Abstract: An image forming apparatus operates in a first image formation mode for forming an image on an image bearing member by using developer under a first predetermined image forming condition and a second image formation mode for forming an image on an image bearing member by using developer under a second image forming condition which is different from the first predetermined image forming condition. The apparatus is set so that the amount of consumption of developer for forming an image in the second image formation mode is smaller than the amount of consumption used for forming an identical image in the first image formation mode.

Abstract: An image forming apparatus has a first image formation mode for forming an image on an image bearing member by using developer under a first predetermined image forming condition and a second image formation mode for forming an image on an image bearing member by using developer under a second image forming condition which is different from the first predetermined image forming condition and is set so that an amount of consumption of developer with respect to an identical image in the second image formation mode is smaller than that in the first image formation mode, the apparatus includes storing means for storing information on an amount of usage of the image bearing member, and control means for changing the second image forming condition in the second image formation mode depending on the information stored in the storing means.

Abstract: An image forming apparatus has a first image formation mode for forming an image on an image bearing member by using developer under a first predetermined image forming condition and a second image formation mode for forming an image on an image bearing member by using developer under a second image forming condition which is different from the first predetermined image forming condition and is set so that an amount of consumption of developer with respect to an identical image in the second image formation mode is smaller than that in the first image formation mode, the apparatus includes storing means for storing information for setting the second image forming condition corresponding to a plurality of levels of an amount of usage of the image bearing member, and control means for changing the second image forming condition in the second image formation mode depending on an amount of usage of the image bearing member and information stored in the storing means.

Abstract: An image forming apparatus has a first image formation mode for forming an image on an image bearing member by using developer under a first predetermined image forming condition and a second image formation mode for forming an image on an image bearing member by using developer under a second image forming condition which is different from the first predetermined image forming condition and is set so that an amount of consumption of developer with respect to an identical image in the second image formation mode is smaller than that in the first image formation mode, the apparatus includes storing means for storing information on an amount of usage of the image bearing member, and control means for changing the second image forming condition in the second image formation mode depending on the information stored in the storing means.

Abstract: A developing apparatus includes a rotatable, developer carrying body for carrying a one-component developer and a rotatable, agitating member for agitating the one-component developer. The one-component developer is magnetic toner at least containing a bonding resin and magnetic iron oxide. When wettability of the magnetic toner relative to a mixture solution of methanol and water is measured at the transmittance of light having a wavelength of 780 nm, a methanol concentration at the transmittance of 80% is within the range of 45 to 65 volume %, and wherein 0.1?b/a?0.2 is established where a (rps) denotes the rotation speed of the developer carrying body, and b (rps) denotes the rotation speed of the agitating member.

Abstract: A developing blade member for regulating a thickness of a layer of a developer on a peripheral surface of a rotatable developing roller enclosing a magnet roller, wherein a scraper for scraping the developer toward longitudinally inside of the developing roller is provided at a longitudinal end of the developing roller, the developing blade member including an elastic member for regulating the thickness of the layer of the developer on the peripheral surface of the developing roller; a metal plate for supporting the elastic member; a projection projecting toward the developing roller, the projection being provided at each of longitudinal ends of the metal plate, wherein an inside end of the projection, with respect to the longitudinal direction of the developing roller, is disposed inside of an inside end of the scraper and in a non-image-formation region.

Abstract: In an image forming apparatus that is capable of forming an image in a plurality of image forming modes that correspond to frequencies of developing bias, a voltage value that reflects the image forming mode and amount of remaining toner is corrected using a correction quantity that conforms to the image forming mode.

Abstract: To provide an image forming apparatus including: an image bearing member; an electrostatic latent image forming means for forming an electrostatic latent image on the image bearing member; a developing means for developing the electrostatic latent image in a development position, the developing means developing the electrostatic latent image using a developer containing a toner and an externally added agent having a charged polarity opposite to that of the toner; a cleaning blade for cleaning the image bearing member; and a bias controlling means for controlling a bias to be applied to the developing means, in which the bias controlling means sets a bias applied to the developing means at the time when an interval area passes the development position according to information related to a length of the interval area at the time when electrostatic latent images for a plurality of pages pass the development position.

Abstract: A developing blade member for regulating a thickness of a layer of a developer on a peripheral surface of a rotatable developing roller enclosing a magnet roller, wherein a scraper for scraping the developer toward longitudinally inside of the developing roller is provided at a longitudinal end of the developing roller. the developing blade member including an elastic member for regulating the thickness of the layer of the developer on the peripheral surface of the developing roller; a metal plate for supporting the elastic member; a projection projecting toward the developing roller, the projection being provided at each of longitudinal ends of the metal plate. wherein an inside end of the projection. with respect to the longitudinal direction of the developing roller, is disposed inside of an inside end of the scraper and in a non-image-formation region.

Abstract: In an image forming apparatus that is capable of forming an image in a plurality of image forming modes that correspond to frequencies of developing bias, a voltage value that reflects the image forming mode and amount of remaining toner is corrected using a correction quantity that conforms to the image forming mode.

Abstract: According to the present invention, a developing apparatus includes:

Abstract: To provide an image forming apparatus including: an image bearing member; an electrostatic latent image forming means for forming an electrostatic latent image on the image bearing member; a developing means for developing the electrostatic latent image in a development position, the developing means developing the electrostatic latent image using a developer containing a toner and an externally added agent having a charged polarity opposite to that of the toner; a cleaning blade for cleaning the image bearing member; and a bias controlling means for controlling a bias to be applied to the developing means, in which the bias controlling means sets a bias applied to the developing means at the time when an interval area passes the development position according to information related to a length of the interval area at the time when electrostatic latent images for a plurality of pages pass the development position.

Abstract: An image forming apparatus includes a developer container for containing a developer, a developer amount detector for detecting the amount of the developer contained in the developer container, a correcting device for correcting the detected value detected by the developer amount detector, and a memory. At least the developer container and the memory are disposed in a unit and the unit is detachably mountable on a main assembly of the image forming apparatus. The memory stores information indicating that the unit is new. The correcting device corrects a next detected value to be detected by the developer amount detector according to the detected value detected by the developer amount detector when the developer amount detector detects information indicating that the unit is new.

Abstract: In a developer container, there are provided a flat antenna for measuring the predetermined range of the developer-remaining-amount, and a plate antenna for measuring the predetermined amount or less of the developer-remaining-amount. When the detected value by the flat antenna is a predetermined value or greater, the minimum detected voltage value of the plate antenna is measured, and this value is stored as PAF (plate antenna full) in the storing means of a cartridge. During the measurement of the predetermined value or less of the developer by the plate antenna, the detected voltage value is calculation-processed and corrected by PAF to thereby obtain the developer amount.

Abstract: In a developer container, there are provided a flat antenna for measuring the predetermined range of the developer-remaining-amount, and a plate antenna for measuring the predetermined amount or less of the developer-remaining-amount. When the detected value by the flat antenna is a predetermined value or greater, the minimum detected voltage value of the plate antenna is measured, and this value is stored as PAF (plate antenna full) in the storing means of a cartridge. During the measurement of the predetermined value or less of the developer by the plate antenna, the detected voltage value is calculation-processed and corrected by PAF to thereby obtain the developer amount.

Abstract: A process cartridge detachably mountable on an electrophotographic image forming apparatus includes (a) an electrophotographic photosensitive member, (b) a developing device having a developer container containing therein a developer for developing an electrostatic latent image formed on the electrophotographic photosensitive member, and (c) a planar developer amount measuring device having a pair of electrodes arranged at a predetermined interval in the developer container, the pair of electrodes of the planar developer amount measuring device being constructed in different patterns in conformity with the initial fill developer amount in the developer container.

Abstract: In conventional art, when a detected electrostatic capacity value of a point at which a developer container is full of a developer is larger or smaller than an initially set value, the developer residual amount is respectively estimated more or less than an actual amount since an output of antenna is sometimes influenced by an antenna tolerance. Therefore, it is provided an image forming apparatus in which a residual amount of a developer can accurately be detected and a cartridge which is detachably mountable on the image forming apparatus.

Abstract: A process cartridge detachably mountable on an electrophotographic image forming apparatus includes (a) an electrophotographic photosensitive member, (b) a developing device having a developer container containing therein a developer for developing an electrostatic latent image formed on the electrophotographic photosensitive member, and (c) a planar developer amount measuring device having a pair of electrodes arranged at a predetermined interval in the developer container, the pair of electrodes of the planar developer amount measuring device being constructed in different patterns in conformity with the initial fill developer amount in the developer container.