Abstract: The purpose is to be provide, in a development apparatus using a two-component developer, a compact development apparatus, image forming apparatus and development method that prevents carrier deterioration and that can carry out good image formation over a long time period. In a development apparatus using a developer in which are mixed a toner, a carrier, and opposite polarity particles that are charged to a polarity opposite to the charging polarity of the toner, the surface charge density of the opposite polarity particles should be in the range of 0.5 to 3.0 times the surface charge density of the carrier.

Abstract: In a development apparatus of the hybrid method using a component developer, a development apparatus and a development method that prevent the reduction of density or the occurrence of residual images (ghost images) and can carry out good image forming over a long period. A development apparatus having the feature that the surfaces of the toner supporting member and the developer supporting member move in a mutually opposite direction at the part that they are opposite to each other, and the electric field in the closest part applied in a direction to recover the toner from the toner supporting member to the developer supporting member is in the range from 2.5×106 V/m to 5×106 V/m, and the share (PD) of the developer in the space of the closest part of the opposing portion satisfies the following relationship. 0.

Abstract: An image forming apparatus for forming an image by developing a latent image formed on an image carrier, using a developer including a toner and a carrier. The image forming apparatus comprises: a developer conveying member that conveys the developer; a first collecting unit that collects, by generating a first electric field, the toner from the developer at a first position that is set halfway through a route of conveyance of the developer by the developer conveying member; and a second collecting unit that collects, by generating a second electric field, residual toner from the developer at a second position that is downstream of the first position in the route of conveyance of the developer.

Abstract: A development apparatus and an image forming apparatus capable of minimizing deterioration of the carrier for a long time, even in the case of continuous formation of images of smaller image area ratio. The charging of toner is assisted by using the developer composed of a mixture of toner and the carrier, to the surface of which is added the reverse polarity particle having a polarity reverse to that of the charged toner. Separation of the toner or reverse polarity particle of the developer prior to the process of development prevents the reverse polarity particle from being consumed in the developing area, whereby the effect thereof is maintained for a long time.

Abstract: A toner current measuring device able to measure a toner current. The toner current measuring device having provided therein a toner deposit capacitor c1 including an electrode 11 and an electrode 12 disposed in opposition, a reference capacitor c2 having a mechanism for adjusting a capacitance thereof; a power supply unit 4; and a measuring unit 10 for measuring, when a voltage is applied to both capacitors to cause a transfer, between the opposing electrodes, of charged toner deposited on the electrode 11, a difference between currents flowing in the toner deposit capacitor c1 and the reference capacitor c2, the difference being measured as a toner current generated as a result of the transfer of the charged toner.

Abstract: A developing device 2a, which is provided with: a developer tank 16 that houses a developer 24 containing a toner, a carrier for charging the toner and reverse polarity particles that are charged with a polarity reversed to the electrostatic charge polarity of the toner by the carrier; a developer-supporting member 11 that supports the developer supplied from the developer tank on the surface thereof, and transports the developer; and a separating mechanism 22 that separates the toner or the reverse polarity particles from the developer supported on the developer-supporting member, and the reverse polarity particles are collected into the developer tank, is provided, and an image-forming apparatus having such a developing device and an image-forming method applied thereto are also provided.

Abstract: An image forming apparatus for forming an image by developing a latent image formed on an image carrier, using a developer including a toner and a carrier. The image forming apparatus comprises: a developer conveying member that conveys the developer; a first collecting unit that collects, by generating a first electric field, the toner from the developer at a first position that is set halfway through a route of conveyance of the developer by the developer conveying member; and a second collecting unit that collects, by generating a second electric field, residual toner from the developer at a second position that is downstream of the first position in the route of conveyance of the developer.

Abstract: A toner current measuring device able to measure a toner current. The toner current measuring device having provided therein a toner deposit capacitor c1 including an electrode 11 and an electrode 12 disposed in opposition, a reference capacitor c2 having a mechanism for adjusting a capacitance thereof; a power supply unit 4; and a measuring unit 10 for measuring, when a voltage is applied to both capacitors to cause a transfer, between the opposing electrodes, of charged toner deposited on the electrode 11, a difference between currents flowing in the toner deposit capacitor c1 and the reference capacitor c2, the difference being measured as a toner current generated as a result of the transfer of the charged toner.

Abstract: A deionized water producing apparatus includes a pretreatment apparatus having a reverse osmosis apparatus, and an electrodeionization apparatus having a diluting compartment filled with an ion exchanger. In order to disinfect the deionized water producing apparatus, hot water of higher than 80° C. is flown through the pretreatment apparatus, and hot water of higher than 60° C. is flown through the electrodeionization apparatus. Hot water flowing thorough the electrodeionization apparatus is gradually heated at a rate of 0.1-10° C./min.

Abstract: The present invention relates to an electrophotographic sensitive member having a photosensitive layer superimposed on an aluminum substrate having an aluminum oxide layer improving the color reproducibility of specific colors' wherein the aluminum oxide layer is colored to have specific maximum absorption wavelength.