Patent application number | Description | Published |
20100034564 | IMAGE FORMING APPARATUS - An image forming apparatus includes a developer carrying member to which a developing bias is applied. A frequency f of a developing bias waveform, a developing area S1 which is a time-integrated value of a difference between a voltage value of the developing bias and a solid electrostatic image potential VL in a developing period of the developing bias, a collecting area S2 which is a time-integrated value of a difference between the voltage value of the developing bias and VL in a collecting period of the developing bias, and a developing contrast value Vcon are used for defining a range of a value of the developing bias frequency f, a range of a value of a voltage change rate α at VL during transition of the developing bias voltage value from a developing-side voltage to a collecting-side voltage, and a range of a value represented by the formula: | 02-11-2010 |
20100159382 | ELECTROPHOTOGRAPHIC DEVELOPMENT CARRIER, TWO-COMPONENT DEVELOPER AND IMAGE-FORMING METHOD USING THE TWO-COMPONENT DEVELOPER - A carrier has an impedance Z having a frequency dependence, obtained by alternating current impedance measurement. When the frequency dependence is fitted by a fitting function, parameter α lies in a range of 0.70 to 0.90 in an electric field of 10 | 06-24-2010 |
20100183971 | MAGNETIC CARRIER, TWO-COMPONENT DEVELOPER AND IMAGE FORMING METHOD - A magnetic carrier having magnetic carrier particles each containing at least a magnetic core particle and a resin; the magnetic carrier having a resistivity of from 1.0×10 | 07-22-2010 |
20100209147 | IMAGE FORMING APPARATUS - A duty ratio Du (%), denoted by (T | 08-19-2010 |
20110111337 | MAGNETIC CARRIER - In the formation of images by a two-component development system, provided is a magnetic carrier that can be used to output an image which has sufficient density, in which few white spots are present in a low-density portion located near the boundary between a high-density region and a low-density region, and in which the low-density portion has good graininess. The magnetic carrier contains magnetic carrier particles each of which has resin and a magnetic particle. The magnetic particle contains ferrite phases and phases comprising a perovskite-structured compound. The ferrite phases and phases comprising a perovskite-structured compound are combined. | 05-12-2011 |
20130216263 | IMAGE FORMING APPARATUS - An image forming apparatus includes: an image bearing member; an electrostatic image forming device; and a developer carrying member. The developer carrying member is provided so as to be rotated in a direction opposite to a rotational direction of the image bearing member at a peripheral speed higher than that of the image bearing member. When the peripheral speed of the image bearing member is Vp (m/sec), the peripheral speed of the developer carrying member is Vs (m/sec), and a time, of movement of the developer from the surface of the developer carrying member to the image bearing member, actually measured in a gap between the image bearing member and the developer carrying member is Tsd (sec), the peripheral speeds Vp and Vs and the time Tsd satisfy the following relationship: (Vs−Vp)×Tsd<3×10 | 08-22-2013 |
20130223861 | IMAGE FORMING APPARATUS - An image forming apparatus includes a photosensitive drum; a first sleeve for carrying a developer containing toner and a carrier having a volume resistivity lower than that of the toner and for developing an image on the drum by rubbing the drum with the developer; a second sleeve for carrying the developer received from the first sleeve and for developing the image by rubbing the drum with the developer carried on the second sleeve; a voltage source for applying a developing bias voltage including a DC voltage component and an AC voltage component to the first sleeve and second sleeve; and a driving device for rotating the first sleeve at a peripheral speed higher than the drum and for rotating the second sleeve at a peripheral speed which is higher than the drum and which is lower than the first sleeve. | 08-29-2013 |
20140161493 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - The developing device includes: a developing container that stores a developer including a non-magnetic toner and a magnetic carrier; a toner bearing member that bears the toner and conveys the toner to a developing portion; and a separating portion wherein a surface of the toner bearing member includes a plurality of recess structures in which a smallest opening width R is equal to or larger than r | 06-12-2014 |
20140270826 | IMAGE FORMING APPARATUS - The image forming apparatus includes an image carrier, a developer carrier, a magnetic field generation unit that is fixedly disposed in a hollow part of the developer carrier and includes a plurality of magnetic poles disposed in a circumferential direction of the developer carrier, a conductive member disposed so as to oppose a predetermined magnetic pole, of the plurality of magnetic poles, which is located odd-number pole upstream of a magnetic pole corresponding to a developing area D in a rotational direction of the developer carrier, a power source that can apply a voltage to the conductive member, a potential detection unit configured to detect pre-development and post-development potentials of a predetermined image formed on the image carrier, and a changing unit configured to change the voltage to be applied from the power source to the conductive member based on a detection result obtained by the potential detection unit. | 09-18-2014 |