Patent application number | Description | Published |
20110229168 | IMAGE FORMING APPARATUS, IMAGE FORMING METHOD, AND COMPUTER PROGRAM PRODUCT FOR CAUSING A COMPUTER TO EXECUTE THE METHOD - An image forming apparatus includes: an image carrier; a toner image forming unit that forms a toner image on the image carrier; a transfer unit that transfers the toner image on the image carrier to a transfer target having ridges and valleys on a surface thereof; an adjusting unit that adjusts a ratio of A/B, where A is a transfer ratio [%] from the image carrier to a valley portion of the transfer target while B is a transfer ratio [%] from the image carrier to a ridge portion of the transfer target, based on an adjustment input by a user; and a control unit that controls a transfer condition of the transfer unit based on the ratio of A/B adjusted by the adjusting unit. | 09-22-2011 |
20120045231 | TRANSFER DEVICE AND IMAGE FORMING APPARATUS INCORPORATING SAME - A transfer device includes a controller that controls a transfer bias supply to cause a transfer bias to increase, between an image carrier and a first rotary body disposed opposite the image carrier, a potential of the first rotary body toward an opposite polarity to a charge polarity of toner of a toner image on the image carrier to be higher than a potential of the image carrier, and to change, on the basis of identified recording medium type, a returning peak value which is one of a peak value of positive polarity and a peak value of negative polarity of the transfer bias and which generates an electric field that causes the toner having moved to the recording medium from the image carrier to return to the image carrier from the recording medium in a transfer nip. | 02-23-2012 |
20120045237 | IMAGE FORMING APPARATUS - An image forming apparatus includes a transfer bias generator including a transfer bias supply that supplies a transfer bias to a transfer nip formed between an image carrier and a first rotary body, and a controller that detects a toner adhesion amount at a predetermined region of the image carrier located immediately upstream from the transfer nip and having a predetermined length in a moving direction of the image carrier. The transfer bias generator outputs at least an alternating current component under one of constant voltage control and constant current control and changes a target output value of the alternating current component according to the toner adhesion amount detected by the controller. | 02-23-2012 |
20120045259 | TRANSFER DEVICE, IMAGE FORMING APPARATUS, AND TRANSFER METHOD - A transfer device includes an image carrier that carries a toner image; a nip forming member that forms a transfer nip between the nip forming member and the image carrier by contacting with a front surface of the image carrier; and a transfer bias applying unit that applies a transfer bias, thereby transferring the toner image carried on the image carrier to a recording material at a position of the transfer nip. The transfer bias applying unit applies the transfer bias in which an AC component and a DC component are superimposed and in which a peak-to-peak voltage of the AC component is larger than 6 times an absolute value of a voltage of the DC component. | 02-23-2012 |
20120230715 | TRANSFER DEVICE AND IMAGE FORMING APPARATUS - According to an embodiment, a transfer device includes: an image carrier from which an image is transferred onto a transfer medium using electrostatic toner, the image carrier being applied with a direct current voltage superimposed with an alternating current (AC) voltage as a transfer bias. An output voltage of a power source for applying the voltage is controlled so that a current level of a direct current component output from the power source is kept at a specified current level. | 09-13-2012 |
20120237234 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - An image forming apparatus includes an image carrier to carry a toner image, a transfer member to form a transfer nip by contacting the image carrier surface, and a power supply to output a voltage to the recording material captured in the transfer nip so as to transfer the toner image formed on the image carrier surface. The voltage is switching alternately between a voltage in the transfer direction and a voltage opposite to the voltage in the transfer direction, and a time average value (Vave) of the voltage is set to have a polarity of the transfer direction, and is set to a value in the transfer voltage side, and a change mode to change a cycle of the voltage output from the power supply can be changed based on the toner deterioration information which determines the deterioration status of the toner. | 09-20-2012 |
20120243892 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image carrying member to carry a toner image, a nip forming member to form a transfer nip with the image carrying member, and a transfer bias outputting unit to output a transfer bias to transfer the toner image from the image carrying member to a recording medium. The transfer bias is composed of a direct current (DC) component and an alternating current (AC) component, and a least one of the DC component and the AC component is subjected to constant voltage control. When constant current control is conducted at a timing other than when the toner image is being transferred from the image carrying member to the recording medium, a detection bias voltage at the transfer nip is detected, and the voltage of at least one of the DC component and the AC component is controlled based on the detected detection bias voltage. | 09-27-2012 |
20130064559 | IMAGE FORMING APPARATUS - An image forming apparatus includes a transfer device to transfer a toner image formed on an image bearing member onto a recording medium, a sheet separation device to separate the recording medium from the image bearing member, a sheet separation bias application device to apply to the sheet separation device a sheet separation bias in which an alternating current (AC) component is superimposed on a direct current (DC) component, and a transfer bias application device to selectively apply to the transfer device one of a DC transfer bias having a DC component and a superimposed transfer bias in which an AC component is superimposed on a DC component. Upon application of the superimposed transfer bias to the transfer device, the sheet separation bias applied to the sheet separation device is changed from the sheet separation bias applied upon application of the DC transfer bias to the transfer device. | 03-14-2013 |
20130089363 | TRANSFER DEVICE AND IMAGE FORMING APPARATUS - A transfer device comprises a freely rotatable transferring member contacting an image bearing member to form a transfer nip therebetween; a transfer bias applying member to apply a first bias created by superimposing an alternating current component on a direct current component to the transferring member to transfer a toner image borne on the image bearing member to a recording medium in the transfer nip; and an applicator to apply a protective agent to a surface of the transferring member. | 04-11-2013 |
20130136468 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image bearing member to bear a toner image on a surface thereof, a transfer device to transfer the toner image onto a recording medium, and a transfer bias power source to apply to the transfer device a superimposed transfer bias in which an alternating current (AC) component is superimposed on a direct current (DC) component in a superimposed transfer mode to transfer the toner image. The superimposed transfer bias has a waveform in which a first polarity in a direction of transferring the toner image onto the recording medium and a second polarity opposite the first polarity switch alternately. The superimposed transfer bias is output such that a standard value of each of the DC component and the AC component is multiplied by a respective correction ratio, and the correction ratio of the DC component is different from that of the AC component. | 05-30-2013 |
20130148993 | IMAGE FORMING APPARATUS - An image forming apparatus includes a nip forming member and a transfer bias output device that outputs a transfer bias to form a transfer electric field in a transfer nip between the nip forming member and an intermediate transfer member. Upon transfer of a composite toner image including a particular toner image onto a recording medium in the transfer nip, the transfer bias output device outputs the transfer bias including a first superimposed bias in which a direct current (DC) component is superimposed on an alternating current (AC) component. Upon transfer of the composite toner image without the particular toner image onto the recording medium in the transfer nip, the transfer bias output device outputs one of the transfer bias including a second superimposed bias having a peak-to-peak value of the AC component smaller than that of the first superimposed bias and the transfer bias including only the DC component. | 06-13-2013 |
20130164011 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image bearing member, a transfer member disposed facing the image bearing member to form a transfer region therebetween, a transfer bias application device to apply to the transfer region a transfer bias including a direct current (DC) component and an alternating current (AC) component to transfer the toner image onto the recording medium as the recording medium passes through the transfer region, and a controller operatively connected to the transfer bias application device to allow, during a bias change period in a sheet absent period in which the image bearing member rotates and no recording medium passes through the transfer region, the transfer bias application device to selectively apply to the transfer region one of the transfer bias without the AC component and the transfer bias with a peak-to-peak voltage of the AC component less than that applied in image formation. | 06-27-2013 |
20130177329 | IMAGE FORMING APPARATUS - An image forming apparatus includes an image carrier that carries an electrostatic latent image; a developing unit that develops the electrostatic latent image using a toner; an intermediate transfer body onto which toner image is transferred; a secondary transfer member that comes in contact with a surface of the intermediate transfer body; a power supply that outputs a voltage for transferring the toner image on the intermediate transfer body onto a recording member; and a protective agent supply unit that applies a protective agent including zinc stearate and boron nitride onto a surface of the image carrier. The voltage is alternatively switched in a transfer direction and an opposite direction. The voltage in the transfer direction enables transfer of the toner image from the intermediate transfer body to the recording member, and the voltage in the opposite direction has polarity opposite to polarity of the voltage in the transfer direction. | 07-11-2013 |
20130195483 | TRANSFER DEVICE AND IMAGE FORMING APPARATUS INCLUDING SAME - A transfer device includes a transfer bias power source, a switching device, and a sheet dependent condition setting device. The transfer bias power source applies to a transfer member, based on sheet dependent conditions for a recording medium onto which a toner image is transferred, one of a DC transfer bias and a superimposed transfer bias including an alternating current (AC) component superimposed on a DC component. The switching device switches a transfer mode between a DC transfer mode in which the DC transfer bias is applied to the transfer device and a superimposed-bias transfer mode in which the superimposed transfer bias is applied to the transfer device. The sheet dependent condition setting device sets arbitrarily at least one of the sheet dependent conditions for the recording medium at the superimposed-bias transfer mode. The sheet dependent conditions include a DC component value and an AC component value. | 08-01-2013 |
20130236201 | IMAGE FORMING APPARATUS - An image forming apparatus includes a toner forced consumption control unit that performs toner forced consumption control in which toner in a developing unit is forcibly consumed when a certain condition to perform the toner forced consumption control is met. The certain condition to perform the toner forced consumption control includes a specific performance condition that a transfer bias switching condition to switch a transfer bias to a superimposed transfer bias in which an alternating current component is superimposed on a direct current component, from a direct current transfer bias is met. When the specific performance condition is met, the toner forced consumption control unit performs preliminary toner forced consumption control in which the toner forced consumption control is performed before an image forming operation using the superimposed transfer bias is started. | 09-12-2013 |
20130294791 | IMAGE FORMING APPARATUS AND METHOD CAPABLE OF REDUCING DENSITY IRREGULARITY IN TONER IMAGES - An image forming apparatus includes an image bearer to bear a latent image formed thereon, a developing device to render visible the latent image borne on the image bearer as a toner image, and a transfer device to transfer the toner image onto a recording medium either directly or via an intermediate transfer member. A granularity detector is provided to detect granularity of the toner image transferred onto the recording medium. A controller is provided to control a transfer rate of toner in the toner image transferred onto the recording medium to reduce the image degradation when the granularity detected by the granularity detector exceeds a prescribed threshold. | 11-07-2013 |
20130308968 | IMAGE FORMING APPARATUS - An image forming apparatus includes a transfer bias output device and an information receiving device. The transfer bias output device outputs a transfer bias including a superimposed bias composed of an AC bias superimposed on a DC bias to form a transfer electric field in a transfer nip between an image bearing member bearing a toner image and a nip forming member, to transfer the toner image onto a recording medium in the transfer nip. A controller operatively connected to the information receiving device and the transfer bias output device causes the transfer bias output device to change a target output of a peak-to-peak voltage of the AC bias based on information received by the information receiving device that affects transfer of the toner image and to reduce a target output of the DC bias as the target output value of the peak-to-peak voltage of the AC bias increases. | 11-21-2013 |
20140029988 | IMAGE FORMING APPARATUS - A novel image forming apparatus includes a photoreceptor to bear an electrostatic latent image on a surface thereof, a developing device to develop the electrostatic latent image into a toner image, an intermediate transfer member onto which the electrostatic latent image is transferred, a primary transfer member to apply a primary transfer bias to the intermediate transfer member to transfer the toner image thereto, a secondary transfer member supplied with a secondary transfer bias to transfer the toner image from the intermediate transfer member onto a recording medium, and a transfer bias power source to selectively apply to the secondary transfer member one of a secondary transfer bias consisting of a direct current (DC) voltage in a DC transfer mode and a secondary transfer bias consisting of a superimposed bias in which an alternating voltage is superimposed on a DC voltage. | 01-30-2014 |
20140079418 | IMAGE FORMING APPARATUS - An image forming apparatus includes a power source to output a voltage having an alternating waveform to transfer a toner image from an image bearing member to a recording medium. A time-averaged value (Vave) of the voltage has a polarity in a transfer direction, in which the toner image is transferred from the image bearing member to the recording medium, and an absolute value of the time-averaged value is greater than a midpoint value (Voff) of the voltage intermediate between a maximum value and a minimum value of the voltage. As a roughness of the recording medium increases, a duty ratio (Duty) expressed by A/(A+B) is reduced, where A is an area of the waveform of the voltage in a return direction opposite the transfer direction relative to the midpoint value in one cycle and B is an area in the transfer direction relative to the midpoint value. | 03-20-2014 |
20140079423 | IMAGE FORMING APPARATUS, IMAGE FORMING METHOD, AND COMPUTER PROGRAM PRODUCT FOR CAUSING A COMPUTER TO EXECUTE THE METHOD - An image forming apparatus includes: an image carrier; a toner image forming unit that forms a toner image on the image carrier; a transfer unit that transfers the toner image on the image carrier to a transfer target having ridges and valleys on a surface thereof; an adjusting unit that adjusts a ratio of A/B, where A is a transfer ratio [%] from the image carrier to a valley portion of the transfer target while B is a transfer ratio [%] from the image carrier to a ridge portion of the transfer target, based on an adjustment input by a user; and a control unit that controls a transfer condition of the transfer unit based on the ratio of A/B adjusted by the adjusting unit. | 03-20-2014 |
20140169817 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - An image forming apparatus includes an image carrier to carry a toner image, a transfer member to form a transfer nip by contacting the image carrier surface, and a power supply to output a voltage to the recording material captured in the transfer nip so as to transfer the toner image formed on the image carrier surface. The voltage is switching alternately between a voltage in the transfer direction and a voltage opposite to the voltage in the transfer direction, and a time average value (Vave) of the voltage is set to have a polarity of the transfer direction, and is set to a value in the transfer voltage side, and a change mode to change a cycle of the voltage output from the power supply can be changed based on the toner deterioration information which determines the deterioration status of the toner. | 06-19-2014 |
20140248064 | IMAGE FORMING APPARATUS - An image forming apparatus includes a rotatable image bearing member, a nip forming member, and a power source. The rotatable image bearing member bears a toner image on a surface thereof and rotates. The nip forming member contacts the surface of the image bearing member to form a transfer nip therebetween. The power source applies a transfer bias to the transfer nip to transfer the toner image from the image bearing member onto a recording medium interposed in the transfer nip. The transfer bias includes a superimposed transfer bias in which an alternating current (AC) component is superimposed on a direct current (DC) component and a polarity of the superimposed transfer bias changes with time. A phase difference between an AC voltage and an AC current output from the power source is equal to or less than 0.47 cycles. | 09-04-2014 |
20140270830 | IMAGE FORMING APPARATUS - An image forming apparatus includes a transfer device to transfer a toner image formed on an image bearing member onto a recording medium, a sheet separation device to separate the recording medium from the image bearing member, a sheet separation bias application device to apply to the sheet separation device a sheet separation bias in which an alternating current (AC) component is superimposed on a direct current (DC) component, and a transfer bias application device to selectively apply to the transfer device one of a DC transfer bias having a DC component and a superimposed transfer bias in which an AC component is superimposed on a DC component. Upon application of the superimposed transfer bias to the transfer device, the sheet separation bias applied to the sheet separation device is changed from the sheet separation bias applied upon application of the DC transfer bias to the transfer device. | 09-18-2014 |