Class / Patent application number | Description | Number of patent applications / Date published |
399285000 | Having applied bias | 40 |
20080219712 | Developing device and image forming apparatus - An image forming apparatus provided with an image carrying member to carry an electrostatic latent image, a toner carrying member to develop the electrostatic latent image on the image carrying member with toner; a first developer carrying member to carry developer containing toner, carrier, reverse polarity particles and to supply toner to the toner carrying member; and a second developer carrying member to carry developer and to recover toner on the toner carrying member, wherein an ability to move the reverse polarity particles from the toner carrying member to the first developer carrying member is larger than an ability to move the reverse polarity particles from the second developer carrying member to the toner carrying member. | 09-11-2008 |
20080232862 | IMAGE FORMING APPARATUS - An image forming apparatus has a photoconductive member, and a developing roller develops a latent image on the photoconductive member by a first alternating-current bias in the form of a rectangular wave. The following relationships are satisfied in calculating the duty ratio (D | 09-25-2008 |
20080232863 | Image forming apparatus - In an image forming apparatus | 09-25-2008 |
20080292365 | IMAGE FORMING APPARATUS AND DEVELOPING DEVICE - An image forming apparatus is characterized in that an absolute value of a difference between a first coefficient of variation in a number distribution of the particle diameter of a toner carried on a developing roller and a second coefficient of variation in a number distribution of the particle diameter of a toner in a two-component developer carried on the magnetic roller is within 5% and an absolute value of a difference between a third coefficient of variation in a number distribution of the particle diameter of a toner of a toner image developed on the outer surface of an image bearing member and the second coefficient of variation is within 6%. With such an image forming apparatus, high-quality images can be stably formed over a long term. | 11-27-2008 |
20090041512 | DEVELOPING DEVICE, PROCESS CARTRIDGE AND IMAGE FORMING APPARATUS - A developing device for developing an electrostatic latent image on an image carrier by supplying a one-component developer to the image carrier. Good images can be obtained over long periods of time, without printing history becoming apparent on account of residual developer. The developing device has a developer carrier that is rotatable and disposed facing an image carrier; and a conductive developer supply and recovery member rotatably arranged so as to abut the developer carrier. The rotation direction of the conductive developer supply and recovery member is opposite to the rotation direction of the developer carrier at a position where the developer carrier and the conductive developer supply and recovery member abut each other. A contact pressure P between the developer carrier and the conductive developer supply and recovery member is set so as to satisfy the relationship 0 (kPa) | 02-12-2009 |
20090060595 | IMAGE FORMING APPARATUS - The present invention teaches and claims an image forming apparatus comprising an image forming portion using a liquid developer having a carrier liquid and toner; an intermediate transfer section which has an endless belt and a plurality of rotating bodies; a second transfer roller which is disposed so that it faces one of the plurality of rotating bodies and abuts the endless belt; a first bias applying section which is connected to the second-transfer roller and applies a transfer bias to the second-transfer roller when the second-transfer is done and applies a reverse transfer bias having a same electric polarity as the transfer bias to the second-transfer roller when the second-transfer is not performed; and a second bias applying section which is connected to the rotating body facing the second-transfer roller and applies a bias to the rotating body facing the second-transfer roller. | 03-05-2009 |
20090103957 | Image forming apparatus and method for developing electrostatic latent image - Provided are an image forming apparatus equipped with a hybrid developing apparatus including a toner-collecting developer-carrying member and a method for developing an electrostatic latent image, which apparatus is capable of stably forming high definition images without occurrence of a leakage current even under a high-humidity environment. In the apparatus, each of a toner-supplying developer-carrying member and the toner-collecting developer-carrying member has a conductive substrate to which a bias voltage is applied, and at least one of the surfaces of the conductive substrates of the toner-supplying developer-carrying member and the toner-collecting developer-carrying member has a resistive layer formed thereon. | 04-23-2009 |
20090123194 | IMAGE FORMING APPARATUS - A developing apparatus includes first and second developer bearing members configured to bear developer and a connecting member configured to connect the first and second developer bearing members to each other such that the second developer bearing member is swingable relative to the first developer bearing member. A first adjusting member which adjusts the positions of magnetic poles of a first magnetic member disposed in the first developer bearing member is fixed to the developing apparatus. A second adjusting member which adjusts the positions of magnetic poles of a second magnetic member disposed in the second developer bearing member is fixed to the connecting member. | 05-14-2009 |
20090142109 | Development Device and Image Forming Apparatus - A development device includes a developer carrier and a developer supply belt. The developer carrier, disposed in contact with an image carrier carrying an electrostatic latent image, carries developer to be charged with a prescribed polarity and develops the electrostatic latent image by application of development voltage. The developer supply belt includes a first roller, a second roller, and a belt. The belt is tightly stretched by the first roller and the second roller, and is disposed in contact with the developer carrier from a contact beginning portion to a contact finishing portion. A potential difference between the development voltage and the voltage of the contact finishing portion is arranged to be zero (0) V or above and 600 V or below. | 06-04-2009 |
20090202277 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - A developing device facing an image carrier and including a developer carrier, a developer flying control member, and a development-noise control member. The developing device develops an electrostatic image formed on the image carrier by causing the developer to fly from the developer carrier to the image carrier upon an application of an alternating-current bias to the developer carrier. Noise produced by the development-noise control member vibrated by an oscillating electric field of the alternating-current bias is smaller than a noise produced by the developer flying control member vibrated by the oscillating electric field. | 08-13-2009 |
20090238612 | Image Formation Device - There is provided an image formation device comprising an electrostatic latent image holding body having an latent image formation surface on which an electrostatic latent image is formed, a developer supply unit to supply developer to the electrostatic latent image holding body to form, on the latent image formation surface, a developer image corresponding to the electrostatic latent image; a developer transfer unit located to face the electrostatic latent image holding body to transfer the developer image to a developer image holding surface; and a contacting member to contact the latent image formation surface at a stage which is after formation of the developer image and before transfer of the developer image to the developer image holding surface. | 09-24-2009 |
20090297231 | Image Forming Apparatus and Image Forming Method - An image forming apparatus includes an image carrier that carries an electrostatic latent image on a surface thereof, a toner carrying roller that is disposed to face the image carrier and rotates in a predetermined rotation direction with charged toner carried on a surface thereof so as to transport the toner in an opposing position for facing the image carrier, and a bias applying unit that develops the electrostatic latent image with the toner by applying an AC voltage as a developing bias to the toner carrying roller. In addition, periodical concavo-convexes that are formed of a plurality of convex portions arranged at a constant pitch in a circumferential direction and concave portions that surround the plurality of convex portions are formed on the surface of the toner carrying roller. When the arrangement pitch is denoted by P, the frequency of the developing bias is denoted by F, and the moving speed of the surface of the toner carrying roller for the circumferential direction is denoted by V, a quotient acquired from dividing V by F is a value acquired from multiplying P by a natural number or an approximately natural number. | 12-03-2009 |
20090324302 | DEVELOPING UNIT AND IMAGE FORMING APPARATUS - An aspect of the invention provides a developing unit that comprises: a developer; an image carrier on which an electrostatic latent image is formed; a first developer carrier configured to develop the electrostatic latent image formed on the image carrier by causing the developer to attract to the electrostatic latent image; a first restriction member configured to be in press-contact with the first developer carrier; a second developer carrier configured to abut to the first developer carrier, and to form a developer layer on the second developer carrier; a second restriction member configured to abut to the second developer carrier; and a supplying member configured to supply the second developer carrier with the developer. | 12-31-2009 |
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 |
20100061776 | DEVELOPER AND IMAGE FORMING APPARATUS - Developer is to be used in an image forming apparatus of an electro-photography type, in which a developer supporting member attaches the developer to a static latent image supporting member for developing a static latent image. The developer includes an outer additive; and base particles. Further, the developer has a charge amount Q | 03-11-2010 |
20100143004 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - Provided is an image forming apparatus including: a latent image carrier; a charging unit; a latent image forming unit; a developing unit; a transferring unit; and a control unit that performs an image forming process by controlling the latent image carrier, the charging unit, the latent image forming unit, the developing unit and the transferring unit, wherein, during execution of the image forming process, the latent image carrier circulates by passing through the charging position, the developing position and the transferring position in a state in which at least one of toner, which is charged with a polarity opposite to the regular charging polarity, and external additive agent, which is separated from the toner and charged with a polarity opposite to the regular charging polarity, is distributed and adhered to the surface of the latent image carrier. | 06-10-2010 |
20100143005 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - Provided is an image forming apparatus including: a latent image carrier; a charging unit; a latent image forming unit; a developing unit; a transferring unit; and a cleaning unit, wherein a voltage of the non-image portion of the latent image carrier is Vo, a voltage of the developing bias at the time when a force generated to bias the toner charged with the regular charging polarity in a direction from the latent image carrier to the toner carrier is maximum is Vmax, and a voltage of the developing bias at the time when a force generated to bias the toner charged with the regular charging polarity in a direction from the toner carrier to the latent image carrier is maximum is Vmin, in the developing position, an equation |Vmax−Vo|>|Vmin−Vo| is satisfied. | 06-10-2010 |
20100143006 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - Provided is an image forming apparatus including: a latent image carrier; a charging unit; a latent image forming unit; a developing unit that has a toner carrier; a transferring unit that transfers the toner image on the transfer medium; and a cleaning unit that removes a toner that remains to be adhered to the latent image carrier, wherein the toner carrier carries a toner layer including a contact toner that is directly in contact with the surface of the toner carrier and a non-contact toner that is not directly in contact with the surface of the toner carrier on the surface thereof, and wherein a voltage of the transferring bias is a DC voltage that does not generate discharge between the image portion of the latent image carrier and the transfer medium but generate discharge between the non-image portion of the latent image carrier and the transfer medium. | 06-10-2010 |
20100232841 | Method for Developing an Electrostatic Latent Image - The purpose is to 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. | 09-16-2010 |
20100239328 | DEVELOPING APPARATUS, IMAGE FORMING APPARATUS, IMAGE FORMING METHOD, AND TONER - A developing apparatus includes: a housing which contains toner; a toner supporting roller; and a regulating blade, wherein bias voltage is applied to the regulating blade, the toner includes, an insulating external additive and an electrically-conductive external additive, satisfies any of the following first to third conditions, the first condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive, the second condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive in which coverage in the toner is higher than that of the electrically-conductive external additive, and the third condition: coverage of the electrically-conductive external additive in the toner is higher than coverage of the insulating external additive that is larger in volume average grain diameter than the electrically-conductive external additive. | 09-23-2010 |
20100239329 | IMAGE FORMING APPARATUS - An image forming apparatus includes a photoreceptor having a first support shaft supported in a first frame body, a photosensitive portion supported by the first support shaft, and a tapered portion having first tapered surfaces on both sides of the photosensitive portion; a development roller opposed to the photoreceptor and having a second support shaft rotatably supported by a second frame body, the development roller being movable in a direction perpendicular to the second support shaft so as to approach and separate from the photoreceptor; roller members disposed on both sides of the development roller coaxially with the second support shaft, the roller member being movable in an axial direction of the second support shaft and including a second tapered surface which abuts against the first tapered surface; a moving member allowing the roller member to move on the second support shaft; and a biasing member biasing the development roller toward the photoreceptor. | 09-23-2010 |
20110002716 | Developer Supply Apparatus and Image Forming Apparatus - An image forming device is provided which includes a developer carrying body and a developer supply device to supply a developer to the developer carrying body. The developer supply device includes a plurality of transfer electrodes, and a transfer voltage applying unit to apply traveling-wave shaped transfer voltages to the plurality of electrodes. The developer includes a fine particle charged in a predetermined polarity and a fine particle charged in an opposite polarity which is opposite to the predetermined polarity. The transfer voltage applying unit is configured to apply the transfer voltages having waveforms, which make a fly height of the fine particle charged in the predetermined polarity higher than a fly height of the fine particle charged in the opposite polarity, to the plurality of transfer electrodes. | 01-06-2011 |
20110188899 | Developer Supply Device and Image Forming Apparatus Having the Same - A developer supply device is provided, which includes a bias controller that, during an image forming operation by an image forming apparatus, applies a first bias to a first transfer board and applies a second bias to between a developer holding body and the first transfer board, so as to make the developer holding body hold development agent thereon while transferring the development agent along a first developer transfer path of the first transfer board. At least one of before and after the image forming operation, the bias controller applies the first bias to the first transfer electrodes without applying the second bias to between the developer holding body and the first transfer board, so as to transfer the development agent along the first developer transfer path without making the developer holding body hold the development agent. | 08-04-2011 |
20110299893 | DEVELOPING DEVICE AND DEVELOPING METHOD - A developing device having a plurality of toner carrying members for carrying toner on their outer peripheral surfaces, the plurality of toner carrying members being placed along a rotating direction of an image carrying member and out of contact with the image carrying member; and a developer carrying member for carrying a developer composed of toner and carriers and for supplying the toner to the plurality of toner carrying members. In the developing device, AC bias voltages are applied to the toner carrying members so as to cause the toner carried by the toner carrying members to stick to an electrostatic latent image formed on the image carrying member by the effect of electric fields induced by a voltage of the electrostatic latent image and the AC bias voltages applied to the toner carrying members. The amount of developing toner sticking on the image carrying member immediately after the image carrying member has passed a development area in an upstream side in the rotating direction of the image carrying member is larger than the amount of developing toner sticking on the image carrying member immediately after the image carrying member has passed a development area in a downstream side in the rotating direction of the image carrying member. | 12-08-2011 |
20120177415 | IMAGE FORMING APPARATUS - An image forming apparatus for forming a toner image on a print medium with a developer composed of toner and carriers, wherein when the first distance is longer than the second distance, an average gap between the first peripheral surface and a member that faces to the first peripheral surface in an area with a length of the first distance extending upstream from the closest point with respect to the specified direction is smaller than an average gap between the first peripheral surface and a member that faces to the first peripheral surface in an area with a length of the first distance extending downstream from the closest point with respect to the specified direction. | 07-12-2012 |
20120177416 | IMAGE FORMING APPARATUS - An image forming apparatus, wherein the packing density at a closest point where the first peripheral surface and the second peripheral surface are the closest to each other is within a range from 0.3 to 0.4; wherein a maximum magnetic flux density of a principal magnetic pole for generating the magnetic field for development is located in an upstream side from the closest point with respect to the specified direction and at a point where the packing density is equal to or greater than 0.2; and wherein a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in a downstream side from the closest point with respect to the specified direction is equal to or less than ½ of a magnetic flux density of the principal magnetic pole at a point where the packing density is 0.2 in the upstream side. | 07-12-2012 |
20130078008 | DEVELOPER DEVICE AND IMAGE FORMING APPARATUS - A developer device includes two developer rollers arranged opposite to an image carrier. A first developer bias voltage (waveform Z) of a rectangular waveform obtained by superimposing an AC voltage on a DC voltage is applied to one of the developer rollers. A second developer bias voltage (waveform A) obtained by superimposing an AC voltage on a DC voltage is applied to the other developer roller. The waveform A is a waveform obtained by deforming the rectangular wave in the first developer bias voltage such that toner adhered to the image carrier is prevented from being dislodged by toner being subsequently scattered. According to the developer device, an optimal image density can be obtained at a low-density potential. | 03-28-2013 |
20130136508 | DEVELOPING APPARATUS, IMAGE FORMING APPARATUS AND PROCESS CARTRIDGE - To provide a developing apparatus, including: a developer bearing member which carries a one-component developer; a charge imparting member disposed in contact with the developer bearing member and charges the one-component developer on the developer bearing member; and a bias supplying member which supplies a bias voltage to the charge imparting member, wherein the one-component developer has a volume resistivity of 8.0 logΩ·cm to 10.9 logΩ·cm, and the developing apparatus satisfies: | 05-30-2013 |
20130279948 | MULTI-TONER DISCHARGED AREA DEVELOPMENT METHOD - Printing methods are provided. A surface charge is provided on the primary imaging member and the surface charge is partially discharged in areas in which a first toner is to develop. The charge pattern is formed with a first area having a surface potential that is at least 30 percent less than a surface potential of an adjacent second area that creates an inter-area field between the first area and second area that extends into a portion of the first area that is proximate to the second area. A first development field is applied and a first toner is partially developed in the first area based upon the influence of the inter-area and first development fields. The charge pattern and the first toner are further developed with a different second toner. The surface charge on the primary imaging member, first toner and second toner have the same polarity. | 10-24-2013 |
20130279949 | PRINTER WITH MULTI-TONER DISCHARGED AREA DEVELOPMENT - Printers are provided in which a charge pattern is formed with a first area having a surface potential that is at least 30 percent less than a surface potential of an adjacent second area that creates an inter-area field between the first area and second area that extends into a portion of the first area that is proximate to the second area. A development station applies a first development field and a first toner is partially developed in the first area based upon the influence of the inter-area and first development fields. The charge pattern and first toner are further developed with a different second toner. The surface charge, the first toner and second toner have the same polarity. | 10-24-2013 |
20130279950 | MULTI-TONER CHARGED AREA DEVELOPMENT METHOD - Methods are provided in which a charge pattern is formed with a second area having a surface potential that is at least 30 percent lower than a surface potential of an adjacent first area that creates an inter-area field between the first area and second area that extends into a portion of the first area. A development station applies a first development field and a first toner is partially developed in the first area based upon the influence of the inter-area and first development fields. The charge pattern and first toner are further developed with a different second toner. The surface charge has a different polarity than a polarity of the first toner and second toner. | 10-24-2013 |
20130279951 | PRINTER WITH MULTI-TONER CHARGED AREA DEVELOPMENT - Printers are provided in which a charge pattern is formed with a second area having a surface potential that is at least 30 percent less than a surface potential of an adjacent first area that creates an inter-area field between the first area and second area that extends into a portion of the first area that is proximate to the second area. A development station applies a first development field and a first toner is partially developed in the first area based upon the influence of the inter-area and first development fields. The charge pattern and first toner are further developed with a different second toner. The surface charge, the first toner and second toner have the same polarity. | 10-24-2013 |
20130343788 | IMAGE FORMING APPARATUS - An image forming apparatus includes a toner carrying member for carrying a toner; an image carrying member, contacting the toner on the toner carrying member, on which a toner image is to be formed with the toner; and an electrode portion provided at an opposing position in which the electrode portion opposes the toner carrying member via the image carrying member interposed therebetween. The toner image is formed on the image carrying member by changing a value of a voltage, on the basis of image information, applied to the electrode portion. The toner carried on the toner carrying member and the image carrying member contact each other in a toner contact area. The toner is moved between the toner carrying member and the image carrying member in a toner movement area by changing the value of the voltage applied to the electrode portion. The toner movement area is present downstream of the toner contact area with respect to a movement direction of the image carrying member. | 12-26-2013 |
20140056623 | DEVELOPMENT METHOD, DEVELOPING DEVICE, AND IMAGE FORMING ASSEMBLY AND IMAGE FORMING APPARATUS INCLUDING THE DEVELOPING DEVICE - A development method is used for a developing device including a toner holding member that faces but is not in contact with an image carrier carrying a latent image and that rotates while holding a nonmagnetic toner, a charging member that charges the toner, and a developing electric field forming unit that forms a developing electric field at least including a direct current component to cause the charged toner to fly and adhere to the latent image to develop the latent image. The method includes, when the developing electric field is applied such that the toner is caused to fly toward the image carrier by the direct current component of the developing electric field alone, maintaining a non-electrostatic adhesion of the toner to the toner holding member to be about 2 nN or more under a low-temperature low-humidity environment of a temperature of 10° C. and a relative humidity of 15%. | 02-27-2014 |
20140255062 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS INCORPORATING SAME - A developing device includes a developer bearer disposed facing a latent image bearer in a development range, and an alternating voltage application unit to apply alternating voltage to the developer bearer to generate an alternating electrical field in the development range to cause toner to move from the developer bearer to the latent image bearer while reciprocating therebetween. The alternating voltage has a frequency within a range from 20 kHz to 60 kHz and a peak-to-peak voltage equal to or greater than 300 V. | 09-11-2014 |
20150132030 | IMAGE FORMING APPARATUS - In an image forming apparatus having a photosensitive drum that carries a toner image, a developing roller that is provided to be capable of rotating while carrying toner, and that supplies the toner to the photosensitive drum in order to develop a latent image, and voltage applying device for applying a voltage to the developing roller, the developing roller includes a conductive base layer and a surface layer covering the base layer, and a surface charge density of the developing roller is equal to or smaller than a surface charge density of the toner. | 05-14-2015 |
20160026113 | DEVELOPING DEVICE AND IMAGE FORMING APPARATUS - A developing device includes a developer including a toner, a developer carrier to carry the developer to an image forming area opposing to a latent image bearing member with rotate, a development casing storing the developer, and a developing bias applying member to apply a developing bias to the developer carrier. There is a contacting part to contact a contacting member grounded electrically and disposed at the development casing, and a gap adjusting member to form a gap between the gap adjusting member and the developing carrier. The gap adjusting member is disposed downstream of a rotating direction of the developer carrier. The development casing is conductive, and an insulation member to insulate the gap adjusting member from the development casing is disposed between the gap adjusting member and the development casing. | 01-28-2016 |
20160085175 | IMAGE FORMING APPARATUS - An image forming apparatus includes a plurality of image forming units. A first image forming unit includes a first image carrier, a first developer carrier that is applied with a first developing voltage, and a first layer-forming member that is applied with a first layer-forming voltage having the same polarity as polarity of the first developing voltage. The second image forming unit includes a second image carrier, a second developer carrier that is applied with a second developing voltage, and a second layer-forming member that is applied with a second layer-forming voltage having the same polarity as polarity of the second developing voltage. An absolute value of the first layer-forming voltage is smaller than an absolute value of the first developing voltage. An absolute value of the second layer-forming voltage is greater than an absolute value of the second developing voltage. | 03-24-2016 |
20160116859 | IMAGE FORMING APPARATUS - An image forming apparatus includes a first power source configured to supply charging voltage to a first charging unit, and a second power source configured to supply predetermined voltage to at least one of a second charging unit, a second developing member, and a second transfer unit. The first and the second power sources are grounded via a common resistor component. When the second power source in a state of supplying no voltage or supplying voltage lower than the predetermined voltage at a first timing starts supplying the predetermined voltage while the first power source is supplying the charging voltage, a control unit causes a separating mechanism to move a first developing member to a separation position before a second timing at which an area of a first photosensitive member that is at a charging position at the first timing reaches a developing position. | 04-28-2016 |
20160202629 | Developing Cartridge Having Electrode | 07-14-2016 |