the image forming substance and the image holding member stably attaching the image forming substance on a surface thereof is changed to an unstable state by the unstabilizing agent. The image forming substance is separated and removed from the image holding member by making a separating member come in close contact with the image forming substance on the image holding member having the provided unstabilizing agent. A processing situation mark showing a processing situation of removal of the image forming substance is formed in the image holding member. The processing situation mark can be removed from the image holding member by the image forming substance removing processing.

Abstract: A lens mounting plate to which a projection lens unit is fixed is brought into contact with a sliding base. The lens mounting plate is pressed against the sliding base by the urging of a coiled spring. The pressing force is set such that the position of the projection lens unit can be held and shifted. A cover is provided with a pipe-shaped projection so as to surround the projection lens unit with a clearance corresponding to the shifting width of the projection lens unit between the pipe-shaped projection and the projection lens unit. A user shifts the position of the projection lens unit with his or her fingers laid on the pipe-shaped projection and the projection lens unit.